Dvora Sahar

bcl-2 and immunoglobulin gene rearrangement in patients with hepatitis C virus infection

An association between chronic hepatitis C virus (HCV) infection and clonal proliferation of B cells, including B cell lymphoma, has recently been demonstrated. However, the mechanism of malignant transformation is still unknown. It has been shown that B cells from patients with type II mixed cryoglobulinaemia (MC), strongly express the antiapoptotic bcl‐2 oncogene product. Therefore, we investigated a possible mechanism of lymphomagenesis, the occurrence of bcl‐2 and immunoglobulin gene rearrangement (IgH) in HCV‐infected patients. Three groups of patients were studied: (1) 44 patients with HCV and MC (anti‐HCV and HCV RNA positive); (2) 59 patients with chronic HCV infection without MC; (3) 50 patients with chronic liver disease (CLD) not related to HCV infection. The t(14;18) translocation (MBR bcl‐2–JH) and IgH rearrangement (FR3/JH) were detected by polymerase chain reaction (PCR) in peripheral mononuclear cells. bcl‐2 translocation was detected in 17/44 (39%), 7/59 (12%) and in none of the patients of groups 1, 2 and 3 respectively (P < 0·01). Monoclonal IgH rearrangement was detected in 15/44 (34%), 5/59 (8·5%) and 2/50 (4%) patients of groups 1, 2 and 3 respectively (P < 0·05). HCV‐infected patients had a higher prevalence of monoclonal IgH rearrangement and bcl‐2 translocation than patients with CLD of other aetiologies. These data suggest that HCV may play a role in the multistep mechanism of lymphomagenesis by inducing clonal proliferation of B cells and inhibition of apoptosis.

Mitochondrial pro-apoptotic ARTS protein is lost in the majority of acute lymphoblastic leukemia patients

Acquired resistance towards apoptosis is the hallmark of most if not all types of cancer. We have previously identified and characterized ARTS, a broadly expressed protein localized to mitochondria. ARTS was initially shown to mediate TGF-β induced apoptosis. Recently, we have found that high levels of ARTS induce apoptosis without additional pro-apoptotic stimuli. Further, ARTS promotes apoptosis in response to a wide variety of pro-apoptotic stimuli. Here, we report that the expression of ARTS is lost in all lymphoblasts of more than 70% of childhood acute lymphoblastic leukemia (ALL) patients. The loss of ARTS is specific, as the related non-apoptotic protein H5, bearing 83% identity to ARTS, is unaffected. During remission, ARTS expression is detected again in almost all patients. Two leukemic cell lines, ALL-1 and HL-60 lacking ARTS, were resistant to apoptotic induction by ara-C. Transfection of ARTS into these cells restored their ability to undergo apoptosis in response to this chemotherapeutic agent. We found that methylation process contributes to the loss of ARTS expression. We conclude that the loss of ARTS may provide a selective advantage for cells to escape apoptosis thereby contributing to their transformation to malignant lymphoblasts. We therefore propose that ARTS can function as a tumor suppressor protein in childhood ALL.

Insect bite-like reaction associated with mantle cell lymphoma: clinicopathological, immunopathological, and molecular studies.

A cutaneous eruption simulating insect bites has been repeatedly described in association with chronic lymphocytic leukemia (CLL). It was only rarely described with mantle cell lymphoma (MCL). Our study was performed to elucidate the clinical, histologic, immunopathological, and molecular characteristics of insect bite like reaction (IBLR) associated with MCL. The clinical presentation and histologic findings in 3 IBLR cases associated with MCL were found to be similar to 3 IBLR cases associated with CLL. The eruptions consisted of itchy erythematous papules, nodules, plaques, and vesicles. Non-vesicular lesions were characterized histologically by normal or mildly spongiotic epidermis. Vesicular lesions were characterized by marked spongiosis and intraepidermal spongiotic vesicles containing eosinophils, or marked subepidermal edema occasionally leading to a dermoepidermal separation. Most of the lesions were characterized by superficial and mid dermal to deep perivascular and interstitial, and occasionally periadnexal, inflammatory-cell infiltrate consisting of mononuclear cells and eosinophils. The densities of the infiltrates varied and the inflammatory-cell infiltrate extended often into the fat lobules. Neutrophils and nuclear dust were found more frequently and abundantly in the IBLR lesions associated with MCL. Immunophenotyping, direct immunofluorescence (DIF) tests, and IgH gene rearrangement studies were performed in the lesions associated with MCL only. The majority of the infiltrating lymphocytes were CD3+, CD5+ and CD43+, more CD4+ than CD8+, and only a small minority was CD20+. The cells did not stain for bcl-1 protein and CD30, and with no evidence of clonality. The DIF test result was negative. The IBLR eruption associated with MCL resembles clinically and histologically IBLR associated with CLL. The eruption seems to be reactive rather than neoplastic, because there is no evidence of MCL involvement in the skin lesions.

