Chromosome 14q32 translocations involving the immunoglobulin heavy chain locus in chronic lymphocytic leukaemia identify a disease subset with poor prognosis

Immunophenotypic studies, fluorescence in situ hybridization (FISH) and conventional karyotyping were used to define the clinicobiological significance of 14q32 translocations involving the immunoglobulin gene locus (14q32/ IGH ) in 252 chronic lymphocytic leukaemia (CLL) patients. The following regions were studied: 13q14, centromere 12, 6q21; 11q22/ ATM ; 17p13/ TP53 , 14q32/ IGH . Patients were classified as group 1 (favourable, i.e. 13q-single or normal), group 2 (intermediate risk, i.e. +12, 6q-, 1–2 anomalies), group 3 (unfavourable, i.e. 17p-, 11q-, complex karyotype), or group 4 (14q32/ IGH translocation). Endpoints were treatment-free survival (TFS) and overall survival (OS). One hundred and ten patients were included in group 1, 99 in group 2, 25 in group 3 and 18 in group 4. 14q32/ IGH translocation partners were identified in eight cases ( BCL2 in five cases, BCL11A , CCND3 and CDK6 in one case each). group 4 showed shorter TFS versus groups 2 and 1 (25% patients treated at 2 months vs. 12 ( P  = 0·02) and 20 months ( P  = 0·002), respectively) and shorter OS (25% patients dead at 18 months versus 50 ( P  = 0·0003) and >60 months ( P  < 0·0001) respectively. The 14q32/ IGH translocation maintained prognostic significance at multivariate analysis on TFS ( P  = 0·025) and OS ( P  < 0·001), along with advanced stage and CD38⁺. These findings show that the 14q32/ IGH translocation predicts for an unfavourable outcome in CLL and that this cytogenetic subset might be included as a separate entity in a hierarchical cytogenetic classification of CLL.     

Monoclonal B‐cell lymphocytosis is closely related to chronic lymphocytic leukaemia and may be better classified as early‐stage CLL

The World Health Organization classification uses a cut‐off point of 5·0 × 10⁹/l cells with a chronic lymphocytic leukaemia (CLL)‐phenotype in peripheral blood to discriminate between monoclonal B‐lymphocytosis (MBL) and B‐CLL. This study analysed 298 MBL patients by multi‐parameter flow cytometry, chromosome banding analysis (CBA)/fluorescence in situ hybridization (FISH), and IGHV mutation status and compared them with 356 CLL patients. In MBL, CBA more frequently revealed a normal karyotype and FISH identified less frequently del(6q), del(13q) (as sole alterations), and del(17)(p13). Within the MBL cohort, a shorter time to treatment (TTT) was found for ZAP‐70‐positivity, 14q32/IGH‐translocations (CBA), del(11)(q22·3) (FISH) and unmutated IGHV status. Higher CD38 and ZAP‐70 expression, del(11)(q22·3) (FISH), trisomy 12 (FISH), and 14q32/IGH‐translocations (CBA) were correlated with a shorter TTT in the combined cohort (MBL + CLL); a sole del(13)(q14) (FISH) correlated with longer TTT. Regarding overall survival, unmutated IGHV status and ‘other’ alterations (CBA) had an adverse impact. There was no correlation between the concentration of CLL‐cells and TTT or overall survival. Multivariate analysis confirmed a negative impact on TTT for del(11)(q22·3)/ATM, trisomy 12 (both by FISH), and 14q32/IGH‐translocations by CBA. These data emphasize a close relationship between MBL and CLL regarding clinically relevant parameters and provide no evidence to strictly separate these entities by a distinct threshold of clonal B‐cells.     

