In both sample matrix, we did not found any difference in enzyme levels or activity when comparing controls, mild and severe cases, similarly to Hung et al. 19, who also observed no differences in plasma MPO levels at 15-20 weeks gestation between healthy pregnant women and women who developed preeclampsia, thus suggesting that the increase in MPO observed by others15,16 after preeclampsia diagnosis may be a consequence instead of a trigger for the disorder. This evidence concerns the gene MPO and preeclampsia.