Genetic Variation of Costimulatory Molecules, Including Cytotoxic T-Lymphocyte Antigen 4, Inducible T-Cell Costimulator, Cluster Differentiation 28, and Programmed Cell Death 1 Genes, in Iranian Patients With Leukemia.

OBJECTIVES

There are limited studies about the possible relationship between genetic variations of costimulatory genes and susceptibility to hematologic malignancies like leukemia and lymphoma.

MATERIALS AND METHODS

This cross-sectional study included 59 leukemia patients. The polymorphisms of costimulatory molecules, including the CTLA-4 gene (-318 C/T, -1722 T/C, -1661 A/G, +49 A/G), PD-1 gene (1.3 A/G, 1.9 C/T), ICOS gene (1720 C/T), and CD28 gene (17 C/T), were analyzed by polymerase chain reaction-restriction fragment length polymorphism methods.

RESULTS

Our results showed that the TT genotype and T allele of the CTLA-4 -318 T/C polymorphism, the AA genotype of CTLA-4 +49 A/G polymorphism, and the CT genotype of PD-1 1.9 C/T polymorphism were significantly higher in healthy controls (P < .05). However, the AG genotype of the CTLA-4 +49 A/G, the CC genotype of the PD-1 1.9 C/T, and the CT genotype of the CD28 +17C/T polymorphism were significantly increased in patients with leukemia (P < .05). When the genotype frequency of costimulatory genes was compared between different leukemia groups, we observed that the A allele of the CTLA-4 +49 A/G and the CC genotype and C allele of the CD28 +17 C/T polymorphism were significantly higher in patients with acute leukemia than in those with chronic leukemia (P < .05). Among leukemia patients, the AA genotype of CTLA-4 +49A/G polymorphism was significantly increased in patients with acute myeloid leukemia, whereas the AG genotype was more prevalent in patients with acute lymphoblastic leukemia (P < .05).

CONCLUSIONS

We show for the first time that genetic variations of costimulatory molecules CTLA-4, CD28, and PD-1 may be associated with susceptibility of Iranian patients to leukemia.