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P Gaulard

Publications and source records attributed to P Gaulard.

At least 19 recordsLinked to original sources
PubMed1998

Prognostic significance of T-cell phenotype in aggressive non-Hodgkin's lymphomas. Groupe d'Etudes des Lymphomes de l'Adulte (GELA).

Peripheral T-cell lymphomas (PTCL) have been generally reported to have a worse prognosis than B-cell lymphomas (BCL). Because of their heterogeneity and scarcity, the outcomes of the different histological subtypes have not been compared. From October 1987 to March 1993, 1,883 patients with diffuse aggressive non-Hodgkin's lymphomas (NHL) included in the LNH87 protocol could be assessed for both morphology and immunophenotyping. Among them, 288 (15%) had PTCL and 1,595 (85%) had BCL. According to the Kiel classification, most PTCL were classified as angioimmunoblastic (AIL; 23%), pleomorphic medium and large T-cell (PML; 49%), or anaplastic large cell (ALCL; 20%) lymphomas. Comparing PTCL with BCL patients, the former had more disseminated disease (78% v 58%), B symptoms (57% v 40%), bone marrow involvement (31% v 17%), skin involvement (21% v 4%), and increased beta2-microglobulin (50% v 34%), whereas BCL patients had more bulky disease (41% v 26%). According to the International Prognostic Index (IPI), PTCL and BCL scores were, respectively: 0 factors, 13% and 15%; 1 factor, 17% and 22%; 2 factors, 24% and 25%; >/=3 factors, 45% and 37% (P = .09). For BCL and PTCL, respectively, complete remission rates were 63% and 54% (P = .004); the 5-year overall survival (OS) rates were 53% and 41% (P = .0004) and event-free survival (EFS) rates were 42% and 33% (P < . 0001). Comparison of the different histological subtypes of lymphoma showed that the 5-year OS rate for T-ALCL (64%) was superior to those of other PTCL (35%) as well as diffuse large B-cell (53%) NHL. When multivariate analysis was applied using the IPI score as one factor, nonanaplastic PTCL remained an independent parameter (P = . 0004). Although the poor prognosis of non-ALCL PTCL could be due in part to the presence of adverse prognostic factors at diagnosis, this study shows that the T-cell phenotype is an independent significant factor, which should be incorporated into the definition of prognostic groups.

Adolescent↗
PubMed1998

Nonhepatosplenic gammadelta T-cell lymphoma: a subset of cytotoxic lymphomas with mucosal or skin localization.

Human gammadelta T lymphocytes represent a minor subset of T cells in the peripheral blood, which exhibit a limited diversity and a tissue-restricted repertoire in contrast to their broad specificity. Most postthymic neoplasms that arise from this T-cell subpopulation belong to the hepatosplenic gammadelta lymphoma entity. Only a few cases of nonhepatosplenic gammadelta lymphomas have been described in detail previously. This study presents the clinicopathologic features of 11 consecutive cases of nonhepatosplenic gammadelta lymphoma. All were characterized by mucosal or skin initial involvement: nasal cavity (n = 3), gastrointestinal tract (n = 3), skin (n = 3), lung (n = 1), larynx (n = 1). Most patients presented with B symptoms (eight of 11), without peripheral lymphadenopathy and bone marrow involvement. A past history of chronic antigen exposure was noted in six cases, and four patients had features of immune deficiency. On histology, they were classified as pleomorphic tumors. Features of epitheliotropism and angiocentrism was observed in most cases. Tumor cells had a CD2+, CD3+, T-cell receptor (TCR)delta-1+), betaF1- phenotype. They were CD5- (9 of 10) and CD4-/CD8- (9 of 10) or CD8+ (1 of 10). A clonal gamma-chain gene rearrangement was detected in all tested cases (9/9). All cases had an activated cytotoxic T-cell intracellular antigen-1 (TIA-1)+, Granzyme B+ phenotype. Epstein-Barr virus (EBV) sequences were detected in six cases by in situ hybridization (ISH). Despite an aggressive clinical course, complete remission was obtained in three patients, and one of the latter required a peripheral blood stem-cell transplantation. Nonhepatosplenic gammadelta peripheral T-cell lymphoma can be regarded as a model of activated cytotoxic lymphoma, occurring in mucosae or skin. These appear to be derived from the subpopulation of tissue-restricted gammadelta lymphocytes, which are involved in the host epithelial surface surveillance. The role of chronic antigen exposure in the pathogenesis of these rare lymphomas can be suggested, in view of the past history observed in at least some patients.

