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Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The lectin jacalin from jackfruit seeds shows a human IgA-subclass specificity by gel precipitation and Western blotting. However, its reactivity with IgA2 is a matter of controversy. We further studied the immunoglobulin isotype specificity of jacalin by affinity chromatography with myeloma sera and by inhibition of jacalin binding to solid-phase IgA1 by purified monoclonal immunoglobulins. The lectin proved to bind IgA2 of both allotypes with a lower apparent affinity than for IgA1 and IgD.
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PMID:Jacalin, the human IgA1 and IgD precipitating lectin, also binds IgA2 of both allotypes. 317 Nov 89

IgG and IgM isotype antibodies to polyclonal human IgA, myeloma IgA1, and myeloma IgA2 were estimated in 38 IgA-deficient children aged between 0.9 and 15 years. All children had IgM anti-IgA antibodies. IgG antibodies against either polyclonal IgA, IgA1, or IgA2 were present in 63% of the IgA-deficient children. IgG anti-IgA antibodies were detected against all three antigens in 8 of 11 severely IgA-deficient children and in 7 of 27 partially IgA-deficient children, but in only 1 of 23 healthy adult controls. The proportion of children with IgG anti-IgA antibodies was significantly greater in the severely IgA-deficient group in comparison with the partially IgA-deficient group and the adult controls (chi-square test, P less than 0.01 and P less than 0.005, respectively). There was a strong correlation within each IgG subclass between antibody responses toward each of the three IgA antigens. Twenty-four children were followed over a period ranging from 0.9 to 11 years (mean, 2.3 years). Three children who were initially IgG anti-IgA antibody negative became antibody positive and three who were antibody positive became antibody negative. Five children with severe IgA deficiency remained severely IgA deficient and IgG antibodies to IgA persisted in all five at follow-up. The presence of IgG anti-IgA antibodies did not influence the normalization of serum IgA at follow-up in 14 of 19 children who were initially partially IgA deficient.
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PMID:Anti-IgA antibodies in IgA-deficient children. 326 81

In the present study we have investigated whether bovine erythrocytes (Eb) specifically sensitized with human polyclonal IgA1 (Eb-IgA1) are able to bind to resident adherent rat peritoneal cells (PM phi). Rat PM phi formed rosettes with Eb-IgA1 at room temperature and at 37 degrees. The formation of these rosettes could be blocked completely by excess human serum IgA or myeloma IgA1. In contrast, human IgG or rat IgG did not inhibit the formation of rosettes, whereas human polymeric myeloma IgA2 only partially inhibited rosette formation. Complete inhibition of rosette formation was also induced by rat monomeric and polymeric myeloma IgA, suggesting species interchangeability. Furthermore, rosette formation could be completely blocked in the presence of excess asialofetuin or D-galactose, while excess ovalbumin or D-mannose had no effect. These results suggest that the oligosaccharides in the hinge region of human IgA1 are involved in the binding of Eb-IgA1 to rat PM phi.
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PMID:Binding of human IgA1 to rat peritoneal macrophages. 339 40

RBCs from one-third of IgA nephropathy patients examined had more IgA1 on their surface than cells from healthy volunteers. The amount of IgA1 on RBCs was estimated to be no more than 30 ng/4 x 10(8) RBCs. The level of IgG on the surface of RBCs from IgA nephropathy patients were the same as those from healthy volunteers. Free IgA1 myeloma protein binds poorly in vitro to RBCs from both an IgA deficient patient and healthy volunteers. Polyethylene glycol precipitate from the sera of IgA nephropathy patients bound to RBCs from an IgA deficient patient. Factor I did not release IgA1 bound to RBCs from IgA nephropathy patients. These results suggest that this binding is mediated through the interaction of IgA1 and RBCs, and that some alteration of the IgA1 molecule (complexes or aggregation) may account for this binding.
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PMID:IgA on the surface of erythrocytes from IgA nephropathy patients. 342 48

Solid-phase radioimmunoassays have been developed for the detection and quantification of human serum and secretory IgA antibodies to a variety of food, bacterial and viral antigens. Monoclonal antibodies specific for IgA1 and IgA2 and capable of binding to serum and secretory IgA were used. The assays were calibrated by reference to standard serum or purified myeloma proteins bound to solid-phase anti-immunoglobulin reagents, and sigmoid calibration curves were constructed by means of computer programs using 4-parameter logistic or weighted logit-log principles. Polymeric and monomeric forms of IgA antibodies were assayed in fractions separated by high performance size exclusion chromatography. These techniques have demonstrated the expected predominance of IgA1 antibodies in serum, and these included polymeric forms. Saliva contained both IgA1 and IgA2 antibodies, and increased proportions of IgA2 antibodies to lipopolysaccharides and lipoteichoic acid were observed.
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PMID:Assay of human IgA subclass antibodies in serum and secretions by means of monoclonal antibodies. 348 56

