Immunoglobulin M Heavy/Light Chain Pair Measurement Independently Predicts Clinical Outcome and Refines Prognostic Information Provided By Interim PET in Patients with Aggressive Lymphomas

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3880-3880
Author(s):  
Patricia Johansson ◽  
Jan Dürig ◽  
Jan Rekowski ◽  
Stefan P Müller ◽  
Bernd Hertenstein ◽  
...  
Keyword(s):  
Clinical Outcome ◽  
B Cell ◽  
Binding Site ◽  
Light Chain ◽  
Research Funding ◽  
Prognostic Value ◽  
Immunoglobulin M ◽  
Prognostic Information ◽  
Interim Pet ◽  
Aggressive Lymphomas

Abstract Introduction: We recently reported the first results of the large multicenter phase III PETAL trial (EudraCT 2006-001641-33, NCT00554164) showing that 18-fluorodeoxyglucose interim PET (iPET) performed after two cycles of chemotherapy is highly predictive of clinical outcome in patients with aggressive lymphomas. Here, the study`s biobank was utilized to exploratively investigate the prognostic value of immunoglobulin M heavy/light chain pair (HLC-M) abnormalities in this patient cohort. Methods: HLC-M κ and λ were measured in pre-treatment serum samples of a representative subset (N=187, 22%) of patients employing the Hevylite® assay (The Binding Site Ltd, Birmingham, UK). Normal HLC-M ratios and concentrations were defined according to the manufacturer`s recommendations. For statistical analysis standard time-to-event methodology (Kaplan-Meier method, Log Rank test, Cox regression) was used. Results: Median age of the 187 pts was 57 years (range 18-80), whereof 92 (49%) were male, and 95 (51%) were female. 174 pts. had CD20-positive B cell lymphomas (73% diffuse large B cell, 13% other aggressive B cell lymphomas, 7% follicular lymphoma grade 3), 13 had peripheral T cell lymphomas (7%). Normal HLC-M were observed in 150 patients (75.8%). 37/187 (20%) of the patients exhibited a monoclonal IgMκ/IgMλ ratio, where 17 (46%) showed a ratio below and 20 (54%) above the reference range. HLC-M abnormalities were significantly associated with adverse clinical characteristics including advanced Ann Arbor stage (p=0.005), high international prognostic index (IPI, p=0.001) and extranodal disease (p=0.003). Patients with abnormal HLC-M ratios had inferior time to treatment failure (TTTF, Figure 1) and overall survival (OS, Figure 2) as compared to their counterparts with normal HLC-M ratios. Of note, subgroup analyses revealed that the prognostic value of HLC-M abnormalities was limited to patients with a favorable iPET and low-intermediate IPI score. In multivariate analysis with the cox model and controlling for the IPI factors (including age), histology, sex as well as FLC κ and λ, monoclonal HLC-M remained predictive for a shorter TTTF (p=0.0181, covariate-adjusted hazard ratio (aHR) 2.195, 95% CI [1.144;4.214]) and OS (p=0.0034, aHR 3.844, 95% CI [1.559;9.476]). Conclusions: Monoclonal HLC-M is an independent predictor of survival in patients with aggressive lymphoma and refines prognostic information provided by iPET and IPI. Figure 1. Figure 1. Disclosures Dürig: The Binding Site: Research Funding, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Gilead: Consultancy; Novartis: Consultancy; Roche: Consultancy, Other: Travel support, Speakers Bureau; Aicuris: Consultancy; Celgene: Consultancy, Other: Travel support, Speakers Bureau. La Rosée:Roche: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria; CTI Lifesciences: Honoraria; Janssen-Cilag: Honoraria; Gilead: Consultancy, Honoraria, Speakers Bureau; Bristol-Myers-Squibb: Honoraria, Research Funding; Mundipharma: Other: Travel support; Takaeda: Consultancy, Honoraria, Other: travel support; Celgene: Honoraria. Dührsen:Amgen: Honoraria, Research Funding; Roche: Honoraria, Research Funding; Alexion Pharmaceuticals: Honoraria, Research Funding. Hüttmann:Amgen: Consultancy, Research Funding; Gilead: Consultancy; Takeda: Consultancy, Other: Travel support; Roche: Research Funding; Celgene: Other: Travel support, Speakers Bureau.

Positron Emission Tomography (PET) Guided Therapy of Aggressive Lymphomas – a Randomized Controlled Trial Comparing Different Treatment Approaches Based on Interim PET Results (PETAL Trial)

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 391-391 ◽  
Author(s):  
Ulrich Duehrsen ◽  
Andreas Hüttmann ◽  
Stefan Müller ◽  
Bernd Hertenstein ◽  
Jörg Kotzerke ◽  
...  
Keyword(s):  
T Cell ◽  
B Cell ◽  
Research Funding ◽  
B Cell Lymphomas ◽  
Interim Pet ◽  
Aggressive Lymphomas ◽  
Altered Glucose ◽  
Study Results ◽  
Secondary Endpoints ◽  
Grade 3

