scholarly journals THE EXPRESSION OF THE MAIN AND ALTERNATIVE TRANSCRIPT (SORL1-Δ2) OF THE SORL1 GENE IN CHRONIC LYMPHOCYTIC LEUKEMIA PATIENTS AFFECTED BY THE CHORNOBYL ACCIDENT

2021 ◽  
Vol 26 ◽  
pp. 273-283
Author(s):  
I. Abramenko ◽  
◽  
N. Bilous ◽  
A. Chumak ◽  
I. Diagil ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Lymphocytic Leukemia ◽  
Expression Level ◽  
Relative Expression ◽  
Stage Of Disease ◽  
Alternative Transcripts ◽  
Relative Expression Level ◽  
Mutational Status ◽  
Ighv Gene ◽  
Sorl1 Gene

Objective: to study clinical-hematological data and expression of the main and alternative transcripts of SORL1 gene in chronic lymphocytic leukemia (CLL) patients affected by the Chornobyl catastrophe. Methods. Analysis was performed in the main group of 34 CLL patients irradiated due to the Chornobyl NPP accident (30 clean-up workers, and 4 evacuees) and in the control group of 27 non-irradiated CLL patients. Groups of patients were comparable by age, sex, stage of disease, mutational status of IGHV genes. Expression of the main and alternative transcripts of SORL1 gene was evaluated by Quantitative Real-time polymerase chain reaction (PCR). The IGHV gene mutational status, TP53 and SF3B1 mutations were studied by PCR followed by direct sequencing. Data were analyzed with the SPSS software package, version 20.0. Results. Relative expression level of the main transcript of SORL1 gene was low (mean 1.71 ± 0.55, median 0.57), did not correlate with the IGHV gene mutational status, TP53 and SF3B1 mutations, stage of disease. The expression of B transcript was not detected, F transcript was expressed at a very low level in 9 patients. The average relative expression level of SORL1-Δ2 transcript was 14.1 ± 6.04 (median 3.48; range 0.01–90.51). The expression of SORL1-Δ2 transcript above the median was more frequent among patients on C stage (p = 0.001), and in patients with unmutated IGHV genes was associated with an extremely negative course of CLL (median of overall survival 9 months vs 61 months at low expression). Relative expression levels of the main and alternative transcripts of SORL1 gene in patients of the main and the control groups did not differ. Conclusions. Our preliminary data suggest that increased expression of SORL1-Δ2 transcript in CLL patients with unmutated IGHV genes can be considered as a negative prognostic marker. Key words: chronic lymphocytic leukemia, SORL1, SORL1-Δ2, Chornobyl NPP accident.

scholarly journals ERIC recommendations on IGHV gene mutational status analysis in chronic lymphocytic leukemia

Leukemia ◽  
2006 ◽  
Vol 21 (1) ◽  
pp. 1-3 ◽  
Author(s):  
P Ghia ◽  
◽  
K Stamatopoulos ◽  
C Belessi ◽  
C Moreno ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Lymphocytic Leukemia ◽  
Mutational Status ◽  
Ighv Gene ◽  
Status Analysis

scholarly journals Intraclonal Diversification Occurs in Chronic Lymphocytic Leukemia Expressing B Cell Receptors Belonging to the IGHV4 Gene Family

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 944-944
Author(s):  
Filippo Vit ◽  
Francesca Maria Rossi ◽  
Tiziana D'Agaro ◽  
Tamara Bittolo ◽  
Antonella Zucchetto ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Research Funding ◽  
Excision Repair ◽  
Lymphocytic Leukemia ◽  
Mrna Levels ◽  
Direct Role ◽  
Region Gene ◽  
Mutational Status ◽  
Ighv Gene