Translocations of 14q32 and deletions of 13q14 are common chromosomal abnormalities in systemic amyloidosis

Systemic monoclonal immunoglobulin light chain amyloidosis (AL) is associated with clonal plasma cell dyscrasias that are often subtle and non-proliferating. AL shares numerical chromosomal changes with multiple myeloma (MM) and monoclonal gammopathy of undetermined significance (MGUS). Illegitimate translocations involving the immunoglobulin heavy chain gene (IGH) at 14q32 and deletions of the long arm of chromosome 13, [del(13q)], commonly occur in MM, MGUS and plasma cell leukaemia. In AL IGH rearrangements have been identified but, to date, there are no reports of del(13q). In this study of 32 patients with AL, 24 with systemic and eight with localized disease, translocations involving IGH and del(13q) were found using dual-colour interphase fluorescence in situ hybridization (FISH). IGH translocations were observed in 11 patients (37% overall and in 46% with systemic disease), of which nine had the IGH/CCND1 fusion from t(11;14)(q13;q32). Two showed IGH translocations other than the t(11;14) or t(4;14)(p16;q32). In one of these patients a breakpoint within the constant region of IGH between Calpha1 and Calpha2 was indicated. In the second a deletion covering Calpha1 and Calpha2 accompanied the translocation. Ten patients (27% overall and 33% of those with systemic disease) showed del(13q). The gain or loss of IGH and CCND1 signals provided evidence of numerical chromosomal changes in three patients.     

Follicular lymphoma lacking the t(14;18)(q32;q21): identification of two disease subtypes

The clinical and pathological features, including karyotype data and BCL2 protein expression pattern, of follicular lymphoma without a t(14;18)(q32;q21) have not been well defined. We have identified and conducted a detailed analysis of 50 cases with follicular lymphoma who lack the t(14;18). Fluorescent in situ hybridization (FISH) analysis was used to exclude cases with a cryptic IGH/BCL2 rearrangement. BCL2 protein expression level was assessed by immunohistochemistry. The karyotypes were assessed for recurrent sites of structural rearrangement, duplications and deletions on a band-by-band basis, and compared with a large cohort of cases with t(14;18). A distinct pattern of chromosomal alterations was identified in the cases without t(14;18). BCL2 protein overexpression was detected in 33% of 49 tested cases. In this minority, the karyotypes frequently showed increased copies of chromosome 18. The majority of cases (67%) did not show BCL2 overexpression and were characterized prominently by the presence of t(3;14)(q27;q32), implying a role for BCL6. Follicular lymphomas that lack a t(14;18) were segregated into two subgroups with distinct cytogenetic, phenotypic and possibly clinical features: one with BCL2 protein overexpression not related to an IGH/BCL2 rearrangement and a second without BCL2 overexpression. Objective identification of BCL2 expression level as well as BCL2 and BCL6 status by cytogenetic or FISH analysis has potential clinical utility and may yield insights into alternative genetic mechanisms associated with B-cell lymphomas with a follicular growth pattern.     

t(14;22)(q32;q11) in non-Hodgkin lymphoma and myeloid leukaemia: molecular cytogenetic investigations

Two non-Hodgkin lymphomas (NHL), one chronic lymphocytic leukaemia/small lymphocytic lymphoma and one diffuse large B-cell lymphoma and three cases of myeloid leukaemia, two chronic (CML) and one acute (AML), showed, by G-banding analysis, apparently identical chromosomal translocations t(14;22)(q32;q11), in three of the cases as the sole abnormality. Fluorescence in situ hybridisation (FISH) analysis with locus-specific probes for ABL at 9q34 [bacterial artificial chromosomes (BACs) 835J22 and 1132H12], IGH at 14q32 [P1 artificial chromosome (PAC) 998D24] and IGL (PAC 1019H10) and BCR (BAC 74M14) at 22q11, as well as multicolour in situ hybridisation (M-FISH) analyses were performed. A three-way variant translocation of the classical t(9;22)(q34;q11), t(9;22;14)(q34;q11;q32), involving both BCR and ABL, was unravelled by the molecular cytogenetic investigations in the three myeloid leukaemia cases; a similar variant translocation has previously been reported in seven CML. The two cases of NHL (one NHL with a similar 14;22-translocation has been reported previously) had no involvement of BCR or ABL, but instead the IGH and IGL genes were shown to be juxtaposed by the t(14;22)(q32;q11). How such a rearrangement with recombination of IGH and IGL might elicit a pathogenetic effect is completely unknown.     

