CTLA-4 Gene Polymorphism in +49 A/G Position: A Case Control Study on Patients with Oral Lichen Planus

BACKGROUND: Oral lichen planus (OLP) is a premalignant mucocutaneous disease in which genetic factors and immune responses play a major role. Cytotoxic T Lymphocyte Antigen-4 (CTLA-4) is a co-inhibitory molecule that down-regulates immune responses to prevent autoimmunity. This study aimed to investigate the relationship between polymorphism of the CTLA-4 gene in +49 A/G position and OLP. MATERIALS AND METHODS: Thirty-five patients with OLP (16 males, 19 females, with a mean age of [± standard deviation (SD)] 55.92 [± 12.83]) and 105 sex- and aged-matched healthy subjects (48 males, 57 females, with a mean age of [± SD] 56.82 [± 14.71]) were recruited in this study. Genomic DNA of both groups was extracted from white blood cells and then CTLA-4 genotypes and allele frequencies were investigated using polymerase chain reaction-restriction fragment length polymorphism methods. The data were collected and examined using Pearson’s Chi square test (SPSS version 11.5). RESULTS: In the patient group, AA, AG, and GG genotypes occurred in position 49 A/G in the CTLA-4 gene with the frequency of 19 (55.9%), 11 (31.4%), and 3 (8.8%), respectively. With respect to the control group, they occurred with the frequency of 58 (55.2%), 39 (37.1%), and 8 (7.6%), respectively. As far as the frequency of A and G alleles in this position was concerned, we had, respectively, 49 (74.24%) and 17 (25.75%) for patients and, respectively, 155 (73.80%) and 55 (26.19%) for the control group. The calculated values were not significantly different between these groups (P > 0.05). CONCLUSION: Polymorphisms of CTLA-4 genes in position +49 A/G did not show any significant relationship with each other in OLP patients in Shiraz, Iran.