We observed that GSTT1-null genotype is associated with lymphocytopenia (OR = 17.67, CI = 1.23–252.73, p-value = 0.034) and GSTP1 rs1695 G/G genotype is associated with increased infections (OR = 12.25, CI = 1.05–143.09, p-value = 0.046). This evidence concerns the gene GSTP1 and infection.