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Biomedical subjects

A Durandy

Publications and source records attributed to A Durandy.

At least 109 records · Page 6Linked to original sources
PubMed1982

Prenatal testing for inherited immune deficiencies by fetal blood sampling.

We attempted to develop a prenatal diagnosis in fetuses at risk for immunodeficiency by fetal blood sampling performed under fetoscopy at 18-22 weeks of gestation. In order to obtain normal values, we first investigated thirty-five control fetuses whose blood punctures were undertaken for the diagnosis of haemoglobinopathies. Surface markers and in vitro mitogen-induced proliferation of the fetal lymphocytes were studied using micromethods. We then examined two fetuses at risk for two different types of severe combined immunodeficiency and established their immunological integrity, hence avoiding an unjustified termination of pregnancy. This immunological integrity was confirmed after birth.

Antigens, Surface↗
PubMed1982

Respective roles and interactions of T-lymphocyte and PGE2-mediated monocyte suppressive activities in human newborns and mothers at the time of delivery.

Recently the concept of a poorly functional humoral immune response in the newborn was proposed. Data have been presented indicating that the impaired newborn B cell maturation, as shown in vitro in a pokeweed mitogen-induced B cell maturation system, is due both to an immaturity of lymphocyte subsets and to an increased suppressive T activity. In the present work, we present evidence that there exists a predominance of a naturally occurring T lymphocyte suppressive activity in the cord blood in that the removal of the suppressive activity by irradiation allows a normal maturation of newborn B cells. Such normal maturation of newborn B cells can also be obtained using mixed cultures of adult T cells and newborn B cells. Newborn suppressor T cells belong to both EA gamma (+) and EA gamma (-) fractions, and it is not known whether these two groups do or do not belong to different subsets. The PGE2-dependent monocyte suppressive activity does not play any role in the suppression observed in newborns since newborn monocytes are poorly suppressive and since they produce a smaller amount of PGE2 than adult monocytes. Some observations suggest, on the contrary, that the suppressive T lymphocytes can regulate the level of the PGE2-dependent monocyte suppressive activity. It should be noticed that similar observations about T lymphocyte and PGE2-dependent monocyte suppressive activities have been made at the same time using mothers' cells. These observations suggest the possibility that such changes in B cell immune regulation may result from an interaction between maternal and fetal lymphoid cells.

B-Lymphocytes↗
PubMed1982

Lack of prostaglandin E2-mediated monocyte suppressive activity in newborn and mothers.

An excess of adult blood adherent cells (monocytes) inhibits mitogen, antigen and allogeneic cell-induced lymphocyte proliferations. This inhibition is dependent on the number of the adherent monocytes in the cultures and is substantially reduced (by 60%) by indomethacin or anti-PGE2 antiserum. Newborn monocytes exert only a weak inhibitory effect and produce about eight times less PGE2 than adult monocytes. The production of PGE2 and the suppression can be induced by incubating newborn monocytes with mixed leucocyte culture supernatants. Both monocytes from mothers at the time of delivery and from newborn infants, usually exert a poor suppressive activity related to a low production of PGE2. We strongly suggest that the expression of the PGE2-mediated suppression by monocytes is under the control of activated short-lived suppressor lymphocytes.

Adult↗
PubMed1982

Inability of newborns' or pregnant women's monocytes to suppress pokeweed mitogen-induced responses.

Although an excess of human adult blood adherent cells inhibits the pokeweed mitogen- (PWM) induced normal adult lymphocyte proliferation and B cell maturation into immunoglobulin-containing cells (ICC), adherent cells collected from newborn infants or pregnant women at time of delivery were unable to exert a similar suppressor activity. After activation by Concanavalin A (Con A), newborns' and pregnant women's adherent cells acquired a suppressor activity comparable to that of control adult adherent cells. The adherent suppressor cell was shown to be radioresistant (3000 rad), indicating its probable monocytic origin. Both monocyte-suppressor activities (MSA) observed in adulthood (spontaneously) and in the neonatal period (after activation) were dependent on prostaglandin E2 (PGE2) secretion, because they were abolished by indomethacin or a specific anti-PGE2 antiserum. Expression of MSA appeared to be under a negative regulation exerted by naturally occurring T suppressor lymphocytes present in the blood of newborns or pregnant women, because incubation of adult monocytes or Con A-activated newborn monocytes with newborns' or pregnant women's T lymphocytes resulted in a dramatic decrease of their MSA. These results strongly suggest that the lack of MSA in the neonatal period and in late pregnancy is a consequence of activation of T suppressor lymphocytes.

B-Lymphocytes↗
PubMed1982

[Immunologic study of familial lymphohistiocytosis. Eight new case reports (author's transl)].

We report 8 cases of familial lymphohistiocytosis collected in 6 families. Several data argue for an hyperactivation of the reticuloendothelial system (RES). An abnormal visualization of all organs was observed in a scintigraphic study after 99technetium labelled red blood cells injection. Blood monocytes contained very low peroxidase activity as detected by cytoenzymology and secreted large quantities of prostaglandin E2 (PGE2). Adherent cells isolated from blood exercised a strong suppressor effect on the proliferation of normal lymphocytes induced by phytohemaglutinin. This effect was reduced by indomethacin and therefore appears PGE2-dependent. One patient's serum exerced an inhibitory activity on antigen-induced proliferation of normal lymphocytes and on mixed leucocyte reaction. In contrast, cellular and humoral functions were not deeply impaired. The hyperactivation of the RES remains unexplained and not related to a graft versus host reaction, which could be excluded in 3 of our patients. Therapeutic attempts were not efficient, all patients dying despite steroid, vincaleucoblastin and indomethacin therapy.