Double-hit lymphoma with t(8;14)(q24;q32) and t(12;14)(q24;q32) chromosomal translocations

A 50-year-old man presented with an ileocecal tumor and a large amount of ascites. Lymphoma cells obtained from the ascitic fluid were CD10(+), CD20(+), CD38(+), HLA-DR(+), BCL6(-), MUM1/IRF4(+), BCL2(+), and immunoglobulin μ/γ(+). The karyotype determined by G-banding and spectral karyotyping was 46, XY, der(3)t(1;3)(q12;p12), -4, +7, t(8;14)(q24;q32), t(12;14)(q24;q32), der(17)t(4;17)(q21;p11). Fluorescence in situ hybridization disclosed that 93% of interphase cells were positive for the c-MYC and immunoglobulin heavy chain gene fusion. The patient was treated with intensive chemo-immunotherapy, resulting in a complete response. The t(8;14)-t(12;14) double-hit may have generated molecular abnormalities analogous to those of a previously cloned three-way translocation t(8;12;14).     

Chronic lymphocytic leukaemia profiled for prognosis using a fluorescence in situ hybridisation panel

A panel of fluorescence in situ hybridisation (FISH) probes was used on 894 cases to target chromosome 11q, 13q, 17p deletions (del), trisomy 12 (+12) in all and 6q deletion in 59. Chronic lymphocytic leukaemia (CLL) immunophenotype (CD5 and CD19 with CD23) was found in 509 cases (average age 67.7 years, 319 males and 190 females). Among the 509 CLL cases 349 (68.6%) had FISH (4-probe panel) abnormalities: 160 del 13q [45.8% (122-del 13q, 18-biallelic del 13q, 20-monoallelic/biallelic del 13q)], 71 tri 12 (20.3%), 17 del ATM (5%), 12 del p53 (3.4%) and 89 > or = 2 FISH abnormalities (25.5%). Of 151/509 cases karyotyped, 108 were normal and 43 (43/151 = 28.5%) abnormal. Del 6q was found in 1/59 (1.6%) FISH cases and in 6/151 (4%) karyotypes. In 14 CD23 negative cases IGH/BCL1 FISH detected t(11;14) and was confirmed to be mantle cell lymphoma. Multiple probes/panels that included IGH probe were ordered for 57 CLL cases, 11 had an IGH rearrangement with an unidentified partner. This study favours the inclusion of del 6q and IGH probes in the CLL panel. The FISH panel could also serve to monitor 13q deletion for secondary changes with adverse prognosis. Understanding prognosis in specific types of 13q deletion would enhance outcome prediction.     

Close relation between 14q32/IGH translocations and chromosome 13 abnormalities in multiple myeloma: a high incidence of 11q13/CCND1 and 16q23/MAF

Many B-cell tumors have chromosomal translocations that result from failures of the immunoglobulin (Ig) gene during V(D)J recombination, somatic hypermutation (SHM), and class switch recombination (CSR). Nearly half of all multiple myeloma (MM) patients have 14q32/IGH translocations in CSR, including the five common translocations of 11q13/CCND1, 6p21/CCND3, 4p16/FGFR3, 16q23/MAF, and 20q11/MAFB. Although 14q32/IGH translocations are closely related to the biological features of MM, the most consistent and powerful prognostic factor has been reported to be the loss of all (monosomy 13/−13) or part of chromosome 13 (del(13)(q14)/13q−). Our fluorescence in situ hybridization (FISH) analysis method was designed to detect −13/13q− and 14q32/IGH rearrangements in 23 MM patients. FISH disclosed 14q32/IGH translocations in 10 of the 23 (43.5%) patients. The common translocation partners of 14q32/IGH were 11q13/CCND1 (five patients) and 16q23/MAF (four patients), followed in third place by 4p16/FGFR3 (one patient). Nine of the ten patients carrying 14q32/IGH translocations had −13/13q−. Abnormalities of chromosome 13 included −13 in seven (70%) and del(13)(q14) in two (20%). Our results suggest a significant correlation between the presence of 14q32/IGH translocations and chromosome 13 abnormalities (P = 0.0276) in MM patients.     

