Immunoglobulin gene mutations and frequent use of VH1-69 and VH4-34 segments in hepatitis C virus-positive and hepatitis C virus-negative nodal marginal zone B-cell lymphoma

Nodal marginal zone B-cell lymphoma (NMZL) is actually considered as a distinct entity that must be distinguished from extra-nodal and splenic marginal zone lymphomas. To define the cell origin and the role of antigen stimulation we determined the nucleotide sequence of the tumor-related immunoglobulin heavy chain variable genes in 10 cases of NMZL. The results were also evaluated on the basis of the presence of chronic hepatitis C virus (HCV) infection. All 10 cases harbored VH somatic mutations with a sequence homology compared to the closest germline gene, ranging from 83.33 to 98.28%. Interestingly, different VH segments were preferentially used in HCV-positive and HCV-negative patients: three of five HCV-negative NMZLs used a VH4-34 segment joined with different D and JH segments whereas three of five HCV-positive NMZLs used a VH1-69 gene joined with a D3-22 and a JH4 segment, with very strong similarities in the CDR3s among the three different cases. These data indicate: 1) NMZL is derived from B cells that have experienced the germinal center reaction; 2) the preferential usage of a VH1-69 segment in the majority of the HCV-positive NMZL cases with similar CDR3s suggests the presence of a common antigen, probably a HCV antigen epitope, involved in the B-cell selection; and 3) the use of a VH4-34 segment suggests a role of yet unknown B-cell superantigen(s) in the selection of tumor B-cell precursors in HCV-negative NMZL.

Group visits improve metabolic control in type 2 diabetes: a 2-year follow-up

OBJECTIVE

To evaluate whether group visits, delivered as routine diabetes care and structured according to a systemic education approach, are more effective than individual consultations in improving metabolic control in non-insulin-treated type 2 diabetes.

RESEARCH DESIGN AND METHODS

In a randomized controlled clinical trial of 112 patients, 56 patients were allocated to groups of 9 or 10 individuals who participated in group consultations, and 56 patients (considered control subjects) underwent individual visits plus support education. All visits were scheduled every 3 months.

RESULTS

After 2 years, HbA(1c) levels were lower in patients seen in groups than in control subjects (P < 0.002). Levels of HDL cholesterol had increased in patients seen in groups but had not increased in control subjects (P = 0.045). BMI (P = 0.06) and fasting triglyceride level (P = 0.053) were lower. Patients participating in group visits had improved knowledge of diabetes (P < 0.001) and quality of life (P < 0.001) and experienced more appropriate health behaviors (P < 0.001). Physicians spent less time seeing 9-10 patients as a group rather than individually, but patients had longer interaction with health care providers.

CONCLUSIONS

Group consultations may improve metabolic control in the medium term by inducing more appropriate health behaviors. They are feasible in everyday clinical practice without increasing working hours.

Missense mutations in the PML/RARalpha ligand binding domain in ATRA-resistant As(2)O(3) sensitive relapsed acute promyelocytic leukemia

BACKGROUND AND OBJECTIVE

Acute promyelocytic leukemia is characterized by the chromosomal translocation t(15;17) which yields the fusion product PML/RARa. All-trans retinoic acid probably induces differentiation of atypical promyelocytes and clinical remission in APL patients by binding to the ligand binding domain (LBD) of the RARa portion of the PML-RARa chimeric protein. Structural alterations of the LBD of the PML/RARa have been revealed in ATRA-resistant APL cell lines and in a few APL patients with acquired clinical resistance to ATRA therapy. Two APL relapsed patients with clinical resistance to ATRA therapy were evaluated for the presence of nucleotide mutations in the LBD of PML/RARa gene and then treated with arsenic trioxide (As2O3).

DESIGN AND METHODS

DNA fragments from the LBD of the PML/RARa chimeric transcript were obtained by reverse-transcribed polymerase chain reaction. Direct sequencing was performed by an unambiguous bi-directional automatic analysis. Samples representative of APL onset and relapse were analyzed from both patients.

RESULTS

In both patients, at the ATRA-resistant relapse, a missense point mutation in the LBD of the PML/RARa gene was found. The mutations, absent at APL onset, led to an Arg272Gln and to an Arg276Trp amino acid substitution, according to the sequence of the RARa protein. Both patients had complete clinical and hematologic remission after treatment with As2O3.

