The Natural History of Smoldering (Asymptomatic) Multiple Myeloma.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3396-3396 ◽  
Author(s):  
Robert Kyle ◽  
Ellen Remstein ◽  
Terry Therneau ◽  
Angela Dispenzieri ◽  
Paul Kurtin ◽  
...  

Abstract Smoldering multiple myeloma (SMM) is characterized by a serum M protein ≥ 3g/dL and/or 10% or more of plasma cells in the bone marrow. However, the definition is not standardized, and it is not known whether both serum M protein levels and bone marrow plasma cell counts are necessary for diagnosis or if one parameter is sufficient. We reviewed the medical records and bone marrows of all patients from Mayo Clinic seen within 30 days of recognition of an IgG or IgA M protein ≥ 3g/dL or a bone marrow containing ≥ 10% plasma cells from 1970 to 1995. This allows for a minimum potential follow-up of 10 years. Patients with end-organ damage at baseline from plasma cell proliferation, including active multiple myeloma (MM) and primary amyloidosis (AL) and those who had received chemotherapy were excluded. A differential of the bone marrow aspirate coupled with the bone marrow biopsy morphology and immunohistochemistry using antibodies directed against CD138, MUM-1 and Cyclin D1 were evaluated in every case in order to estimate the plasma cell content. In all, 301 patients fulfilled either of the criteria for SMM. Their median age was 64 years and only 3% were less than 40 years of age; 60% were male. The median hemoglobin value was 12.9 g/dL; 7% were less than 10 g/dL, but the anemia was unrelated to plasma cell proliferation. IgG accounted for 75%, IgA 22%, and biclonal proteins were found in 3%. The serum light-chain was κ in 67% and λ in 33%. The median serum M spike was 2.9 g/dL; 11% were at least 4.0 g/dL. Uninvolved serum immunoglobulins were reduced in 81%; only 1 immunoglobulin was reduced in 31% and both were decreased in 50%. The urine contained a monoclonal κ protein in 36% and λ in 18% and 46% were negative. The median size of the urine M spike was 0.04 g/24h; only 5 (3%) were > 1 g/24h. The median bone marrow plasma cell content was 15 – 19%; 10% had less than 10% plasma cells, while 10% had at least 50% plasma cells in the bone marrow. Cyclin D-1 was expressed in 17%. Patients were categorized into 3 groups: Group 1, serum M protein ≥ 3g/dL and bone marrow containing ≥ 10% plasma cells (n= 113, 38%); Group 2, bone marrow plasma cells ≥ 10% but serum M protein < 3g/dL (n= 158, 52%); Group 3, serum M protein ≥ 3g/dL but bone marrow plasma cells < 10% (n= 30, 10%). During 2,204 cumulative years of follow-up 85% died (median follow-up of those still living 10.8 years), 155 (51%) developed MM, while 7 (2%) developed AL. The overall rate of progression at 10 years was 62%; median time to progression was 5.5 yrs. The median time to progression was 2.4, 9.2, and 19 years in groups 1, 2, and 3 respectively; correspondingly at 10 years, progression occurred in 76%, 59%, and 32% respectively. Significant risk factors for progression with univariate analysis were serum M spike ≥ 4g/dL (p < 0.001), presence of IgA (p = 0.003), presence of urine light chain (p = 0.006), presence of λ urinary light chain (p = 0.002), bone marrow plasma cells ≥ 20% (p < 0.001) and reduction of uninvolved immunoglobulins (p < 0.001). The hemoglobin value, gender, serum albumin, and expression of cyclin D-1 were not of prognostic importance. On multivariate analysis, the percentage of bone marrow plasma cells was the only significant factor predicting progression to MM or AL.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1487-1487 ◽  
Author(s):  
Angela Dispenzieri ◽  
Robert A. Kyle ◽  
Jerry A. Katzmann ◽  
Dirk Larson ◽  
Joanne Benson ◽  
...  