Abstract Introduction: The predictive value of 18-fluorodeoxyglucose PET performed after a few cycles of chemotherapy has been questioned in aggressive lymphomas. Inconsistent study results, however, may be due to procedural differences rather than an inability of the method to predict outcome. Whether changing treatment in pts. with an unfavorable interim PET (iPET) improves outcome, has not been determined in a randomized study. The PETAL trial (EudraCT 2006-001641-33, NCT00554164) was initiated to resolve these issues. Methods: Pts. aged 18 to 80 yrs. with newly diagnosed aggressive lymphomas and a positive baseline PET received 2 cycles of rituximab (R), cyclophosphamide (C), doxorubicin (H), vincristine (O) and prednisone (CHOP) followed by iPET. The conditions of iPET were strictly defined: 3-week interval between the 2nd R-CHOP cycle and iPET to avoid inflammatory reactions (Eur J Nucl Med Mol Imaging 30:682, 2003), no G-CSF after the 2nd R-CHOP cycle to avoid altered glucose biodistribution (J Nucl Med 47:950, 2006), standardized uptake value (SUV)-based PET interpretation to improve objectivity of evaluation (favorable iPET response: reduction of maximum SUV by > 66 % compared to baseline; J Nucl Med 48:1626, 2007). Pts. with CD20-positive lymphomas and a favorable iPET were randomized to receive 4 additional cycles of R-CHOP or the same treatment plus 2 extra doses of R (Part A of the trial). Pts. with an unfavorable iPET were randomized to continue standard R-CHOP for 6 additional cycles or receive 6 blocks of a more complex and more intensive protocol yielding excellent results in Burkitt and other aggressive lymphomas (Part B). Its main components were hyperfractionated alkylating agents (C, ifosfamide) and high doses of methotrexate and cytarabine, with dose reductions in pts. > 60 yrs. Other constituents were R, H, O, vindesine, etoposide and dexamethasone (Blood 120: abstr 667, 2012). R was omitted in pts. with CD20-negative lymphomas. Sample size was based on the empirically derived assumption that treatment failure after 2 yrs. (TF: progression, relapse, treatment discontinuation due to toxicity, start of alternative therapy, death of any cause) could be improved from 80 % to 90 % in Part A and from 30 % to 45 % in Part B (alpha=0.05, power=0.8). Complete remission (CR), overall survival (OS) and toxicity were secondary endpoints. Results: From 2007 to 2012 926 pts. were recruited by 57 participating oncological centers and analyzed by PET in 23 nuclear medicine institutions. With a median follow-up of 33 months 853 pts. are currently evaluable in the intent-to-treat population. 757 pts. had CD20-positive B cell lymphomas (80 % diffuse large B cell [DLBCL], 3 % primary mediastinal B cell, 8 % follicular lymphoma grade 3), 13 had CD20-negative B cell lymphomas and 83 had peripheral T cell lymphomas. Interim PET was favorable in 746 pts. (87 %) and unfavorable in 107 (13 %). It was highly predictive of outcome, time to TF being significantly higher in Part A than Part B (2-year probability: 79 % vs. 47 %; hazard ratio (HR) for B 3.4, 95 % confidence interval (CI) 2.6 – 4.6, p<0.0001; Figure). On multivariate analysis iPET response, International Prognostic Index and B vs. T cell lineage independently predicted TF. Interim PET was also predictive of OS (HR 3.9, CI 2.7 – 5.7, p<0.0001). In pts. with CD20-positive lymphomas and a favorable iPET, addition of 2 extra doses of R failed to improve TF (HR for 2 extra doses 1.2, CI 0.8 – 2.1) and all secondary endpoints. Likewise, in pts. with an unfavorable iPET response, a switch from R-CHOP to the Burkitt-type regimen showed no beneficial effect on TF (HR for Burkitt 1.6, CI 0.9 – 2.7), CR rate (50 % vs. 31 %, p=0.10) or OS (HR 1.0, CI 0.5 – 2.1). Similar results were obtained, when the analysis was restricted to DLBCL, and for covariate adjusted Cox regression of all survival endpoints. Although treatment related deaths (3 vs. 2 pts.) were comparable in both treatment arms, the Burkitt protocol was associated with more severe grade 3/4 leukopenia (84 % vs. 67 %, p=0.043), thrombocytopenia (63 % vs. 35 %, p=0.007) and mucositis (41 % vs. 12 %, p=0.002). Conclusion: Applying strict rules to the procedure and its interpretation iPET proved highly predictive of outcome in pts. with aggressive lymphomas in this large multicenter trial. Because switching to a more aggressive protocol failed to improve outcome, our results do not support a change in cytotoxic regimen in poor iPET responders. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures Duehrsen: Amgen: Honoraria, Research Funding; Roche: Honoraria, Research Funding. Klapper:Roche: Research Funding. Hoelzer:Amgen: Speakers Bureau; Medac: Membership on an entity's Board of Directors or advisory committees.

Positron Emission Tomography (PET) Guided Therapy of Aggressive Lymphomas - Interim PET-Based Outcome Prediction and Treatment Changes in Patients with T Cell Lymphomas Participating in the PETAL Trial

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 185-185
Author(s):  
Andreas Hüttmann ◽  
Stefan P Müller ◽  
Jan Rekowski ◽  
Bernd Hertenstein ◽  
Christiane Franzius ◽  
...  
Keyword(s):  
T Cell ◽  
Treatment Failure ◽  
B Cell ◽  
Research Funding ◽  
Cell Lymphoma ◽  
Interim Pet ◽  
Aggressive Lymphomas ◽  
T Cell Lymphomas ◽  
Study Population ◽  
Treatment Changes

