ASSOCIATION OF LEWIS BLOOD-GROUP PHENOTYPES WITH URINARY-TRACT INFECTION IN CHILDREN

Many blood group antigens, genetically controlled carbohydrate molecul es, are found on the surface of uroepithelial cells and may affect bac terial adherence and increase the frequency of urinary tract infection (UTI) in adults. Sixty-two children aged 2 weeks to 17 years (mean, 2 .3 years) who were hospitalized with fever in association with UTIs ca used by Escherichia coli had complete (n = 50) or partial (n = 12) ery throcyte antigen typing to determine the role of erythrocyte antigens and phenotypes in UTI in children; 62 healthy children undergoing nonu rologic elective surgery, matched 1 to 1 for age, sex, and race to the patient group, formed the control group. In univariate tests, patient s and control subjects did not differ in ABO, Ph, P, Kell, Duffy, MNSs , and Kidd systems by the McNemar test of symmetry (p>0.05). the frequ ency of the Lewis (Le) (a-b-) phenotype was higher (16/50 vs 5/50; p = 0.0076) and the frequency of the Le(a+b+) phenotype was lower (8/50 v s 16/50; p = 0.0455) in the patient population than in the control sub jects. A stepwise logistic regression model to predict UTI with the ex planatory variables A, B, O, M, N, S, s, PI, Le(a), and Leb showed tha t only the Le(a) and Leb antigens entered the model with p<0.1. The Le (a-b-) phenotype was associated with UTI in this pediatric population. The relative risk of UTI in children with the Le(a-b-) phenotype was 3.2 (95% confidence interval, 1.3 to 7.9). Specific blood group phenot ypes in pediatric populations may provide a means to identify children at risk of having UTI.