Allogeneic stem cell transplantation for patients with chronic myeloid leukemia: risk stratified approach with a long-term follow-up.

The use of allogeneic stem cell transplantation (SCT) for chronic myeloid leukemia (CML) was almost abandoned in recent years for very effective targeted therapy with tyrosine kinase inhibitors (TKIs). However, approximately one third of patients still need another treatment including SCT. 38 consecutive CML patients were treated (most in preimatinib era) with allogeneic SCT, using partial T cell depletion (TCD) and preemptive donor lymphocyte infusion (DLI), without post‐transplant graft‐versus‐host disease (GvHD) prophylaxis. Conditioning included busulfan, cyclophosphamide, antithymocytic globulin, and fludarabine followed by donor stem cell transfusion. With a median follow up of 90.5 months (1–134), 32 patients are alive. 97% engrafted. 5‐year leukemia free survival (LFS) and overall survival (OS) were 78.95% and 84.2%, respectively. All patients are in major molecular remission and 78% in complete molecular remission. Transplant‐related mortality (TRM) was 13%. Twenty‐four patients received DLI for residual disease. Acute GvHD, mostly Grades I‐II, occurred in 18% of patients post‐transplant and in 24% of patients receiving DLI. In conclusion, the risk‐adapted approach using only partial TCD and preemptive escalated dose of DLI precluded the need for immunosuppressive medications and reduced the risk of significant GvHD without compromising engraftment and long‐term disease control. Am. J. Hematol. 2012.

T-cell receptor gene rearrangement studies using the GeneScan technique as an adjunct to the histopathological diagnosis of mycosis fungoides.

Abstract:T-cell receptor gene rearrangement studies are considered to be an adjunct to the histopathological diagnosis of mycosis fungoides (MF). Fluorophore-coupled primers in polymerase chain reactions followed by fragment analysis with a capillary electrophoresis device (GeneScan analysis) have been recently advocated and widely used. This study was performed to assess T-cell receptor &ggr;-gene rearrangement GeneScan as an adjunct to the histopathological diagnosis of MF. We studied 163 cases. The rates of clonality using this technique were found to be 22/37 (59.5%) in early patch MF, 30/46 (65.2%) in more advanced stages, 13/34 (38.2%) in inconclusive cases, and 10/46 (21.7%) in benign inflammatory dermatoses. Our results support the histopathological criteria for the diagnosis of early patch MF, because of the close rates of clonality obtained in early patch MF with subtle histopathological findings, and in the more advanced subtypes of MF with more overt and specific histopathological criteria.

Transformation of Sézary syndrome into CD30+ anaplastic large T-cell lymphoma after alemtuzumab therapy with evidence of clonal unity.

Alemtuzumab is a humanized mouse antibody targeting the CD52 cell surface, which has been effective in patients with advanced stage mycosis fungoides (MF) including erythrodermic MF and Sézary syndrome. There are a few descriptions of large cell transformation after its administration. A young patient with an acute onset of Sézary syndrome treated initially unsuccessfully with fludarabine and cyclophosphamide and later on successfully with alemtuzumab has been described. Three weeks after the beginning of therapy, however, she developed transformed T-cell lymphoma indistinguishable from CD30 anaplastic large-cell lymphoma. After bone marrow transplantation, the transformed CD30 cutaneous T-cell lymphoma recurred as a transformed CD30 plaque MF. All 3 types of lesions showed the same T-cell receptor clonal gene rearrangement, which supports the notion that Sézary syndrome, CD30 anaplastic large-cell lymphoma, and MF are interrelated.