Abstract Introduction: The PETAL trial is a multicenter randomized controlled study for patients with aggressive lymphomas of diverse histologies (EudraCT 2006-001641-33, NCT00554164). In the study population as a whole interim PET (iPET) reliably predicted time to treatment failure (TTTF) and overall survival (OS). Interim PET-based treatment changes, however, had no impact on outcome (ASH 2014, abstract 391). Here we report the exploratory analysis for peripheral T cell lymphomas (PTCL). Methods: Pts. aged 18 to 80 yrs. with newly diagnosed aggressive lymphomas and a positive baseline PET received 2 cycles of rituximab (R), cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) followed by iPET. R was omitted in pts. with CD20-negative lymphomas. The conditions of iPET were strictly defined: 3-week interval between the 2nd (R-)CHOP cycle and iPET to avoid inflammatory reactions (Eur J Nucl Med Mol Imaging 30:682, 2003), no G-CSF after the 2nd cycle to avoid altered glucose biodistribution (J Nucl Med 47:950, 2006), standardized uptake value (SUV)-based PET interpretation to improve reproducibility (favorable iPET response: reduction of maximum SUV by > 66 % compared to baseline; J Nucl Med 48:1626, 2007). PTCL pts. with CD20-negative lymphomas and a favorable iPET uniformly received 4 additional cycles of CHOP (part A of the trial). Pts. with an unfavorable iPET were randomized to continue CHOP for 6 additional cycles or receive 6 blocks of a more complex methotrexate-, cytarabine- and etoposide-based regimen originally designed for Burkitt lymphoma (Blood 124: 3870, 2014; part B). Sample size of the entire study population was based on the empirically derived assumption that treatment failure after 2 yrs. (progression, relapse, treatment discontinuation due to toxicity, start of alternative therapy, death of any cause) could be improved from 30 % to 45 % in part B (alpha=0.05, power=0.8). Secondary endpoints included OS and toxicity. Results: Fifty-seven oncological centers and 23 nuclear medicine institutions participated in the trial. Between 2007 and 2012 1072 pts. were registered, and 862 (80.4 %) had a positive baseline PET, received 2 cycles (R-)CHOP, underwent iPET and were allocated to one of the post-iPET treatment arms detailed above. Reference pathology was available in 98 %, and median follow-up is 52 months. All in all, there were 76 pts. (8.8 % of all treated pts.) with T-cell lymphomas of whom 21 had ALK+ anaplastic large cell lymphoma (ALCL), 13 ALK- ALCL, 18 angioimmunoblastic T-cell lymphoma (AITL) and 20 PTCL not otherwise specified (NOS). Interim PET was favorable in 57 pts. (75 %) and unfavorable in 19 pts. with T-cell lymphomas (25 %). It was highly predictive of outcome, TTTF and OS being significantly higher in part A than B (2-year probability for TTTF: 63 % vs. 21 %; univariate hazard ratio (HR) for B 3.4, 95 % confidence interval (CI) 1.8 - 6.4, p<0.0001; OS: 79 % vs. 25 %; univariate hazard ratio (HR) for B 5.0, 95 % CI 2.4 - 10.3, p<0.0001; Figure). Interestingly, the proportion of T-cell lymphoma pts. with an unfavorable iPET response was more than twice as high as the corresponding proportion of B-cell lymphoma pts., and the difference in survival between pts. with a favorable vs. unfavorable iPET response was more pronounced in T-cell lymphomas than in B-cell lymphomas. TTTF (2-year probability: 81 % vs. 46 % vs. 49 % vs. 35 %; p=0.0110) and OS (90 % vs. 69 % vs. 52 % vs. 50 %; p=0.0026) were better in ALK+ ALCL than in ALK- ALCL, AITL or PTCL NOS. In pts. with an unfavorable iPET response, a switch from CHOP to the alternative regimen failed to improve TTTF or OS. The latter was associated with more frequent grade 3/4 neutropenia (40 % vs. 0 % vs. 11 %, p=0.0279), thrombocytopenia (70 % vs. 33 % vs. 23 %; p=0.0106), infection (60 % vs. 44 % vs. 18 %, p=0.0057) and mucositis (40 % vs. 33 % vs. 4 %, p=0.0025) as compared to 6 or 4 post-iPET cycles of CHOP, respectively, but treatment-related mortality was similar in all treatment arms (2 vs. 1 vs. 2 deaths). Conclusion: In this large multicenter trial iPET proved highly predictive of outcome in PTCL. A favorable iPET was found in 75 % of pts., and this was associated with long-term survival in about 70 %. In pts. with an unfavorable iPET response, outcome was dismal and could not be improved by switching to a more aggressive regimen. Novel strategies are required for PTCL pts. failing to respond to the first 2 cycles of CHOP. Disclosures Hüttmann: Gilead, Amgen: Other: Travel cost; Bristol-Myers Squibb, Takeda, Celgene, Roche: Honoraria. Giagounidis:Celgene Corporation: Consultancy. Klapper:Roche, Novartis, Amgen, Takeda: Research Funding. Duehrsen:Roche: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Alexion Pharmaceuticals: Honoraria, Research Funding.

scholarly journals Positron Emission Tomography (PET) Guided Therapy of Aggressive Lymphomas - Interim PET-Based Outcome Prediction and Treatment Changes in Patients with B Cell Lymphomas Participating in the PETAL Trial

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1857-1857 ◽  
Author(s):  
Ulrich Duehrsen ◽  
Stefan P Müller ◽  
Jan Rekowski ◽  
Bernd Hertenstein ◽  
Christiane Franzius ◽  
...  
Keyword(s):  
B Cell ◽  
Research Funding ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
B Cell Lymphomas ◽  
Interim Pet ◽  
Aggressive Lymphomas ◽  
Study Population ◽  
Treatment Changes ◽  
Grade 3

Abstract Introduction: The PETAL trial is a multicenter randomized controlled study for patients with aggressive lymphomas of diverse histologies (EudraCT 2006-001641-33, NCT00554164). In the study population as a whole interim PET (iPET) reliably predicted time to treatment failure (TTTF) and overall survival (OS). Interim PET-based treatment changes, however, had no impact on outcome (ASH 2014, abstract 391). Here we report the exploratory analysis for aggressive B cell lymphomas. Methods: Pts. aged 18 to 80 yrs. with newly diagnosed aggressive lymphomas and a positive baseline PET received 2 cycles of rituximab (R), cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) followed by iPET. The conditions of iPET were strictly defined: 3-week interval between the 2nd R-CHOP cycle and iPET to avoid inflammatory reactions (Eur J Nucl Med Mol Imaging 30:682, 2003), no G-CSF after the 2nd cycle to avoid altered glucose biodistribution (J Nucl Med 47:950, 2006), standardized uptake value (SUV)-based PET interpretation to improve reproducibility (favorable iPET response: reduction of maximum SUV by > 66 % compared to baseline; J Nucl Med 48:1626, 2007). Pts. with CD20+ lymphomas and a favorable iPET were randomized to receive 4 more cycles of R-CHOP or the same treatment plus 2 extra doses of R (part A of the trial). Pts. with an unfavorable iPET were randomized to continue R-CHOP for 6 additional cycles or receive 6 blocks of a more complex methotrexate-, cytarabine- and etoposide-based regimen originally designed for Burkitt lymphoma (Blood 124: 3870, 2014; part B). R was omitted in pts. with CD20- lymphomas. Sample size of the entire study population was based on the empirically derived assumption that treatment failure after 2 yrs. (TF: progression, relapse, treatment discontinuation due to toxicity, start of alternative therapy, death of any cause) could be improved from 80 % to 90 % in part A and from 30 % to 45 % in part B (alpha=0.05, power=0.8). Secondary endpoints included OS and toxicity. Results: Fifty-seven oncological centers and 23 nuclear medicine institutions participated in the trial. Between 2007 and 2012 1072 pts. were registered, and 862 (80.4 %) had a positive baseline PET, received 2 cycles R-CHOP, underwent iPET and were allocated to one of the post-iPET treatment arms detailed above. Reference pathology was available in 98 %, and median follow-up is 52 months. All in all, there were 779 patients with CD20+ aggressive B-cell lymphomas (90.4 % of all treated pts.) of whom 606 had diffuse large B-cell lymphoma (DLBCL), 42 primary mediastinal B-cell lymphoma (PMBCL) and 42 follicular lymphoma grade 3 (FL3). Interim PET was favorable in 691 pts. (88.7 %) and unfavorable in 88 pts. with CD20+ lymphomas (11.3 %). It was highly predictive of TTTF for CD20+ lymphomas in general and for each of the DLBCL, PMBCL and FL3 subgroups (Table). In CD20+ lymphomas and DLBCL, the iPET response predicted TF independently of the International Prognostic Index, and it was also predictive of OS. The groups of PMBCL and FL3 were too small for multivariate analyses. In part A, adding 2 extra doses of R failed to improve TTTF and OS in all histological entities. Separate analyses for subgroups defined by sex, age (< vs. > 60 yrs.) or a combination of the two showed no statistically significant benefit of extra doses of R in any of the subgroups. In pts. with an unfavorable iPET response, a switch from R-CHOP to the Burkitt regimen failed to improve TTTF or OS in CD20+ lymphomas in general (Figure) and in the DLBCL, PMBCL and FL3 subgroups. In part B, the Burkitt protocol was associated with more grade 3/4 leukopenia (82 % vs. 57 %, p=0.02), thrombocytopenia (59 % vs. 18 %, p=0.0001), infection (41 % vs. 16 %, p=0.017) and mucositis (39 % vs. 7 %, p=0.0007) than R-CHOP, but treatment-related mortality was similar in both arms (1 death each). Conclusion: In this large multicenter trial iPET proved highly predictive of outcome in pts. with CD20+ aggressive B-cell lymphomas, DLBCL, PMBCL or FL3 treated with R-CHOP. In pts. with a favorable iPET response, addition of 2 extra doses of R to 6 cycles R-CHOP failed to improve outcome in CD20+ lymphomas in general and in subgroups defined by histology, sex or age. In pts. with an unfavorable iPET response, switching to a more aggressive protocol also failed to improve outcome in any of the entities. Novel strategies are required for aggressive B-cell lymphomas failing to respond to the first 2 cycles of R-CHOP. Table Table. Figure Figure. Disclosures Duehrsen: Roche: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Alexion Pharmaceuticals: Honoraria, Research Funding. Giagounidis:Celgene Corporation: Consultancy. Grube:BMS, Sanofi: Consultancy. Klapper:Roche, Novartis, Amgen, Takeda: Research Funding. Hüttmann:Bristol-Myers Squibb, Takeda, Celgene, Roche: Honoraria; Gilead, Amgen: Other: Travel cost.