Abstract Background: Smoldering multiple myeloma (SMM) is an asymptomatic plasma cell proliferative disorder with a high risk of progression to symptomatic multiple myeloma. Identification of risk factors that predict progression of SMM to symptomatic MM could identify higher risk patients who might benefit from chemoprevention or more intensive surveillance. We hypothesized that increased monoclonal free kappa or lambda immunoglobulin light chains in smoldering myeloma (SMM), as detected by the serum free light chain (FLC) assay, indicates an increased the risk of progression to active myeloma. Methods: Of 276 pathologically confirmed SMM patients seen at the Mayo Clinic from 1970 to 1995, baseline serum samples obtained within 30 days of diagnosis were available in 273. Results: At a median follow-up of surviving patients of 12.4 years, transformation to active disease has occurred in 161 (59%) patients. An abnormal FLC ratio was present at baseline in 90% of patients. The best break-point for predicting risk of progression was a FLC ratio less than or equal to 0.125 or greater than or equal to 8 (hazard ratio, 2.3; 95% CI, 1.6–3.2) [Figure 1]. The extent of abnormality of FLC ratio was independent of SMM risk categories defined by number of plasma cells in the bone marrow and size of serum M-proteins (bone marrow plasma cells ≥ 10% and serum M protein ≥ 3 g/dL; bone marrow plasma cells ≥ 10% but serum M protein < 3 g/dL; and serum M protein ≥ 3 g/dL but bone marrow plasma cells < 10%). Incorporating the FLC ratio into the risk model, the division of patients into high-, intermediate-, and low-risk groups is 28, 42, and 30% with 5 year progression rates of 76, 51, and 25%, respectively [Figure 2]. Conclusions: The serum immunoglobulin FLC ratio is an important additional determinant of clinical outcome in patients with SMM. Figure Figure Figure Figure


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4838-4838
Author(s):  
L. Rosiñol ◽  
S. Montoto ◽  
J. Bladé ◽  
M.T. Cibeira ◽  
M. Rozman ◽  
...  

Abstract Background: MGUS is a common disorder characterized by the presence of a small serum M-protein in individuals with no evidence of multiple myeloma (MM), Waldenström’s macroglobulinemia (WM) or primary amyloidosis (AL). Although about one fourth of these individuals will evolve into a malignant disease with a transformation rate of 1% per year, there are not well-established predictors of outcome. Aim: To identify predictor features of malignant transformation in a large series of patients with MGUS and prolonged follow-up. Patients and methods: Four hundred and thirty-four patients (200 M/234 F; median age 66 years) diagnosed with MGUS in a single institution from September 1970 to January 2001 with a minimum follow-up of one year were included in the study. All patients had an M-protein size < 30g/L. Bone marrow aspirates were reviewed independently by two of the authors and the proportion of bone marrow plasma cells (BMPC) were estimated from a 500 cell-count by each observer. The median follow-up was 5.2 years (range: 1–28.8 years) with 84 patients followed for more than 10 years. Results: The type of M-protein was IgG in 67.2% of the cases, IgA in 18.8%, IgM in 11.9%, light chain in 1% and biclonal in 1%. The light chain was kappa type in 56.4% of the patients. The median M-protein size was 15.6 g/L (<10 g/L in 10.8%, 10–20 g/L in 61.7%, and > 20g/L in 27.4%). The median percentage of BMPC in 305 reviewed samples was 4.6% (range: 0.4–25). After a median follow-up of 5.2 years, 50 patients (11.5%) have evolved into a malignant monoclonal gammopathy (44 MM, 5 WM and 1 AL). The median time to progression was 5.4 yrs (range: 1.4 – 16.9). The risk of transformation was 15.4% (95% CI: 10.5–20.3) and 34% (95% CI 22.6–45.3) and 34% (95% CI: 22.6–45.3) at 10 and 20 years, respectively. The variables associated with a higher risk of transformation were IgA-type (p=0.003), kappa light chain (p=0.009), the amount of M-protein (<15 vs >15 g/L, p=0.005) and the percentage of BMPC (<5% vs >5%, p=0.007). Conclusions: In this series of patients with MGUS, the type (i.e. IgA or kappa) and size of M-protein (>15g/L) as well as the percentage of bone marrow plasma cells (>5%) significantly predicted malignance transformation.


2013 ◽  
Vol 31 (34) ◽  
pp. 4319-4324 ◽  
Author(s):  
Taxiarchis V. Kourelis ◽  
Shaji K. Kumar ◽  
Morie A. Gertz ◽  
Martha Q. Lacy ◽  
Francis K. Buadi ◽  
...  