Abstract Background. The pivotal role of the Immunoglobulin (Ig) receptor and antigenic stimulation have been proven to be landmarks for the understanding of the ontogeny and evolution of chronic lymphocytic leukemia (CLL). In addition, the mutational status of the Immunoglobulin Heavy-Chain Variable region gene (IGHV) was confirmed to be a reliable prognostic factor, supporting an antigen-driven model of CLL development. To clarify aspects regarding an antigenic involvement in CLL evolution, studies focusing on intraclonal diversification (ID) of Ig genes have provided relevant information, although mainly conducted in a pre-Next Generation Sequencing (NGS) era. Aim. To apply a NGS approach to investigate ID in CLL. Methods. IGHV genes from 530 CLL patients with Royal Masden Hospital score 4-5 (Fig. 1A) was sequenced using NGS (Lymphotrack). The bio-informatic pipeline was based on the pRESTO/ChangeO packages. Specific pathological clones were selected based on the presence of same IGHV, junction genes and with similar HCDR3 sequence according to Hamming's distance. Through the R-Alakazam package, we generated rarefaction curves to evaluate the clonal diversity inside the pathological clone (Fig. 1B). Focusing on the Simpson index (represented by the Hill number of order q=2), which gives more weight to larger clones minimizing the smaller ones (Fig. 1B), we selected a Diversity Score (DS) of 4 for the definition of cases without ID (clonal; DS <4) and cases with ID (intraclonal; DS ≥4) (Fig. 1B). Results. Using the reported threshold we identified 469 (88.5%) clonal cases, expressing a single clone (Fig. 1C), and 61 (11.5%) cases with ID (median DS 9.2, range 4.4-66.0) characterized by the presence of two or multiple pathological clones expressing the same IGHV gene and HCDR3 (Fig. 1C). Notably, cases with ID expressed both a mutated (M) (39/61, 63.9%) and an unmutated (UM) (22/61, 36.1%; p=0.066) IGHV gene configuration (Fig. 1C). Of note, we observed a significant skewing toward the usage of VH4-family genes when comparing cases with ID (38/61, 62.3%) vs. cases without ID (78/469, 16.6%; p<0.0001, Fig 1D). Moreover, the IGHV4-39 and IGHV4-34 genes were the most used genes in the context of cases with ID (Fig. 1E), although none of them belonging to known stereotyped subsets. By focusing on VH4-family only cases, we observed that cases with ID and UM IGHV genes displayed higher mutation frequencies in WA/TW motifs, a mutational signature which suggests an involvement of both Activation-Induced (Cytidine) Deaminase (AID) and error-prone polymerase eta (Fig. 1F), a pattern not observed in its counterpart with UM IGHV genes but without ID (Fig. 1F). Conversely, in cases with ID and M IGHV genes, mutations preferentially clustered in AID hotspots (WRC/GYW motifs), suggesting a direct role of AID and the Base Excision Repair machinery in the mutational overload (Fig. 1F). Consistently, M IGHV cases with ID expressed significantly higher AID mRNA levels than M IGHV cases without ID (p=0.0024; Fig. 1G). These expression levels were overall comparable with those found in UM IGHV cases, irrespective to the evidence of ID (Fig. 1G), which however were not associated with an increased number of mutations in AID-specific hotspots (Fig. 1F). Conclusions. By taking advantage of a new method for ID assessment in CLL, we demonstrated that ID prevalently affects VH4-family cases which display different mutational patterns dependent to the IGHV gene status. This data are in keeping with previous reports indicating the IGHV4 genes as particularly prone to generate immunoglobulin subjected to continuous/persistent stimulation by external/auto-antigens, hence particularly prone to generate features of ID. Further experiments in selected cases with ID through a non-random barcode strategy are needed. Disclosures Zaja: Sandoz: Honoraria; Celgene: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Amgen: Honoraria; Janssen: Honoraria; Takeda: Honoraria; Abbvie: Honoraria.

scholarly journals EXPRESSION OF LIPOPROTEIN LIPASE AND c-MYC ONCOGENE IN PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA AFFECTED BY THE CHORNOBYL ACCIDENT

2020 ◽  
Vol 25 ◽  
pp. 421-429
Author(s):  
N. Bilous ◽  
◽  
I. Abramenko ◽  
A. Chumak ◽  
I. Diagil ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Lipoprotein Lipase ◽  
Direct Sequencing ◽  
Lymphocytic Leukemia ◽  
Expression Levels ◽  
Myc Oncogene ◽  
Mutational Status ◽  
Ighv Gene ◽  
Lpl Gene ◽  
Myc Gene

