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Biomedical subjects

E Oksenhendler

Publications and source records attributed to E Oksenhendler.

At least 19 recordsLinked to original sources

Role of human immunodeficiency virus replication in defective in vitro growth of hematopoietic progenitors.

A number of hematologic abnormalities, including cytopenias, have been observed in patients with human immunodeficiency virus (HIV) infection. To elucidate their mechanisms, a group of 27 patients with HIV-1 infection was studied. In all patients, a marked reduction of in vitro colony formation by erythroid, granulomacrophagic, and megakaryocytic bone marrow progenitors was observed in comparison to normal donors. HIV-1 infection of marrow progenitors was investigated in studying individual colonies with the polymerase chain reaction (PCR) technique. No HIV-1 DNA could be detected in these colonies, suggesting either that marrow progenitors were not infected or that infected progenitors were not able to generate colonies in vitro. The addition of antisense oligonucleotides directed against HIV tat or nef sequences in the culture medium led to a significant increase in colony formation, suggesting that HIV replication in hematopoietic progenitors could be responsible for their defective growth. However, no HIV-1-infected colonies could be detected by PCR after the antisense treatment, indicating that the increase in colony number was not due to the proliferation and differentiation of infected progenitors but to an inhibition of HIV replication in an accessory cell. This last hypothesis was further confirmed by the absence of effects of antisense oligomers on the plating efficiency of hematopoietic progenitors grown from CD34+ cells. These data indicate that hematologic abnormalities of HIV-infected patients cannot be explained by a direct infection of hematopoietic progenitor cells and suggest that a defective modulation of progenitor cell growth by HIV replication outside these cells might play a role in these abnormalities.

Acquired Immunodeficiency Syndrome

CD8 lymphocytosis and pseudotumoral splenomegaly in HIV infection.

Three patients infected with human immunodeficiency virus (HIV) presented with pseudotumoral splenomegaly, CD8 lymphocytosis (3.5-5.1 x 10(9)/l), and hypergammaglobulinaemia. Spleen and bone marrow showed diffuse CD8 lymphocyte and plasma-cell infiltration. Amplification of the T-cell-receptor gamma chain gene did not reveal any clonal T-cell population. Phenotypic analysis showed a predominance of CD8/CD57 suppressor T cells with expression of activation markers (DR and CD38). No cytotoxic T lymphocytes specific for HIV could be detected. The three patients shared the HLA haplotype A1, B8, DR3. The association with this haplotype suggests a genetically determined host immune response to HIV.

Acquired Immunodeficiency Syndrome

Presence of cross-reactive antibody between human immunodeficiency virus (HIV) and platelet glycoproteins in HIV-related immune thrombocytopenic purpura.

We previously reported the presence in platelet eluates of autoantibodies directed against epitopes of the platelet glycoprotein (GP)IIb/IIIa complex in acquired immunodeficiency syndrome (AIDS)-free human immunodeficiency virus (HIV)-infected patients with immunologic thrombocytopenic purpura (ITP). We investigated whether HIV antibodies recognized platelet membrane antigens to determine whether the virus might be directly or indirectly responsible for the thrombocytopenia in this context. Direct eluates of platelets from 25 patients with HIV-related ITP contained IgG reacting with HIV-GP160/120 and also, in 45% of patients, detectable antiplatelet antibodies, immunochemically characterized as anti-GPIIb and/or anti-GPIIIa in 5 patients. Furthermore, serum HIV-GP160/120 antibodies could be absorbed on and eluted from platelets from normal non-HIV-infected healthy blood donors (indirect eluates). In contrast, GP160/120 antibodies present in the serum of nonthrombocytopenic HIV-infected patients were not absorbable on normal platelets in most patients, suggesting a pathogenic role in HIV-related ITP. We performed detailed studies of a patient with the highest titer of both HIV-GP160/120 and GPIIb/IIIa antibodies in direct and indirect platelet eluates. No antibody binding to GPIIb/IIIa-deficient Glanzmann thrombasthenic platelets was detected. Furthermore, binding/elution experiments conducted with insoluble recombinant GP160 (expressed in baculovirus) and purified platelet GPIIb/IIIa demonstrated that the patient's IgG bound specifically, through the F(ab')2 portion, to a common epitope of HIV-GP160/120 and platelet GPIIb/IIIa. This common epitope was present on a recombinant GP160 expressed in baculovirus but absent from another recombinant GP160 expressed in vaccinia virus, suggesting that the cross-reactivity is dependent on the glycosylation or conformational structure of the GP. We conclude that molecular mimicry between HIV-GP160/120 and platelet GPIIb/IIIa may explain at least some cases of ITP in AIDS-free HIV-infected patients.

