Principal component analysis of anti-glycan antibody responses. Scatterplots of first (PC1) and second factor (PC2) loadings derived from principal component analysis of IgE and IgG responses to 135 synthetic N-glycans. Box-and-whisker plots show comparison of PC1 and PC2 scores between S. mansoni infected and uninfected individuals. The plots show a horizontal line denoting the median, a box indicating the interquartile range (IQR), and whiskers drawn using the Tukey method (1.5 times IQR). Outliers (greater than 1.5 times IQR away from the median) are plotted as individual points. Panels a and b show IgE and IgG profiles, respectively, among rural participants. Panels c and d show IgE and IgG profiles, respectively, among urban participants. Associations between factor loading scores and S. mansoni infection and intensity were assessed by linear regression analysis in Stata 13.1. Crude and age- and sex-adjusted p values are shown for significant associations. All analyses were adjusted for survey design using the ‘svy’ command in Stata. PC1: Principal Component 1; PC2: Principal Component 2; Sm: S. mansoni infection determined by detection of eggs in a single stool sample by Kato-Katz and/or PCR (rural infected n = 84, uninfected n = 113; urban infected n = 6, uninfected n = 42); CCA: S. mansoni infection determined by a positive urine circulating cathodic antigen (CCA) result (rural infected n = 118, uninfected n = 81; urban infected n = 21, uninfected n = 37).