Purpose There is consensus that patients with light chain (AL) amyloidosis with hypercalcemia, renal failure, anemia, and lytic bone lesions attributable to clonal expansion of plasma cells (CRAB criteria) also have multiple myeloma (MM). The aim of this study was to examine the spectrum of immunoglobulin AL amyloidosis with and without MM, with a goal of defining the optimal bone marrow plasma cell (BMPC) number to qualify as AL amyloidosis with MM. Patients and Methods We identified 1,255 patients with AL amyloidosis seen within 90 days of diagnosis between January 1, 2000, and December 31, 2010. We defined a population of patients with coexisting MM on the basis of the existence of CRAB criteria (AL-CRAB). Receiver operating characteristic analysis determined the optimal BMPC cut point to predict for 1-year mortality in patients with AL amyloidosis without CRAB to produce two additional groups: AL only (≤ 10% BMPCs) and AL plasma cell MM (AL-PCMM; > 10% BMPCs). Results Among the 1,255 patients, 100 (8%) had AL-CRAB, 476 (38%) had AL-PCMM, and 679 (54%) had AL only. Their respective median overall survival rates were 10.6, 16.2, and 46 months (P < .001). Because the outcomes of AL-CRAB and AL-PCMM were similar, they were pooled for univariate and multivariate analyses. On multivariate analysis, pooled AL-CRAB and AL-PCMM retained negative prognostic value independent of age, Mayo Clinic AL amyloidosis stage, prior autologous stem-cell transplantation, and difference between the involved and uninvolved free light chain. Conclusion Patients with AL amyloidosis who have more than 10% BMPCs have a poor prognosis, similar to that of patients with AL-CRAB, and should therefore be considered together as AL amyloidosis with MM.


Blood ◽  
1984 ◽  
Vol 64 (2) ◽  
pp. 352-356
Author(s):  
GJ Ruiz-Arguelles ◽  
JA Katzmann ◽  
PR Greipp ◽  
NJ Gonchoroff ◽  
JP Garton ◽  
...  

The bone marrow and peripheral blood of 14 patients with multiple myeloma were studied with murine monoclonal antibodies that identify antigens on plasma cells (R1–3 and OKT10). Peripheral blood lymphocytes expressing plasma cell antigens were found in six cases. Five of these cases expressed the same antigens that were present on the plasma cells in the bone marrow. Patients that showed such peripheral blood involvement were found to have a larger tumor burden and higher bone marrow plasma cell proliferative activity. In some patients, antigens normally found at earlier stages of B cell differentiation (B1, B2, and J5) were expressed by peripheral blood lymphocytes and/or bone marrow plasma cells.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3948-3948
Author(s):  
Jeremy T Larsen ◽  
Shaji Kumar ◽  
S. Vincent Rajkumar

