Rare Blood Group p [Tj(a-)] Among the Northeastern-Thai Population : A Report of Two Cases Over 20 Years

Abstract

Abstract : Blood group p (pp) or Tj(a-) is a very rare blood type which belongs to the P system. The frequency of p blood group is very rare. The gene frequency of p is <001. The p blood group is most clinically significant since the serum of p individual contains naturally occuring hemolytic anti-PP₁P^k, which induces spontaneous abortions during early pregnancy, hemolytic disease of the newborn, and severe hemolytic transfusion reactions. We report two cases of the p blood group with anti-PPP found among the northeastern-Thai population. The first case was found in 1985 in a nine year old boy suffering with residual poliomyelitis. The second patient was found in 1993 in a 24 year old first time pregnant woman, who had bleeding due to an incomplete abortion. This report is the first report of p (pp) blood type among the Thai population, which was found over 20 years (1976-1997) of service at the Blood Transfusion Centre, Faculty of Medicine, Khon Kaen University, Thailand.