Interleukin-18 in Lichen Planus: A clinical, genetic and biochemical study

Abstract

Background: Lichen planus (LP) represents aninflammatory mucocutaneous disorderof unclear aetiology.Interleukin-18 (IL-18) is a pleiotropic immune-regulatory cytokine. IL-18 serum level and single nucleotide polymorphism (SNP) were reported to be associated with many immune-inflammatory disorders, but little is recognisedregarding their role in LP. Objectives: to investigate IL-18 gene polymorphism (607C/A and 137G/C) and IL-18 serum level in a trial of LP patients in Egyptian population and to correlate their results with the clinical aspects of LP in the studied cases. Methods:This case control study included 38 LP patients and 19 controls. IL-18  serum levels by ELISA and IL-18(607C/A) and (137G/C)SNPsbyPCR-RFLPtechnique were done.Results: IL-18 serum level had significant high concentrationsin LP patients than controls (p=0.03). IL-18 607 C/A genotypes CA and AA, and allele A were significantly observed in LP patients than controls increasing the risk of developing LP by 7, 13 and 3 times (P=0.04, OR=6.9) (P=0.02, OR=13.0) (P=0.02, OR=2.5), respectively. However, IL-18 137 G/C genotypes and alleles distribution showed non-significant differences among the studied groups. Both IL-18 607 C/A and IL-18 137 G/C genotypes showed non-significant associations with serum ranks of IL-18 in LP patients.Study limitations: The small number of the studied subjects. Conclusions: IL-18 may play an active role in the disease processof LP and its targeting may have appraising effects in clinical application in LP management.IL-18 607 C/A gene polymorphism might contribute to development of LP in Egyptian population.