Adult↗
PubMed1998

Hodgkin's disease of donor origin after allogeneic bone marrow transplantation for myelogeneous chronic leukemia.

Secondary malignancies (lymphomas, leukemias, and solid tumors) occurring after bone marrow transplantation are now more frequently reported, as the patients surviving the early phase of the graft and remaining free of their original disease are more numerous. Besides early Epstein-Barr virus-associated B-cell lymphoproliferative diseases, which are the most common type and most often of donor origin, few late-occurring lymphomas have been described that might represent a distinct entity. We report here a case of Hodgkin's disease developing 8 years after allogeneic bone marrow transplantation for chronic myelogeneous leukemia. Only two Hodgkin's diseases after allogeneic bone marrow transplantation have been reported in the literature so far. The case we report is of interest because of its donor origin and its association with Epstein-Barr virus infection.

Adult↗
PubMed1998

Differences in Epstein-Barr virus expression between primary and secondary cutaneous angiocentric lymphomas. French Study Group of Cutaneous Lymphomas.

BACKGROUND: Epstein-Barr virus (EBV) has been demonstrated in angiocentric immunoproliferative lesions, suggesting that it could be a causative factor. We investigated for the presence of EBV in 12 primary and 2 secondary cutaneous angiocentric lymphomas (CALs). OBSERVATIONS: In the 2 secondary CALs, strong reactivity for EBV RNAs and latent membrane protein 1 were detected on paraffin-embedded sections. In contrast, 10 of 12 primary CALs were completely negative for EBV RNAs and latent membrane protein 1. In 2 primary CALs, EBV RNAs and latent membrane protein 1 were detected in few tumor cells. In the group of primary CALs, 8 of 12 were still alive at last follow-up, 3 died of systemic lymphoma, and 1 died of another cause, whereas both patients with secondary CALs died of disease within 1 year. CONCLUSION: Differences in the presence of EBV and clinical behavior between primary and secondary CALs suggest that different mechanisms are operative in the pathogenesis of these conditions, and indicate that the 2 groups should be considered separately.

Adult↗
PubMed1998

High-dose therapy followed by stem cell transplantation in partial response after first-line induction therapy for aggressive non-Hodgkin's lymphoma.

Patients with aggressive non-Hodgkin's lymphoma who fail to achieve a complete remission (CR) with standard induction therapy have a poor prognosis with conventional-dose salvage therapy alone. Retrospective series have suggested that early introduction of high-dose salvage therapy with autologous stem cell transplantation (ASCT) may benefit partial-responder (PR) patients. However, two randomized studies (of 69 and 51 patients with partial clinical responses) failed to demonstrate any advantage of intensive therapy. By contrast, the GELA comparative study on 94 PR-patients (residual disease being histologically documented in 53 patients) suggested that high-dose therapy with ASCT improves survival. Interpretation of all these results is complicated by the heterogeneity of patient populations with respect to initial prognostic factors, induction regimens and, in particular, the criteria used to define partial response. Gallium CT scan and magnetic resonance imaging are now used to better explore residual masses. In the future, early restaging with these imaging techniques might be used to delineate patients who are likely to achieve CR from those who will fail to induction treatment and could be candidates for experimental treatments.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

Primary anaplastic large-cell lymphoma in adults: clinical presentation, immunophenotype, and outcome.

Anaplastic, CD30+, large-cell lymphoma is now a well-recognized pathologic entity that accounts for 2% to 8% of all lymphomas. Recent progress has been made in the understanding of certain biologic features found in anaplastic large-cell lymphoma, but information about its clinical behavior, in comparison to other large-cell lymphomas, is limited. The pathologic review of a large multicenter study of the treatment of aggressive lymphoma identified 146 cases of anaplastic large-cell lymphoma (ALCL) on the basis of morphology and CD30 expression. We compared initial presentation, immunophenotype, and clinical outcome of these cases with those of the 1,695 nonanaplastic diffuse large-cell lymphomas (non-ALCL) included in the same trial. Patients with ALCL were more likely to be male (P = .018) and were younger (P < .0001) than those with non-ALCL. B symptoms were more frequent in ALCL (P = .006). Skin (P < .0001) and lung (P < .05) involvement was also more frequent in ALCL, but frequency of bone marrow involvement was identical (P = . 5). Tumor cell phenotype was B in 56 cases (38%), T in 49 cases (34%), and null in 33 cases (22%). Response to chemotherapy (P = . 001), event-free survival (P = .006), and overall survival (P = . 0004) were better for ALCL than for non-ALCL. Multivariate analyses identified anaplastic character as an independent factor that predicted a longer survival. Tumor cell phenotype did not influence event-free survival (P = .72) or overall survival (P = .83). ALCL in adults is a clinicopathologic entity which, independent of its phenotypic characteristics, has a better outcome than other diffuse large-cell lymphomas.