INTERPRETATION AND CONCLUSIONS

LBD missense mutations appear to be a significant mechanism of acquired ATRA-resistance in vivo, closely related to clinical APL relapse. The two cases reported here provide the first in vivo evidence of APL relapsed patients, who have become ATRA-resistant for molecular reasons, being sensitive to arsenic trioxide.

Chronic myeloid leukemia with thrombocythemic onset may be associated with different BCR/ABL variant transcripts

Ph-positive chronic myeloid leukemia (CML) mimicking essential thrombocythemia (ET) at onset seems to be a distinct clinical entity. Whether this rare clinical form of CML is associated with single, specific variants of BCR/ABL transcripts is a matter of debate. Among 82 consecutive patients with Ph-positive CML, we identified 3 patients in which the disease mimicked ET at presentation, because of marked thrombocytosis and moderate leukocytosis, with few immature myeloid cells in peripheral blood and blood basophilia in 2 of them. Molecular analysis with the reverse transcriptase-polymerase chain reaction technique showed the presence of b2a2, b3a2, and b3a2-b2a2 transcript variants in the three patients, respectively. The results of our study together with a review of literature data suggest that different BCR/ABL transcript variants may occur in CML mimicking ET, without an apparently significant prevalence of one type.

Occurrence of a novel t(11;19)(q13;q13.3) in complete remission of acute promyelocytic leukemia

A woman with t(15;17) and PML/RAR alpha positive acute promyelocytic leukemia (APL-M3v) achieved a complete remission (CR) with cytogenetic and molecular conversion, after one-month ATRA plus idarubicin treatment. During CR, less than one-month after consolidation therapy with topoisomerase II inhibitors, a novel t(11;19) (q13;q13.3) was detected in peripheral blood stem cells and later in harvest bone marrow cells. Persisting CR and the negativity for BCL1 and PRAD1 genes rearrangement, the autotransplantation was performed, with good outcome. The patient is still in CR eighteen months post-transplant, in spite of the persistence of a small t(11;19) clone in BM cells. The emergence of a novel chromosomal change during CR of acute leukemia is a rare phenomenon. This is the first t(11;19)(q13;q13.3) described in APL. This finding raises the issue of whether the abnormal karyotypes at remission might represent a risk of tumor recurrence. The meaning of this genomic instability is yet unknown.

YAC clone H10 discriminates between 3q26.2 and 3q27 chromosome rearrangements in hematological disorders

To discriminate with molecular-cytogenetic resolution between 3q26.2 breakpoint, associated to various myeloproliferative disorders, and 3q27 breakpoint, recurrent in several types of non-Hodgkin lymphoma, we tested the feasibility of using a yeast artificial chromosome, YAC clone H10, mapped on 3q26.3. Fluorescent in situ hybridization of the biotinylated polymerase chain reaction product of the YAC H10 was performed in three myeloproliferative diseases and one follicular non-Hodgkin lymphoma carrying different rearrangements of chromosome 3 involving region q26-q27. Our study shows that YAC H10 signal was telomeric to all three myeloid breakpoints, while it was centromeric in the lymphoid one thus showing that this probe can discriminate between these two subsets of chromosome 3 rearrangements. These results point out the opportunity of using additional YACs in the characterization of polymorphic chromosome alterations acquired in neoplastic cells.

Assessment of minimal residual disease in acute promyelocytic leukaemia with t(15;17) by chromosome painting

To detect the minimal residual disease (MRD) in acute promyelocytic leukaemia patients treated with all-trans retinoic acid, we compared the sensitivity of metaphase fluorescence in situ hybridization (FISH) with conventional analysis of G-banded metaphases. 5 out of 6 patients studied at diagnosis showed the t(15;17) translocation. 4 out of 5 patients carrying t(15;17) achieved complete remission and conventional cytogenetic conversion. In 3 cases the whole chromosome painting (WCP) probe 17 discovered one normal chromosome 17 and two fragments indicative of t(15;17) persistence. The FISH-WCP technique seems to be highly sensitive and recommendable in monitoring leukaemias with specific chromosome rearrangements.