The t(14;19)(q32;q13)-positive small B-cell leukaemia: a clinicopathologic and cytogenetic study of seven cases

The t(14;19)(q32;q13), involving the BCL3 locus at chromosome 19q13 and the immunoglobulin heavy chain gene at 14q32, is a rare recurrent cytogenetic abnormality identified in B-cell neoplasms, most of which have been classified as chronic lymphocytic leukaemia (CLL) in the literature. We describe the clinicopathological, immunophenotypic and cytogenetic findings in seven patients with B-cell neoplasms associated with t(14;19)(q32;q13). There were five men and two women, with a median age of 48 years (range 33-68). All had absolute lymphocytosis, six had lymphadenopathy, and one had splenomegaly. Lymphocytes in blood and bone marrow aspirate smears were predominantly small and cytologically atypical. Flow cytometric immunophenotyping showed an atypical immunophenotype with low CLL scores. The growth pattern in bone marrow biopsy specimens was interstitial to diffuse; immunohistochemical stains were positive for bcl3 and negative for cyclin D1. Lymph node biopsy specimens of two patients revealed total architectural effacement by neoplasm with proliferation centres. In addition to t(14;19), cytogenetic studies demonstrated trisomy 12 in five patients. These results suggest that B-cell neoplasms with the t(14;19)(q32;q13) present frequently as leukaemia composed of small B-lymphocytes and share many features with CLL. However, these neoplasms also differ from CLL cytologically and in their immunophenotype.     

Genetic analysis of splenic lymphoma with villous lymphocytes: a Groupe Français d'Hématologie Cellulaire (GFHC) study

In order to characterize the genetic diversity in splenic lymphoma with villous lymphocytes (SLVL), we have undertaken cytogenetic and molecular analyses of CCND1 expression and BCL1-IgH PCR rearrangement in 76 cases diagnosed predominantly on morphological criteria. Cytogenetic abnormalities were detected in 19/44 (43%) of cases, including in 16/25 (64%) of cases with an absolute lymphocytosis. Abnormalities included those involving chromosome 14q32 (9/19, 47%), predominantly t(11;14)(q13;q32) (5/19, 26%), chromosome 3 (26%), predominantly 3q, chromosome 17p (26%) and trisomy 12 (3/19, 16%) and were thus suggestive of pathogenetic diversity. CCND1 was expressed in 8/30 (27%) cases, including in all t(11;14) cases, 5/10 (50%) CD5-positive cases and also in 3/20 (15%) CD5-negative cases. Three CCND1-positive SLVL demonstrated immunophenotypic features similar to mantle cell lymphoma (MCL) but the majority differed in their CD5 negativity or CD23 positivity. BCL1-IgH rearrangement was only seen in 1/62 (2%) of cases overall and in none of the t(11;14) cases, which demonstrated FISH breakpoints both centromeric and telomeric to the BCL1/MTC, suggesting that, if genomic clustering exists in t(11;14) SLVL, it differs from MCL. Although CCND1 expressing SLVL more commonly had marked lymphocytosis, they did not demonstrate a more aggressive clinical course than their negative counterparts, demonstrating that the detection of CCND1 expression or of a t(11;14) should not suffice to alter diagnostic classification in the absence of other criteria.     

Detection of t(4;14)(p16.3;q32) chromosomal translocation in multiple myeloma by double-color fluorescent in situ hybridization.