Adult↗
PubMed1997

Cytotoxic protein expression in natural killer cell lymphomas and in alpha beta and gamma delta peripheral T-cell lymphomas.

Lymphomas with T-cell phenotype represent a heterogeneous group of diseases differing in histopathology, tumour site, and cell origin. They include peripheral T-cell lymphomas (PTCLs) derived from alpha beta cells, but also some recently recognized entities such as gamma delta, hepatosplenic lymphomas and natural killer (NK) cell lymphomas. Only a few studies have investigated the possibility that at least some PTCLs could be derived from lymphocytes with cytotoxic potential. In order to investigate this possibility, 60 cases of PTCL, including 27 cases expressing the alpha beta T-cell receptor (TCR alpha beta), 15 TCR gamma delta cases and 18 cases expressing neither TCR (TCR silent), as well as 14 cases of NK-cell lymphomas, were studied by immunohistochemistry for the expression of TIA-1, perforin, and granzyme B proteins. Expression of TIA-1 is characteristic of cytotoxic cells regardless of their activation status, whereas expression of perforin and granzymes is highly increased in activated cytotoxic cells and correlates with the induction of cytolytic activity. All NK-cell lymphomas (11 sinonasal, three systemic cases) expressed TIA-1, perforin, and granzyme B in most tumour cells. All gamma delta PTCLs (15 cases) expressed TIA-1 protein in most tumour cells, with a different cytotoxic antigen profile in hepatosplenic gamma delta PTCL (TIA-1+, perforin-, granzyme B-) and in non-hepatosplenic gamma delta PTCLs (three nasal, one skin, one lung), the latter expressing the three cytotoxic proteins. Of the 45 cases of alpha beta and TCR silent PTCL, 15 (33 per cent) were considered to be derived from cytotoxic lymphocytes with expression of at least one cytotoxic protein (TIA-1, 15/45; perforin, 10/41; granzyme B, 14/38) in tumour cells. This cytotoxic protein expression appeared to be related to the site of localization, since 7/13 (54 per cent) extranodal and only 8/32 (25 per cent) nodal alpha beta and TCR silent PTCLs expressed TIA-1, and to histology, since this pattern was observed in a proportion of anaplastic (6/8, 75 per cent) and pleomorphic (8/17, 47 per cent) lymphomas, but not in AILD-type NHL (0/16). Taken together, our data suggest that NK-cell lymphomas and non-hepatosplenic gamma delta PTCLs represent tumours of activated cytotoxic NK cells and gamma delta T cells, respectively; that hepatosplenic gamma delta PTCLs represent tumours of non-activated cytotoxic gamma delta T cells; and that a small proportion of alpha beta and TCR silent PTCLs, mostly extranodal cases, or nodal anaplastic lymphomas, represent tumours of cytotoxic T cells.

Granzymes↗
PubMed1997

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. We observed a spontaneously regressive evolution in 6 out of 9 CD30 positive primary cutaneous large cell-lymphomas diagnosed during a 5-year period. Clinicopathological data of regressive cases were analysed. The mean age of patients was 56.5 years. They were 3 males and 3 females. Skin lesions were solitary nodule or plaque measuring from 1.5 cm to 11 cm in diameter. Histologically, the lesions were classified as pleomorphic, medium and large cell (5 cases) or large cell anaplastic lymphoma (1 case) according to the updated Kiel classification. Delay for spontaneous regression varied from 1 to 6 months. Three of the 6 patients had cutaneous relapses, followed by a spontaneous regression. All patients remained disease-free with an overall median follow-up of 30 months. Histologically, some distinctive signs such as epidermal pseudo-epitheliomatous hyperplasia, epidermotropism, edema, dermal vascular hyperplasia, seemed to be more frequently associated with spontaneously regressive evolution.

Adult↗
PubMed1997

Benefit of autologous bone marrow transplantation over sequential chemotherapy in poor-risk aggressive non-Hodgkin's lymphoma: updated results of the prospective study LNH87-2. Groupe d'Etude des Lymphomes de l'Adulte.