scholarly journals Identification of an octamer-binding site in the mouse kappa light-chain immunoglobulin enhancer.

1989 ◽  
Vol 9 (10) ◽  
pp. 4239-4247 ◽  
Author(s):  
R A Currie ◽  
R G Roeder
Keyword(s):  
B Cell ◽  
Binding Site ◽  
Light Chain ◽  
Specific Binding ◽  
Specific Factor ◽  
Immunoglobulin Gene ◽  
Kappa Light Chain ◽  
Nf Kappa B ◽  
Light Chain Immunoglobulin ◽  
A Site

A 215-base-pair (bp) region of the mouse MOPC 41 kappa light-chain immunoglobulin gene enhancer has been analyzed for specific binding of lymphoid and nonlymphoid nuclear factors. Mobility shift assays with a series of overlapping DNA fragments have mapped DNA-binding sites for three unique factors. The B-cell-specific (OTF-2) and ubiquitous (OTF-1) octamer-binding transcription factors specifically bound to a site centered about 136 bp 5' of the nuclear factor NF-kappa B site. A third specific factor, NF-kappa E, bound to a site that was about 75 bp 5' of the NF-kappa B site and within a region important for enhancer function. This novel factor was found in both mature B and HeLa cell nuclei. B-cell OTF-2, B-cell OTF-1, and HeLa OTF-1 bound to the kappa enhancer and kappa promoter octamer sites with similar affinities despite a 2-bp difference in the kappa enhancer octamer sequence. However, DNase I footprint analyses indicated that affinity-purified OTF-2 bound both to the enhancer OTF site and, surprisingly, to 80 bp of A + T-rich flanking sequence. Moreover, methylation interference studies demonstrated distinct differences in OTF interactions between the consensus octamer in the kappa promoter and the nonconsensus octamer identified in the enhancer. This novel observation of an OTF-binding site in the kappa enhancer provides a common link with the OTF sites in the promoter-proximal regions of all kappa promoters and thus mirrors the structural arrangement of OTF sites found in the promoters and enhancers of immunoglobulin heavy-chain genes.

Molecular Analysis of Immunoglobulin Variable Genes in HIV-Related Non-Hodgkin Lymphoma: Implications for Disease Pathogenesis and Histogenesis.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 330-330
Author(s):  
Daniela Capello ◽  
Eva Berra ◽  
Michaela Cerri ◽  
Annunziata Gloghini ◽  
Davide Rossi ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Molecular Analysis ◽  
Light Chain ◽  
Mutation Frequency ◽  
Aggressive Lymphoma ◽  
Antigen Binding ◽  
High Affinity ◽  
Aggressive Lymphomas ◽  
Selection For

Abstract Molecular analysis of immunoglobulin variable region (IGV) genes can provide insights into the histogenesis and clonal history of B-cell NHL. We investigated 67 HIV-related NHL (HIV-NHL), including 30 HIV-diffuse large B cell lymphomas (DLBCL), 21 HIV-Burkitt lymphoma (BL), 6 HIV-primary effusion lymphomas (PEL) and 10 HIV-plasmablastic lymphomas (PBL) for usage, mutation frequency and intratumoral heterogeneity of clonal IGV rearrangements as well as mutation profile and CDR3 structure of IGHV, IGKV and IGLV genes. Results were compared to 200 IGV rearrangements from aggressive lymphomas of immunocompetent hosts and to the normal B-cell repertoire. We identified a total of 65 IGHV and 56 IGV light chain rearrangements in HIV-NHL. A functional IGHV rearrangement was found in 60/67 (90%) cases, a functional IGKV chain rearrangement in 17/38 (44.7%) cases and a functional IGLV rearrangement in 21/38 cases (55.3%). Fifty-three of 60 HIV-NHL (88.3%) showed somatic hypermutation in IGHV and/or IGV light chain genes. The average mutation frequency was 9.42% (median 7.50%, range 2.04%–23.3%) for IGHV genes and 5.42% (median 4.20%, range 2.01%–12.5%) for IGV light chain genes. IGV germline rearrangements selectively associated with HIV-PBL (p&lt;0.001). Among mutated cases, average mutation frequencies did not differ among HIV-NHL groups. HIV-NHL showed a significant overrepresentation of the IGHV4 family (28/60; 46.6%) and a significant underrepresentation of IGHV3 family (18/60, 30.0%) compared to aggressive lymphomas of immunocompetent hosts (p&lt;0.05) and to normal B-cells (p&lt;0.05). IGHV4–34 was the IGHV gene most frequently rearranged (17/60; 28.3%) and was overrepresented in HIV-NHL versus aggressive lymphoma of immunocompetent hosts (17%; p&lt;0.03) and normal B-cells (4%; p&lt;0.001). IGHV4-34 expressing cells preferentially associated with lambda chain rearrangements (70%). The IGKV4-1 gene was the IGKV segment most frequently rearranged (6/17; 35.3%) and its usage was biased in HIV-NHL compared to normal B-cells (5.30; p&lt;0.001). The single IGLV gene most frequently encountered was IGLV1-44 (6/17; 35,3%). Distribution of replacement and silent mutations in IGHV sequences showed tendency to conserve FR sequences and maintain antigen binding in 34/52 (65.4%) cases. A higher than expected number of CDR replacement mutations, suggesting selection for high affinity antigen binding, occurred in 17/52 (32.7%) cases. Analysis of intraclonal heterogeneity showed the presence of ongoing mutations in only 1 HIV-BL and 2 HIV-DLBCL. Implications of these data are multifold. First, most HIV-NHL derive from B-cells persistently subjected to GC reaction, suggesting a potential role for antigen stimulation in the pathogenesis of these lymphomas. This hypothesis is supported by the finding of antigen binding preservation in the majority of HIV-NHL and selection for high affinity antigen binding in a fraction of cases. Second, the preferential usage of IGHV4-34 and IGKV4-1 genes in a fraction of HIV-NHL may suggest a role for stimulation of pre-neoplastic B-cells with polyreactive and/or autoreactive antigens. Finally, at variance with NHL of immucompetent hosts, the presence of intraclonal heterogeneity is a rare finding in HIV-NHL, suggesting a derivation from B-cells that have concluded the GC-reaction.