Chromosomal translocations involving the immunoglobulin heavy chain (IGH) locus at chromosome 14q32 represent a common mechanism of oncogene activation in lymphoid malignancies. In multiple myeloma (MM), variable chromosome partners have been identified by conventional cytogenetics, including the 11q13, 8q24, 18q21, and 6p21 loci. We and others have recently reported a novel, karyotypically undetectable chromosomal translocation t(4;14)(p16. 3;q32) in MM-derived cell lines, as well as in primary tumors. The 4p16.3 breakpoints are relatively scattered and located less than 100 kb centromeric of the fibroblast growth factor receptor 3 (FGFR3) gene or within the recently identified WHSC1 gene, both of which are apparently deregulated by the translocation. To assess the frequency of the t(4;14)(p16.3;q32) translocation in MM, we performed a double-color fluorescent in situ hybridization (FISH) analysis of interphase nuclei with differently labeled probes specific for the IGH locus (a pool of plasmid clones specific for the IGH constant regions) or 4p16.3 (yeast artificial chromosome (YAC) 764-H1 spanning the region involved in breakpoints). Thirty MM patients, the MM-derived cell lines KMS-11 and OPM2, and six normal controls were examined. The identification of a t(4;14) translocation, evaluated as the presence of a der(14) chromosome, was based on the colocalization of signals specific for the two probes; a cutoff value of 15% (mean + 3 standard deviation [SD]) derived from the interphase FISH of the normal controls (range, 5% to 11%; mean +/- SD, 8.16 +/- 2.2) was used for the quantification analysis. In interphase FISH, five patients (one in clinical stage I, two in stage II, one in stage III, and a plasma cell leukemia) were found to be positive (approximately 15%). FISH metaphases with split or colocalized signals were detected in only two of the translocated cases and confirmed the pattern found in the interphase nuclei. Furthermore, in three of the five cases with the translocation, FISH analysis with the IGH joining probe (JH) showed the presence of the reciprocal product of the translocation [der(4) chromosome]. Overall, our study indicates that the t(4;14)(p16. 3;q32) chromosomal translocation is a recurrent event in MM tumors and may contribute towards the detection of this lesion and our understanding of its pathogenetic and clinical implications in MM.     

Additional acquisition of t(1;21)(p32;q22) in a patient relapsing with acute myelogenous leukemia with NUP98-HOXA9

We report a 29-year-old Japanese male with acute myelogenous leukemia (AML)-M4 with a cryptic t(7;11)(p15;p15), in which a chimeric NUP98-HOXA9 fusion was detected by polymerase chain reaction analysis and a chromosomal analysis showed 46,XY. The patient received intensive chemotherapy and underwent autologous stem cell transplantation, and remission was confirmed by the disappearance of NUP98-HOXA9. However, 6 months after transplantation, the patient relapsed; NUP98-HOXA9 was detected again and karyotypic analysis revealed 46,XY, t(1;21)(p32;q22). Fluorescent in situ hybridization (FISH) analysis using an AML1-ETO translocation dual probe, showed that the 21q22 breakpoint involved AML1 locus. A retrospective FISH analysis showed that t(1;21) was absent at onset. This is the first reported case with AML who had a cryptic t(7;11)(p15;p15), and additionally acquired t(1;21)(p32;q22) at relapse.     

Translocations t(X;14)(q28;q11) and t(Y;14)(q12;q11) in T-cell prolymphocytic leukemia

We report a case of T-cell prolymphocytic leukemia (T-PLL) in a 41-year-old male. Classical cytogenetic, spectral karyotyping (SKY) and fluorescence in situ hybridization (FISH) studies of a blood sample obtained at diagnosis revealed the co-existence of t(X;14)(q28;q11), t(Y;14)(q12;q11) and a ring chromosome derived from i(8)(q10). Immunophenotypic studies revealed involvement of T-cell lineage, with proliferation of CD4(-) CD8+. The co-existence of two translocations involving both sex chromosomes in a case of T-PLL is rare. Chromosomal instability associated with the disease progression may have allowed the emergence of cell clones with translocations involving the sex chromosomes and the ring chromosome observed.     

