SummaryThe genotypes of the ABO blood group system were investigated in Korean living in

Genotypes of the ABO blood group system were studied by PCR-RFLP analysis of the eight polymorphic nucleotide positions (nps) 261, 467, 526, 646, 703, 796, 802 and 803 of the cDNA from A transferase. In 169 unrelated German individuals, 17 genotypes were found and the calculated allele frequencies of A(Pro), A(Leu), B, O(T), O(A) and O2 were 0.2130, 0.0770, 0.0473, 0.4260, 0.2160 and 0.0207, respectively. These frequency data may provide useful additional information for disputed paternity and stain testing. A variant O allele, O2, was fout at a polymorphic frequency. As the nucleotide (np 261) of the O2 allele is the same as that of A and B alleles, the analysis of at least three nucleotide positions, i.e. nps 261, 526 and 802, is necessary to avoid mistyping of the ABO genotype.

The nucleotides (nt) at positions 467 and 646 of the ABO blood group system were analyzed in a Japanese population by means of the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) methods. Two types at nt467, tentatively designated ‘Pro’ and ‘Leu’, were found in the common A (=A¹) alleles, and two types at nt646 named ‘T’ and ‘A’ were found in·alleles. The types at nt467 of B and·alleles were Pro and those at nt646 of A and B alleles were T. Therefore, A alleles were divided into A(Leu) and A(Pro) suballeles and·alleles were divided into O(T) and 0(A). The allele frequencies in the present survey were calculated as ABO*A(Pro) = 0.0712, ABO*A(Leu) = 0.2163, ABO*B = 0.1779, ABO*O(T) = 0.2731 and ABO*O(A) = 0.2615. No O² (or O₍₃₎) allele was observed in the population samples. At least five alleles with polymorphic frequencies and 15 genotypes are present in the Japanese sample.

The genotyping of ABO blood groups was performed using the polymerase chain reaction (PCR) method. The 4 DNA fragments containing the nucleotide position 261, 526, 703 and 796 of cDNA from A-transferase were amplified by PCR, and the amplified DNA subjected to restriction fragment length polymorphism (RFLP) analysis. The different nucleotide at position 803 was clearly distinguished by electrophoresis of the PCR products amplified with allele-specific primers. By analyzing the electrophoresis patterns, ABO genotyping was conclusively accomplished. The frequencies of ABO genotypes found in Japanese blood donors with A and B phenotypes were as follows: in the phenotype A group, AA = 19.8% and AO = 80.2%; and in the phenotype B group, BB = 12.8% and BO = 87.2%.

SUMMARYNeutrophils activated by soluble parliculate stimuli generate superoxide anion and subsequently form hydrogen peroxide and other oxygen radicals. The effect o\' hydrogen peroxide on the complement system in normal serum was investigated. Treatment of normal serum with hydrogen peroxide resulted in a diminution ofthe haemolytic activity ofthe total and alternative complement pathways and the haemolytic titres of C3 and C^ but not of C2. in normal scrum. These decreases in complcEiient aclivity depended on the conccntraiion of hydrogen peroxide added to the serum. Immunoelectrophoretic analysis of hydrogen peroxide-treated serum showed ihat C3 and C5 proteins were activated. Complemeni degradation products C3a and C5a were produced in normal serum treated with hydrogen peroxide, and 20 mM EDTA abolished C3a and C5a production in hydrogen peroxide-treated scrum but 20 mM Mg-EGTA did not, Cataiase completely abolished and dimethylsulphoxidc and t>-mannitol. hydroxyl radical scavengers, partially inhibited the hydrogen peroxide-mediated complement activation. Hypochlorite. ineubated with normal serum, significantly inhibited scrum haemolytic activity, and sodium thiosulphale. a reducing agent, abolished the effect of hypochlorite. Nonnal scrum incubaled with activated neutrophils showed neutrophil chemotactic activity and decreased serum haemolytic activity, and the addition of catalase or mcthionine (5 niM) completely abolished the elTects of activated neutrophils. These results suggest that hydrogen peroxide activates complement via an alternative pathway of complement activalion and that hydroxyl radicals and other hydrogen peroxide-related species such as hypochlorite are most likely involved in hydrogen peroxidc-mcdialcd complement activation. Complement aclivation by oxygen radicals produced by activated nentrophils may be one of the mechanisms by which complement is activated in human immune complex diseases. Keywords hydrogen peroxide hypochlorite complement aetivation neutrophils[NTRODUCTION The aclivation of the complement system by immune eomplexes via the classical pathway may be involved in initiating and sustaining the inllammatory process and subsequent tissue injury in immune complex diseases such as systemic lupus erylhematosus (SLF.) and rheumatoid arlhritis (RA), The aclivation of complement at sites of immune complex deposition in tissue plays an important role in the pathogenesis of vascular injury in such diseases. Complement fragments generated from the native complement components following aetivation of complement, arc biologically active, act as inflammatory mediators and produce tissue damage by stimulating the