Rural-urban comparisons of anti-glycan antibody responses. (a,e) Box-and-whisker plots showing background-subtracted and log2-transformed median fluorescence intensities (MFI) representing IgE and IgG reactivity to individual α3Fuc- and/or β2Xyl-carrying Man3GlcNAc2 core structures in rural versus urban participants. 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. Mann-Whitney (IgE responses) and unpaired t test (IgG responses) were conducted within the framework of a Monte Carlo simulation algorithm based on 1000 permutations, to assess differences between rural and urban individuals. (b,f) First and second principal component loadings of N-glycan-specific IgE and IgG responses among all participants, irrespective of survey setting. (c,d,g,h) Box-and-whisker plots showing comparison of PC1 and PC2 scores between rural and urban individuals. Associations between PC scores and survey setting were assessed by linear regression 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. *p < 0.05; **p < 0.01; ***p < 0.001. PC1: Principal Component 1; PC2: Principal Component 2.