Cyclin D3 is a target gene of t(6;14)(p21.1;q32.3) of mature B-cell malignancies.

Chromosomal translocation t(6;14)(p21.1;q32.3) has been reported as a rare but recurrent event not only in myeloma and plasma cell leukemia but also in diffuse large B-cell non-Hodgkin lymphoma (B-NHL) (diffuse large B-cell lymphoma [DLBCL]) and splenic lymphoma with villous lymphocytes (SLVL); however, the nature of the target gene(s) has not been determined. This study identified t(6;14)(p21.1;q32.3) in 3 cases of transformed extranodal marginal zone B-NHL, in 1 case of SLVL, and in 1 case of a low-grade B-cell lymphoproliferative disorder. In a sixth case, a CD5(+) DLBCL, the translocation was identified by molecular cloning in the absence of cytogenetically detectable change. Two chromosomal translocation breakpoints were cloned by using long-distance inverse polymerase chain reaction methods. Comparison with the genomic sequence for chromosome 6p21.1 showed breakpoints approximately 59 and 73.5 kilobases 5' of the cyclin D3 (CCND3) gene with no other identifiable transcribed sequences in the intervening region. Although Southern blotting with derived genomic 6p21.1 probes failed to detect other rearrangements, fluorescent in situ hybridization assays, using BAC (bacterial artificial chromosome) clones spanning and flanking the CCND3 locus, along with probes for IGH confirmed localization of 6p21.1 breakpoints within the same region, as well as fusion of the CCND3 and IGH loci. Furthermore, in all cases, high-level expression of CCND3 was demonstrated at RNA and/or protein levels by Northern and Western blotting and by immunohistochemistry. These data implicate CCND3 as a dominant oncogene in the pathogenesis and transformation in several histologic subtypes of mature B-cell malignancies with t(6;14)(p21.1;q32.3) and suggest that CCND3 overexpression seen in about 10% of DLBCL cases may have a genetic basis.     

BCL10 nuclear expression and t(11;18)(q21;q21) indicate nonresponsiveness to Helicobacter pylori eradication of Chinese primary gastric MALT lymphoma

The eradication of Helicobacter pylori (H. pylori) with antibiotics induces complete remission in 75% of patients with gastric MALT lymphoma. We investigated the efficacy of H. pylori eradication and assessed the predictive value of BCL10 nuclear expression and t(11;18)(q21;q21) regarding resistance to H. pylori eradication in primary gastric mucosa-associated lymphoid tissue lymphoma (MALT lymphoma) patients from mainland China. Twenty-two gastric MALT cases (Stage I_E) underwent H. pylori eradication with antibiotics, and sequential endoscopic-bioptic follow-ups were performed and assessed with regular morphologic and immunohistochemical examinations. BCL10 nuclear expression and interphase fluorescence in situ hybridization (FISH) for MALT1 and API2/MALT1 were tested. Thirteen out of the 22 cases (59.1%) achieved complete regression (CR) after the eradication of H. pylori. The longest follow-up period in the 22 patients was 68 months, with 12 patients longer than 24 months. For the 13 CR patients, the longest follow-up period after H. pylori eradication was 53 months, with 6 patients longer than 24 months. BCL10 nuclear expression was detected by immunohistochemical staining in 9 cases, including 7 (77.8%) of 9 cases who showed no response (NR) and 2 (15.4%) of 13 patients who achieved CR following eradication therapy (P < 0.05). t(11;18)(q21;q21) was evaluated by interphase FISH in 18 cases including 11 CR and 7 NR patients after H. pylori eradication. t(11;18)(q21;q21) was found in 4 (57.1%) of 7 patients who showed NR following H. pylori eradication, but one in 11 CR patients (P < 0.05). A total of 59.1% of patients with early gastric MALT lymphoma recruited in this study achieved CR after H. pylori eradication. BCL10 nuclear expression and t(11;18)(q21;q21)-positive gastric MALT lymphomas are likely to be related to a failure to respond to H. pylori eradication in Chinese patients. Both G. Dong and C. Liu are treated as co-first authors.     

