ABSTRACT
Serologic ABO blood typing is routinely performed using anti-A and anti-B sera to distinguish four phenotypes (A, B, AB, and O). Restriction fragment length polymorphisms (RFLPs) and DNA sequence studies offer the possibility of direct ABO genotyping. We used polymerase chain reaction-RFLP analysis to determine the frequency of O(1) and O(2) alleles in 82 unrelated blood donors in São Paulo, Brazil, known to be group O. Genomic DNA was extracted from blood leukocytes by a modified salting-out method. Different genotypes (O(1)O(1), O(1)O(2), O(2)O(2)) were identified after digestion with restriction enzymes KpnI, HpaII, and AluI, followed by agarose gel electrophoresis. Of 82 samples analyzed, 74 were O(1)O(1), 7 were O(1)O(2), and 1 was O(2)O(2). These results showed the frequency of O(1)O(1), O(1)O(2), and O(2)O(2) genotypes to be 90.24 percent, 8.53 percent, and 1.22 percent, respectively, in blood donors in São Paulo, Brazil.
ABSTRACT
A 12-year-old Caucasian male with cystinosis received a kidney from his mother, whose red blood cells typed as group O, D+, E-. Her serum contained an anti-E with an IgG1 titer of 16 (score 31). The recipient's type was group O, D+, E+, with a negative antibody screen in the pretransplant period. The recipient and donor Rh phenotypes were most likely DCcEe and Dccee, respectively. Because the recipient's mother had no transfusion history, she was probably immunized by the fetal red blood cells of her one pregnancy (the recipient). The kidney had been immediately perfused with saline after removal from the donor. No acute or delayed hemolysis was observed clinically or in laboratory tests performed immediately after the transplant and at 7, 15, and 30 days after the transplant. Antibody screens were still negative at 6 months. In this case, anti-E was not present in the transplanted kidney in sufficient concentration to cause hemolysis of the recipient's red blood cells and transplanted lymphocytes did not synthesize sufficient anti-E to be detectable or to cause hemolysis.
