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Biomedical subjects

M Jeannet

Publications and source records attributed to M Jeannet.

At least 163 records · Page 9Linked to original sources
PubMed1980

HLA-DRw antigens associated with acute leukemia.

In mice, susceptibility to leukemia is closely linked to "Ia" antigens coded by the major histocompatibility complex and is transmitted recessively. To test this hypothesis in man, 89 patients with acute leukemia were typed for the eight known HLA-DRw specificities, representing the human counterpart of the Ia system, and compared with a normal unrelated control population (n=123). Phenotypes showing only one identifiable DRw antigen were significantly increased in patients with acute leukemia. Within such phenotypes, there was a predominant and significant occurrence of DRw antigens 3, 6, and 7, depending on the type of leukemia (AML, ALL in adults, and ALL in children respectively). These findings are most probably due to an excess of homozygotes for these particular DRw antigens, thus suggesting a recessive mode of transmission of susceptibility to leukemia in man.

Adult↗
PubMed1980

Increased frequency of HLA-DRw3 in systemic lupus erythematosus.

The distribution of HLA antigens was studied in 40 patients suffering from systemic lupus erythematosus. For loci A and B, increased frequencies of A1, B8 and the presence of only one B antigen were found. Nevertheless, in relation to the number of antigens tested, this increase was not significant. For the DRw locus, DRw3 was significantly increased (P < 0.001, after correction for the 39 antigens tested). However, the patients with DRw3 did not show any correlation with a specific clinical picture or the presence in their serum of lymphocytotoxic antibodies or autoantibodies against T and B lymphocytes.

Adult↗
PubMed1980

Blood transfusions and antibody response in patients waiting for a kidney transplant.

Cold and warm B and T cell antibodies have been investigated following blood transfusion in patients waiting for a kidney transplant. 18 out of 28 patients were sensitized after a single transfusion: half of them presented a B-warm pattern and the other half either a T-warm or a B-cold pattern. Several sera collected after one transfusion were absorbed with pooled platelets. All three T-warm sera have become negative after absorption. Out of 21 B-warm sera, 6 remained B-warm, 3 became B-cold and 12 were negative after absorption. There was no difference in strength between the B-warm sera which were absorbed and those which resisted to absorption. Dilution studies showed that sera followed a similar trend: they convert from T-warm to B-warm and B-cold patterns. Sequential sera from patients receiving systematic transfusions were tested at regular intervals after each transfusion. Most patients produced B-warm antibodies.

Absorption↗
PubMed1980

Lymphocyte-mediated cytotoxicity and humoral antibodies in human pregnancy.

Lymphocyte-mediated cytotoxicity, antibody-dependent cell cytotoxicity and complement-dependent antibody assays were used to study maternal immune response to fetal antigens present on cord lymphocytes at delivery. Among 24 cell-mediated lympholysis tests, 4 were found slightly positive and accompanied by a complement-dependent antibody and/or an antibody-dependent cell cytotoxicity response. The humoral immune response was found more often positive than the cellular response.

Antibodies↗
PubMed1980

Immunobiology of pregnancy: evidence for a fetal immune response against the mother.

In a study of 11 pregnancy sera, four retroplacental sera were found to contain antibodies directed against the current pregnancy. In two cases, cord sera were also positive. Surprisingly, the first serum contained antibodies apparently directed against the mother but not the father, thus suggesting an immune response of the fetus. Interestingly, the second was also positive despite the fact that it was a primigravida.

Antibodies↗
PubMed1979

[Progress in bone marrow transplantation in acute leukemia and aplastic anemia].

Experience with 17 allogeneic bone marrow transplantation (BMT) patients with refractory acute leukemia is reported. The authors show that it is extremely difficult to cure patients with end stage disease by this procedure. Based on experience that, if performed early, BMT can bring about over 50% potential cures, it is postulated that marrow grafts should be performed much earlier than is done at present. From the results in 45 patients with severe aplastic anemia it is concluded that the majority do not have a defect at the pluripotent stem cell itself. There is disturbed maturation to functional end cells which can be corrected in most instances by ALG, infusion of allogeneic marrow and low dose androgens. BMT between HLA-identical siblings need not cause major problems, but it involves a considerable risk of fatal complications such as irreversible marrow rejection and GvH.

Acute Disease↗
PubMed1979

[Immunosuppression, bone marrow infusion and low dose androgens, successful therapy of severe aplastic anemia].

