Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023890 (cirrhosis)
 42,195 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

IgG, IgA, IgM, and albumin are primarily known as plasma proteins. Their presence in platelets is poorly understood. The total platelet content of IgG, IgA, and albumin, measured in solubilized platelets by an enzyme-linked immunosorbent-assay (ELISA) technique, was greater than 90% secreted after stimulation by thrombin, consistent with an alpha-granule location. The platelet concentrations of these proteins correlated with their plasma concentrations in normal subjects and over a wide range of abnormalities in patients with IgG or IgA myeloma or liver cirrhosis. IgM was not detectable in normal platelets but was measurable and related to the plasma IgM concentration in patients with macroglobulinemia. In patients with idiopathic thrombocytopenic purpura (ITP), the platelet concentrations of IgG, IgA, and albumin were all twofold to threefold higher than normal despite normal plasma concentrations. Platelet surface IgG, measured by 125I-monoclonal antibody binding, constituted less than 1% of the total platelet IgG, and it appeared to be a pool distinct from the alpha-granule IgG since its concentration in normal subjects and patients did not correlate with either plasma or total platelet IgG concentrations. These observations are consistent with hypotheses that megakaryocytes incorporate plasma proteins into developing alpha-granules by pinocytosis and that the increased ratio of platelet to plasma of IgG, IgA, and albumin in ITP may reflect a younger average age of these platelets.
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PMID:Platelet IgG, IgA, IgM, and albumin: correlation of platelet and plasma concentrations in normal subjects and in patients with ITP or dysproteinemia. 339 Jun 11

Serum IgA M-components, secretory IgA separated from colostrum, and IgA from serum of patients with cirrhosis of the liver were digested with pepsin at pH 4.1. The IgA M-components segregated into two groups on the basis of their relative rates of peptic digestion. Serum and colostral IgA were digested at a total rate intermediate to that of the two groups of IgA myeloma proteins. It appeared, however, that colostral IgA may have been initially more resistant to peptic digestion than serum IgA. The variability in the rate of peptic digestion was not related to electrophoretic mobility, light-chain type, or IgA subclass. Experimental conditions related to enzyme to substrate ratio or to the pH of the reaction mixture did not appear to explain the differences found.These findings indicate that (a) two groups of IgA proteins can be distinguished on the basis of susceptibility to proteolysis with pepsin, and (b) secretory piece confers, at most, only a minor increase in stability to the IgA molecule against the digestive action of pepsin.
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PMID:Two distinct groups of immunoglobulin A(IgA) revealed by peptic digestion. 418 23

Serum levels of sIgA were quantitated by a new radioimmunoassay in patients with a variety of diseases, lactating women and clinically healthy blood donors. Significantly elevated levels compared to controls were found in lactating women, patients with Crohn's disease and patients with cirrhosis, but not in patients with rheumatoid arthritis, IgA myeloma or neoplastic disease. Patients with inflammatory disease and serum IgA levels at least two-fold greater than the normal mean and patients with a variety of other diseases did not show elevated levels of sIgA. In the two latter groups, patients with hepatic disease were excluded. High levels of sIgA were found in four patients with liver metastases from extrahepatic neoplasms. The results indicate that the liver is important for the maintenance of normal serum levels of sIgA.
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PMID:Reassessment of levels of secretory IgA in pathological sera using a quantitative radioimmunoassay. 728 96