GSTM1 and TNF-α gene polymorphisms and relations between blood lead and inflammatory markers in a non-occupational population

Inflammation is known to be an important underlying condition in the development of a variety of diseases. To investigate whether blood lead induces inflammatory reactions in non-occupationally exposed adults and the effects of genetic susceptibility associated with GSTM1 and TNF-α gene polymorphisms on this inflammatory response, we measured blood lead levels in 300 healthy university students. Total serum TNF-α and IL-6 levels and WBC counts were determined to evaluate the inflammatory response. Allelic loss of GSTM1 and the TNF-α–308 G > A polymorphism were determined by PCR and RFLP. Positive relations between blood lead and three inflammation biomarkers were shown in male subjects with blood lead ≥2.51 μg/dl (median value) (TNF-α, p = 0.015; IL-6, p = 0.082; and WBC, p = 0.044). However, subgroup analysis by genotype showed an effect of blood lead on the three biomarkers only in individuals with the GSTM1 null (TNF-α, p = 0.020; IL-6, p = 0.096; and WBC, p = 0.017) or TNF-α GG (TNF-α, p = 0.017; IL-6, p = 0.088; and WBC, p = 0.095) genotype, and not in individuals with GSTM1 present (all three inflammatory biomarkers, p > 0.1) or the TNF-α GA or AA (all three biomarkers, p > 0.1) genotype. These results suggest that blood lead affects the inflammatory response and that GSTM1 and TNF-α gene polymorphisms are genetic factors associated with lead-induced inflammatory response.