Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0029713 (immaturity)
 4,335 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Studies of ontogenesis contribute to better understanding of regulatory events underlying the striking heterogeneity in B-cell differentiation pathways employed in the human mucosal immune system. This disparity is probably explained by exogenous environmental factors, although regional differences probably also exist in accessory cells and cytokines involved in local immune responses. IgA deficiency signifies a heterogeneous syndrome but is basically a manifestation of a defect in B-cell differentiation. The immaturity of the IgA system revealed in this disorder bears a striking resemblance to that seen in newborn infants. It may therefore be worthwhile to consider IgA deficiency in relation to the ontogeny of mucosal immunity.
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PMID:Ontogeny of the mucosal immune system and IgA deficiency. 191 20

The differentiation status of T and B cells was evaluated in patients with common variable immunodeficiency (CVI), selective IgA deficiency (IgA), X-linked agammaglobulinemia (XLA), and the acquired immune deficiency syndrome (AIDS) with the use of conventional lymphocyte markers and four new monoclonal antibodies that identify lymphocyte subpopulations. These antibodies are HB 4, which identifies a subpopulation of resting B cells; HB 5, which identifies the C3d/EBV receptor on mature B cells; HB 7, which identifies immature B lymphocytes; and HB 10, which reacts with virgin but not activated or memory T cells. T and B cells from the IgA patients typically had normal phenotypic profiles, whereas diverse patterns of lymphocyte maturation were observed in CVI. In 11 of 16 CVI patients, B cells had normal antigenic phenotypes. Although B cells from four other CVI patients had normal frequencies of HB 5 and HB 7 antigen expression, few expressed the HB 4 antigen, suggesting that they were activated. In contrast, a large percentage of B cells from one CVI patient were of an immature phenotype. The expression of the HB 10 antigen by T cells in CVI patients was also variable, being normal in 10 of 16 patients, yet significantly decreased in six others. The vast majority of the limited numbers of IgM B cells from five XLA patients (greater than 100-fold reduction) has an immature phenotype (HB 4-5-7+). Interestingly, the circulating T cells in XLA patients were phenotypically similar to those in normal newborns, suggesting that T cell immaturity or defective T cell activation may occur in these B cell-deficient individuals. Circulating B cells from AIDS patients were mostly HB 7-, with variable expression of the HB 4 antigen and significantly decreased expression of the HB 5 antigen. Most of the T cells from AIDS patients were HB 10-, and thus appeared to be activated.
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PMID:Evaluation of lymphocyte differentiation in primary and secondary immunodeficiency diseases. 316 Jul 79

J chain synthesis was investigated by in vitro pokeweed mitogen (PWM) stimulated peripheral blood lymphocyte (PBL) cultures in eight patients with selective IgA deficiency and compared with that of normal persons. In normals, all IgM-containing cells always had the J chain but only in a portion of IgG- and IgA-containing cells was J chain detectable. The percentage of J chain-positive cells amongst IgG or IgA cells increased during culture, reached a peak at days 5-6 or 6-7, respectively, and then decreased. IgA-deficient patients had very few IgA-containing cells and an increased number and percentage of J chain-positive IgG cells, except for one patient, who had a significant number of IgA-containing cells without IgA secretion into the culture supernatants. Measurement of Ig in culture supernatants by radioimmunoassay revealed that lymphocytes from seven patients secreted significantly smaller amounts of IgG and IgM than did the normal controls, in addition to the defect in IgA production. These results suggested the presence of some ontogenetic relationship between J chain-positive IgG cells and the precursors of IgA-producing cells, and some functional immaturity of most IgG-producing clones seen in patients with selective IgA deficiency.
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PMID:J chain synthesis in lymphocytes from patients with selective IgA deficiency. 680 35

In order to prevent the penetration of intraluminal material such as micro-organisms, food antigens, toxins etc. across the intestinal mucosa, a complex defence mechanism has been developed. This mechanism consists of non-immunological defence with enzymatic detoxification as well as an immunological one. The nature of the immunological defence has been thoroughly elucidated during the past 10-15 years. This mechanism is in man based on a special local immunological resistance, where production of secretory IgA plays the main role. Immunoglobulin producing plasma cells appear relatively late after birth in the lamina propria of the gut mucosa. Therefore a physiological immaturity of the immunological defence during first weeks of life can be anticipated. The role of the immunological defence system in the control of dietary antigen penetration across gut epithelium has been much discussed. Circulating antibodies to cow's milk proteins in small infants after milk ingestion and the almost constant finding of such antibodies in high titre in patients with selective IgA deficiency even without intestinal disease indicate a highly significant function of this local immunity in antigen handling. It has been suggested that the apparently high incidence of food allergy in infancy is due to immaturity of this system. Cow's milk protein induced enteropathy is also strictly bound to this age group.
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PMID:The immune response of the intestinal mucosa to foreign proteins. 696 45