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V Leblond

Publications and source records attributed to V Leblond.

At least 109 records · Page 6Linked to original sources
PubMed1994

An inhibitor of cytotoxic functions produced by CD8+CD57+ T lymphocytes from patients suffering from AIDS and immunosuppressed bone marrow recipients.

An inhibitor of the cytotoxic functions (ICF) mediated by human immunodeficiency virus (HIV)- or HLA-specific cytotoxic T lymphocytes, natural killer and lymphokine-activated killer (LAK) cells is secreted by CD8+CD57+ T lymphocytes, a subset expanded during infection with HIV and after bone marrow transplantation. We previously showed an apparent molecular mass of 20-30 kDa for this soluble glycosylated concanavalin A-binding inhibitor which is distinct from known cytokines. Here, we report a characterization of the mechanism of action of this CD8+CD57+ ICF. We show that the ICF-induced inhibition of LAK cell cytolytic activity is transient, with a spontaneous recovery of cytolytic potential after 18 h. When testing interactions of ICF with a large set of cytokines we found that the ICF-mediated inhibition of cytotoxic functions is antagonized by two cytokines: recombinant interleukin (rIL)-4 and recombinant interferon (rIFN)-gamma. Finally, we show that ICF acts at the level of cytolytic effector cells, where it induces a significant increase of cyclic AMP (cAMP) level. In contrast, no modification of either cell surface antigen expression or of target/effector cell conjugate formation could be evidenced. Addition of rIL-4 and rIFN-gamma reverses such an increase of cAMP levels and in parallel restores the cytolytic activity. Altogether, these data demonstrate that the glycoprotein ICF produced by CD8+CD57+ cells (1) inhibits cell-mediated cytotoxicity by sensitizing cytolytic effector cells to the cAMP pathway, and (2) is part of a cytokine network controlling cell-mediated cytotoxic functions.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Chicken pox and acute monocytic leukaemia skin lesions in an HIV-seropositive man.

Lymphoid neoplasia is now well known to occur in patients with human immunodeficiency virus (HIV) infection but the first case of acute monocytic leukaemia in an HIV-seropositive man has been only recently described. We report the case of an HIV-infected patient who simultaneously developed skin lesions of acute monocytic leukaemia and chicken pox. We suggest that HIV may produce a malignant transformation of monocytic cells.

AIDS-Related Opportunistic Infections↗
PubMed1994

Late CD8+ lymphocytic alveolitis after allogeneic bone marrow transplantation and chronic graft-versus-host disease.

Late-onset interstitial pneumonitis following allogeneic bone marrow transplantation (BMT) is a rare condition usually caused by a variety of infective agents, although in some cases these are idiopathic. We investigated noninfectious late interstitial pneumonitis with lymphocytic alveolitis in seven allogeneic BMT recipients using bronchoalveolar lavage (BAL), lymphocyte phenotyping analysis, CT lung scans, and pulmonary function tests. The results were compared with those of a control group composed of similar patients with no pulmonary symptoms. Of 65 long-term survivors, seven were included in the study. All had chronic graft-versus-host disease (GVHD) and developed interstitial pneumonitis a median of 210 d (range 120 to 445 d) after BMT. BAL revealed lymphocytosis, with an overall expansion of CD8+ subsets (38 to 90%). Lymphocytic alveolitis was not observed in the control group. Pulmonary function tests revealed a restrictive syndrome, and biopsy samples obtained from 2 patients showed interstitial lymphoid infiltration with fibrosis of the alveolar walls. Of the 7 patients, six were cured by starting immunosuppressive drugs or increasing the dosage with a drastic improvement in respiratory symptoms within 1 mo. These findings suggest that CD8+ alveolitis may be observed in late interstitial pneumonitis in allogeneic BMT recipients and may be a pulmonary manifestation of chronic GVHD.

Adult↗
PubMed1993

High-dose chemoradiotherapy and autologous blood stem cell transplantation in multiple myeloma: results of a phase II trial involving 63 patients.

