Lack of association between Kidd blood group system and chronic kidney disease

BACKGROUND: The Kidd blood group system has three antigens, Jk(a), Jk(b) and Jk3, found on red blood cells and on endothelial cells of the inner lining of blood vessels in the renal medulla. These are known as urea transporter B (UT-B). Researchers have found that individuals carrying the Jk(a − b−) or Jk-null (UT-B null) phenotypes have a lower urine-concentrating capability and risk of severe renal impairment. This study evaluated the distribution of the Kidd phenotypes in patients with chronic kidney disease and a possible association of Kidd antigens with the development of renal disease. METHODS: Jk(a) and Jk(b) antigens were phenotyped using the gel column agglutination test (ID-cards Bio-RAD) in 197 patients with chronic kidney disease and 444 blood donors, as the control group. The phenotype and antigen frequencies between patients and controls were evaluated using the Chi-square method with Yates correction and logistic regression after adjustments for gender and age. RESULTS: No differences were observed between the Kidd phenotypes frequency distribution between patients with chronic kidney disease and blood donors [Jk(a − b+) = 22.3% and 27.2%; Jk(a + b−) = 30.5% and 24.3%; Jk(a + b+) = 47.25% and 48.4%, respectively]. CONCLUSION: The distribution of Kidd phenotypes found in the studied population is expected for Caucasians; Jk(a) and Jk(b) antigens and phenotypes were not found to be related to susceptibility for chronic kidney disease.