IL4 and bacterial vaginosis: Furthermore, our data showed that the IL-4, IL-5, IL-13, and IL-17 protein expression levels in the sera of the PM2.5 + BV group were significantly decreased compared with those of PM2.5 induced rats (2.916 ± 0.310, 3.750 ± 0.380, 0.179 ± 0.027, 2.667 ± 0.895; P = 0.034, P < 0.001, P = 0.044).