Sixty-three patients with high tumor mass multiple myeloma were treated with high-dose chemotherapy and total body irradiation supported by autologous blood stem cell transplantation. After high-dose therapy, they were monitored for a median of 44 months. Seven patients died early from toxicity. All the other patients, including those whose disease was resistant to previous therapies, showed a tumor mass reduction. At 6 months postengraftment, 40 (71%) of the surviving patients had minimal residual disease and 11 (20%) were in apparent complete remission. During follow-up, 25 out of the 63 (39%) patients relapsed and 16 of these died; 31 (49%) had a sustained remission. The median overall and event-free survival times after transplantation were 59 and 43 months, respectively. The initial serum beta 2-microglobulin value (> or < 2.8 mg/L) and length of previous therapy (> or < 6 courses of chemotherapy) were the only significant prognostic factors. In all surviving patients, blood stem cell autograft provided satisfactory and sustained haematopoietic reconstitution most often within 15 days. High dose chemoradiotherapy followed by autologous blood stem cell transplantation is thus an important therapeutic option for young patients with aggressive multiple myeloma.

Adult↗
PubMed1993

[Changes in collagen type IV metabolism in diabetes].

In Diabetes Mellitus, type IV collagen biosynthesis is increased: the alpha 1(IV) procollagen specific mRNA concentration is elevated, particularly in the kidney, and the type IV collagen protein is accumulating is the thickened basement membranes. Aldose reductase inhibitors like sorbinil do prevent basement membrane thickening and type IV collagen overproduction. The latter seems related to intracellular sorbitol accumulation and also to protein kinase C activation. Autocrine or paracrine TGF beta may be involved in the type IV collagen oversecretion. The secreted type IV collagen is subject to posttranslational alterations, especially glycation which leads to advanced glycation end-products and covalent crosslinks. This decreases collagen extractability and susceptibility to collagenases and favours basement membrane thickening. Disaccharide unit-specific alpha-glucosidase activity is inhibited by glucose (Kp = 7.5 mM). Type IV collagenase activity secreted by endothelial cells cultured at high glucose concentrations appears to be diminished. Therefore type IV collagen catabolism may be decreased in Diabetes Mellitus.

Animals↗
PubMed1993

Allogeneic bone marrow transplantation for adult acute lymphoblastic leukemia in first complete remission: factors predictive of transplant-related mortality and influence of total body irradiation modalities.

In a retrospective multicentre study, we analyzed 184 consecutive patients who underwent bone marrow transplantation (BMT) from identical siblings for adult acute lymphoblastic leukemia in first complete remission between March 1980 and May 1989. The main causes of transplant-related mortality were GVHD and interstitial pneumonitis. Univariate and multivariate analyses identified the mode of total body irradiation (TBI) as the only independent predictive factor of transplant-related mortality. Ninety-one patients received single-dose TBI and 93 received fractionated-dose TBI as part of the conditioning regimen prior to BMT. Transplant-related mortality was more frequent in the single dose group (p = 0.017). The incidence of interstitial pneumonitis, acute and chronic GVHD and veno-occlusive disease of the liver was not statistically different between the two irradiation groups. However, fatal interstitial pneumonitis was significantly more frequent in the single dose irradiation group (p = 0.031). These results show that transplant-related mortality is closely associated with the mode of TBI administration. The increased relapse rate in the fractionated group explains why there was no difference between the two groups in terms of overall leukemia-free survival.

Adolescent↗
PubMed1993

Granulocyte-macrophage colony-stimulating factor in association to timed-sequential chemotherapy with mitoxantrone, etoposide, and cytarabine for refractory acute myelogenous leukemia.

Recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF), given intravenously 5 micrograms/kg per day, was administered on days 4-8 of timed-sequential chemotherapy (TSC) with mitoxantrone, 12 mg/m2 per day on days 1-3, etoposide, 200 mg/m2 per day on days 8-10 and cytarabine, 500 mg/m2 per day on days 1-3 and 8-10, in 22 patients aged < 60 years with refractory acute myelogenous leukemia in an attempt to increase recruitment of leukemic cells in S phase before the second sequence of TSC. Thirty-eight patients treated with TSC without GM-CSF in a previous trial served as historical controls. In GM-CSF-treated patients, median duration of neutropenia < 0.5 x 10(9)/1 was 33 days and of platelet transfusion requirement 30 days, without any increase by comparison with controls. WHO grade 3 or more extra-hematologic toxicity included sepsis in 60% of patients, vomiting in 30%, diarrhea in 15%, hyper-bilirubinemia in 15%, and mucositis in 10%, without any difference with controls. Among 20 evaluable patients six individuals (30%), with a 95% confidence interval (CI) ranging from 12-54% achieved complete remission, 11 (55%, CI 31-77%) did not respond to therapy and three (15%, CI 3-38%) died from infection. There was no demonstrable in vivo proliferation of leukemic cells during the 5 days of administration of GM-CSF. The average percentage of bone marrow cells in S phase in five patients was 4.0 +/- 2.8 on day 4 and 7.0 +/- 7.2 on day 8 (p = NS). In this cohort of patients refractory to cytarabine, addition of GM-CSF did not increase efficacy of TSC by comparison with historical controls.