PURPOSE: To update the randomized study that compared consolidative sequential treatment (ifosfamide, etoposide, asporaginase, and cytarabine) versus the high-dose regimen of cyclophosphamide, carmustine, and etoposide (CBV) followed by autotransplantation in patients with aggressive non-Hodgkin's lymphoma in first complete remission and to focus on high-intermediate and high-risk patients identified by the international prognostic index. PATIENTS AND METHODS: Nine hundred sixteen patients received induction treatment on the LNH84 protocol with open randomization for the anthracycline. In a subsequent randomization, 541 patients in complete remission were assigned to receive consolidation by either sequential chemotherapy (n = 273) or autotransplant (n = 268). Among the higher risk population (two or three risk factors), 236 patients in complete remission were assessable for the consolidation phase, with 111 in the sequential chemotherapy arm and 125 in the autotransplant arm. RESULTS: Among 541 randomized patients, disease-free survival and survival did not differ significantly between the two consolidative treatment arms. In the higher risk population, CBV was superior to sequential chemotherapy, with 5-year disease-free survival rates of 59% (95% confidence interval, 49% to 69%) and 39% (95% confidence interval, 28% to 50%), respectively (P = .01, relative risk = 1.19). The 5-year survival rate was superior in the CBV group at 65% (95% confidence interval, 56% to 74%) compared with 52% in the sequential chemotherapy group (95% confidence interval, 42% to 62%) (P = .06, relative risk = 1.49). CONCLUSION: This study shows a superior disease-free survival for higher risk patients in complete remission. Dose-intensive consolidation therapy should be considered for patients at higher risk who achieve complete remission after induction treatment.

Adolescent↗
PubMed1997

Follicular large-cell lymphoma treated with intensive chemotherapy: an analysis of 89 cases included in the LNH87 trial and comparison with the outcome of diffuse large B-cell lymphoma. Groupe d'Etude des Lymphomes de l'Adulte.

PURPOSE: The aims of this study were as follows: (1) to analyze clinical, histopathologic characteristics, treatment outcome, and prognostic factors of patients with follicular large-cell lymphoma (FLCL); and (2) to compare them with those of patients with diffuse large B-cell lymphoma (DLCL) treated in the same therapeutic trial. PATIENTS AND METHODS: Eighty-nine FLCL patients who were histologically reviewed and who received an intensive chemotherapy regimen according to the LNH 87 protocol were analyzed and compared with 1,096 B-cell DLCL patients included in the same protocol. RESULTS: After intensive induction treatment, 59 patients (67%) achieved a complete remission [CR]. Estimated 5-year survival was 59%, and estimated 5-year freedom from progression (FFP) was 39%. Prognostic factors associated with shorter FFP were age greater than 60 years (P = .02), advanced clinical stage (P = .01), abnormal lactic dehydrogenase (LDH) level (P = .02), abnormal beta-2 microglobulin (P = .02), B symptoms (P = .03), bone marrow involvement (P = .04), and high expression of bcl-2 protein (P = .05). When compared with B-cell DLCL patients, FLCL patients were younger (P = .02), had a better Eastern Cooperative Oncology Group (ECOG) status (P = .05), less bulky mass (P = .04), more advanced clinical stages (P < .001), and more bone marrow involvement (P = .02). No significant difference was observed between FLCL and DLCL patients for response to therapy (67% v 67% of CR), 5-year overall survival (58% v 51%), 5-year disease-free survival (53% v 57%), or FFP survival (39% v 43%). CONCLUSION: FLCL patients have a favorable response rate and survival when treated with intensive chemotherapy. Their outcome is similar to that of B-cell DLCL patients, and a long-term FFP is observed for a substantial number of patients. Some adverse prognostic factors (including those of the International Prognostic Index, bone marrow involvement, and beta-2 microglobulin) have been identified to define a subset of patients who require other therapeutic approach.

Adolescent↗
PubMed1997

Interleukin-13 responsiveness and interleukin-13 receptor expression in non-Hodgkin's lymphoma and reactive lymph node B cells. Modulation by CD40 activation.

Interleukin-13 (IL-13) responsiveness was examined in lymph node B cells from patients with non-Hodgkin's lymphoma (NHL) and patients with benign reactive immune disorders. Proliferation assays showed that NHL B cells from 8 of 21 patients responded to IL-13 in the absence of a co-activation signal. IL-13-unresponsive NHL B cells from 9 of the 13 remaining patients were induced to respond to IL-13 upon antibody-triggered CD40 activation, as did reactive B cells. Binding experiments with radiolabeled IL-13 revealed that the constitutive expression of IL-13 receptors (IL-13R) was associated with IL-13 responsiveness in the absence of CD40 activation. In IL-13-unresponsive cells, IL-13R expression was induced after CD40 activation. This effect was enhanced by IL-10, which was able to potentiate the IL-13 response of CD40-activated cells. Furthermore, IL-13 was found to increase the viability of cultured NHL cells, but not that of non-malignant cells. These results suggest that IL-13, which behaves as a potent co-factor for normal lymph node B cell activation, might provide growth and/or survival advantages to NHL B cells.

