Children with the Le(a+b-) blood group have increased susceptibility to diarrhea caused by enterotoxigenic Escherichia coli expressing colonization factor I group fimbriae

Abstract

Recent studies have shown that children with blood group A have increased susceptibility to enterotoxigenic Escherichia coli (ETEC) diarrhea and that Lewis blood group "a" antigen (Le(a)) may be a candidate receptor for ETEC colonization factor (CF) antigen I (CFA/I) fimbriae. Based on these findings, we have attempted to determine if children with the Le(a+b-) phenotype may be more susceptible to diarrhea caused by ETEC, in particular ETEC expressing CFA/I and related fimbriae of the CFA/I group, than Le(a-b+) children. To test this hypothesis, we have determined the Lewis antigen expression in 179 Bangladeshi children from a prospective birth cohort study in urban Dhaka in which ETEC expressing major CFs such as CFA/I, CS3, CS5, and CS6 was the most commonly isolated diarrhea pathogen during the first 2 years of life. The Lewis blood group phenotypes were determined by a dot blot immunoassay using saliva samples and by a tube agglutination test using fresh red blood cells. The results indicate that Le(a+b-) children more often had symptomatic than asymptomatic ETEC infections (P < 0.001), whereas symptomatic and asymptomatic ETEC infections were equally frequent in Le(a-b+) children. We also show that children with the Le(a+b-) blood type had significantly higher incidences of diarrhea caused by ETEC expressing fimbriae of the CFA/I group than Le(a-b+) children (P < 0.001). In contrast, we did not find any association between the Lewis blood group phenotype and diarrhea caused by ETEC expressing CS6 or rotavirus.

FIG. 1.

Association between Lewis blood groups and symptomatic (Symp) and asymptomatic (Asymp) ETEC infections. The chi-square test was used to compare the symptomatically and asymptomatically infected children with different blood groups.