18 patients with severe aplastic anemia (SAA) but without an HLA-identical sibling were treated by antilymphocyte globulin (ALG) followed by infusion of marrow cells from a semi-compatible family donor. 13 of these received low dose androgens after ALG: 11 (85%) achieved stable remission without transfusion requirement. One patient relapsed after 4 months, one patient with only partial remission died from infection. None of the 4 patients who did not receive androgens after ALG achieved remission. ALG, marrow and low-dose androgens represent a promising therapy for SAA and can be favorably compared with allogeneic bone marrow transplantation.

Adolescent↗
PubMed1979

Blood transfusions, cytotoxic antibodies, and kidney graft survival. Preliminary results of a systematic transfusion protocol.

Since pretransplant blood transfusions have been shown to prolong the survival of kidney grafts, a new transfusion policy has been started in the frame of Swisstransplant. Before surgery all patients receive at least two and, if possible, five transfusions (whole blood or packed red blood cells). The present study includes 101 recipients of primary cadaver grafts. Of these, 41 were transfused regularly according to the new protocol, 46 had irregular transfusions because of therapeutic necessity, and 14 had no transfusion before grafting. The 1-year survival rate in pretransfused patients was over 70% as compared to 45% in the nontransfused group. There was no significant association with the number of transfusions, but a slight improvement in graft survival was seen in patients deliberately transfused when compared with those transfused because of severe anaemia. A delay of more than 3 months between the last transfusion and transplantation significantly decreased graft survival at 6 months (84 versus 58%; P less than 0.02). The occurrence of cytotoxic antibodies, both antiperipheral blood lymphocytes (PBL) and anti-B cell antibodies, was investigated in relation to the number of transfusions received. Broad-spectrum anti-PBL antibodies (greater than 50% of random panel) were found in 5 of 74 patients transfused according to the protocol (7%) and in 15 of 93 patients transfused for severe anaemia (16% P, not significant). Of 71 recipients followed up for 6 months, 15 (21%) produced anti-PBL antibodies with limited specificity (less than 50%), and 4 (6%) produced broad-spectrum antibodies. Anti-B cell antibodies (less than 50%) were produced in 21 of 64 patients (33%). Six patients (9%) had broad-spectrum activity. The occurrence of these antibodies was not associated with the number of transfusions received and did not significantly influence the graft survival at 6 months. The change in transfusion policy seems to have improved graft survival without producing strong presensitization in a prohibitive proportion of the patients on hemodialysis.

Antilymphocyte Serum↗
PubMed1979

Increased frequency of HLA--DRw2 and DRw3 in multiple sclerosis.

Previous studies of multiple sclerosis patients showed the existence of a positive association between multiple sclerosis and HLA--A3 and --B7, as well as a negative association with B12. These observations have been confirmed. In addition, a more marked association has been observed with two recently identified B-cell antigens, DRw2 and DRw3, closely related to the HLA--D locus. The presence of cold lymphocytotoxic antibodies was found to bear no relationship with those two specificities. These results suggest that two genes of the HLA--DR region may play a role in the pathogenesis of multiple sclerosis.

Epitopes↗
PubMed1979

Evidence for an HLA-linked resistance gene in Buerger's disease.

The incidence of Thromboangiitis Obliterans in brothers and the high prevalence in some ethnic groups have led us to investigate the histocompatibility HLA-A, B and DR antigens of 46 Buerger's disease patients. The main result indicates a marked decreased freqeuncy of the B12 antigen: 2.2% vs 28% in controls. Our study suggests that Buerger's disease is, on the basis of HLA antigens, a distinct immunogenetic entity and not a particular form of arteriosclerosis. Moreover, this disorder may represent a clue to the existence of resistance genes linked to HLA.

Adult↗
PubMed1979

A screening program for anti-DR typing reagents.

A total of 694 sera have been tested in a screening program aimed at identifying monospecific reagents for HLA--DR typing. All sera were first tested on a panel of enriched B and T cells without absorption on platelets. Only sera reacting more frequently on B than on T lymphocytes were absorbed on platelets and retested on the panel. This procedure saved a considerable amount of platelets and proved to be reasonably efficient. One-hundred-and-fifty sera were found to contain an anti-B cell antibody. Significantly less frequent B cell reactivity was found when HLA--A, --B, --C antibodies could not be detected. Twenty-five sera were demonstrated to be specific for well-defined DR antigens.

Antibodies, Anti-Idiotypic↗