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Biomedical subjects

B Dupont

Publications and source records attributed to B Dupont.

At least 415 records · Page 23Linked to original sources
PubMed1980

DR-positive maternal engrafted T cells in a severe combined immunodeficiency patient without graft-versus-host disease.

A 2 1/2-year-old male infant with severe combined immunodeficiency was documented by HLA typing and the presence of a female karyotype in the few spontaneously dividing cells to have an intrauterine-derived maternal lymphocyte graft. The presence of DR antigens on the engrafted maternal E rosette-forming T cells was demonstrated by both cytotoxicity and immunofluorescence techniques using both conventional and monoclonal antihuman DR antisera. These DR antigens were of the same allospecificity, DR4, as the mother's peripheral blood B cells. The patient's B cells and monocytes expressed DR alloantigens DR4 and DR3, corresponding to his genotype. Although fresh maternal lymphocytes react strongly in vitro against patient non-T cells, the engrafted maternal T lymphocytes no longer show this activity. Furthermore, clinical evidence suggesting mild graft-versus-host disease was completely resolved by the end of his first year. The presence of the DR-positive maternal cells may reflect the survival of a group of activated suppressor cells mediating graft tolerance of host tissue.

Child, Preschool↗
PubMed1980

Genetically appropriate expression of HLA and DR (IA) alloantigens on human melanoma cell lines.

Studies of the expression of HLA and DR alloantigens on cultured human melanoma cells in comparison with those expressed on peripheral lymphocytes and B-cells derived from the same patients have shown that the HLA-A,B, and C locus antigens expressed on the cultured tumor cells were consistent with those expected from the typing of peripheral blood lymphocytes. One melanoma cell line failed to express all the HLA antigens expected from donor typing. All five of the lines tested also expressed DR antigens and in three instances these could be demonstrated to have genetically consistent allotypes. However, in preliminary studies stimulation of allogeneic lymphocytes by the DR positive melanoma cells could not be demonstrated.

Aspartate Aminotransferases↗
PubMed1980

Cryptic 21-hydroxylase deficiency in families of patients with classical congenital adrenal hyperplasia.

Serum androgens and 17-hydroxyprogesterone concentrations and HLA genotypes were determined in 124 families of patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency (CAH). In 8 pedigrees, we discovered 16 pubertal or postpubertal family members of either sex who had biochemical evidence of 21-hydroxylase deficiency but were without clinical symptoms of excess virilism, amenorrhea, or infertility. We designated these family members as individuals with cryptic 21-hydroxylase deficiency. Within each generation, the family members with cryptic 21-hydroxylase deficiency were HLA identical. It is proposed that these family members are genetic compounds, having 21-hydroxylase deficiency as a result of two recessive gene defects: 1) a severe 21-hydroxylase gene defect present in the index case with classical CAH (21-OHCAH) and 2) a mild 21-hydroxylase gene defect (21-OHCRYPTIC). Thus, the CAH genotype in the family members with cryptic 21-hydroxylase deficiency is 21-OHCAH/21-OHCRYPTIC. Lod score analysis for linkage between the cryptogenic 21-OH trait and HLA gave a combined Lod score for males and females of theta = 0.00 of 3.409. Close genetic linkage between HLA and 21-OHCRYPTIC was thus established. This study provides support for the previously reported heterogeneity of 21-hydroxylase deficiency which may result from allelic variability at the locus for steroid 21-hydroxylase.

17-alpha-Hydroxypregnenolone↗
PubMed1980

Progressive multifocal leukoencephalopathy (PML): in vitro cell-mediated immune responses to mitogens and JC virus.

Cell-mediated immunity was studied by in vitro tests in seven patients with progressive multifocal leukoencephalopathy (PML). Lymphocyte proliferation in response to mitogenic stimulation was reduced to a variable degree in all patients, indicating a general impairment of cell-mediated immune responsiveness, although mitogen-induced production of the lymphokine migration inhibitory factor (LIF) was normal in most cases. Cell-mediated immunity to JC virus (JCV) was assessed by LIF production in response to JCV antigen. In the six PML patients tested, LIF production with JCV antigen was absent despite the presence of antibody to JCV in serum. This contrasted with positive LIF production in seropositive normal individuals and patients and patients with other diseases. These results provide the first in vitro evidence of a depressed cell-mediated immune response to JCV in patients with PML, and support the hypothesis that PML is accompanied by a selective marked deficiency in cellular response to this virus in association with a general depression of cell-mediated immunity of variable severity.

Adult↗
PubMed1980

Fatal graft-versus-host disease following blood transfusion in Hodgkin's disease documented by HLA typing.

Fatal graft-versus-host disease (GVHD) developed in a patient with Hodgkin's disease treated with combined chemotherapy and radiotherapy following the transfusion of 2 U of packed red blood cells. Clinical features of the GVHD included the development of exfoliative dermatitis, progressive hepatic dysfunction, aplastic anemia, and finally progressive fatal pneumonia. GVHD was documented by skin biopsy and chimerism by HLA typing. The HLA phenotype of the patient's skin fibroblasts [A3, Bw44 (w4)/A2, B15 (w4)] was appropriate for parental haplotypes and probably represented her true HLA phenotype. Lymphocytes from the patient (peripheral blood and lymph node biopsy) were of a different HLA phenotype (A3; Bw35, w38, w4, w6; Cw4), which was inappropriate for parental HLA haplotypes but identical to the HLA phenotype of one of the blood donors. The HLA-DR typing of the patient's family and of the blood donor demonstrated that the patient and the donor probably were HLA-DR identical (DRw5/DRw6), although no B lymphocytes could be obtained from the patient for direct DR typing. We are currently irradiating all blood products administered to patients with Hodgkin's disease receiving intensive treatment. Further observations will be necessary to determine whether transfusions to other cancer patients with immunodeficiency states should be restricted to irradiated blood products.

