Genetic markers of predisposition to oral lichen planus recurrence development

Aim. To search for genetic markers of oral lichen planus development and recurrence risk based on the study of polymorphic variants of tumor necrosis factor α (TNFα rs1800630, rs1800629, rs361525) and interleukin-18 (IL-18 rs187238) genes in patients from the Volga-Ural region of Russia.

Methods. Standard methods of molecular genetic analysis were used in the study. Deoxyribonucleic acid was isolated from peripheral blood lymphocytes by deproteinization with phenol and chloroform. Genotyping of studied polymorphic loci was performed by real time polymerase chain reaction using TaqMan-competing probes. In order to identify the association of polymorphic loci in different models (additive, dominant, recessive, overdominant) the method of logistic regression was used.

Results.. Statistical analysis using logistic regression revealed that polymorphic locus rs187238 in IL-18 gene is associated with the risk of lichen planus development in a recessive model (p=0.042). In addition, the association of a polymorphic locus rs187238 in IL-18 gene with the recurrence risk was described: rs187238*C/C genotype is a genetic marker of increased risk of oral lichen planus recurrence (p=0.01). Analysis of the association of polymorphic loci rs1800630, rs1800629, rs361525 in tumor necrosis factor α gene with the disease severity and the recurrence risk did not reveal any statistically significant results.

Conclusion. The study results confirm the cytokine genes contribution to the oral lichen planus development and disease reccurrence.