Rapid detection of antibodies to immunoglobulin A molecules by using the particle gel immunoassay.
OBJECTIVE
Antibodies to immunoglobulin A (IgA) molecules are thought to be frequently responsible for anaphylactic reactions in transfusion medicine, but practical tests for the detection of antibodies to IgA are not yet available.


METHODS
Red, high-density polystyrene beads were coated with purified IgA molecules and then used to test serum samples collected from unselected healthy blood donors (n = 105) and patients with common variable immunodeficiency and/or IgA deficiency (n = 44). For testing, the standard gel-agglutination technique (ID-Micro Typing System) was employed.


RESULTS
None of the normal serum samples were reactive with IgA-coated beads and samples from only 10 patients were positive (titre range 1 : 2 to 1 : 256). Only one out of all patients studied had a history of an anaphylactic reaction and this was related to the administration of Rh(D) prophylaxis (anti-D immunoglobulin). The beads did not show non-specific agglutination and could be used repeatedly for longer than 6 months. The results were reproducible in all patients tested.


CONCLUSIONS
The new test allows a specific and rapid detection of antibodies to IgA molecules. In order to evaluate the clinical relevance of the test, analysis is required of a wider range of antibodies that produce anaphylactic reactions.
Salama
A
A
Blood Bank, Charité, Campus Virchow-Clinic, Berlin, Germany. abdulgabar.salama@charite.de
Schwind
P
P
Schönhage
K
K
Genth
R
R
Cotting
C
C
Hustinx
H
H
Krieg
R
R
Nydegger
U
U
Aebischer
I
I
D000328:Adult; D000888:Antibodies, Anti-Idiotypic / Q000097:blood*; D002648:Child; D002850:Chromatography, Gel; D017074:Common Variable Immunodeficiency / Q000097:blood / Q000188:drug therapy; D005260:Female; D006801:Humans; D017098:IgA Deficiency / Q000175:diagnosis* / Q000188:drug therapy; D007118:Immunoassay / Q000379:methods; D007070:Immunoglobulin A / Q000276:immunology; D016756:Immunoglobulins, Intravenous / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D008863:Microspheres; D008875:Middle Aged; D013997:Time Factors
D000888:Antibodies, Anti-Idiotypic; D007070:Immunoglobulin A; D016756:Immunoglobulins, Intravenous; C049937:anti-IgA