Abstract Abstract 3948 Background: Smoldering multiple myeloma (SMM) is an asymptomatic precursor disease of multiple myeloma, and is defined by excess bone marrow plasma cells and monoclonal protein without evidence of end-organ damage (hypercalcemia, renal insufficiency, anemia, or bone lesions [CRAB]). The identification of SMM patients with more aggressive underlying disease remains a challenge. We hypothesize that SMM is a clinical entity comprised of both premalignant, high-risk MGUS and early multiple myeloma in transition to malignant disease, which may be differentiated with the use of the serum FLC (FLC) ratio. Methods: This was a retrospective analysis of 586 patients with newly diagnosed SMM from 1970–2010 with available stored serum samples around the time of diagnosis to be utilized for quantification of FLC ratios. SMM was defined by the International Myeloma Working Group 2003 definition; serum M-protein ≥ 3 g/dL and/or ≥ 10% bone marrow plasma cells with no evidence of CRAB features. The immunoglobulin FLC assay (Binding Site, U.K.) was used for testing. The FLC ratio was calculated as κ/λ (reference range 0.26–1.65). The involved/uninvolved FLC ratio was recorded to simplify the reporting of data. Receiver Operating Characteristics (ROC) curves were created to assess the ability of the FLC ratio to discriminate patients who progressed to symptomatic multiple myeloma (MM) in the first 2 years or at any point during follow-up versus patients without evidence of progression. Patients with less than 24 months follow-up without progression were censored. The optimal diagnostic cut-point for FLC involved/uninvolved ratio to identify patients with progressive disease from the ROC curve was >88.6 (equivalent to <0.011 or >88.6). For ease of clinical application, the optimal value for involved/uninvolved FLC ratio was rounded to >100. Time to progression (TTP) from date of the initial FLC to active MM was calculated using Kaplan-Meier analysis and compared to patients with a high (>100) and low (<100) involved/uninvolved FLC ratio at time of SMM diagnosis. TTP within 24 months of the initial FLC was also calculated. Results: During the study period, 54% of patients progressed to active MM. On ROC analysis, a cut-point of >100 corresponded to a sensitivity of 25% (95% CI, 20.5–30.4) and specificity of 99.3% (97.3–99.9), with positive likelihood (+LR) ratio of 33.9 (38.1–41.0), negative likelihood ratio (−LR) of 0.75 (0.2–3.0), positive predictive value (PPV) of 97.6 (91.5–99.7) and negative predictive value of 53.0 (48.5–57.4). Using the ROC to assess progression to MM within 24 months (Figure 1), sensitivity was 29.6% (23.5–36.4), specificity 94.5% (91.7–96.5), +LR 5.36 (4.3–6.6), -LR 0.75 (0.5–1.1), PPV 85.8 (77.7–91.8), and NPV 54.3 (49.8–58.9). Median TTP to active MM in the FLC >100 group was 15 months (9–17) versus 52 months (44–60) in the FLC <100 group (p <.0001) [Figure 2]. In the FLC ratio >100 group, progression at 1 year was 47%, 76% at 2 years, and 90% at 3 years. Only 25% of the FLC <100 patients had progressed at 2 years. The most common progression event was bone disease (42%), followed by anemia (26%), renal impairment (23%), and hypercalcemia (5%). Conclusion: Elevation of the FLC ratio >100 (or <0.01) is highly specific for the future development of active MM, with 76% of these patients developing end-organ damage requiring therapy within 2 years. Risk of transformation to MM in the FLC <100 group was similar to previously reported rates of 10% per year for the first 5 years. Development of an FLC ratio >100 is associated with increasing disease burden and in this study behaved in a malignant fashion rather than a precursor state. The FLC is a simple and useful predictor of progression to MM in SMM, and patients with FLC ratios of <0.01 or >100 within the first 2 years of SMM diagnosis should be monitored especially closely. Future studies are needed to determine optimum cutoffs for FLC ratio to where a change in definition of MM could be considered. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3369-3369 ◽  
Author(s):  
Veronica Gonzalez de la Calle ◽  
Ramon Garcia-Sanz ◽  
Eduardo Sobejano ◽  
Enrique M. Ocio ◽  
Noemi Puig ◽  
...  

