Ctla-4 gene polymorphism in +49 a/g position: a case control study on patients with oral lichen planus

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.

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).

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).

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.