Association of transforming growth factor-β1 gene polymorphism with Visceral leishmaniasis in an Iranian population

Visceral leishmaniasis (VL) or Kala-azar is a parasitic disease caused by a protozoan of Leishmania genus and in Iran by Leishmania infantum. Cytokines have a major role in determining progression and severity of clinical manifestations in VL. The role of TGF-β1 in VL has been recognized since 1992. We investigated polymorphism in the TGF-β1 gene, which is a cytokine known to have a role in onset and severity of the disease. This descriptive and cross-sectional study was done on 85 pateints with confirmed VL, 106 healthy seronegative controls and 99 seropositive controls. Salting out method was used to extract DNA and the amplification refractory mutation system (AR1MS)-PCR procedure was used for detecting polymorphism at TGFβ1 (-509) C/T. The frequency of TGF-β1 CC, CT and TT genotypes among all subjects were 21.4%, 71% and 7.6% respectively. Statistical analysis of distribution of genotypes was performed using Chi-Square test and reveal a significant difference among groups (P = 0.00). To our knowledge this study demonstrates for the first time the association of the cytokine transforming growth factor-β1 gene polymorphism in Iranian patients with VL. Individuals with the transforming growth factor-β1 (-509) CT genotype may have increased susceptibility to Visceral leishmaniasis.