B-Lymphocytes↗
PubMed1997

Donor or recipient origin of post-transplantation lymphoproliferative disorders: evaluation by in situ hybridization.

Post-transplantation lymphoproliferative disorders (PTLDs) have been reported after bone marrow and solid-organ transplantation. It might be of interest to know the origin of PTLDs, because it has been suggested that a donor origin could be related to a better prognosis. We studied five cases of PTLD in sex-mismatched allografted recipients by in situ hybridization technique for chromosome Y on isolated cells as well as on frozen and on routinely fixed and paraffin-embedded material. Two proved to be of donor origin, including the only case of PTLD arising in the graft, and three of recipient origin. The best results were obtained on isolated cells, but it must be emphasized that hybridization on tissue sections from frozen material or from material fixed in formalin or in formalin-acetic acid-alcohol and then paraffin embedded also gave good results. Hybridization after fixation in Bouin's liquid was not reliable. These results suggest that evaluation of the origin of PTLDs can easily be performed on routinely processed cytologic and histologic material.

Adult↗
PubMed1996

CD5-CD56+ T-cell receptor silent peripheral T-cell lymphomas are natural killer cell lymphomas.

Non-Hodgkin's lymphomas are divided into B- and T-cell neoplasms. The existence and the clinical relevance of lymphomas derived from the third lymphocyte lineage, ie, natural killer (NK) cells are still controversial. NK cells are lymphocytes that mediate cytotoxicity without prior sensitization. NK cells also have phenotypic and genotypic characteristics: they express the NK-related antigen CD56, T-cell markers such as CD2 and CD7, but do not express CD5 and T-cell receptor (TCR) proteins, and their TCR locus is not rearranged. Therefore, if NK cell lymphomas exist, they should express some T-cell markers, but not alpha beta or gamma delta TCR proteins. Such lymphomas are actually called TCR silent peripheral T cell lymphomas (PTCL). To detect and characterize NK cell lymphomas, we investigated the immunophenotype and immunogenotype of 35 patients with TCR silent PTCL. The first group included 16 patients with a lymphoma of CD5-CD56+ phenotype, which is identical to normal NK cells. These patients had either a nasal/nasopharyngeal lymphoma (11 cases) or a lymphoma with predominant non-nasal/non-nodal initial involvement (five cases). Eight of the nine cases for which immunogenotypic data were available lacked clonal rearrangement of the TCR gamma genes. Thus, these tumors are likely to be NK cell lymphomas. The second group of 15 cases had a CD5+ phenotype (14 were CD56-, and 1 was CD56+) and clonal rearrangement of TCR gamma genes, indicating that they were true PTCL with unproductive TCR rearrangement. The four remaining cases were CD5- CD56- lymphomas and disclosed either a clonal (two cases) or no clonal (two cases) rearrangements of the TCR gamma genes. Altogether these findings show that CD5-CD56+ so-called "TCR silent PTCL" bear the immunophenotype and immunogenotype of normal NK cells and display peculiar clinical features distinct from true PTCL.

Adolescent↗
PubMed1996

Prognostic significance of bcl-2 protein expression in aggressive non-Hodgkin's lymphoma. Groupe d'Etude des Lymphomes de l'Adulte (GELA).