Objective. to determine the association between the expression of lipoprotein lipase (LPL) and c-MYC genes in peripheral blood cells of chronic lymphocytic leukemia (CLL) patients affected by the Chornobyl catastrophe depending on the mutational status of IGHV genes. Methods. Analysis was performed in the group of 69 CLL patients irradiated due to the Chornobyl NPP accident (58 clean-up workers of 1986 year, 6 inhabitants of radionuclide contaminated areas, and 5 evacuees). The IGHV gene mutational status was studied by polymerase chain reaction (PCR) followed by direct sequencing. LPL and c-MYC expression was evaluated by Quantitative Real-time PCR. Data were analyzed with the SPSS software package, version 20.0. Results. Relative LPL expression levels in CLL samples ranged from 0 to 1663.5 (mean 138.47 ± 30.69, median 26.1). A strong correlation between individual LPL expression levels and IGHV mutational status was found (r = 0.684; p < 0.0001). The average relative c-MYC expression level was 5.7 ± 0.87 (median 2.86; range 0–48.5). No association between c-MYC expression and IGHV mutational status was found. Among unmutated IGHV cases, a correlation between LPL and c-MYC gene expression levels was identified: r = 0.351; p = 0.013. Conclusions. Our data confirm the dominant concept that unmutated IGHV CLL cases are more sensitive to the action of proliferative stimuli compared to mutated IGHV CLL cases. This is manifested by an increase in the expression of a functionally significant LPL gene, is one for the strongest negative prognostic markers in CLL. Key words: lymphocytic leukemia, LPL, c-MYC, IGHV genes, Chornobyl NPP accident.

scholarly journals Are surrogates of IGHV gene mutational status useful in B-cell chronic lymphocytic leukemia? The example of Septin-10

Leukemia ◽  
2007 ◽  
Vol 22 (1) ◽  
pp. 224-226 ◽  
Author(s):  
D Benedetti ◽  
R Bomben ◽  
M Dal-Bo ◽  
D Marconi ◽  
A Zucchetto ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Lymphocytic Leukemia ◽  
Mutational Status ◽  
Ighv Gene ◽  
Cell Chronic Lymphocytic Leukemia

Distinct IGHV Repertoire Features In Chinese Chronic Lymphocytic Leukemia Patients

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 5279-5279
Author(s):  
Yi Xia ◽  
Wei Xu ◽  
Lei Fan ◽  
Chun Qiao ◽  
Li Wang ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Heavy Chain ◽  
Conflicts Of Interest ◽  
Lymphocytic Leukemia ◽  
Western World ◽  
Antigenic Difference ◽  
Mutational Status ◽  
Ighv Gene ◽  
Variable Heavy ◽  
Gene Usage

Abstract Mounting evidence indicates that immunoglobulin variable heavy-chain (IGHV) repertoire and mutational status in chronic lymphocytic leukemia (CLL) patients are prognostically relevant. However, rare data is available in Chinese CLL population. Our group investigated 270 Chinese CLL patients for their IGHV sequences and discovered significant differences between Chinese and European CLL patients. First of all, 169 (62.6%) patients in our group got mutated IGHV and 101 (37.4%) were unmutated, rendering a considerable higher percentage of mutated subgroup compared with European patients (55%) (Figure 1). While IGVH3 is still the most frequently used IGVH gene in Chinese CLL patients (135/270, 50%), discrepancy occurs in the usage of IGVH1 gene, which only presents in 13.7% (37/274) patients in our cohort whereas 23.79% for European (Figure 2). Regarding IGHV subgroups, IGHV3-23 and IGHV4-34 are more often used in Chinese CLL patients (10.7% and 10.4%, respectively). Remarkably, IGHV1-69, the most prevalent IGHV subgroup in European CLL patients (12.81%), only accounts for 5.2% (14/270) Chinese cases.Figure 1Higher percentage of mutated IGHV in Chinese CLL patientsFigure 1. Higher percentage of mutated IGHV in Chinese CLL patientsFigure 2Different IGHV gene usage between Chinese and European CLL patients, with IGVH1 gene accounts for 23.79% of European CLL patients and for only 13.70% of Chinese CLL patients.Figure 2. Different IGHV gene usage between Chinese and European CLL patients, with IGVH1 gene accounts for 23.79% of European CLL patients and for only 13.70% of Chinese CLL patients.Figure 3IGVH1-69 is the most prevalent IGHV gene among European CLL patients(12.81%), however, only 5.20% Chinese CLL patients use VH1-69. IGVH4-39 and IGVH4-59 are more often used in Chinese CLL patients (7.80% vs 3.73% and 5.60% vs 2.75%, respectively).Figure 3. IGVH1-69 is the most prevalent IGHV gene among European CLL patients(12.81%), however, only 5.20% Chinese CLL patients use VH1-69. IGVH4-39 and IGVH4-59 are more often used in Chinese CLL patients (7.80% vs 3.73% and 5.60% vs 2.75%, respectively). We further studied the distribution of stereotyped BCR in our cohort. Thirty-eight patients (14.07%) with stereotyped BCR that belonged to 21 subsets were identified, with 1 to 7 sequences contained each. Among them, subset 1 and subset 8 are the most common types with 6 and 7 cases respectively. Three new subsets were discovered (Table 1). Notably, only 1 case belonged to subset 2, the subset with largest group size in western world. Hence, we conclude that Chinese CLL patients show unique IGHV repertoire features compared to patients from western countries. While the mechanism within remains unknown, the discrepancy might due to antigenic difference in geographically remote areas.Table 1Three new subsets of BCR stereotypy in Chinese CLL patientsNO.IGHVIGHDIGHJM/UMIdentityHCDR3 AA sequenceLengthNovel 1NJ-15IGHV4-59*083-22*016*03UM100,00%ARGNYYDSSGYYYVGYYYYYMDV23NJ-31IGHV4-59*013-22*016*03UM99,65%ARGDYYDSSGYYYVGYYYYYMDV23Novel 2NJ-186IGHV3-23*013-22*014*02M96.60%AKGYRDNYDGDQSSVFDS18NJ-23IGHV3-23*012-21*014*02M96,53%AKGYRDNYDGDQSSVFDS18Novel 3NJ-36IGHV4-34*016-6*015*02M93,33%AKLMAGRPNWFDP13NJ-123IGHV4-34*016-6*015*02M91,67%AKLMAGRPNWFDP13 Disclosures: No relevant conflicts of interest to declare.

