No Association ofIFNG+874T/ASNP andNOS2A-954G/CSNP Variants with Nitric Oxide Radical Serum Levels or Susceptibility to Tuberculosis in a Brazilian Population Subset

Abstract

Tuberculosis (TB) is one of the most common infectious diseases in the world.Mycobacterium tuberculosisinfection leads to pulmonary active disease in approximately 5–10% of exposed individuals. Both bacteria- and host-related characteristics influence latent infection and disease. Host genetic predisposition to develop TB may involve multiple genes and their polymorphisms. It was reported previously that interferon gamma (IFN-γ) and nitric oxide synthase 2 (NOS2) are expressed on alveolar macrophages from TB patients and are responsible for bacilli control; thus, we aimed this study at genotyping single nucleotide polymorphismsIFNG+874T/ASNP andNOS2A-954G/CSNP to estimate their role on TB susceptibility and determine whether these polymorphisms influence serum nitrite andNOx-production. This case-control study enrolled 172 TB patients and 179 healthy controls. Neither polymorphism was associated with susceptibility to TB.NOS2A-954G/CSNP was not associated with serum levels of nitrite andNOx-. These results indicate that variants ofIFNG+874T/ASNP andNOS2A-954G/CSNP do not influence TB susceptibility or the secretion of nitric oxide radicals in the study population.