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Biomedical subjects

M Jeannet

Publications and source records attributed to M Jeannet.

At least 109 records · Page 6Linked to original sources
PubMed1986

[The HLA system and genetic control of the cellular immune response].

The HLA system or major histocompatibility complex (MHC) is implicated in the rejection of organ grafts, but its fundamental biologic function is to ensure an adequate immune response to infectious agents. Recent findings indicate that the MHC also contributes to the control of hematopoiesis and of other biological processes such as cell differentiation and oncogenesis. The associations frequently observed between certain HLA antigens and autoimmune diseases can probably be explained by abnormal function of the corresponding MHC genes, but other genes also appear to be involved.

Animals↗
PubMed1986

[Transplantation of allogeneic bone marrow treated in vitro with Campath-1 monoclonal antibody].

Out of 14 bone marrow transplants, 12 patients received transplantations with allogeneic bone marrow after in vitro T-cell depletion with monoclonal Campath 1. The patients also received short term cyclosporin. This small series is in agreement with the results of larger series using T-depleted marrow as far as the prevention of graft versus host disease is concerned, and with respect to mixed chimerism, slow take, late rejection and, possibly, increased risk of recurrence.

Aged↗
PubMed1986

[12 years' experience in bone marrow transplantation in leukemic patients in Switzerland].

Between 1974 and December 1985 180 bone marrow transplants were performed in Switzerland for patients with leukemia. They were performed in 4 centers (Basle 133, Zurich 28, Geneva 17, Berne 2). The overall probability of survival at 10 years for all patients is 20%. Results are better for younger patients, for patients transplanted in recent years and for patients transplanted either in the first complete remission of acute leukemia or in the chronic phase of chronic myeloid leukemia.

Adolescent↗
PubMed1986

[Persistent generalized lymphadenopathies in homosexuals and drug addicts: changes in humoral and cellular immunity].

In two groups of subjects at risk for acquired immune deficiency syndrome (AIDS), homosexual males and intravenous drug users with persistent generalized lymphadenopathy, humoral and cell-mediated immunity were compared. A small group of patients with definite AIDS were also studied. It was found that levels of immunoglobulins, serological markers for virus and other infections, cell-mediated immunity and histology of lymph nodes were similar in homosexuals and drug users, whereas the lymphocyte sub-populations differed completely. The number of T4+ lymphocytes was markedly decreased in homosexuals but normal in drug users; the number of T8+ lymphocytes was much higher in drug users than in homosexuals. This discrepancy may explain the extremely low prevalence of AIDS cases observed among Swiss drug users as compared with the high frequency noted among homosexuals.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Characteristics and clinical relevance of autolymphocytotoxins in patients with aplastic anemia.

Serum of 68 patients with aplastic anemia was tested for the presence of autolymphocytotoxins (auto-LTs). Prior to specific disease treatment, 16 patients (24%) displayed antibodies cytotoxic to their own lymphocytes. These antibodies had the characteristics of cold-reactive lymphocytotoxins. Their detection in patients' sera was found unrelated to a viral or toxic cause of the disease or the patients' HLA genotype. Broadly reactive anti-HLA antibodies were less frequent in pretreatment sera containing auto-LTs, suggesting that these autoantibodies could modulate alloantibody production. However, after specific disease treatment, the alloantibody frequency was comparable in patients with or without auto-LTs. We found no significant difference in response to antilymphocyte serum or bone marrow graft outcome in the patients in relation to the presence or absence of pretreatment auto-LTs. This observation suggests that the detection of these autoantibodies in aplastic anemia has no clinical relevance.

Adolescent↗
PubMed1986

Altered functions of peripheral blood monocytes in homosexual males and intravenous drug users with persistent generalized lymphadenopathy.

Persistent generalized lymphadenopathy (PGL) is observed predominantly in subjects at risk of developing AIDS. Twenty-seven individuals belonging to such groups: twelve homosexual males and fifteen intravenous drug users, were investigated for immunological abnormalities with particular attention to monocyte functions. They were compared with five AIDS patients. Twenty out of twenty-two individuals had anti-LAV/HTLV-III antibodies and most had abnormalities characteristic of AIDS: polyclonal hypergammaglobulinemia, decreased cell-mediated immunity, inverted T-cell helper/suppressor ratio and histological alterations of lymph nodes. As for peripheral blood monocyte functions, phagocytic capacity and production of O2- were normal and bactericidal capacity was decreased. Monocytes cultured in the presence of concanavalin A produced less PGE2 and more IL-1/MCF than normal monocytes. Similar abnormalities were found using monocytes from AIDS patients. These data suggest that monocytes from patients with PGL have functional alterations that may be either intrinsic or secondary to lymphocyte dysfunction(s); these alterations do not account for the decreased capacity of lymphocytes to respond to mitogens but may explain the uncontrolled activation of B cells.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Treatment of severe aplastic anemia.

A total of 100 patients with severe aplastic anemia were treated and evaluated in a prospective study at our hospital between January 1976 and October 1983: 28 patients had an HLA-identical sibling donor and were treated with bone marrow transplantation, and 72 patients without an HLA-identical sibling donor were given antilymphocyte globulin followed by oral low-dose androgen therapy. At 1 1/2-9 years after treatment, 13 patients (46%) survive in the transplant group and 45 patients (75%) survive in the second group. All except one in the second group have self-sustaining hematopoiesis without need for transfusions. There is one major difference between the two therapies. Marrow transplantation restores bone marrow function completely and no late hematologic complications have been seen in this group. The majority of patients treated with antilymphocyte globulin in contrast have residual abnormalities of hematopoiesis: macrocytosis, mild granulocytopenia, and mild thrombopenia. Relapse (11 of 72 patients) and clonal hematologic disorders, such as paroxysmal nocturnal hemoglobinuria (four patients) and leukemia (one patient) can occur years after complete bone marrow reconstitution with antilymphocyte globulin. These late disorders are of concern. Despite this, we conclude that antilymphocyte globulin treatment is an effective therapy with low early mortality and morbidity and a high chance for a long, sustained remission. Results are better or at least equivalent to bone marrow transplantation and patients with donors should be given the option of transplant or antilymphocyte globulin.