Adolescent↗
PubMed1993

Alterations in natural anticoagulant levels during allogeneic bone marrow transplantation: a prospective study in 27 patients.

The natural anticoagulants (antithrombin III, protein C, protein S), plasminogen and tissue plasminogen activator antigen (t-PA ag), were measured in 27 consecutive patients following allogeneic BMT. Thrombosis and veno-occlusive disease were not seen in this study. Changes in the levels of these proteins occurred mainly during acute GVHD. There were 14 patients who had no acute GVHD (group I) and 13 patients who had acute GVHD (group II). No changes in antithrombin III (ATIII), protein C, protein S and t-PA levels were found in group II before the appearance of acute GVHD when compared with group I. However, we noted a significant rise in protein S (p = 0.01), antithrombin III (p = 0.001) and t-PA ag (p = 0.0004) levels during acute GVHD. In contrast, protein C levels decreased early in GVHD (p = 0.005), and then increased progressively over the course of a month post-GVHD. No changes in plasminogen levels were observed. These results might reflect activation of and/or damage to endothelial cells during GVHD.

Acute Disease↗
PubMed1992

[Primary bladder lymphoma in kidney transplant recipients: report of a case].

The authors report the case of a type B EBC (+) primary lymphoma of the bladder occurring in a renal transplant patient 14 months after the graft. The postoperative course had been marked by three episodes of early rejection, the last of which required the use of anti-CD3 antibody, then the later addition of cyclosporin. After immune labelling showing oligoclonal proliferation, the lesion was treated with CD24 and CD21 monoclonal antibodies. Ten months after treatment, the patient is in remission with renal function at 200 mumol plasma creatinine. Azathioprine and cyclosporin have been stopped. This apparently unique case provides the authors with an opportunity to review the usual characteristics of lymphocyte tumours in transplant patients and to stress the rarity of primary lesions of the urinary tract. They conclude that the new therapeutic approach based upon monoclonal antibodies is of value in comparison with the attempts at surgery, radiotherapy and/or chemotherapy used in the past.

Adult↗
PubMed1992

Combined therapy with all-trans-retinoic acid and high-dose chemotherapy in patients with hyperleukocytic acute promyelocytic leukemia and severe visceral hemorrhage.

Acute promyelocytic leukemia (APL) is associated with a high incidence of disseminated intravascular coagulation (DIC) and early hemorrhagic death. The risk of early fatal hemorrhage is increased when high peripheral-blood blast count and severe DIC accompanied by visceral hemorrhage are present at diagnosis. Progressive cytolysis induced by daily increased doses of chemotherapy, or differentiation all-trans-retinoic acid (ATRA) therapy have been proposed for initial control of DIC, but both are dangerous in hyperleukocytic APL patients. We report our results obtained in three high-risk APL patients treated with a combination of conventional chemotherapy and ATRA. All patients had documented hyperleukocytic APL [M3 or M3-variant subtype, (15, 17) translocation] with DIC, and all had critical clinical course before treatment. Patient 1 presented with cerebral hemorrhage, patients 2 and 3 had acute respiratory failure probably due to pulmonary leukemic infiltration and pulmonary hemorrhage. In order to minimize the severity of DIC during chemotherapy-induced acute cytolysis, ATRA (45 mg/m2 per day) was started on the first or second day of chemotherapy and withdrawn when complete remission (CR) was achieved. Despite adverse clinical features, CR was obtained in these three high-risk patients. Patient 1 showed no increase of cerebral bleeding during therapy. Patients 2 and 3 required transient intensive care, with mechanical ventilation from day 4 to day 11 for one of them. Differentiating granular cells were present in peripheral blood of all patients from the day 5, 12 and 8 of cytotoxic therapy. For the three patients, the number of days with white blood cell count < 1 x 10(9)/l was only 2, 7 and 11 days respectively. These results suggest that differentiation therapy with ATRA may be useful even in hyperleukocytic APL patients, when ATRA is used in combination with chemotherapy. The mechanisms of this putative beneficial effect are discussed.

