COMPARISON OF SOLID-PHASE ANTIBODY SCREENING-TESTS WITH POOLED RED-CELLS IN BLOOD-DONORS

Solid-phase systems are very sensitive for detection of erythrocyte al loantibodies in serum and suitable for large scale donor screening. Se rum samples of 10,008 blood donors were screened by three solid-phase tests (Capture R Ready Screen, Solidscreen II, and Solidscreen II-Dono r) with pooled red cells derived from two donors. The prevalence of an tierythrocyte IgG and IgM antibodies in donor sera was 0.56% (IgG anti bodies: 0.42%). The test efficiency for IgG antibodies was 1.40 with C apture R Ready Screen (test sensitivity 97.6%, test specificity 99.39% ), 1.78 with Solidscreen II (95.1, 99.88%), and 1.95 with Solidscreen II-Donor (92.7, 99.98%). The IgG antibody titers differed significantl y between all tests including a gel matrix test: Capture R > ID-Gel > Solidscreen II > Solidscreen II-Donor. Previously characterized antibo dies that were not detected after long-term follow-up by any of the th ree solid-phase tests had a prevalence of 0.10%. All three solid-phase tests detected the alloantibodies, which were of higher titers and co nsidered clinically relevant in blood components. The significant diff erence in antibody titers between the tests was not matched by a simil ar variance in the detection of donors with antibodies. Even with sens itive solid-phase tests, many antibodies may not be detected after lon g-term follow-up.