Autoantibodies

[Toxoplasmosis: new aspects, diagnosis and treatment].

The position of visceral toxoplasmosis in HIV infection has changed in the late 1980's. The strong prevalence of toxoplasmosis in the French population and the regression of pneumocystosis due to generalization of primary prophylaxis have made cerebral toxoplasmosis the initial manifestation of AIDS in about 20% of the cases. At the same time, a better management of AIDS patients has made it possible to hope for a longer survival, even in patients with very deep immunodeficiency. Altogether, these various elements are in favour of developing a primary prophylaxis in patients at high risk for visceral toxoplasmosis. During the last few years, other visceral forms of this infection have emerged, which are either localized (chorioretinitis, diffuse encephalitis) or disseminated, affecting the lung, liver, heart, muscles, bone marrow and other viscera. These forms usually imply a very severe immunodeficiency. Because of the toxicity of the reference therapy, sulfadiazine-pyrimethamine, attempts are being made at developing more effective and better tolerated treatments. At the moment, the clindamycin-pyrimethamine combination is a possible alternative. Other compounds, and in particular macrolids, are still under study.

Acquired Immunodeficiency Syndrome

Prospective study with combined low-dose chemotherapy and zidovudine in 37 patients with poor-prognosis AIDS-related non-Hodgkin's lymphoma. French-Italian Cooperative Study Group.

The French-Italian Cooperative Study Group included patients with poor-prognosis AIDS-related non-Hodgkin's lymphoma (NHL), defined as those with performance status (PS) > or = 3 and/or opportunistic infections (OI), in a prospective study with a 50% reduced-dose combination chemotherapy regimen: CHVmP-Vincristine-bleo (cyclophosphamide 300 mg/m2 i.v. day 1, doxorubicin 25 mg/m2 i.v. day 1, teniposide 30 mg/m2 i.v. day 1, prednisone 20 mg/m2 per os days 1-5, vincristine 2 mg i.v. day 15, and bleomycin 10 mg i.v. day 15), given every 21 days for eight cycles, and concomitant zidovudine 500 mg per os per day. The aims of this combined treatment were to reduce bone marrow toxicity and infectious complications related to chemotherapy (with a low-dose chemotherapy regimen), and to control the HIV and related infectious complications (with zidovudine therapy). Thirty-seven patients entered this prospective study. At the time of the NHL diagnosis, 41% of the patients had asymptomatic HIV infection, 27% had ARC and 32% had already had CDC-defined diagnoses of AIDS. The median CD4+ cell count was 35 mm3. Only 29 patients are evaluable for response, since 8 received only one cycle of chemotherapy. Fifteen of 29 (52%) patients obtained objective responses, with only 4 (14%) achieving complete remissions (CR) of 1, 4, 14 and 29+ months. Three (16%) CRs were achieved in 19 evaluable patients included in the study because of poor PS, and only one CR was observed in 10 evaluable patients with histories of OI, either alone or with poor PS. The most common side effect was bone marrow toxicity with 2 related toxic deaths.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Antithyroid hormone antibodies induced by interferon-alpha.

A 40-yr-old woman known for a multinodular goiter had hyperthyroidism. Treatment with antithyroid drugs and iodine therapy was effective. One year later, she received interferon-alpha for treatment of essential cryoglobulinemia. At that time, the patient was euthyroid. Testing for antithyroglobulin, antimicrosome, anti-TSH receptor, and antithyroid hormone antibodies was negative. After a 1-yr course of interferon-alpha, goiter enlargement was noticed. Apparently elevated free T3 and T4 serum values were measured by RIA, contrasting with clinical euthyroidism and normal TSH values. High serum levels of antithyroid hormone antibodies were found in the patient's serum, using a radiolabeled hormone immunoprecipitation assay. Antithyroglobulin and antimicrosome antibodies titers were also elevated and paralleled antithyroid hormone antibodies. After cessation of interferon-alpha therapy, clinical status and TSH levels remained normal, while thyroid hormone values and antithyroid hormone antibody levels progressively normalized. To our knowledge, this is the first report of antithyroid hormone antibodies induced by interferon-alpha. Since thyroid dysfunction is described in 10-15% of treated patients, the fact that interferon-alpha can induce antithyroid hormone antibodies has important implications: 1) the prevalence or intensity of thyroid dysfunction could be overestimated; and 2) artifactually elevated free T3 and T4 serum values could lead to inappropriate therapy of thyroid disease or cessation of interferon treatment.