Adolescent↗
PubMed1986

[HLA markers in leukemia patients].

The relationship of genes of the HLA system with leukemogenesis has been controversial for many years. However HLA antigens such as A2, B12 and DR7, have been found associated with prolonged survival in patients with acute leukemia. Recent studies have also shown an excess of shared HLA antigens (especially DR) among the parents of patients with acute leukemia. This phenomenon may possibly reflect the expression in patients of recessive immune response genes linked to the HLA complex; the role of such immune response genes in susceptibility or resistance to virus-induced leukemia has clearly been established in mice.

Animals↗
PubMed1986

Macro-creatine kinase type 1. Immunological studies in 14 patients with comments on clinical significance.

Circulating autoantibodies directed at creatine kinase (CK) BB isozyme are detected in plasma in the form of an immune complex (immunoglobulin CK BB) termed macro-CK type 1. Fourteen patients presented a falsely elevated CK MB isozyme fraction as measured by the immunoinhibition method; they were found to have IgG-CK BB complexes, which was considered to be indirect evidence of circulating anti-CK BB autoantibodies. No evident clinical association between the detection of this autoantibody in complexed form and autoimmune disease could be established, there was no significantly increased incidence of other autoantibodies, and there was no specific alteration in immunoglobulin and complement levels; however, the HLA haplotype A1,B8,DR3, which is known to be associated with autoimmunity, was present in five patients.

Adult↗
PubMed1985

[Quantitative determination of human bone marrow T cells following in vitro depletion by Campath-1 monoclonal antibody].

Bone marrow T cell depletion is an effective graft vs host disease prophylaxis in allogeneic bone marrow transplantation. Standard methods of identifying T cells are not sensitive enough to determine small numbers of residual T cells following T cell depletion. A rapid and sensitive method, using limiting dilution culture technology and radionucleotide labelling and allowing the detection of 1/10(4)-1/10(5) residual T cells, has been developed. Its usefulness in the evaluation of the number of T cells after monoclonal antibody (Campath-1) + autologous complement marrow treatment is demonstrated.

Antibodies, Monoclonal↗
PubMed1985

[Transplantation of allogeneic bone marrow treated in vitro with Campath-1 monoclonal antibody].

5 patients underwent bone marrow transplantation for severe aplastic anemia (2) and acute leukemia (ALL) in first remission (3). Graft versus host disease prophylaxis was performed by depleting T lymphocytes in the donor bone marrow with the rat monoclonal Campath-1 and autologous complement. In addition, patients received cyclosporin A. Engraftment occurred normally in all 5 patients but 1 patient (SAA) had a late graft failure. Two patients suffered mild degrees of GvHD. All patients are currently in complete remission, one having undergone a second transplantation.

Adult↗
PubMed1985

[In vivo detection of alloreactive T cells of host origin after rejection of HLA-identical allogeneic bone marrow transplant].

Rejection and graft vs host disease after HLA-identical allogeneic bone marrow transplantation are probably due to in-vivo T-cell reactivity against non-MHC antigens. Peripheral blood lymphocytes from a patient transplanted for aplastic anemia have been obtained during graft failure and tested for their alloreactivity towards unrelated and marrow donor lymphocytes. Their caryotype was determined. Our results demonstrate (1) alloreactive T cells of host origin and (2) the presence of donor-specific host cells in vivo, providing evidence for rejection following in vivo sensitization to non-MHC antigens.

Anemia, Aplastic↗
PubMed1985

[Incidence, characteristics and clinical importance of autolymphocytotoxins in aplastic anemias].

Sixteen (24%) of 68 patients with aplastic anemia had antibodies cytotoxic to their own lymphocytes before specific disease treatment. These antibodies displayed the characteristics of cold reactive lymphocytotoxins (LTs). No correlation existed between the detection of auto-LTs and a viral or toxic cause of the disease or the patients' HLA genotype. A lower frequency of anti-HLA antibodies was recorded in the pretreatment sera of patients with auto-LTs. However, the response rate to antilymphocyte serum treatment and the outcome of the bone marrow grafts were comparable among the patient's groups with or without pretreatment auto-LTs.

Adolescent↗
PubMed1985

[High intravenous doses of immunoglobulins for treatment of autoimmune neutropenias].

Two patients respectively with acute agranulocytosis and with chronic neutropenia were treated with high-dose immunoglobulins. In the first case, immunologic tests revealed the presence of antigranulocytic autoantibodies: all other tests (antinuclear antibodies, anti-DNA antibodies, immune complexes, latex) were negative. In the second case, all the above mentioned tests were negative. In both patients, neutrophil number returned to normal after the second immunoglobulin injection. Eight months after treatment, the neutrophil count was normal in the first patient and anti-granulocyte tests had become negative. In the second patient there was a late recurrence of neutropenia. The diagnosis of autoimmune neutropenia is difficult to confirm. In the case of peripheral "idiopathic" neutropenia, with infectious complications, high-dose immunoglobulin administration thus appears justified regardless of the results of the immunologic tests. This therapy also has the advantage of avoiding side effects of steroid treatment or of splenectomy.

Adult↗