Jean-Pierre Farcet

Presence of HTLV‐I proviral DNA in patients with adult T‐Cell leukemia/lymphoma in Taiwan

Lymphomatoid granulomatosis (LG) and polymorphic reticulosis (PR), originally described as distinct entities, now are considered as a single disease process. Common histopathologic features include necrosis, vasculitis, and a granulomatous infiltrate. Such features have led to consider lymphomatoid granulomatosis as a systemic vasculitis; alternatively the possible emergence of an overt lymphoma has suggested that it could be a lymphoproliferative process. To investigate this later hypothesis, the authors analyzed the cellular infiltrate of tissue specimens from two patients with histologic features of LG. The analysis included the study of T‐cell antigen expression and DNA rearrangement of the beta T‐cell receptor gene. In one patient, the T‐cell phenotype of infiltrating cells was abnormal because of antigen loss. In both patients, the cells contained rearranged DNA indicating the presence of a clonal T‐cell proliferation. It is concluded that some cases of LG and PR, if not all, are related to a neoplastic T‐cell lymphoproliferative disorder.

VJ REARRANGEMENTS OF THE TCRγ LOCUS IN PERIPHERAL T-CELL LYMPHOMAS: ANALYSIS BY POLYMERASE CHAIN REACTION AND DENATURING GRADIENT GEL ELECTROPHORESIS

Using Southern blotting for the diagnosis of clonality in peripheral T‐cell lymphomas (PTCLs), analysis of the T‐cell receptor (TCR) γ gene rearrangement was shown to be more informative than that of the TCR β gene rearrangement. In order to amplify every VJγ rearrangement, a polymerase chain reaction (PCR) procedure using newly designed GC‐clamp primers has been developed. All primers can be mixed in a single multiplex PCR. PCR products are analysed by denaturing gradient gel electrophoresis (DGGE), providing tumour‐specific imprints inasmuch as the procedure characterizes N sequence polymorphism at the VJ junctions. In a series of 30 PTCL cases, the PCR procedure demonstrated 27 cases to be clonally rearranged and failed in three cases. PCR was more accurate than Southern blotting, showing 47 rearranged γ alleles, four of which were undetectable on the Southern blot. When lymphomas were studied at different sites and at relapse, the DGGE pattern remained unchanged. In PTCL, the proposed PCR is helpful for the diagnosis and staging of the disease and should improve the follow‐up monitoring. The undetectability of clonal rearrangements in a few cases is discussed in the light of concepts of lymphomagenesis and T‐cell differentiation.

PATTERNS OF EPSTEIN-BARR VIRUS LATENT AND REPLICATIVE GENE EXPRESSION IN EPSTEIN-BARR VIRUS B CELL LYMPHOPROLIFERATIVE DISORDERS AFTER ORGAN TRANSPLANTATION

B cell lymphoproliferative disorders arising in organ transplant recipients (B cell posttransplant lymphoproliferative disorders [PTLD]) are generally associated with EBV. In previous reports, B cell PTLD were shown to express the full pattern of EBV latent genes, as in vitro-established lymphoblastoid cell lines. Although viral linear DNA was detected in 40% of lymphoproliferative disorders from immunocompromised hosts, immunophenotypic studies failed to detect late EBV replicative antigens. The aim of this study was to investigate the relationship of EBV latent gene expression in B cell PTLD to morphology, clonality, and immunophenotype, and to examine the replicative state of EBV in malignant cells. For this purpose, 9 cases of EBV-related B cell PTLD were analyzed. Immunoglobulin gene rearrangements were detected by Southern blot analysis. The presence of EBV was assessed by Southern blot and by in situ hybridization. B cell differentiation antigens, adhesion and activation molecules, and EBV latent and replicative gene expression were studied using immunohistochemistry techniques. We demonstrated that EBV-related B cell PTLD exhibited varying patterns of latent viral gene expression. Higher levels of adhesion molecules were detected in latent membrane protein 1 (LMP1) or LMP1 plus EBV nuclear antigen 2 (EBNA2)-positive tumors than in LMP1 and EBNA2-negative tumors. In contrast, there was no relationship between CD21 and CD23 expression and latent EBV phenotype. Activation of the EBV replicative cycle was highlighted by BamHI Z left frame 1 expression in 5 of 9 cases. Less frequent expression of late viral proteins suggested that the initiation of the EBV lytic cycle might not always lead to virions production.

Bone marrow histologic and immunohistochemical findings in peripheral. T-cell lymphoma: A study of 38 cases.

