An enzyme-linked immunosorbent assay applicable to screen blood donors for IgA deficiency.
OBJECTIVE
In order to build panels of IgA deficient blood donors, an assay is described that is sensitive, inexpensive and easily adaptable to the automated sample processors and turnaround times of blood banks.


METHODS
We developed a two-step enzyme-linked immunosorbent assay (ELISA) carried out in microwell plates coated with rabbit anti-human IgA antibody. Captured IgA was revealed with the same antibody conjugated to horseradish-peroxidase. The assay was adapted to the automatic pipetting system and ELISA processors used in routine blood donor screening.


RESULTS
The assay sensitivity was 0.1 microg/mL. Intra-assay coefficient of variation (CV) for IgA concentrations between 0.1 and 100 microg/mL ranged from 0.69% to 3.80%. The median interassay CV was 3.05% (range: 1.2-7.9%). Coated plates can be stored frozen for at least 3 months without any loss in performance. The assay takes around 80 min to be performed. By using this ELISA we found 32 IgA-deficient individuals among 20,000 blood donors (prevalence 1:625).


CONCLUSIONS
The ELISA has a good sensitivity, is reproducible, precise and timesaving. It is easily adaptable to the automated sample processors and operating procedures used in blood banks. This facilitates the building of panels of IgA-deficient blood donors.
Sanz
C
C
Service of Hemotherapy and Hemostasis, Hospital Clínico, Villarroel 170, 08036 Barcelona, Spain. csanz@medicina.ub.es
Freire
C
C
Ordinas
A
A
Pereira
A
A
D001331:Automation; D001782:Blood Donors; D004797:Enzyme-Linked Immunosorbent Assay / Q000295:instrumentation / Q000379:methods*; D005188:False Negative Reactions; D006801:Humans; D017098:IgA Deficiency / Q000097:blood* / Q000175:diagnosis; D008403:Mass Screening; D012680:Sensitivity and Specificity