Female↗
PubMed1981

T-cell subset analysis by monoclonal antibodies in primary immunodeficiencies.

T-cell subsets have been analysed in 23 cases of primary immunodeficiency with monoclonal antibodies. Functional assays investigating T-cell function--proliferative response to mitogens, antigens, and allogeneic cells, cytotoxicity generated against allogeneic target cells and helper function to pokeweek mitogen-induced immunoglobulin synthesis--were performed in parallel in the same patients. The results enabled us to delineate four groups of patients. The first group consisted of patients in whom marker and function studies show concordant data, with either normal or strongly decreased T-cell number and function. The second group consisted of patients in whom various degrees of functional abnormality coexist with subnormal T-cell number and increased suppressor T-cell proportion. In the third group, we collected all patients who showed functional deficiencies without marker abnormalities. Finally, there was a small group composed of patients whose T-cell pattern was strongly suggestive of abnormal differentiation.

Adenosine Deaminase↗
PubMed1981

Dysfunctions of pokeweed mitogen-stimulated T and B lymphocyte responses induced by gammaglobulin therapy.

Lymphocytes obtained from nonimmuno deficient children treated with commercially available preparations of gammaglobulin failed to proliferate and to mature into plasma cells in vitro after stimulation with pokeweed mitogen. The influence of the treatment on lymphocyte functions varied according to the cell population considered. A T helper cell activity was detected in these patients but only in the cell subset bearing receptors for IgG after irradiation. T lymphocytes exerted a suppressive effect that disappeared after irradiation or incubation at 37 degrees C. The suppressive cells were found among E rosette-forming cells depleted of leukocytes bearing receptors for IgG. Their suppressive effect was expressed only in the presence of normal radioresistant T lymphocytes that did not bear Fc receptors for IgG. Similar dysfunctions could be induced in vitro by incubation of normal T and B lymphocytes with gammaglobulin preparations. Because F(ab)'2 fragments or deaggregated preparations of gammaglobulin failed to activate T suppressor lymphocytes, this activation was likely triggered by attachment of Fc portion of denatured IgG to the corresponding membrane receptor. This activation step was prostaglandin E(2)-dependent, suggesting that activated monocytes were involved in the activation process. B lymphocyte responses appeared directly inhibited by attachment of denatured gammaglobulin on membrane Fc receptor. Our observations suggest that immunological effects of gammaglobulin therapy are not limited to antibody transfer, since it also induces subtle modifications of in vitro pokeweed mitogen-stimulated T and B cell responses. These modifications must be considered in interpreting results obtained in immunodeficient patients investigated under gamma-globulin therapy.

Antigens, Surface↗
PubMed1981

Role of prostaglandin E2 in the induction of nonspecific T lymphocyte suppressor activity.

Activated human monocytes and concanavalin A (Con A)-activated T lymphocytes are known to suppress T and B lymphocyte proliferation and B cell maturation into immunoglobulin-producing cells. We have now shown that monocyte suppressive activity is predominantly mediated through release of prostaglandin E2 (PGE2), which is active only in the presence of a "short-lived," radiosensitive T lymphocyte subset. PGE2, at high concentration, can activate T suppressor lymphocytes (TS), which display the same characteristics as Con A-activated TS lymphocytes. Moreover, Con A activation of TS lymphocytes was obtained only in the presence of PGE2, as specific anti-PGE2 antiserum or indomethacin prevented TS activation; this suggested a double signal as a prerequisite for activation of the nonspecific TS cell subset. We propose that TS lymphocytes modified by Con A become sensitive to small amounts of PGE2 produced by monocytes that must be present during the Con A-stimulated activation phase of suppressive cells.

B-Lymphocytes↗
PubMed1980

Transplantation of lymphoid cells in patients with severe combined immunodeficiency (SCID).

The effects of bone marrow or fetal lymphoid organ transplants in 15 patients with severe combined immunodeficiency disease are reported. The benefits and dangers inherent to the various transplantation strategies are discussed. Our studies indicate that, even in the group of patients with B cells, bone marrow transplantation may be the best procedure to obtain the reconstitution of cellular and humoral functions.

B-Lymphocytes↗
PubMed1980

Circulating immune complexes containing rubella antigens in late-onset rubella syndrome.

Eight infants with late-onset rubella syndrome were investigated. All patients had been infected by rubella virus during gestation but had minimal clinical symptoms at birth and during a latent period of several months. They presented secondarily an acute phase characterized by a severe multisystem disease. Antirubella antibody titers were present at low levels before and during the first weeks of the acute phase, contrasting with high serum levels of IgM. The percentage of T lymphocytes was very low and an increase of B lymphocytes was observed. The presence of circulating immune complexes which appeared to contain rubella antigens was demonstrated. These findings suggest that the lesions observed in late-onset rubella syndrome are partly due to CIC, and that suscepibility to infection can be related to a peripheral T and B lymphocyte disequilibrium.

Antigen-Antibody Complex↗