GSTT1 and GSTM1 polymorphisms with human papillomavirus infection in women from southern Brazil: a case-control study

Important risk factors for the most common sexually transmitted infection (STI) in the world, human papillomavirus (HPV), include early sexual activity, use of contraceptives, tobacco smoking, and immunological and genetic factors. This study aimed to investigate the relationship between GSTM1 and GSTT1 polymorphisms and HPV infection and associated risk factors in a group of women assisted in the public health system of southwestern Paraná, Brazil.

A case-control study was designed with 21 women with HPV matched by age in the case group and 84 women without the virus in the control group. Viral detection was conducted via polymerase chain reaction (PCR) and GSTM1 and GSTT1 genotyping by Multiplex PCR. The results showed that the GSTT1 null allele was a protective factor against infection (OR_adj 0.219; 95% CI 0.078-0.618; p = 0.004). No relationship was observed for the GSTM1 gene. Smoking was defined as a risk factor (OR_adj 3.678; 95% CI 1.111-12.171; p = 0.033), increasing the chances of HPV by up to 3.6 times.

This study showed, for the first time, the relationship between GSTM1 and GSTT1 genetic polymorphisms and HPV. We found that this relationship protected women from southern Brazil from viral infection, but not from susceptibility.