Determination of anti-IgA antibodies with a flow cytometer-based microbead immunoassay (MIA).
A flow cytometer-based microbead immunoassay (MIA) was employed to detect anti-IgA antibodies in patients with IgA deficiency. 3 microns latex particles were coated with purified IgA and serum anti-IgA antibodies of the IgG class were detected with FITC-conjugated anti-human IgG. Antibodies against three different IgA preparations were tested from 22 patients samples as well as 20 controls and compared with a conventional enzyme-linked immunosorbent assay (ELISA) and a passive hemagglutination assay (HA). There was a very close correlation between the results obtained with the MIA and the ELISA assay and between MIA and the HA. Because of the low intra-assay variation and good linearity of the assay, the analysis of one single serum dilution was sufficient to determine the anti-IgA level of a patient and no titration series was required. We conclude that MIA is a satisfactory alternative method for routine anti-IgA antibody determinations. For laboratories already equipped with a flow cytometer the assay is cost effective.
Syrjälä
M T
MT
Finnish Red Cross Blood Transfusion Service, Helsinki, Finland.
Tölö
H
H
Koistinen
J
J
Krusius
T
T
D000361:Agammaglobulinemia / Q000276:immunology; D000888:Antibodies, Anti-Idiotypic / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005434:Flow Cytometry; D006386:Hemagglutination Tests; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007070:Immunoglobulin A / Q000276:immunology*; D008863:Microspheres
D000888:Antibodies, Anti-Idiotypic; D007070:Immunoglobulin A