Association and clonal distribution of trisomy 12 and 13q14 deletions in chronic lymphocytic leukaemia

The coexistence of trisomy 12 and deletions of chromosome 13 (13q12-q32) has rarely been observed in chronic lymphocytic leukaemia (CLL). Fluorescence in situ hybridization (FISH) performed on 600 consecutive CLL patients revealed the association of trisomy 12 and 13q14 deletion, of at least one of the three markers analysed (RB1, D13S319 and D13S25), in 55 cases (9% of 600 and 46% of 120 trisomy 12 cases). Trisomy 12 and isolated RB1 deletion were seen in 14/120 cases, trisomy 12 and D13S319/D13S25 deletion with diploid RB1 in 19/118, and trisomy 12 and deletion encompassing the three 13q markers studied in 22/118 cases. The heterogenous distribution of trisomy 12 and 13q deletions within the neoplastic B cells suggests that they are secondary rather than primary events in CLL leukaemogenesis.     

Molecular diagnosis of t(11;14) in mantle cell lymphoma using two-colour interphase fluorescence in situ hybridization

t(11;14) is observed in up to 70% of mantle cell lymphoma (MCL) cases and is therefore an important diagnostic element. In routine practice, detection of t(11;14) by conventional cytogenetic techniques is hindered by the low yield and quality of tumour metaphases. Molecular techniques (Southern blot, PCR) are unable to detect a large number of 11q13 breakpoints due to scattering over distances up to 1 Mb. Using 23 MCL patients with karyotypically determined t(11;14) and eight negative controls, we have devised a two-colour interphase FISH assay for detection of the 14q+ chromosome. We chose an 11q13 probe telomeric to the major 11q13 translocation cluster sites and an IGH probe centromeric of the 14q32 breakpoints. This method detected the translocation in all 23 t(11;14) positive patients, with an overall average of 60% nuclei showing colocalized signals. Widespread application of this technique will constitute an important diagnostic aid in clinical management of MCL patients. Since FISH is a convenient method for retrospective analysis of large numbers of patient specimens, this method should contribute to an accurate estimation of t(11;14) frequency in MCL and other chronic B-cell malignancies and consequently to their better nosological characterization.     

The clinical and biological features of a series of immunophenotypic variant of B‐CLL

Objectives: To describe the clinical and biological features of a series of immunophenotypic variant of B‐CLL (v‐CLL) characterised by intermediate RMH score, in the absence of t(11;14)(q13;q32) in FISH analysis in comparison with a series of typical CLL. Methods: We studied the clinical and biological features of 63 cases of v‐CLL and 130 cases of CLL. Results: We observed significant differences in terms of age <70 yr (P < 0.001), lymphocytosis <20 × 10⁹/L (P < 0.001), lymphocyte doubling time ≤12 months (P = 0.02), high serum β2‐microglobulin levels (P < 0.001) and splenomegaly (P = 0.002); CD38, CD49d, CD1c were more expressed in v‐CLL, CD43 in CLL (P < 0.001). IgV_H mutation and trisomy 12 were more frequent in v‐CLL group (P = 0.001; P < 0.001); del13q14 in CLL (P = 0.008). Gene expression profiling of nine v‐CLL and 60 CLL indicated that the atypical group presented a specific molecular pattern. After a median follow‐up of respectively, 55 (4–196) and 60 months (6–180), 25/42 patients with v‐CLL (48%) and 55/93 patients with CLL (59%) were treated. Time to treatment was significantly shorter in IgV_H‐mutated v‐CLL vs. mutated CLL (P = 0.006). The median overall survival was worse in v‐CLL‐mutated cases (P = 0.062). Conclusion: v‐CLL should be identified and dealt with separately from classic CLL. In particular, the prognostic markers that are routinely used to characterise classical B‐CLL should not be interpreted as having the same meaning.