Adult↗
PubMed1992

Peripheral blood stem cell collection and autografting in high risk lymphomas.

Peripheral blood stem cells (PBSC) were collected from 29 patients with high risk Hodgkin's disease (n = 3) or non-Hodgkin's lymphoma (n = 26) in partial remission or first sensitive relapse. Patients had either bone marrow involvement or hypoplastic bone marrow. The conditioning regimen prior PBSC collection included amsacrine and cytosine arabinoside (Ara-C) or Ara-C alone. PBSC collection was performed after leukocyte counts reached 1 x 10(9)/1. A good yield was obtained in 23 patients, whereas sufficient numbers of CFU-GM were not obtained in six cases. Twenty-one patients have been transplanted. All patients except one achieved bone marrow engraftment. Eight patients are in complete remission (mean duration 15 months). The estimated 2 years survival rate is 46.4% (CI 25-68%). This procedure would seems a good alternative in poor prognosis lymphomas.

Adult↗
PubMed1991

A soluble factor released by CD8+CD57+ lymphocytes from bone marrow transplanted patients inhibits cell-mediated cytolysis.

We report a new inhibitory activity of CD8+CD57+ peripheral blood lymphocytes from allo-bone marrow transplant patients. Positively selected CD8+CD57+ lymphocytes act as potent inhibitors of allospecific cytolytic T lymphocyte and lymphokine activated killer cell cytolytic activities. These suppressor cells are mature T cells expressing the CD2, 5, 7, CD3-TcR alpha beta complex, and lack natural killer cell markers as well as cytolytic function. Their inhibitory activity on both cytolytic processes and T-cell proliferation is mediated by a non-antigen-specific soluble factor released by CD8+CD57+ cells in culture supernatants. Preliminary characterization suggests that the CD8+CD57+ cells' inhibitory activity is mediated by a low molecular weight, glycosylated factor as indicated by its less than 1S coefficient of sedimentation and its binding to concanavalin A lectin.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1991

Intensive sequential chemotherapy with mitoxantrone and continuous infusion etoposide and cytarabine for previously treated acute myelogenous leukemia.

Intensive sequential chemotherapy with mitoxantrone, 12 mg/m2/d on days 1 through 3, etoposide, 200 mg/m2/d as a continuous infusion on days 8 through 10, and cytarabine, 500 mg/m2/d as a continuous infusion on days 1 through 3 and 8 through 10 was administered to 72 patients aged less than 60 years with previously treated acute myelogenous leukemia (AML). Forty patients had refractory AML (nonresponse to prior therapy, early first relapse, or multiple relapse) and 32 had late first relapse. Sixty-one percent of patients, with a 95% confidence interval (CI) ranging from 49% to 72%, achieved complete remission (CR), including 45% (CI: 30% to 62%) of refractory patients and 81% (CI: 64% to 93%) of late first relapse patients. Twenty-nine percent of patients (CI: 19% to 41%) did not respond to therapy and 10% (CI: 4% to 19%) died from therapy-related toxicity. Median duration of aplasia was 30 days. Nonhematologic WHO grade 3 or more toxicity included sepsis (57% of patients), vomiting (10%), mucositis (35%), diarrhea (7%), skin rash (6%), and hyperbilirubinemia (11%). Postinduction therapy was attempted in 36 of 44 CR patients: 16 of them received a second course of the same regimen, 7 received maintenance chemotherapy, 4 underwent autologous bone marrow transplantation (BMT), and 9 allogeneic BMT. At a median follow-up of 20 months, 23 of the 44 complete remitters have relapsed, 1 to 14 months after achievement of CR, including 19 of 31 patients not undergoing BMT. Median survival is 7 months with 16% (CI: 4% to 28%) projected survival at 47 months. Median disease-free survival is 6 months with 21% (CI: 3% to 39%) of CR patients projected to remain disease-free at 46 months. Twenty-six percent (CI: 13% to 43%) of the evaluable patients who did not receive transplantation had inversion of CR duration. Among patients younger than 50 years, there was no significant difference in disease-free survival between patients receiving postinduction chemotherapy and those receiving BMT. We conclude that this chemotherapy regimen is highly efficient and could be used as first-line therapy in young patients with AML.

Antineoplastic Combined Chemotherapy Protocols↗