Background: Tuberculosis (TB) is an acute or chronic bacterial infection caused by Mycobacterium tuberculosis. It primarily affects the lungs, but may spread to other organs (extra-pulmonary TB).

Objectives: Studies have shown that genetic predisposition can decrease the persistence and growth of M. tuberculosis. The current study highlights the effect of CTLA-4 (+49A/G) gene polymorphism on the risk of TB.

Patients and Methods: This case-controlled study used tetra-primer amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) to analyze theCTLA-4 (+49A/G) gene polymorphism in 100 patients with TB and 91 healthy individuals.

Results: Data analysis indicated that the frequencies of AA, AG and GG genotypes were 42%, 38%, and 20% in patients with TB and 43%, 47%, 1% in the control subjects, respectively. The GG genotype of CTLA-4 (+49A/G) showed a significantly increased risk of disease (OR = 20.48; 2.63-159.60)

Conclusions: The results revealed a significant relationship between the GG genotype of CTLA-4 and the increased risk of TB.