Computational Algorithm Based On Serum Immunoassays for the Identification of Haematological Disease May Identify Patients with Other Acute Disorders

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4001-4001
Author(s):  
David Sutton ◽  
Jeffrey Faint ◽  
Anandram Seetharam ◽  
Alan Macwhannell ◽  
Stephen Harding ◽  
...  
Keyword(s):  
Binding Site ◽  
Light Chain ◽  
Cox Regression ◽  
Immunoglobulin M ◽  
Haematological Malignancies ◽  
Laboratory Findings ◽  
Site Group ◽  
Normal Ranges ◽  
Increased Risk

Abstract Abstract 4001 Introduction Serum free light chain (FLC) measurements are used routinely to identify monoclonal immunoglobulin (M-Ig) production in patients. In addition, summated kappa + lambda concentrations have recently been shown to have prognostic value in chronic lymphocytic leukaemia (CLL), Hodgkins lymphoma and HIV patients; presumably reflecting immune stimulation. A recently developed companion assay to FLC testing measures intact immunoglobulin heavy chain/light chain (HLC) pairs in serum calculating Ig'κ/Ig'λ ratios as a reflection of clonality. Here we report on a computational approach combining FLC and HLC measurements to identify clonal disease, hyper- and hypo-gammaglobulinemia, and as markers of immune dysfunction. Furthermore, we comment on the potential of such an algorithm to risk stratify haematological and non-haematological malignancies. Patients, Materials and Methods 1468 patients referred to the Royal Wolverhampton Hospital for haematological evaluation were enrolled on to the study. Median patient age was 64 years, with a slight female preponderance (60%). Patient sera were analysed at presentation using routine electrophoresis tests (serum protein electrophoresis, SPEP and immunofixation, IFE). FLC and HLC (IgG, IgA and IgM) were measured by nephelometric immunoassay. Each immunoassay result was assessed with respect to individual normal ranges (FLCκ = 3.3–19.4mg/L, FLCλ = 5.71–26.30mg/L, IgGκ = 4.03–9.78g/L, IgGλ = 1.97–5.71g/L, IgAκ = 0.48–2.82g/L, IgAλ = 0.36–1.98, IgMκ = 0.29–1.82g/L, IgMλ = 0.17–0.94g/L) and ratios (FLCκ/FLCλ = 0.26–1.65, Gκ/Gλ = 0.98–2.75, Aκ/Aλ = 0.8–2.04, Mκ/Mλ = 0.96–2.3). The results were used to create an algorithm which assessed the degree of abnormality individually and with respect to the other results generated. Diagnosis was recorded ∼3 months after the analysis and patients were followed for up to 3 years. Results 293/1468 (19%) samples had an abnormal SPEP of which 95/293 were confirmed by IFE including: 10 intact immunoglobulin Multiple Myeloma (MM, 6 IgGκ, 1 IgGλ, 2 IgAκ, 1 IgAλ), 6 light chain MM (LCMM, 4 FLCκ, 2 FLCλ), 2 Waldenstrom macroglobulinemia (2 IgMκ), 1 IgMκ cryoglobulinemia, 3 CLL, 1 mantle cell lymphoma, 3 other lymphoma, 1 IgGκ plasmacytoma, and 68 MGUS patients, 26/68 were confirmed MGUS (1 FLCκ, 13 IgGκ, 4 IgGλ, 4 IgAκ, 2 IgMκ, 2 IgMλ), 42 were laboratory findings requiring follow up (1FLCκ, 3 FLCλ, 19 IgGκ, 5 IgGλ, 4 IgAκ, 1 IgAλ, 8 IgMκ, 1 IgMλ). FLC/HLC algorithm identified 85/95 IFE positive patients; of the 10 patients reported not identified by the algorithm, 3 had oligoclonal banding indicative of infection and 7 had monoclonal bands secondary to other diagnoses (including 2 colon cancer patients and 2 rheumatoid arthritis patients). In addition the algorithm identified 15 IFE negative patients with M-Ig production including: 2 AL amyloid patients, 1 asymptomatic LCMM, 1 patient with ∼1g/L FLCκ (lost to follow up), 1 follicular lymphoma patient and 1 CLL; diagnosis was not available for 9/15 patients. Furthermore, the algorithm identified 205/1468 patients as having elevated polyclonal FLC (cFLC) >50mg/L without evidence of clonal production. In a subset analysis comparing matched numbers of patients with elevated or normal cFLC concentrations, cFLC >50mg/L predicted all cause mortality (logistic regression odds ratio 9.96, 95% CI 4.72–21.0, p<0.001), and was associated with poorer overall survival (Kaplan Meier p<0.001, Cox regression hazard ratio 8.73, 95% CI 4.47–17.02). Discussion MM presents with disparate and vague symptoms pervasive in an elderly population. Current guidelines recommend SPEP and FLC analysis reflexing to IFE for confirmation in the event of abnormality. However, SPEP and IFE require interpretation making the assessment variable. Standardised immunoassays (FLC+HLC) may obviate the need for interpretation and in this study identified additional haematological malignancies. Furthermore, standard assessments can be used to identify M-Ig, but in the absence of this finding may offer little information pertaining to the symptoms that prompted referral. By contrast this algorithm identified patients with elevated cFLC which in agreement with other reports was associated with increased risk of mortality. Further work is required to assess the algorithm, and determine if cFLC measurements should be used as a prompt for additional diagnostic investigations. Disclosures: Faint: The Binding Site Group, Ltd.: Employment. Harding:The Binding Site Group Ltd.: Membership on an entity's Board of Directors or advisory committees. Mirbahai:The Binding Site Group, Ltd: Employment.

