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

BACKGROUND: The Kidd blood group system has three antigens, Jka , Jkb 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: Jka and Jkb 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; Jka and Jkb antigens and phenotypes were not found to be related to susceptibility for chronic kidney disease.