Adult

Infection of megakaryocytes by human immunodeficiency virus in seropositive patients with immune thrombocytopenic purpura.

Twenty-one human immunodeficiency virus (HIV)-positive patients, including 11 acquired immunodeficiency syndrome (AIDS)-free patients with immune thrombocytopenic purpura (ITP), were studied to determine whether the megakaryocytic/platelet lineage was infected by HIV. Because purification of platelets did not reach a level sufficient for unequivocal results by the polymerase chain reaction, in situ hybridization was thus performed. Purified marrow megakaryocytes (MK) from 10 HIV-infected ITP patients were studied using a 35S HIV riboprobe, antisense of an HIV ENV sequence. HIV transcripts were clearly detected in MK from five of these 10 patients, although heterogeneity among MK was observed. In three of these five cases, small amounts of HIV glycoproteins were detected in MK by means of immunofluorescence. In addition anti-HIV antibodies could be eluted from platelets of all patients. In contrast, HIV transcripts were not detected in MK derived from colony-forming units-MK (CFU-MK) cultured in suspension, suggesting either that MK are infected by HIV during terminal differentiation or that HIV-infected CFU-MK are unable to differentiate in vitro. In conclusion, this study suggests that HIV infection of MK may be implicated in the pathogenesis of thrombocytopenia of HIV-positive patients.

Blood Platelets

AIDS-associated Kaposi's sarcoma in female patients.

Kaposi's sarcoma (KS) is very unusual in Caucasian women with AIDS. We conducted a retrospective survey of 12 female AIDS patients with KS, including 11 Caucasian women. HIV infection was thought to have been acquired after sexual contact, intravenous drug use (nine cases) or blood transfusion (three cases). In these patients KS was often the first manifestation of AIDS and showed an aggressive course. The disease was associated with a severe immunodeficiency (CD4 T lymphocyte count less than 100 x 10(6)/l in 50% of cases) and a poor prognosis. In four patients, lesions first developed on areas of sexual contact, supporting the hypothesis that KS is a sexually transmitted disease.

Acquired Immunodeficiency Syndrome

[Non-Hodgkin's lymphoma in HIV infection. A multicenter retrospective study of 21 cases].

The incidence of non-Hodgkin's malignant lymphoma is known to be increased in patients who are seropositive for the human immunodeficiency virus (HIV). We report here a multicentre retrospective study of 21 HIV-positive patients with non-Hodgkin's lymphoma seen between 1985 and 1987. All phenotype B lymphomas of intermediate or high malignancy grade according to the Working Formulation are difficult to classify histologically. Because of this problem, reexamination of the specimens by several pathologists and perhaps also the use of other morphological prognostic criteria, such as mitotic index, seem to be desirable. In more than one-third of our patients the presence of a lymphoma led to the finding of HIV seropositivity in subjects who were all issued from populations at risk. Median age was 39 years. Spread evaluation showed stage III or IV in most cases with, in 4 out of 5 patients, extranodal sites, notably the neuromeningeal system, liver, gastrointestinal tract and bone marrow. The median overall survival was 5 months, but in April 1989 2 patients had survived for more than 30 months. Obtaining complete remission (11/21 cases) was imperative for a 10 months' survival. Eight of the 11 patients in whom complete remission was obtained had received the heavy induction chemotherapy required by the degree of malignancy, but no death due to drug toxicity was recorded. 17 patients died, with active lymphoma (12 cases) and/or infection (8 cases) being documented at the time of death. The finding of more than 500/sq. mm CD4 lymphocytes in peripheral blood in 10 cases while the lymphoma was developing, and the heterogeneity of the Epstein-Barr virus (EBV) profile in serum raise the question of the role played by T-cell immunodeficiency and by EBV infection in the physiopathogenesis of these lymphomas.

