LARGE-SCALE DNA TYPING FOR HUMAN PLATELET ALLOANTIGENS BY PCR-PHFA (PREFERENTIAL HOMODUPLEX FORMATION ASSAY)

Alloimmunization against human platelet alloantigens (TTPA) is known t o be involved in disorders such as neonatal alloimmune thrombocytopeni c purpura, posttransfusion purpura, and refractoriness to platelet tra nsfusion therapy. HPA typing is essential in diagnosis and management of patients. Therefore a reliable and speedy method is necessary for H PA typing. We have successfully applied a new DNA typing method, PCR-p referential homoduplex formation assay (PHFA) method, to typing for th e HPA-1, -2, -3, -4, -5 and -6 systems. This method is based on DNA st rand competition during hybridization under a precisely controlled tem perature gradient between a double-labelled amplicon (standard DNA), p repared from biotin- and DNP-labelled primers, and an unlabelled ampli con (sample DNA). The results obtained by PCR-PHFA typing were in good agreement with the allotypes determined by serological typing and by other DNA typing methods. The PCR-PHFA method can be easily automated, is suitable for typing both small and large numbers of samples, and t hus is applicable to routine HPA typing.