The histologic and immunohistochemical findings in bone marrow (BM) biopsies from 38 patients with peripheral T-cell lymphoma (PTCL) are reported. Routine light microscopy showed that BM involvement was unequivocal in 12 cases and questionable in 14 cases. There was no histologic evidence of lymphoma in the remaining 12 cases. Immunohistochemistry performed on BM frozen sections demonstrated the T-cell origin of the infiltrating lymphoid cells in 24 of the 26 patients with unequivocal or questionable involvement. The malignant nature of these cells was suggested by demonstration of an aberrant T-cell phenotype identical to that observed in the other sites of involvement. In addition, in four of the 12 cases with apparently normal BM at routine light microscopy, immunohistochemistry revealed a minimal but phenotypically abnormal T-cell population, suggesting mild infiltration by lymphoma. These combined histologic and immunohistochemical data documented a high incidence (73%) of BM involvement by PTCL. In addition, a very peculiar sinusal pattern of BM involvement was found in five patients who presented an unusual type of hepatosplenic T-cell lymphoma expressing the gamma delta T-cell receptor. The present study demonstrates the high incidence of BM involvement by PTCL and emphasizes the value of frozen section immunohistochemistry to establish this diagnosis, especially when routine light microscopy findings are questionable.

Distinctive clinicopathologic features associated with regressive primary CD30 positive cutaneous lymphomas: analysis of 6 cases

A distinct group of cutaneous lymphomas has been described on the basis of CD30 antigen expression by at least 75% of the tumoral cells. When confined to the skin, these CD30 positive cutaneous lymphomas seem to be associated with a better prognosis than CD30 negative counterparts and spontaneous regression may even occur.

Differentiation of antitumor-specific cytotoxic T lymphocytes from autologous tumor infiltrating lymphocytes in non-Hodgkin’s lymphomas

The present study describes a new culture protocol allowing the activation and proliferation of autologous tumor infiltrating T lymphocytes (TIL), and the generation of antitumor specific CTL in non-Hodgkins lymphoma (NHL). Cells from eight patients with indolent NHL were used. We performed 3-week co-cultures of TIL with irradiated autologous malignant B cells in the presence of low doses of IL-1beta, IL-2 and IL-12. The proliferation, phenotype and cytotoxicity, and antitumor specificity of T cells recovered were studied. T-cell clonality was analyzed using TCRgamma gene rearrangement amplification by a multiplex PCR. Under these culture conditions, TIL proliferated, and the CD8+ T lymphocytes that were in a minority at the beginning of the culture increased dramatically in 6 out of 8 cases. In two cases, CD4+ T lymphocytes expanded. We showed that an oligoclonal selection of reactive T cells occurred in culture. Specific cytotoxicity developed against autologous malignant B cells in the 6 cases where there was an expansion of CD8+ T lymphocytes. Inhibition experiments performed with mAb directed against HLA class I and II molecules, CD4, CD8 and TCRgammadelta showed that the cytotoxic effector cells were CD8+ T lymphocytes probably expressing TCRalphabeta+. Cytokine secretion was analyzed in culture medium, and we detected significant levels of IFN-gamma, TNF-alpha, and IL-10 and no IL-4 (except in one case). Our results demonstrate that memory T cells from lymphoma patients can be amplified and differentiated into antitumor cytotoxic cells using a combination of the cytokines IL-1beta, IL-2, and IL-12 in association with non modified tumor cells.

Therapeutic drug monitoring is predictive of loss of response after de-escalation of infliximab therapy in patients with inflammatory bowel disease in clinical remission

BACKGROUND There is no evidence that therapeutic drug monitoring is helpful in patients with inflammatory bowel disease patients in clinical remission with infliximab therapy. METHODS Eighty consecutive inflammatory bowel disease patients in clinical remission on infliximab maintenance therapy were included and followed-up for at least one year. Infliximab trough level and antibody to infliximab concentration were measured prior to enrollment. At the time of enrollment, physicians in charge were free to alleviate infliximab therapy. Discrepancies between blind and therapeutic drug monitoring-based adjustments were assessed at the end of the follow-up period. Relapse-free survival was analyzed using univariate and multivariate analyses. RESULTS The mean infliximab trough level was 3.1 μg/mL. Antibody to infliximab was found in 15 (19%) patients. At the end of the follow-up period, 18 (22.5%) patients experienced a relapse. The 3, 6, 9 and 12-month relapse-free rates were 98%, 87%, 86% and 80%, respectively. In our multivariate analysis, relapse-free survival was negatively associated with discrepancies between therapeutic drug monitoring-based and blind adjustments of infliximab therapy, absence of concomitant immunomodulator, the absence of mucosal healing, prior use of infliximab, infliximab therapy duration>2 years and C-reactive protein levels>5mg/L at the time of enrollment. CONCLUSION In patients with inflammatory bowel disease in clinical remission on infliximab therapy, de-escalation of infliximab therapy should be considered based on therapeutic drug monitoring rather than according to symptoms and CRP.