A uniform method for the simultaneous blood group phenotyping of Fya, Fyb, Jka, Jkb, S, (s)over-bar, P1, k applying lateral-flow technique

Background and Objectives A lateral flow assay for simultaneous blood group typing of ABO, RhD, C, E, c, e, Cw and K with stable end-point and without centrifugation is in routine use since several years (MDmulticard (R)). The typing of extended phenotype parameters belonging to the Duffy, Kidd, MNSs blood group systems and others, however, has not yet been demonstrated for this technique. Reliable detection of Fy(x), a weak Fy(b) phenotype with a pronounced quantitative reduction of the number of Fy(b) antigens on the erythrocyte surface, remains a weakness of current serological blood grouping techniques. Material and Methods The performance characteristics of the following reagents were evaluated in donor and patient samples in lateral flow technology (MDmulticard (R)): Anti-Fy(a), -Fy(b), -Jk(a), -Jk(b), -S, (s) over bar, -P1 and -k. The sensitivity to detect Fy(x) was in addition evaluated with Fy(x) positive samples, which had been preselected by MALDI-TOF MS-based genotyping. ResultsAll results obtained with the MDmulticard((R)) were in full accordance with those of the CE-certified reference products for all the eight reagent formulations used: Anti-Fy(a), -Fy(b), -Jk(a), -Jk(b), -S, (s) over bar, -P1 and -k. Also, all Fy(x) phenotypes of the selected population of 93 positive samples, originally identified by MALDI-TOF MS-based genotyping, were reliably detected by the lateral flow assay. Conclusion Extended phenotype blood group parameters, including the serologically challenging Fy(x) phenotype, can be determined simultaneously, rapidly and accurately using the lateral flow (MDmulticard((R))) technology, even in cases when IgG class antibodies are the only source of diagnostic antibodies.