Little is known about the expression of bcl-2 protein in intermediate and high grade non-Hodgkin's lymphoma (NHL) and its clinical and prognostic significance. We performed immunohistochemical analysis of bcl-2 expression in tumoral tissue sections of 348 patients with high or intermediate grade NHL. These patients were uniformly treated with adriamycin, cyclophosphamide, vindesine, bleomycin, and prednisone (ACVBP) in the induction phase of the LNH87 protocol. Fifty eight cases were excluded due to inadequate staining. Of the 290 remaining patients, 131 (45%) disclosed homogeneous positivity (high bcl-2 expression) in virtually all tumor cells, whereas 65 (23%) were negative and 94 (32%) exhibited intermediate staining. High bcl-2 expression was more frequent in B-cell NHL (109 of 214, 51%) than in T-cell NHL (6 of 35, 17%) (P = .0004), and was heterogeneously distributed among the different histological subtypes. Further analysis was performed on the 151 patients with diffuse large B-cell lymphoma (centroblastic and immunoblastic) to assess the clinical significance and potential prognostic value of bcl-2 expression in the most frequent and homogeneous immunohistological subgroup. High bcl-2 expression, found in 44% of these patients (67 of 151), was more frequently associated with III-IV stage disease (P = .002). Reduced disease-free survival (DFS) (P < .01) and overall survival (P < .05) were demonstrated in the patients with high bcl-2 expression. Indeed, the 3-year estimates of DFS and overall survival were 60% and 61%, respectively (high bcl-2 expression) versus 82% and 78%, respectively (negative/intermediate bcl-2 expression). A multivariate regression analysis confirmed the independent effect of bcl-2 protein expression on DFS. Thus bcl-2 protein expression, as demonstrated in routinely paraffin-embedded tissue, appears to be predictive of poor DFS, in agreement with the role of bcl-2 in chemotherapy-induced apoptosis. It might be considered as a new independent biologic prognostic parameter, which, especially in diffuse large B-cell NHL, could aid in the identification of patient risk groups.

Adult↗
PubMed1996

Epstein-Barr virus in non-Hodgkin's lymphomas of the upper respiratory tract: association with sinonasal localization and expression of NK and/or T-cell antigens by tumour cells.

Fifty-five cases of non-Hodgkin's lymphoma (NHL) of the upper respiratory tract, comprising 27 sinonasal (SN) and 28 Waldeyer's ring (WR) NHL, were investigated for expression of Epstein-Barr virus (EBV)-encoded EBER transcripts and latent membrane protein-1 (LMP-1) by RNA in-situ hybridization (RISH) and immunohistochemistry, respectively. Thirty-two cases were B-cell tumours (10 SNHLs and 22 WRNHLs) and 23 cases expressed natural killer (NK) and/or T-cell antigens (17 SNHLs and 6 WRNHLs). EBER transcripts were detected in tumour cells in 19 lymphomas expressing NK and/or T-cell antigens (16/17 SHNHLs and 3/6 WRNHLs) but in only 2/32 B-NHLs (1/10 SNHLs and 1/22 WRNHLs). LMP-1 expression was found in tumour cells in the 19 EBER-positive tumours expressing NK and/or T-cell antigens but in none of the B-cell lymphomas. All the LMP-1-positive lymphomas expressed the CD30 molecule in tumour cells. These results indicate that in lymphomas of the upper respiratory tract, EBV is strongly associated with sinonasal localization and expression of NK and/or T-cell antigens by tumour cells. EBV can also be detected in some cases of WRNHLs expressing NK and/or T-cell antigens, whereas it is rarely found in B-cell SNHLs and WRNHLs. Furthermore, the detection of the LMP-1 protein in tumour cells in most SNHLs and some WRNHLs expressing NK and/or T-cell antigens, in view of the LMP-1 transforming potential, suggests that EBV may play a role in the pathogenesis of these lymphomas.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1996

VJ rearrangements of the TCR gamma 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) gamma gene rearrangement was shown to be more informative than that of the TCR beta gene rearrangement. In order to amplify every VJ gamma 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 gamma 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.

Base Sequence↗
PubMed1996

Nasopharyngeal lymphomas: further evidence for a natural killer cell origin.

The authors report four cases of sinonasal lymphomas with immunophenotypic (four cases) and genotypic (three cases) studies. These lymphomas are frequent in Oriental countries, but unusual in Western populations, particularly in France. Although they have been originally considered as T-cell lymphomas, their origin remains unclear, and several authors have recently suggested that they are a natural killer (NK)-cell proliferation. The tumor cells of the four cases reported here showed characteristics of NK cells. On cryostat sections, they were CD3 negative, but CD2 and CD56 positive. The cytoplasm of the tumor cells exhibited azurophilic granulations. Using polymerase chain reaction (PCR), no clonal rearrangement of the T-cell receptor gamma gene was present. Furthermore, clinically, two presented a pharyngeal involvement, and two were also characterized by hepatosplenic involvement at the time of the diagnosis. Thus, the present cases provide additional evidence toward the NK-cell origin of these rare lymphomas. Many sinonasal lymphomas, including the present cases, are positive for Epstein-Barr virus (EBV) (LMP-1 antibody and EBER-messenger RNA probes). This may suggest an important role of EBV as a local factor in their pathogenesis.

Adult↗