Clinical Responses In Patients Infused With T Lymphocytes Redirected To Target κ-Light Immunoglobulin Chain

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 506-506 ◽  
Author(s):  
Carlos A. Ramos ◽  
Barbara Savoldo ◽  
Enli Liu ◽  
Adrian P. Gee ◽  
Zhuyong Mei ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Light Chain ◽  
Stable Disease ◽  
Research Funding ◽  
B Cell Malignancies ◽  
Car T Cells ◽  
Car T

Abstract Adoptive transfer of T cells with a CD19-specific chimeric antigen receptor (CAR) to treat B-cell malignancies shows remarkable clinical efficacy. However, long-term persistence of T cells targeting CD19, a pan-B cell marker, causes sustained depletion of normal B cells and consequent severe hypogammaglobulinemia. In order to target B-cell malignancies more selectively, we exploited the clonal restriction of mature B-cell malignancies, which express either a κ or a λ-light immunoglobulin (Ig) chain. We generated a CAR specific for κ-light chain (CAR.κ) to selectively target κ+ lymphoma/leukemia cells, while sparing the normal B cells expressing the reciprocal λ-light chain, thus minimizing the impairment of humoral immunity. After preclinical validation, we designed a phase I clinical trial in which patients with refractory/relapsed κ+ non-Hodgkin lymphoma (NHL) or chronic lymphocytic leukemia (CLL) are infused with autologous T cells expressing a CAR.κ that includes a CD28 costimulatory domain. The protocol also included patients with multiple myeloma with the aim of targeting putative myeloma initiating cells. Three dose levels (DL) are being assessed, with escalation determined by a continual reassessment method: 0.2 (DL1), 1 (DL2) and 2 (DL3) ×108 T cells/m2. Repeat infusions are allowed if there is at least stable disease after treatment. End points being evaluated include safety, persistence of CAR+T cells and antitumor activity. T cells were generated for 13 patients by activating autologous PBMC with immobilized OKT3 (n=5) or CD3/CD28 monoclonal antibodies (n=8). In 2 patients with >95% circulating leukemic cells, CD3 positive selection was performed using CliniMACS. After transduction, T cells (1.2×107±0.5×107) were expanded ex vivo for 18±4 days in the presence of interleukin (IL)-2 to reach sufficient numbers for dose escalation. CAR expression was 81%±13% by flow cytometry (74,112±23,000 transgene copy numbers/mg DNA). Products were composed predominantly of CD8+ cells (78%±10%), with a small proportion of naïve (5±4%) and memory T cells (17%±12%). CAR+ T cells specifically targeted κ+ tumors as assessed by 51Cr release assays (specific lysis 79%±10%, 20:1 E:T ratio) but not κ–tumors (11%±7%) or the NK-sensitive cell line K562 (26%±13%). Ten patients have been treated: 2 on DL1, 3 on DL2 and 5 on DL3. Any other treatments were discontinued at least 4 weeks prior to T-cell infusion. Patients with an absolute leukocyte count >500/µL received 12.5 mg/kg cyclophosphamide 4 days before T-cell infusion to induce mild lymphopenia. Infusions were well tolerated, without side effects. Persistence of infused T cells was assessed in blood by CAR.κ-specific Q-PCR assay and peaked 1 to 2 weeks post infusion, remaining detectable for 6 weeks to 9 months. Although the CAR contained a murine single-chain variable fragment (scFv), we did not detect human anti-mouse antibodies following treatment and CAR.κ+T cell expansion continued to be observed even after repeated infusions. We detected modest (<20 fold) elevation of proinflammatory cytokines, including IL-6, at the time of peak expansion of T cells, but systemic inflammatory response syndrome (cytokine storm) was absent. No new-onset hypogammaglobulinemia was observed. All 10 patients are currently evaluable for clinical response. Of the patients with relapsed NHL, 2/5 entered complete remission (after 2 and 3 infusions at dose level 1 and 3, respectively), 1/5 had a partial response and 2 progressed; 3/3 patients with multiple myeloma have had stable disease for 2, 8 and 11 months, associated with up to 38% reduction in their paraprotein; and 2/2 patients with CLL progressed before or shortly after the 6-week evaluation. In conclusion, our data indicate that infusion of CAR.κ+ T cells is safe at every DL and can be effective in patients with κ+ lymphoproliferative disorders. Disclosures: Savoldo: Celgene: Patents & Royalties, Research Funding. Rooney:Celgene: Patents & Royalties, Research Funding. Heslop:Celgene: Patents & Royalties, Research Funding. Brenner:Celgene: Patents & Royalties, Research Funding. Dotti:Celgene: Patents & Royalties, Research Funding.

Fcgammariib Expression As a Prognostic Marker in Chronic Lymphocytic Leukemia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1727-1727
Author(s):  
Rosa Bosch ◽  
Gerardo Ferrer ◽  
Eva Puy Vicente ◽  
Alba Mora ◽  
Rajendra N. Damle ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Clinical Outcome ◽  
B Cell ◽  
Research Funding ◽  
Lymphocytic Leukemia ◽  
Leukemic Cells ◽  
Disease Stage ◽  
Advanced Stage ◽  
Fcγ Receptor ◽  
Expression Levels