Extensive intraclonal diversification in a subgroup of chronic lymphocytic leukemia patients with stereotyped IGHV4-34 receptors: implications for ongoing interactions with antigen

Blood ◽  
2009 ◽  
Vol 114 (20) ◽  
pp. 4460-4468 ◽  
Author(s):  
Lesley-Ann Sutton ◽  
Efterpi Kostareli ◽  
Anastasia Hadzidimitriou ◽  
Nikos Darzentas ◽  
Athanasios Tsaftaris ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Large Scale ◽  
Lymphocytic Leukemia ◽  
Leukemic Cells ◽  
Strongly Correlated ◽  
Class Switch ◽  
Mutational Status ◽  
Ighv Gene ◽  
The Common ◽  
Low Levels

Abstract Several studies indicate that the development of chronic lymphocytic leukemia (CLL) may be influenced by antigen recognition through the clonotypic B-cell receptors (BCRs). However, it is still unclear whether antigen involvement is restricted to the malignant transformation phase or whether the putative antigen(s) may continuously trigger the CLL clone and affect not only the progenitor cell but also the leukemic cells themselves. To address this issue, we conducted a large-scale subcloning study of rearranged immunoglobulin heavy variable (IGHV) genes of diverse mutational status from 71 CLL cases (total, 1496 subcloned sequences), belonging to both the common IgM/IgD variant and the rare IgG-positive variant. Although most cases showed no or low levels of intraclonal diversification (ID), we report intense ID in the IGHV genes of selected cases, especially a subgroup of 13 IgG-switched cases expressing stereotyped, mutated IGHV4-34 rearrangements (subset 4). We demonstrate that the ID evident in subset 4 cases cannot be attributed to IGHV4-34 usage, IGHV gene-mutated status, class-switch recombination, or BCR stereotypy in general; rather, it represents a unique phenomenon strongly correlated with the distinctive BCR of subset 4. In such cases, the observed ID patterns may imply a stereotyped response to an active, ongoing interaction with antigen(s).

Characterization of the Proteomic and Genomic Profiles of Chronic Lymphocytic Leukemia Patients with Distinct Clinical Prognosis According to the Mutational Status of the IgVH and BCL6 and Expression Level of CD38 and ZAP70.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3272-3272
Author(s):  
Miguel Marin ◽  
Eloisa Jantus-Lewintre ◽  
Libia Sanz ◽  
Angel Garcia-Martin ◽  
Cristina Reinoso ◽  
...  
Keyword(s):  
Gene Expression ◽  
Chronic Lymphocytic Leukemia ◽  
Differential Expression ◽  
Gene Expression Profile ◽  
Expression Profile ◽  
Lymphocytic Leukemia ◽  
Expression Level ◽  
Clinical Prognosis ◽  
Mutational Status ◽  
Significant Difference

