Association of Lewis blood group phenotypes with urinary tract infection in children.

Many blood group antigens, genetically controlled carbohydrate molecules, are found on the surface of uroepithelial cells and may affect bacterial 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 caused by Escherichia coli had complete (n = 50) or partial (n = 12) erythrocyte antigen typing to determine the role of erythrocyte antigens and phenotypes in UTI in children; 62 healthy children undergoing nonurologic elective surgery, matched 1 to 1 for age, sex, and race to the patient group, formed the control group. In univariate tests, patients and control subjects did not differ in ABO, Rh, P, Kell, Duffy, MNSs, and Kidd systems by the McNemar test of symmetry (p > 0.05). The frequency 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 vs 16/50; p = 0.0455) in the patient population than in the control subjects. A stepwise logistic regression model to predict UTI with the explanatory variables A, B, O, M, N, S, s, Pl, Lea, and Leb showed that only the Lea 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 phenotypes in pediatric populations may provide a means to identify children at risk of having UTI.

Relationship among vesicoureteral reflux, P-fimbriated Escherichia coli, and acute pyelonephritis in children with febrile urinary tract infection.

Ninety-four children with febrile urinary tract infection were studied prospectively to determine the relationship between vesicoureteral reflux, P-fimbriated Escherichia coli, and acute pyelonephritis, and to evaluate the diagnostic reliability of commonly used clinical and laboratory observations. By using renal scan with dimercaptosuccinic acid labeled with technetium 99m as the standard of reference, we documented acute pyelonephritis in 62 (66%) of 94 patients. Vesicoureteral reflux was demonstrated in 29 (31%) of the total group and in only 23 (37%) of 62 patients with pyelonephritis. Of the 70 E. coli urinary isolates, 48 (69%) were P-fimbriated, including 30 (64%) of 47 isolates from patients with pyelonephritis and 18 (78%) of 23 isolates from patients with normal renal scans. The prevalence of P-fimbriated E. coli in patients with pyelonephritis and vesicoureteral reflux was 46%, compared with 71% in those with pyelonephritis who had no concurrent vesicoureteral reflux (p = 0.222). Multiple clinical and laboratory variables commonly used in the diagnosis of acute pyelonephritis did not adequately predict the presence or absence of parenchymal involvement. These data show the following: (1) Acute pyelonephritis in the absence of demonstrable vesicoureteral reflux is common. (2) Febrile urinary tract infections in children are commonly associated with P-fimbriated E. coli, both in the presence and absence of vesicoureteral reflux. (3) The presence of P fimbriae alone does not fully explain the pathophysiology of renal parenchymal invasion by bacteria in the absence of vesicoureteral reflux. (4) The diagnosis of acute pyelonephritis in children with febrile urinary tract infections on the basis of clinical and laboratory observations is unreliable.