Tumor necrosis factor-α and interleukin-1β gene polymorphisms and risk of brain abscess in North Indian population.
OBJECTIVE
Brain abscess develops in response to a parenchymal infection with pyogenic bacteria. Tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) are the most crucial pro-inflammatory cytokines with both beneficial and destructive properties for the central nervous system. The present study evaluated the association of specific alleles/genotypes of TNF-α and IL-1β with brain abscess.


MATERIAL AND METHODS
A total of 90 brain abscess patients and 100 healthy controls were included in the study. Predisposing factors were identified in 56 (62.2%) patients with brain abscess. TNF-α (-308 G>A) and IL-1β (-511 C<T) genotypes were detected by PCR-RFLP. Levels of TNF-α and IL-1β were determined in patients' sera and in pus samples by ELISA and correlated with different genotypes.


RESULTS
TNF-α genotypes AA and GA (p<0.001 for AA and p=0.001 for GA), and IL-1β genotypes C/C and C/T (p<0.001 for C/C and p=0.049 for C/T) were significantly associated with brain abscess. Homozygous AA genotype of TNF-α had significant association with brain abscess patients having identified predisposing factors (p=0.026). Patients with heterozygous or homozygous A allele in TNF-α (-308 G>A) and C allele in IL-1β (-511 C<T) had significantly higher levels of TNF-α and IL-1β.


CONCLUSION
TNF-α (-308 G>A) and IL-1β (-511 C<T) polymorphisms that lead to increased production of TNF-α and IL-1β appear to be risk for development of brain abscess in North Indian population.