Abstract BACKGROUND Smoldering multiple myeloma (SMM) is a plasma cell proliferative disorder with no related organ or tissue impairment. It is associated with a risk of progression to symptomatic multiple myeloma (MM) of approximately 10% per year. Several prognostic factors for the progression to active disease have been identified, such as those defined by the Mayo Clinic including the proportion of bone marrow plasma cells, the serum monoclonal protein level at diagnosis and the serum immunoglobulin free light chain ratio (FLC); or those defined by the Spanish Group including the proportion of bone marrow aberrant plasma cells assessed by flow cytometry plus immunoparesis. The presence of Bence Jones (BJ) proteinuria is a myeloma feature associated with renal function and tumor burden as well. There is lack of evidence about the role of BJ proteinuria in SMM as predictor marker of progression to symptomatic disease. AIMS The goal of the present study was to investigate the role of the presence of Bence Jones proteinuria at diagnosis in SMM as predictor of progression to symptomatic disease. METHODS We reviewed 147 medical records of SMM patients from area of Castilla y León (Spain), diagnosed between 1983 and 2013, according to the criteria of the International Myeloma Working Group. The primary endpoint was time to progression to active multiple myeloma (hypercalcemia, renal insufficiency, anemia or bone lesions). RESULTS 147 patients with SMM were included in the analysis. The median age at diagnosis was 69 years-old (range: 34-90).The serum M-protein at diagnosis ranged from 1 to 26 g/l (median,25). 70% of SMM were Ig G subtype. The proportion of bone marrow plasma cells ranged from 1% to 55% (median, 14). In 64 % of SMM, the percentage of aberrant plasma cells assessed by flow cytometry was superior to 95% and 51% had immunoparesis. Bence Jones proteinuria was detected at diagnosis in 40 patients (27%) and the average amount of urinary monoclonal light chain was 236 mg per 24h. Of those patients, 58% had a monoclonal kappa light chain. The FLC ratio was assessed in 18 patients and it was abnormal (<0.26 or >1.65) in 83% of them. The median level of involved Immunoglobulin was 88.5 mg/l (range, 13-1200) and the median ratio of involved to uninvolved was 10.8 (range, 2.2-3360). In 4 patients, FLC ratio was greater than 100. At a median follow-up of 54 months, progression to active disease occurred in 49%. Anemia was the most common CRAB feature at the time of progression. Median time to progression (TTP) to symptomatic disease in the whole series was 63 months. SMM with BJ proteinuria had a significantly shorter median TTP to active disease as compared with patients without BJ proteinuria (21.7 months vs 82.9 months ;HR: 2.44, IC 95%: 1.48-4.02; p<0.001). The progression risk at 2 years in the BJ group of SMM was 53%. Multivariate analysis selected BJ proteinuria at diagnosis as an independent variable for progression to symptomatic MM (HR: 2.47, IC 95%: 1.32-4.63; P=0.005). Using this independent variable, we identified 4 risk categories according to amount of urinary monoclonal light chain: 0 mg per 24h; 1-250 mg/24h; 251-500 mg/24h ; or more than 500 mg/24h, with a median TTP of 83, 37, 16 and 7 months, respectively; p <0.001. CONCLUSIONS The presence of Bence Jones proteinuria at diagnosis in SMM patients is associated with significantly higher risk of progression to active MM (53% risk of progression at 2 years). Moreover, the presence of more than 500 mg of BJ proteinuria can be considered as a marker for the identification of ultra high risk SMM. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 5067-5067
Author(s):  
Meletios Athanasios Dimopoulos ◽  
Evangelos Terpos ◽  
Maria Gkotzamanidou ◽  
Evangelos Eleutherakis-Papaiakovou ◽  
Magdalini Migkou ◽  
...  

