Relevance of Stereotyped B-Cell Receptors in the Context of the Molecular, Cytogenetic and Clinical Features of Chronic Lymphocytic Leukemia

Highly homologous B-cell receptors, characterized by non-random combinations of immunoglobulin heavy-chain variable (IGHV) genes and heavy-chain complementarity determining region-3 (HCDR3), are expressed in a recurrent fraction of patients affected by chronic lymphocytic leukemia (CLL). We investigated the IGHV status of 1131 productive IG rearrangements from a panel of 1126 CLL patients from a multicenter Italian study group, and correlated the presence and class of HCDR3 stereotyped subsets with the major cytogenetic alterations evaluated by FISH, molecular prognostic factors, and the time to first treatment (TTFT) of patients with early stage disease (Binet A). Stereotyped HCDR3 sequences were found in 357 cases (31.7%), 231 of which (64.7%) were unmutated. In addition to the previously described subsets, 31 new putative stereotypes subsets were identified. Significant associations between different stereotyped HCDR3 sequences and molecular prognostic factors, such as CD38 and ZAP-70 expression, IGHV mutational status and genomic abnormalities were found. In particular, deletion of 17p13 was significantly represented in stereotype subset #1. Notably, subset #1 was significantly correlated with a substantially reduced TTFT compared to other CLL groups showing unmutated IGHV, ZAP-70 or CD38 positivity and unfavorable cytogenetic lesions including del(17)(p13). Moreover, subset #2 was strongly associated with deletion of 13q14, subsets #8 and #10 with trisomy 12, whereas subset #4 was characterized by the prevalent absence of the common cytogenetic abnormalities. Our data from a large and representative panel of CLL patients indicate that particular stereotyped HCDR3 sequences are associated with specific cytogenetic lesions and a distinct clinical outcome

Prospective validation of predictive value of abdominal computed tomography scan on time to first treatment in Rai 0 chronic lymphocytic leukemia patients: results of the multicenter O-CLL1-GISL study

We performed an external and multicentric validation of the predictive value of abdominal computed tomography (aCT) on time to first treatment (TTFT) in early stage chronic lymphocytic leukemia (CLL) patients. METHODS: aCT was performed at diagnosis in 181 Rai 0 patients enrolled in the O-CLL1-GISL trial (clinicaltrial.gov ID:NCT00917549). RESULTS: Fifty-five patients showed an abnormal aCT. Patients with an abnormal aCT showed a significantly shorter TTFT than those with normal aCT (P < 0.0001). At multivariate analysis, aCT (P = 0.011), \u3b2-2 microglobulin (P = 0.019), and CD38 expression (P = 0.047) correlated with TTFT. Following IWCLL 2008 criteria, 112 (61.9%) cases remained at Rai 0, while 69 (38.1%) satisfied the criteria of clinical monoclonal B-cell lymphocytosis (cMBL). Reclassified Rai 0 patients with an abnormal aCT showed a significantly shorter TTFT than those with a normal aCT (P < 0.0001). At multivariate analysis, only aCT (P = 0.011) correlated with TTFT. Eleven cMBL cases (15.9%) showed an abnormal aCT and were reclassified as small lymphocytic lymphomas (SLL); nonetheless, TTFT was similar for cMBLs and SLLs. CONCLUSION: Our results confirm the ability of the abnormal aCT to predict progression in early stage cases

Association between gene and miRNA expression profiles and stereotyped subset #4 B-cell receptor in chronic lymphocytic leukemia

In this study we investigated specific biological and clinical features associated with chronic lymphocytic leukemia (CLL) patients carrying stereotyped BCR subset #4 (IGHV4-34) among a prospective cohort of 462 CLL/MBL patients in early stage (Binet A). All subset #4 patients (n = 16) were characterized by the IGHV mutated gene configuration, and absence of unfavorable cytogenetic lesions, NOTCH1 or SF3B1 mutations. Gene and miRNA expression profiling evidenced that the leukemic cells of subset #4 cases showed significant downregulation of WDFY4, MF2A and upregulation of PDGFA, FGFR1 and TFEC gene transcripts, as well as the upregulation of miR-497 and miR-29c. The transfection of miR-497 mimic in primary leukemic CLL cells induced a downregulation of BCL2, a known validated target of this miRNA. Our data identify biological characteristics associated with subset #4 patients, providing further evidence for the putative role of BCR in shaping the features of the tumor cells in CLL

The proportion of different BCR-ABL1 transcript types in chronic myeloid leukemia. An international overview

There are different BCR-ABL1 fusion genes that are translated into proteins that are different from each other, yet all leukemogenic, causing chronic myeloid leukemia (CML) or acute lymphoblastic leukemia. Their frequency has never been systematically investigated. In a series of 45503 newly diagnosed CML patients reported from 45 countries, it was found that the proportion of e13a2 (also known as b2a2) and of e14a2 (also known as b3a2), including the cases co-expressing e14a2 and el 3a2, was 37.9% and 62.1%, respectively. The proportion of these two transcripts was correlated with gender, e13a2 being more frequent in males (39.2%) than in females (36.2%), was correlated with age, decreasing from 39.6% in children and adolescents down to 31.6% in patients &gt;= 80 years old, and was not constant worldwide. Other, rare transcripts were reported in 666/34561 patients (1.93%). The proportion of rare transcripts was associated with gender (2.27% in females and 1.69% in males) and with age (from 1.79% in children and adolescents up to 3.84% in patients &gt;= 80 years old). These data show that the differences in proportion are not by chance. This is important, as the transcript type is a variable that is suspected to be of prognostic importance for response to treatment, outcome of treatment, and rate of treatment-free remission

The proportion of different BCR-ABL1 transcript types in chronic myeloid leukemia. An international overview

There are different BCR-ABL1 fusion genes that are translated into proteins that are different from each other, yet all leukemogenic, causing chronic myeloid leukemia (CML) or acute lymphoblastic leukemia. Their frequency has never been systematically investigated. In a series of 45503 newly diagnosed CML patients reported from 45 countries, it was found that the proportion of e13a2 (also known as b2a2) and of e14a2 (also known as b3a2), including the cases co-expressing e14a2 and e13a2, was 37.9% and 62.1%, respectively. The proportion of these two transcripts was correlated with gender, e13a2 being more frequent in males (39.2%) than in females (36.2%), was correlated with age, decreasing from 39.6% in children and adolescents down to 31.6% in patients ≥ 80 years old, and was not constant worldwide. Other, rare transcripts were reported in 666/34561 patients (1.93%). The proportion of rare transcripts was associated&nbsp;with gender (2.27% in females and 1.69% in males) and with age (from 1.79% in children and adolescents up to 3.84% in patients ≥ 80 years old). These data show that the differences in proportion are not by chance. This is important, as the transcript type is a variable that is suspected to be of prognostic importance for response to treatment, outcome of treatment, and rate of treatment-free remission