Adult

Peripheral polyneuropathies associated with monoclonal IgM. Antibody activity of monoclonal IgM and therapeutic implications.

Monoclonal IgM from patients with peripheral neuropathy react in nearly 80% of the cases with some components of myelin. The main target is myelin associated glycoprotein (50% of the cases); several types of glycolipids or gangliosides have been identified as the reactive antigen in the other cases. Anti-MAG IgM share little cross reactive idiotopes. Only primate antisera identified a combining site related public idiotope. In fact, these IgM use various light and heavy chains belonging to different variability subgroups. The preliminary results of an ungoing trial aimed to establish the benefit of plasmapheresis in these patients are discussed.

Adult

HIV-related thrombocytopenia.

About 5-10% of HIV seropositive individuals, in all risk groups, develop a syndrome of immunological thrombocytopenic purpura (ITP). Despite the clear association between HIV infection and thrombocytopenia, the exact immune mechanism leading to the peripheral platelet destruction remains unclear. Whereas some data support the direct effect of autoantibodies to platelet constituents, other findings argue in favour of the deposition of immune complexes containing anti-HIV antibodies. Although viral components could not be detected in the immune complexes or on the platelet membrane, megakaryocytes were shown to contain viral RNA and there is some evidence for a direct or indirect role of HIV in the pathophysiology of this disorder. Steroids, intravenous high dose polyvalent immunoglobulin, anti-rhesus immunoglobulin, danazol and vincristine usually induce only a transient increase in platelet counts. Zidovudine was shown to provide a sustained response in 40-60% of the patients and appears to be the treatment of choice for HIV-related thrombocytopenia. Splenectomy has been effective in many cases with persistent, profound and symptomatic thrombocytopenia and, on a 4-year follow-up, does not influence the progression rate to AIDS or survival. Patients with thrombocytopenia are not at greater risk for the development of AIDS than seropositive non-thrombocytopenic patients. Thus, thrombocytopenia should not be viewed as a stage in the progression from asymptomatic infection to AIDS.

Adrenal Cortex Hormones

Kikuchi's histiocytic necrotizing lymphadenitis.

Histiocytic necrotizing lymphadenitis (HNL) or Kikuchi's Disease is a peculiar condition most commonly affecting cervical lymph nodes in young women. Histology and immunohistochemistry demonstrate a florid T-cell and histiocytic reaction associated with necrotic areas which must be carefully distinguished from malignant lymphoma. Usually, the disease resolves spontaneously within a few weeks or months. The etiology is unknown and the physiopathology discussed.

Diagnosis, Differential

Toxoplasma gondii pneumonia in patients with the acquired immunodeficiency syndrome.

PURPOSE: To perform a retrospective and descriptive study of Toxoplasma gondii pneumonia in patients infected with the human immunodeficiency virus (HIV). Clinical presentation, diagnostic procedures, results of therapy, and hypotheses on pathophysiology are discussed. PATIENTS AND METHODS: The study consisted of 13 HIV-infected patients who had developed T. gondii pneumonia. Eight had acquired immunodeficiency syndrome (AIDS) prior to T. gondii pneumonia and three of them had non-Hodgkin's lymphoma. Mean CD4 cell count was 32 x 10(6)/L. Serum anti-toxoplasma antibody titers were measured by an indirect hemagglutination assay and/or by an indirect immunofluorescence assay. RESULTS: All patients had fever and bilateral pulmonary infiltrates; two of them presented with septic shock. Mean arterial oxygen tension was 47 +/- 12 mm Hg. The diagnosis was established by bronchoalveolar lavage in 10 of 11 cases, open lung biopsy in one case, and postmortem biopsy in two cases. Serologic evidence of past infection was observed in 11 of 12 cases, while one patient presented with acute disseminated disease and absence of serum anti-toxoplasma antibody response. Extrapulmonary involvement was present in seven patients: liver (four), brain (three), bone marrow (two), heart (two), stomach (one). Ten patients recovered from T. gondii pneumonia. CONCLUSION: T. gondii pneumonia must be considered in AIDS patients with severe diffuse bilateral pneumonia, especially when associated with a very low CD4 cell count or non-Hodgkin's lymphoma. In most of these cases, disseminated disease was associated with reactivation of prior latent infection.

Acquired Immunodeficiency Syndrome