Abstract Abstract 5067 The incidental finding of a monoclonal gammopathy during workup for various conditions or in the context of a routine check-up is increasingly common. Several “patients” are then referred for diagnostic evaluation of their monoclonal gammopathy and additional workup is needed. It has been proposed that a bone marrow (BM) aspirate and biopsy is indicated when the monoclonal protein (M-protein) is ≥1.5 g/dL, when abnormalities are noted in the complete blood cell count, serum creatinine level, serum calcium level, or radiographic bone survey, in individuals with non-IgG monoclonal gammopathy and in those with an abnormal serum free light chain (FLC) ratio. The aim of this study was to identify factors that could aid in the evaluation of individuals presenting with asymptomatic monoclonal gammopathy and in whom invasive diagnostic testing with a bone marrow biopsy is considered. Thus, we analyzed our database and identified patients who were referred to the Department of Clinical Therapeutics of the University of Athens, Greece, for evaluation of asymptomatic monoclonal gammopathy and in whom a BM trephine biopsy, a serum and urine protein electrophoresis (SPEP) with immunofixation and quantitative immunoglobulins were performed. SPEPs were scanned and M-protein was measured using imaging analysis software. Patients with a monoclonal M-protein ≥ 3 g/dl (30 g/L), i.e. those diagnosed with asymptomatic/smoldering myeloma (SMM) or Waldenstrom's macorglobulinemia based on the standard criteria, were not included in the analysis. Clonality of BM plasma cells or lymphoplasmacytes was assessed by immunohistochemistry. Patients who eventually were diagnosed with plasma cell related conditions (i.e. amyloidosis, peripheral neuropathy, dermatoses, etc.) were also excluded from the analysis. Our analysis included 161 patients: 53% were females, median age was 64 year (range 33–89 years), 53% had a monoclonal IgG protein, 15.5% had a monoclonal IgA protein, 24% a monoclonal IgM protein and 2.5% had only a monoclonal light chain, while 4% had a biclonal protein. In 64% of patients the monoclonal light chain was kappa and in 37% was lambda. The median serum M-protein was 0.948 g/dl (range 0.1–2.99 g/dl); 52% of patients had an M-protein of <1 g/dl and 79% of <2 g/dl. Immunoparesis of at least one of the uninvolved immunoglobulins was present in 38% of cases and of both of the uninvolved immunoglobulins in 6%. Median BM infiltration by monoclonal plasma cells or lymphoplasmacytes was 15%. In 66.5% of individuals there was a BM infiltration of ≥10% by monoclonal plasma cells or lymphoplasmacytes, while in 10% of the studied cases the BM infiltration was ≥50%. A significant correlation of the size of M-protein and of the infiltration of the BM was found (R=0.592, p<0.001). However, 27% of patients with M-protein <0.5 g/dl had ≥10% clonal plasma cells or lymphoplasmacytes in their BM biopsies. The respective rates were 46% for those with M-protein <1 g/dl, 54% for those with M-protein 1.5 g/dl and 58% for those with M-protein <2 g/dl. Ninety per cent of those who had immunoparesis of at least one of the uninvolved immunoglobulins had ≥10% clonal plasma cells or lymphoplasmacytes. A BM infiltration of ≥10% was more frequent in individuals with a monoclonal IgG or IgA protein (72% and 80%, respectively) vs. 45% of those with a monoclonal IgM protein (p=0.015). Light chain isotype, age and gender were not predictive of the degree of BM plasma cell infiltration. In multivariate analysis, immunoparesis of at least one of the uninvolved immunoglobulins (OR: 6.45, 95% CI: 2.32–18, p<0.001), an IgG or IgA monoclonal protein (OR: 2.67, 95% CI: 1.1–6.4, p=0.028) and an M-protein of ≥1 g/dl (OR: 5.4, 95% CI: 2.23–13) were independently associated with the presence of ≥10% of clonal infiltration in BM biopsy. By combining the above risk factors we found that in those who had all three, 97% had ≥10% clonal cells in the BM biopsy, while in those with 0–1 of the above factors the probability to find ≥10% clonal cells was 43%. These findings indicate that even patients with low risk for BM infiltration by clonal plasma cells, may be diagnosed as SMM when a BM biopsy is performed. In conclusion, our data on a large number of individuals with asymptomatic monoclonal gammopathy who underwent a BM biopsy may indicate that the latter exam may provide useful information and could be included in the standard initial workup of these individuals. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3152-3152
Author(s):  
H. Robert Bergen ◽  
David L Murray ◽  
Diane F. Jelinek ◽  
Renee C. Tschumper ◽  
David R Barnidge ◽  
...  

Abstract Proteomics with great sensitivity and specificity effectively analyzes proteins by prior tryptic digestion and subsequent analysis by LC-MS/MS of the tryptic digest. We have utilized this approach in the development of a LC-MS/MS method to characterize minimum residual disease in multiple myeloma. The abundant antibodies produced by multiple myeloma plasma cells are identical and appear as a spike (M-spike) upon protein electrophoresis. The M-spike and histological examination of the bone marrow constitute part of the myeloma diagnostic repertoire. Upon treatment, myeloma cells and the antibodies they produce are reduced in number and amount and become increasingly hard to detect. The bone marrow biopsy serves as the “gold standard” test for clinical remission. We have developed a sensitive test for the presence of the monoclonal antibody produced by the plasma cells which may serve as a substitute for invasive bone marrow biopsy. We have focused on tryptic peptides comprising the variable CDR regions of the Ig light chains that are unique to each patients antibody clone. Utilizing 2-5 µL of patient plasma/serum from the initial M-spike sample we have utilized SDS-PAGE to yield a crudely purified immunoglobulin light chain. The light chain band is isolated, reduced, alkylated and trypsin digested with subsequent LC-MS/MS analysis to identify CDR specific tryptic peptide(s). These can be identified as variable peaks (elution time and mass) in a base peak ion chromatogram where constant region peptides of either lambda or kappa light chains (clone dependent) serve as “internal standards” for identifying the CDR tryptic peptides. The peptide’s mass and its corresponding MS/MS spectra are unique to this CDR tryptic peptide and this patient’s clone. The unique diagnostic peptide is isolated in subsequent samples by immunoaffinity purification of the target kappa/lambda clone, SDS-PAGE separation and LC-MS/MS analysis of the light chain gel band. An extracted ion chromatogram is generated based upon the CDR peptides identified in the initial analysis of the M-spike sample. In patients in clinical remission the presence of a significant signal from the targeted peptides indicates that targeting a CDR peptide from the M-spike protein is more sensitive than currently available diagnostic tools including immunofixation. Comparison of this test to the gold standard bone marrow biopsy will be examined. Disclosures: Barnidge: Mayo Foundation: provisional patent application for technology, provisional patent application for technology Patents & Royalties.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 5319-5319
Author(s):  
Daniela Lakomy ◽  
Stephanie Lemaire-Ewing ◽  
Cedric Rossi ◽  
Jessica Borgeot ◽  
Jean-Noël Bastie ◽  
...  

