Validation of the Accuracy of Self-Reported ABO Blood Types in the Japan Nurses’ Health Study

Abstract

Background: The associations between ABO blood type and risk of diseases including cancer have been reported<br />from epidemiological studies. Self-reporting is one of the most widely used methods of collecting the ABO blood type<br />information. Verifying the accuracy of self-reporting is important to consider measurement errors. We aimed to conduct<br />validation of self-reported ABO blood types in the Japan Nurses' Health Study (JNHS), which is a large prospective<br />cohort study. Methods: The concordance rate between self-reported and serologically or genetically inferred ABO<br />blood groups was investigated for a subsample of 41 subjects from the Gunma Nurses' Health Study, which was a pilot<br />cohort study that preceded the JNHS. The presence of antibodies to A or B antigens in serum (serological test) and<br />allele types of the ABO gene (genotyping test) were determined by using frozen blood samples that were preserved<br />for approximately 7 years. ABO blood types were determined from these tests and compared with self-reported data.<br />Results: All of the nurses reported that their ABO blood groups were concordant with those determined by a serological<br />and/or genotyping test. Self-reported ABO blood types of 35 of 38 (92.1%) participants were consistent with the results<br />from serological typing, while the answers of three participants were not. In these three participants, ABO genotypes<br />that were inferred from genotyping of three single nucleotide polymorphisms in ABO loci perfectly matched with their<br />self-reported ABO types, and all of these were O-type. Conclusions: Japanese health professionals report their blood<br />type with a high degree of accuracy. Special attention should be paid to the O-type group in serological analysis of<br />blood samples that have been preserved for several years in longitudinal studies.