Toll-like receptor 9 polymorphism in patients with erythema multiforme, Stevens Johnson syndrome and Stevens Johnson syndrome/toxic epidermal necrolysis overlap syndrome

Background: "Toll like receptor" (TLR) 9 functions in stepping in of native immune system against different viral and bacterial pathogens and induction of adaptive immune response effectively. TLR 9 gene polymorphism makes host predisposed to microbial pathogens by affecting the functional capabilities of the receptor. Objective: We aimed to determine if TLR 9 gene polymorphism makes a predisposition to "erythema multiforme" (EM), "Stevens Johnson syndrome" (SJS) and "Stevens Johnson syndrome/toxic epidermal necrolysis overlap syndrome" (SJS/TEN). Methods: Forty-two patients clinically and/or histopathologically diagnosed as EM, SJS, and SJS/TEN overlap syndrome and 50 healthy control subjects were enrolled in our study. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was applied for TLR 9 gene 1237 thymine/cytosine (T/C) polymorphism. Genotypes were determined according to bands occurring on agarose gel electrophoresis. Results: In patients group, the frequencies of IT and TC genotypes were 73.8 % and 26.2 % while CC genotype wasn't detected. In control group, the frequencies of TT, TC and CC genotypes were 74 %, 24 %, and 2 %. There wasn't a statistically significant difference for TT, TC and CC genotypes between patients and controls. The frequencies of T and C alleles were 84.5 % and 15.5 % in patients and 86 % and 14 % in controls, respectively. Conclusion: Our results showed that there isn't any association between TLR gene polymorphism and EM, SJS, SJS/TEN overlap syndrome (Tab. 1, Fig. 1, Ref. 30)