Toll-like receptor 3 gene polymorphisms in Japanese patients with Stevens–Johnson syndrome

Background and aim: Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are acute-onset mucocutaneous diseases induced by infectious agents and/or inciting drugs. Given the association between the onset of SJS/TEN and infections, the possibility that there is an association between SJS/TEN and a disordered innate immune response was considered. The first line of defence against infection is comprised of evolutionarily conserved sets of molecules, the Toll–like receptors (TLRs). TLR3 recognises double-stranded RNA associated with viral infections. Methods: The Japanese single-nucleotide-polymorphism (JSNP) database reports 7 polymorphisms consisting of 7 SNPs in the human TLR3 gene; 3 of the 7 SNPs are coded in exon regions, (ie, 293248A/G, 293391A/G and 299698T/G), and the other 4 are coded in intron regions, (ie, 294440G/C, 294732C/T, 208036T/C and 298054C/T). These 7 SNPs were analysed in 57 Japanese patients with SJS/TEN with ocular surface complications and in 160 Japanese healthy controls. Results: SNP 299698T/G and the genotype patterns of 293248A/A and 299698T/T were strongly associated with SJS/TEN. Conclusion: The results suggest that polymorphisms in the TLR3 gene could be associated with SJS/TEN in the Japanese population.