Abstract Introduction: In recent years several molecular prognostic factors have been identified in Chronic Lymphocytic Leukemia B (B-CLL). These include mutations in the variable region of the immunoglobulin genes (IgVH), somatic mutations in the BCL6 gene (Leukemia (2004) 18, 743–746) and the expression level of CD38 and ZAP70. However its biological significance is not clear. In order to identify novel molecular markers with prognostic and therapeutic value we have analyzed the proteomic and genomic profile of 40 B-CLL patients (Binet stage A). Material and methods: 100 μg of total PBMC proteins were used for IEF followed by 2D electrophoresis. Image analysis of scanned gels was used to identify statistically significant differentially expressed proteins. Image acquisition and analysis were performed using the Image Master Platinum software. Selected spots were subjected to automatic digestion and the proteins were identified by MALDI-TOF (Voyager DE-Pro, Applied Biosystems) peptide mass fingerprint using the Protein Prospector software. To confirm the initial identification amino acid sequencing of selected peptide ions was carried out by collision-induced dissociation (CID) with a nESI-QTRAP mass spectrometer from Applied Biosystems. 100 ng of total RNA was used to analyze the expression profile by cDNA microarrays (Whole Human Genome U133 Plus 2.0 Array from Affymetrix). Differential gene expression has been analyzed using the corresponding module (pomelo) from the GEPAS web tools (http://www.gepas.org). Results and Discussion: We found 126 proteins and 25 genes exhibiting differential expression (p&lt;0.05, Student t-test, FDR-adjusted for multiple testing contrasts). We found 34 proteins and 18 genes with different expression according to the mutational status of IgVH. We also classified patients according to mutations in the BCL6 gene, which we previously showed clinical relevance (Leukemia (2004) 18, 743–746), and found 36 proteins and 2 genes with differential expression. Next, we compared samples attending to the mutational status of both genes, results are summarized in the following table: Compared groups attending to the mutational status of IgVH and BCL6 genes targets IgVH wt/BCL6 wt IgVH mut/BCL6 mut 16 proteins / 10 genes IgVH mut/BCL6 wt 28 proteins / 9 genes Of particular interest is the comparision between BCL6 status in IgVH mutated patients where we found 27 proteins with differential expression but no difference in the gene expression profile. This result suggest that the bad prognostic associated to BCL6 mutation may be due solely to postransductional modification of proteins. CD38 and ZAP70 expression level have also been associated with bad clinical prognosis, however, we found no significant difference in the gene expression profile according to CD38 or ZAP70 expression level. We are currently assessing a wider number of patients in order to obtain stronger conclusions. The study of these proteins and genes may lead to a better understanding of the different clinical behaviour of these B-CLL forms.

High CD49d Protein Expression Predicts Short Overall Survival and Early Progression in Chronic Lymphocytic Leukemia Patients.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3097-3097
Author(s):  
Valter Gattei ◽  
Pietro Bulian ◽  
Maria Ilaria Del-Principe ◽  
Antonella Zucchetto ◽  
Luca Maurillo ◽  
...  
Keyword(s):  
Overall Survival ◽  
Chronic Lymphocytic Leukemia ◽  
Clinical Stage ◽  
Lymphocytic Leukemia ◽  
Prognostic Impact ◽  
Color Flow ◽  
Entire Cohort ◽  
Mutational Status ◽  
Ighv Gene ◽  
The Impact

Abstract B-cell chronic lymphocytic leukemia (CLL) is a heterogeneous disease with highly variable clinical courses which can be at least in part foreseen by investigating the expression of known prognosticators, including the IGHV gene mutational status or CD38/ZAP-70 expression. By analysing the coordinated expression of several surface antigens in a series of CLL with known clinical courses, we identified the simultaneous over-expression of CD38 and CD49d as part of the signature characterizing the subgroup with the worst outcome. The aim of the present study was to investigate the relationship between CD49d and other well-established biologic prognosticators (CD38 and ZAP-70 expression, IGHV gene mutational status), or markers of tumor burden (Rai clinical stage, beta2-M, sCD23), and to define the independent prognostic impact of CD49d in predicting overall survival (OS) and disease progression (evaluated as time-to-treatment, TTT) in CLL patients. The study includes samples from 303 patients affected by CLL according to the current diagnostic criteria (median age: 63.5 years, range 32–97). The entire cohort of patients was utilized to investigate the impact of CD49d and other prognosticators (CD38, ZAP-70, IGHV gene mutational status) on OS. TTT information and additional laboratory parameters (beta2-M, sCD23) were available for 232/303 patients, whose therapies were established according to NCI-WG criteria. CD49d expression was determined by three-color flow cytometry combining anti-CD49d, anti-CD19 and anti-CD5 mAbs; its expression was demonstrated to be stable over-time and the 30% of positive CD5+CD19+CLL cells was chosen as cut-off to discriminate CD49dlow from CD49dhigh cases. CD49d, whose expression was strongly associated with that of CD38 (p=2.2×10exp-16) and ZAP-70 (p=2.6×10exp-5), or with IGHV gene status (p=1.1×10exp-6), was independent predictor for OS (HR=4.39; p=0.0081) along with IGHV status (HR=5.54; p=0.0005) or, if this parameter was omitted, with ZAP-70 (HR=2.90; p=0.0092). CD49d also effectively predicted TTT and refined the prognostic relevance of all the investigated prognosticators. Notably, a CD49dhigh phenotype, while not changing the outcome of good prognosis (ZAP-70low, mutated-IGHV) CLL, was necessary to correctly predict the bad clinical courses of ZAP-70high (HR=3.12; p=0.023) or unmutated-IGHV (HR=2.95; p=0.002) cases. These findings support the introduction of CD49d detection in routine prognostic assessment of CLL patients, and suggest both pathogenetic and therapeutic implications for CD49d expression in CLL, e.g. envisioning the use of a humanized anti-CD49d monoclonal antibody, currently employed in multiple sclerosis (Natalizumab), for selcted CLL patients.