Abstract Introduction The evaluation of multiple myeloma response to treatment as defined by international guidelines is currently based on morphologic examination of bone marrow plasma cells, serum protein electrophoresis (SPEP), immunofixation electrophoresis (IFE) and serum free light chain assay. For several years new tools are available as bone marrow plasma cell immunophenotyping and the HevyliteTM assay. HevyliteTM IgA assay provides an automated evaluation of serum heavy/light chain ratio (HLC) of the involved and uninvolved immunoglobulin (Ig) (i.e. IgAΚ/IgAλ). This is particularly interesting in IgA myeloma where the use of SPEP is limited due to a frequent comigration of monoclonal IgA with other proteins. We therefore compared the IgA quantification by Hevylite™ assay and the bone marrow plasma cell immunophenotyping for response evaluation and residual disease characterisation in IgA myeloma. Methods Hevylite™ assay, SPEP, IFE were performed in eleven IgA myeloma patients at different times: after induction chemotherapy, after the consolidation phase and after autologous stem-cell transplantation (ASCT). In the same time, minimal residual disease (MRD) assessment was performed on bone marrrow by multiparameter flow cytometry (MFC). Hevylite™ assay was performed on a Binding Site SPAplus analyser (Hevylite, Binding Site, Birmingham, UK) following the manufacturer recommendations. SPE and IFE were realized on Sebia Hydrasys analyser (Sebia, Evry, France) and results were read by two experienced biologists. Results 1. We found a perfect agreement between the IFE and immunophenotyping results at each time of evaluation, for positive results as for negative results. 2. The SPEP was contributive only in two patients and in these cases it was less sensitive than IFE. In the other patients, the monoclonal IgA migrated in beta region and/or as multiple bands, making the quantitative estimation difficult. 3. In all patients, when MRD by MFC was undetectable and IFE was negative, the HLC ratio was normal. 4. In 3 patients, HLC ratio was consistent with the IFE and MRD by MFC at each time of evaluation. Nevertheless, in 8 patients out of 11, while HLC ratio became normal, MRD by MFC and IFE were still positive. In all cases, the normalization of HLC ratio was followed, at the next step of evaluation, by the normalization of MFC and IFE. 5. In 5 patients, the normalization of HLC ratio occurred before ASCT, while IFE and MRD by MFC were still positive. Nevertheless, after ASCT, IFE and MRD by MFC became also negative, in accordance with the HLC ratio (Table 1). Conclusions During the evaluation of response to treatment of IgA myeloma, we observed a normalization of HLC ratio (Hevylite™ IgA assay) preceding the normalization of MRD by MFC and IFE. This could be explained by the fact that IFE and immunophenotyping provide very sensitive information but only on the monoclonal component. HLC ratio reflects the balance between the monoclonal and polyclonal Igs of involved and uninvolved isotype. A normalization of HLC ratio can be interpreted as an increasing polyclonal Ig proportion parallel with a decreasing monoclonal Ig proportion and may reflect the reconstitution of polyclonal plasma cells. If confirmed by other studies and long term follow-up, HLC ratio could be a non-invasive predictive marker of a good response in IgA myeloma. Disclosures: No relevant conflicts of interest to declare.


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