[Transfusion security].

Ten donors positive for antibodies to hepatitis C were discovered in the community of Aarhus after the introduction of screening of blood donors. These donors had donated blood products to 123 recipients. Of these recipients 76 were dead and 21 were not contacted for various reasons. Follow-up of anti-HCV status was performed in the remaining 26 recipients. Twenty-four (92%) of the recipients were positive in the RIBA confirmatory test, one was inconclusive and one was negative. Nine (90%) of the donors were hepatitis C virus RNA positive, while 17 (68%) of the recipients were HCV-RNA positive. Altogether (donors and recipients) 25 (76%) of the HCV-RNA positive patients had abnormal liver enzymes, while all HCV-RNA negative patients had normal enzyme levels. Eight of eleven HCV-RNA positive patients had an abnormal liver biopsy, while one patient in the HCV-RNA negative group had an abnormal liver biopsy. Three have been treated with interferon. In view of the liver damage already found only few years after transfusion, follow-up investigations in order to identify younger persons transfused with hepatitis C positive donations should be carried out and patients offered treatment if necessary. The National Board of Health has decided to recommend this strategy.

Blood Donors↗

PubMed1998

A novel single missense mutation identified along the RH50 gene in a composite heterozygous Rhnull blood donor of the regulator type.

Rare individuals who lack all of the Rh blood group antigens are called Rhnull and may be classified as "regulator" or "amorph" types. The suppression of Rh antigen expression for regulator types may be attributed to mutations of the RH50 gene, which is independent of the RH locus. The RH50 gene encodes a glycoprotein that interacts with the Rh proteins to form a functional complex within the red blood cell membrane. This report describes an RH50 gene mutation for a previously unclassified Rhnull donor. Sequencing cDNA clones from Rh50 mRNA revealed a single base change (G836A) yielding a missense and nonconservative mutation (Gly279Glu) within a predicted hydrophobic domain for this membrane protein. Genomic DNA studies using polymerase chain reaction (PCR) restriction analysis and sequencing showed that the Rhnull propositus was a composite heterozygote for this mutation, carrying two alleles with the A and G at nucleotide 836, respectively. In contrast, cDNA studies showed that only the A836 sequence was present, suggesting that the second allele with G836 was apparently silent (no transcript detected). Family studies showed that the mutant RH50 allele (836A) was inherited maternally, whereas the silent RH50 allele (836G) was from paternal transmission. These findings provide further evidence that rare but diverse genetic alterations may occur along the RH50 gene where the Rhnull syndrome of the regulator type occurs. The single amino acid change (Gly to Glu) provides insight into the critical value of these residues for assembly of the Rh antigen complex within the membrane.

Blood Donors↗