Adolescent↗
PubMed1979

Prenatal diagnosis of congenital adrenal hyperplasia (21-hydroxylase deficiency) by HLA typing.

Congenital adrenal hyperplasia (C.A.H.) due to 21-hydroxylase deficiency is an HLA-linked recessive disorder. HLA-A and B antigens are expressed on amniotic cells. Prenatal diagnosis of C.A.H. by HLA typing of families and amniotic cells was attempted in two at-risk families. In one family HLA typing indicated that the fetus would have C.A.H., and this prediction was confirmed after birth. In the second family, HLA typing indicated that the fetus would be an unaffected, phenotypically normal carrier of the disease gene, and this prediction was also confirmed after birth.

Adrenocortical Hyperfunction↗
PubMed1979

[Trypanosomiasis presenting with trypanids and complicated by myopericarditis (author's transl)].

In a 26-year-old man who had spent time in a trypanosome endemic zone, lesions of erythema marginatum progressing by acute exacerbations for 2 years despite various forms of treatment led to the discovery of a multiple lymphadenopathy and a greatly accelerated sedimentation rate. These findings suggested a diagnosis which was confirmed by the discovery of Trypanosoma gambiense in the blood and lymph node aspirate. In addition, there was an albumino-lymphocytic reaction in the cerebrospinal fluid. Finally, an atrioventricular block was discovered. All these symptoms and signs responsed to treatment with melarsoprol but a pericardial reaction developed, possibly of immunoallergic origin.

Adult↗
PubMed1979

Prostaglandin effect on lymphokine production in multiple sclerosis.

Production of the lymphokine LIF (leukocyte migration inhibitory factor) by normal lymphocytes on stimulation with mitogens in inhibited by E type prostaglandins (PGE). It has been reported that the leukocytes of patients with multiple sclerosis (MS) are resistant to this inhibitory effect. We have studied 10 MS patients using an indirect technique for measuring LIF activity. This allows separation of the effects of PGE on lymphocyte LIF production from the effects on the action of LIF on the target granulocytes. There was no difference between normal subjects and MS patients in the effects of prostaglandins E1 and E2 in concentrations of 2.5 and 0.25 microgram per milliliter, on LIF production, or on granulocyte response to LIF. These results do not support the hypothesis that the chronic inflammatory process in MS is the result of resistance to the normal inhibitory effects of PGE on the cellular immune response.

Humans↗
PubMed1979

Secondary MLC responses of primed lymphocytes after selective sensitization to non-HLA-D determinants.

Two HLA-B,D-identical siblings, who differed only for the HLA-A region because of a maternal recombinational event, were studied in primary (1 degrees) and secondary (2 degrees) mixed lymphocyte culture (MLC). The HLA-A:B recombinant child did not respond to its HLA-B,D-identical sibling in either 1 degrees or 2 degrees MLC. In the reciprocal combination the non-recombinant child responded only weakly in 1 degrees MLC but responded significantly in 2 degrees MLC to the HLA-A:B recombinant child. Thus, it was possible to selectively prime to a non-HLA-D determinant, which is controlled by a gene located distal to HLA-B. Because this determinant was not present on T-cells, it could be distinguished from the serologically defined antigen controlled by the HLA-A locus. Such primed lymphocytes, as well as lymphocytes primed between HLA-identical siblings, revealed high autologous control responses which were not observed when using lymphocytes primed in conventional one-haplotype combinations. The significant 2 degrees MLC response to autologous cells after sensitization to allogeneic cells may reflect recognition of self antigens and raises the question to what extent genetic similarity between responding and stimulating cells is required in the priming phase to elicit a 2 degrees response to autologous cells.

Child↗
PubMed1979

HLA-DR antigens in Black North-Americans and their association with HLA-D.

A random population of 108 Black North-Americans, 79 of whom had also been typed for HLA-D in Mixed Leukocyte Culture (MLC), were serologically tested for DRw with Seventh International Histocompatibility Workshop trays. Clusters of B cell alloantisera were identified which defined several DRw antigens. Although the clusters for DRw1, DRw2, DRw3 and DRw7 showed similarities with the clusters derived during the Seventh International Histocompatibility Workshop, distinct differences were observed which should be taken into account for the assignment of the DRw antigens in Blacks. DRw6 was defined by a cluster of sera which also reacted with DRw1 and DRw2 cells. The tails of these sera were used to assign DRw6, but this was only possible with DRw1 and DRw2 negative cells. It was not possible to identify serum clusters specific for DRw4 or WIA8. The associations between DRw and the corresponding Dw specificities were reasonably good for DRw1, DRw2 and DRw7, but weaker for DRw3 and DRw5. The cumulative gene frequencies for DRw1, DRw2, DRw3, DRw5, DRw6 and DRw7 was 0.86. The frequencies of these six DRw antigens fitted into a Hardy-Weinberg distribution, suggesting that DRw in Blacks is controlled by a single gene with multiple alleles.

Black People↗
PubMed1979

Standardization of the human in vitro cell-mediated lympholysis technique.

Cytotoxic lymphocytes (CTL) can be generated in mixed lymphocyte culture and cryopreserved after a 6-day sensitization phase. CTL tested after storage in liquid nitrogen do not show lysis of autologous target cells and can mediate strong cytotoxicity against other target cells. This lysis shows the same specificity as that of the corresponding fresh CTL. The ability to cryopreserve CTL enables performance of sequential CML testing. Data from separate CML experiments can be pooled using a percent relative cytotoxic response (%RCR) to normalize values within individual experiments. Together, these methods provide a standardized cell-mediated lympholysis technique.

Cytotoxicity, Immunologic↗