Abstract BACKGROUND The Fcγ receptor IIb (FcγRIIb) is an inhibitory Fcγ receptor that suppresses B-cell activation when coligated with B-cell antigen receptor (BCR). Previous studies from our group indicate that the ability of the FcγRIIb to inhibit BCR signaling after coligation is attenuated in Chronic Lymphocytic Leukemia (CLL). Furthermore, in contrast to what has been described in normal murine B-cells, stimulation of the FcγRIIb alone induces proliferation of CLL cells. However, the correlation between FcγRIIb expression, immunophenotypic characteristics, and clinical variables in patients with CLL has not been studied. AIM The aim of this study was to correlate the expression of FcγRIIb on leukemic cells from previously untreated CLL patients and its immunophenotypic features and clinical parameters. METHODS The study population included 112 patients with untreated CLL for whom cryopreserved peripheral blood samples were available before treatment. The diagnosis was based on IWCLL 2008 criteria. The median patients' follow up was 57.92 months (range: 2.23-439.78 months). FcγRIIb expression levels were determined by flow cytometry on CD5+/CD19+ CLL cells using a specific Alexa488-conjugated murine mAb specific for human FcγRIIb. The following combinations were assessed: FcγRIIb/CD38/CD19/CD5, FcγRIIb/CD49d/CD19/CD5, and FcγRIIb/CD69/CD19/CD5. Results were expressed as the ratio between the MFI for FcγRIIb and the MFI for the corresponding isotype (MFIR). FcγRIIb expression levels were correlated with: i) expression of CD49d, CD38 and CD69, ii) clinico-biological characteristics, and iii) clinical outcome. Differences of FcγRIIb expression on dichotomized clinicopathological variables were assessed with Mann Whitney test. Kaplan-Meier survival and Cox regression analysis were performed to evaluate the correlation of FcγRIIb expression with clinical outcome. Best cut-offs for overall survival (OS) and treatment-free survival (TFS) were determined by ROC curves. RESULTS All CD5+CD19+ leukemic cells samples expressed FcγRIIb. However, FcγRIIb expression levels markedly varied between patients (median MFIR: 45.8; interquartile range: 14.9-76.6; 5th -95th percentile: 17.15-111.4). FcγRIIb expression was significantly higher in patients who had high (≥30%) CD49d expression than in those with low (<30%) CD49d expression (p =0.009). No correlation was observed between FcγRIIb expression and age, disease stage, IGHV mutational status or chromosomal abnormalities analyzed by fluorescence in situ hybridization, ZAP70 and CD38. Furthermore, within individual clones, FcγRIIb expression levels were higher on CD38+ or CD49d+ cells than on CD38- or CD49d- cells, respectively (median MFIR: 49.05 vs. 36.72, p =0.001 for CD38+ vs. CD38- cells; and 58.87 vs. 35.55, p <0.001 for CD49d+ vs. CD49d- cells). In univariate analysis, low FcγRIIb expression levels (MFIR< 26.67) were associated with shorter OS (HR 4.01, 95%CI 1.15-13.90, p=0.029), together with older age, advanced stage, and expression of CD38 and CD49d. Advanced stage, unmutated IGHV, and CD38, CD49d and ZAP-70 expression were also associated significantly with shorter TFS. Thus, patients with higher levels of FcγRIIb had better survival than those with lower levels (Log rank test, p = 0.018). A multivariate analysis adjusted for FcγRIIb expression, age, disease stage, CD38, and CD49d identified older age (≥65 yrs) (HR 150.76, 95%CI 5.39-4212.42, p =0.003), low FcγRIIb expression (HR 111.91, 95%CI 6.71-1866.97, p =0.001), advanced stage (B/C) (HR 17.44, 95%CI 1.45-210.24, p =0.024) and CD38 expression (HR 5.02, 95%CI 1.01-25.18, p =0.050) as independent predictors for shorter OS. CONCLUSIONS In this study, FcγRIIb expression on leukemic cells from untreated patients with CLL was found to be an independent prognostic marker for OS, overcoming the prognostic value of CD49d, which is consistent with the key role of the FcγRIIb in the pathogenesis of CLL. Further analysis aimed at validating this observation and to better understand the functional cooperation of FcγRIIb with other molecules, particularly CD49d, are warranted. These studies could open a new venue in CLL treatment. Disclosures Gorlatov: MacroGenics: Employment. Sierra:Novartis: Research Funding; Celgene: Research Funding; Amgen: Research Funding.

The Acidic Region of Factor VIII Light Chain Contains the Thrombin-Binding Site(s) Responsible for the Cleavage at Arg1689

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2270-2270
Author(s):  
Hiroaki Minami ◽  
Keiji Nogami ◽  
Midori Shima
Keyword(s):  
Binding Site ◽  
Board Of Directors ◽  
Light Chain ◽  
Research Funding ◽  
Coagulation Cascade ◽  
Cross Linking ◽  
C2 Domain ◽  
Advisory Committees ◽  
Acidic Residues ◽  
Dose Dependent

Abstract Thrombin-catalyzed activation of factor (F)VIII by cleavages at Arg372, Arg740, and Arg1689 is essential for the propagation phase of blood coagulation cascade. Activated FVIII (FVIIIa) forms the tenase complex and markedly amplifies the activation of FX as a cofactor of FIX. We had already demonstrated that thrombin interacts with FVIII through the residues 392-394 and 484-509 in the A2 domain and the C2 domain, and each association regulates cleavage at Arg740, Arg372, and Arg1689, respectively (Nogami K, JBC 2000, 2005; BJH 2008), and recently reported that the A1 acidic clustered region 340-350 involving the sulfated tyrosine regulate the cleavage of Arg372 (Minami et al. 55th ASH). On the other hand, Fay and colleague suggested that recombinant FVIII lacking the C2 domain retains greater than 50% cofactor activity (JBC 2010), supporting the presence of other thrombin-binding region responsible for cleavage at Arg1689 of the light chain. In this study, we attempted to identify this thrombin-binding site(s). We focused on the acidic residues 1659-1669 and 1675-1685 within the light chain, which had similar sequence to the A1 residues 340-350 in terms of involving the clustered acidic residues and sulfated tyrosine as well as hirugen residues 54-65. We prepared four of synthetic peptides corresponding to the residues 1659-1669 and 1675-1685 with sulfated tyrosine, P(1659-69s) and P(1675-85s), and with non-sulfated tyrosine, P(1659-69) and P(1675-85). The inhibitory effect on the thrombin-catalyzed FVIII activation by each peptide was evaluated in a one-stage clotting assay. Each peptide showed a dose-dependent inhibition on thrombin-catalyzed activation. These inhibitory effects were greater in order of P1675-85s, P1659-69s, P1675-85, P1659-69, and the IC50 were 25, 67, 71 and 225 µM, respectively. The peptides with sulfated tyrosine had approximately 3-fold greater inhibition of the FVIII activation by thrombin than with non-sulfated tyrosine. The IC50 in the presence of mixture of P1675-85s and P1659-69s was 30.4 µM, suggesting that these peptides had no an additive effect. The impacts of P1659-69s and P1675-85s on the thrombin-catalyzed cleavage at Arg1689 were examined by SDS-PAGE/western blotting. These peptides blocked the cleavage at Arg1689 in dose-dependent fashions. In timed-course assay, the presence of P1659-69s and P1675-85s decreased the cleavage rate of Arg1689 by 61.3 % and 81.8 %, respectively compared to its absence. The direct binding of P1659-69s and P1675-85s to thrombin was examined by surface resonance plasmon (SPR)-based assay and by the zero-length cross-linking reagent EDC. In SPR-based assay using a Biacore T200TM, thrombin bound to immobilized P1659-69s and P1675-85s directly with high affinity. The Kd values adjusted to 1:1 binding model of global fitting were 203 nM and 94 nM, respectively. EDC cross-linking in fluid-phase assay revealed that formation of EDC cross-linking products between biotinylated P1659-69s or P1675-85s and thrombin were observed in dose-dependent fashions. The products between the biotinylated peptides (800 nM) and thrombin were competitively reduced by the addition of non-biotinylated peptides. Moreover, N-terminal sequence analysis of cross-linking products between both peptides-thrombin indicated that thrombin bound to the residues 1664-1669 and 1683-1684. Taken together, we demonstrated that the A3 residues 1659-1669 (QEEIDYDDTIS) and residues 1675-1685 (EDFDIYDEDEN) contained the thrombin binding-sites responsible for proteolytic cleavage at Arg1689 of the A3 domain. Disclosures Nogami: Bayer, NovoNordisk, Baxalta, Chugai, Kaketsuken, Pfizer, Biogen: Honoraria; Chugai: Membership on an entity's Board of Directors or advisory committees; Bayer, Novo Nordisk, Baxalta. Biogen: Research Funding. Shima:Chugai Pharmaceutical Co., Ltd. and F. Hoffmann-La Roche Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Evaluation of the Concordance of Two Free Light Chains Assays to Identify High Risk Smoldering Myeloma Patients.