IgG anti-IgA antibodies were measured by an enzyme-linked immunosorbent assay using one IgA1 and one IgA2 (m1) myeloma and a pooled IgA protein preparation as antigens. Class-specific anti-IgA antibodies occurred in 0.8% of non-IgA-deficient sera and 24.3% of IgA-deficient sera. Antibodies reacting with IgA1 only occurred in 2.6% of non-IgA-deficient sera and 6.7% of IgA-deficient sera. Antibodies reacting with IgA2 only occurred in 0.6% of non-IgA-deficient sera and 2.7% of IgA-deficient sera. The prevalence of anti-IgA in IgA deficients with inflammatory disease was higher (81.8%) than in IgA deficients without disease (24.1%) and was accounted for by class-specific antibodies.
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PMID:IgG anti-IgA1 and anti-IgA2 antibodies: their measurement by an enzyme-linked immunosorbent assay and their relationship to disease. 348 73

Serum samples from 26 normal volunteers were evaluated by isotype-specific ELISA for the presence of IgG and IgM antibodies directed at IgA. Although there were wide variations in antibody levels, anti-IgA antibodies of both isotypes were found in all individuals tested. The anti-IgA activity was detected against a variety of polymeric and monomeric IgA1 and IgA2 myeloma proteins containing both kappa and lambda light chains. By using Fab and Fc fragments generated by incubation of an IgA1 myeloma protein with IgA1 protease, it was shown that the anti-IgA activity was specific for the Fab portion of the IgA molecule. It was also demonstrated that the serum of two individuals contained both IgG and IgM activity directed at autologous affinity-purified IgA. IgM antibody levels against both whole IgA and Fab of IgA were significantly higher than IgG antibody levels. Cells producing anti-IgA antibodies of both isotypes were detected in lipopolysaccharide-stimulated human spleen.
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PMID:Normal human sera contain antibodies directed at Fab of IgA. 349 62

IgA1-2 subclass distribution was determined in a series of 62 sera with diagnosed IgA paraprotein. Throughout the series the participation of IgA1 : IgA2 subclasses showed a ratio 9 : 1 even after division of the series into myeloma and nonmyeloma paraproteinemias. On dividing the series according to the antigenic type of the light chains, IgA2 paraproteins with kappa light chains predominated over the lambda type (6 : 1).
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PMID:Distribution of subclasses in a series of 62 sera with IgA paraprotein. 376 10

A series of 20 bone marrow trephines biopsy and necropsy specimens were strained for IgA1 and IgA2 activity, together with total IgA, by means of an indirect immunoperoxidase technique using murine monoclonal antibodies applied to paraffin sections. The specimens showed normal histology and had been taken from patients not known to be suffering from haematological or related systemic disease. The IgA1, IgA2, and total IgA containing cells were counted and expressed as a percentage of all nucleate cells in the marrow cavities. Remarkably constant percentages of and ratios between these cell types were found. The same was true for a further 10 trephines taken from patients undergoing staging procedures for epithelial malignancies, where the marrow histology was normal. The pooled mean percentage of IgA1 containing cells from both groups was 1.18% of all cells, that for IgA2 containing cells 0.18%, and for total IgA positive cells 1.41%. In addition, 12 trephines containing known IgA producing myeloma were examined. Of these, 11 contained IgA1, the remainder contained IgA2 subclass.
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PMID:Distribution of IgA1 and IgA2 subclasses in normal bone marrow trephines and in trephines infiltrated by IgA producing multiple myeloma. 381 84

In this study we describe an ELISA using monoclonal antibodies to IgG 1, 2, 3, 4, IgA1 and IgA2 for determining the subclass distribution of human-specific antibodies. No cross-reactivity of the subclass-specific reagents under the conditions used was observed. The sensitivity was 0.5 ng/ml for IgG1, 3, 4; 1.5 ng/ml for IgG2 and 50 ng/ml for IgA1 and IgA2. The reproducibility as described by the coefficient of variation calculated on repeated runs was 8-26% if the data were obtained by relating the absorbance values to a positive serum run in the assay, 17-58% when relating the OD figures to those of a standard myeloma plate. The method may be considered semiquantitative with high sensitivity and specificity, easy to handle and with small day-to-day variation. The assay has been applied to a number of antigens of protein and polysaccharide nature.
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PMID:Enzyme-linked immunosorbent assay for subclass distribution of human IgG and IgA antigen-specific antibodies. 398 Oct 13


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