Immune Thrombocytopenia in Patients with Chronic Lymphocytic Leukemia Is Associated with Stereotyped B-Cell Receptors

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2847-2847
Author(s):  
Francesco Maura ◽  
Carlo Visco ◽  
Elisabetta Novella ◽  
Ilaria Giaretta ◽  
Giacomo Tuana ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Immune Thrombocytopenia ◽  
Initial Level ◽  
Conflicts Of Interest ◽  
Cell Receptor ◽  
Lymphocytic Leukemia ◽  
Mutational Status ◽  
Ighv Gene ◽  
Cytotoxic Treatment

Abstract Abstract 2847 Chronic lymphocytic leukemia (CLL) is frequently complicated by autoimmune disorders, primarily autoimmune hemolytic anemia and immune thrombocytopenia (ITP). In order to investigate biological features related to ITP development, we retrospectively analyzed 463 CLL patients characterized for immunoglobulin heavy-chain variable (IGHV) gene mutational status, cytogenetic features and B-cell receptor (BCR) configuration (HCDR3) at the time of diagnosis. Thirty-six patients (7.7%) had developed ITP, according to our previously reported criteria (Visco et al, Blood 2008): i) an otherwise unexplained rapid (< 2 weeks) and severe fall (at least half of the initial level and below 100*109/L) of the platelet count; ii) normal or augmented number of megakaryocytes in the bone marrow; iii) no or limited (not palpable) splenomegaly and iv) no cytotoxic treatment in the last month. Stereotyped BCR configuration was defined by means of pair-wise alignment with known stereotyped sequences available from different public databases (Stamatopoulos et al, Blood 2007; Bomben et al, Br J Hematol 2009; Murray et al, Blood 2008), specifically excluding pairs of sequences whose length differed more than 3 amino acids and sharing more than 60% identity on alignments showing less than 3 gaps, as described by others and by our group (Stamatopoulos et al, Blood 2007; Maura et al, Plos One, in press). Our results indicated that the occurrence of ITP was strongly associated with unmutated (UM) IGHV (p<0.0001), unfavorable cytogenetic lesions (P =0.005), and interestingly, the occurrence of stereotyped HCDR3 (P =0.006). Additionally, the UM IGHV mutational status, unfavorable cytogenetic lesions, or stereotyped BCR were significantly associated with shorter time to ITP development (P <0.0001, P =0.02 and P =0.005 respectively) compared to other patients. As regards to the most represented HCDR3 subsets, we observed that subsets #1 (IGHV1-5-7/IGHD6-19/IGHJ4; 16/16 UM) and #7 (IGHV1-69 or IGHV3-30/IGHD3-3/IGHJ6; 13/13 UM) were significantly associated with ITP development (P =0.003 and P =0.001, respectively). Moreover, restricting the analysis to UM patients, subset #7 retained a significant association with the occurrence of ITP (P =0.02). Time to ITP development was also significantly shorter in subsets #1 and #7 patients than in all others patients (P =0.0076 and P <0.0001, respectively). Overall, our data suggest that patients with CLL and peculiar BCR conformations are at higher risk of developing secondary ITP, and that stereotyped BCR may be involved in the pathogenesis of this complication. Disclosures: No relevant conflicts of interest to declare.

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