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2070-2070 ◽  
Author(s):  
Caroline Moreau ◽  
Emmanuel Rouger ◽  
Basile Henriot ◽  
Martine Escoffre ◽  
Martine Sebillot ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
High Risk ◽  
Binding Site ◽  
Light Chain ◽  
Research Funding ◽  
Plasma Cells ◽  
Organ Damage ◽  
Free Light Chain ◽  
Poor Correlation ◽  
Specificity And Sensitivity

Abstract Background Smoldering multiple myeloma (SMM) is a precursor disease of multiple myeloma (MM). According to 2003 classification, the IMWG (International Myeloma Working Group) recommended only to treat patients with end organ damage - often referred as CRAB criteria (hypercalcemia, renal failure, anemia and radiological bone lesions). The standard of care for SMM was to postpone treatment until progression to symptomatic disease occurred. The average annual risk of progression of SMM to MM was 10%/year. In 2014 IMWG proposed a revised classification including 3 new criteria that enable early diagnosis of MM before organ damage. The new criteria of MM needs the presence of more than 10% clonal bone marrow plasma cells combined with either the presence of end organ damage (CRAB criteria) or one of following new biomarkers of malignancy: bone marrow plasma cells ≥60%, serum free light chains (FLC) ratio ≥100 and ≥2 focal lesions on MRI. The FLC criteria were established with Freelite™ assay (The Binding Site Company) and have not been validated with other available assays. Freelite™ assay which used polyclonal antibodies was available since 2001. More recently N Latex assay (Siemens Healthyneers) using monoclonal antibodies has been commercialized in Europe. It is now well know that there is a good correlation between the 2 assays even though results in absolute values are not numerically identical. In this context, the aim of this study was to evaluate the concordance between the two assays to identify high risk SMM, when considering the biomarker of malignancy FLC ratio ≥100. Methods This is a retrospective study including 185 patients with SMM according to 2003 IMWG criteria. FLC concentration and ratio were evaluated in frozen sera with both assays in a BN Prospec and evolution status was collected. Results The average age was 62.5 (± 10.2) years old. Results revealed poor correlation between the 2 assays with a Slope Passing-Bablok value of 0.63 (0.57-0.67) for the FLC κ and of 0.44 (0.35-0.62) for the κ/ λ ratio ≥ 100, and concordance in determining the level of FLC λ with a Slope Passing-Bablok 1.16 (0.99-1.40). A Freelite™ratio ≥ 100 was found in 27 patients (14.3%), and a N Latex ratio ≥ 100 was found in 10 patients (5.3%). All but one patients with an N Latex ratio ≥ 100 had also a Freelite™ ratio ≥ 100. Mean of follow up was 2.4 years. A progression toward MM was observed in 77 (40.7%) patients. Among the 27 patients with Freelite™ ratio ≥ 100, 14 patients (55.5%) have evolved toward MM (figure 1A). Specificity and sensitivity for a Freelite™ ratio ≥ 100 were respectively 88.7% (95% CI 81.8 to 94.0%) and 20.3% (95% CI 11.8 to 31.2%). With the N Latex Assay, only 10 patients had a FLC ratio ≥ 100, in which 7 patients have evolved towards MM. Specificity and sensitivity for a N-Latex ratio ≥ 100 were respectively be 67.0% (95% CI 57.4 to 75.6%) and 53.2% (95% CI 41.5 to 64.7%). Given the poor predictive performance of a N-Latex ratio ≥ 100 we determined that a N-Latex ratio ≥ 70 have adequate specificity of 95.5% (95% CI 89.9 to 98.5%) and a sensitivity of 13.0% (95% CI 6.4 to 22.6%) (figure 1B). 15 patients (8.1%) patients had a N-Latex ratio ≥ 70. Among these, 10 patients (66.6%) have evolved toward MM. Conclusion Our study shows poor correlation between the two FLC assays in SMM patients. A Freelite™ ratio ≥ 100 had a lesser specificity than previously described (specificity 95% in Larsen study [1]). The 100 cut-off value was not performant enough for N-Latex assay. A new ratio is thus needed and was found to be 70 to have sufficient specificity and sensitivity. This result need to be validated in an independent cohort. However, with a Freelite™ ratio ≥ 100 or an N Latex ratio ≥ 70, a significant number of patients would have been overtreated. Physicians should be aware of the limits of both assays. 1.Larsen JT, Kumar SK, Dispenzieri A, Kyle RA, Katzmann JA, Rajkumar SV. Serum free light chain ratio as a biomarker for high-risk smoldering multiple myeloma. Leukemia. 2013;27:941-6. Figure 1 probability of progression to overt multiple myeloma (A) according to Freelite™ ratio (cut-off 100) (B) according to N-Latex ratio (cut-off 70) Figure 1. probability of progression to overt multiple myeloma (A) according to Freelite™ ratio (cut-off 100) (B) according to N-Latex ratio (cut-off 70) Disclosures Moreau: The Binding Site: Other: supply of free light chain assays ; SIEMENS: Other: supply of free light chain assays , Research Funding. Decaux:The Binding Site: Other: supply of free light chain assays , Research Funding; SIEMENS: Honoraria, Other: supply of free light chain assays , Research Funding.

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