Polymorphism of rs2076530 allele in BTNL2 gene in patients with skin sarcoidosis compared to skin sarcoidal reaction and normal skin: A case-control study

Background: In 10-30% of the cases with sarcoidosis, skin lesions appear solely without any systemic signs or symptoms. BTNL2 gene, which is a member of the immunoglobulin gene super family and is associated with CD86 and CD80 co-stimulatory receptors, is identified to play an important role in the establishment of sarcoidosis. We aimed to evaluate the role of this gene in patients with skin sarcoidosis in comparison with skin sarcoidal reaction patients and those with normal skin. Methods: The nucleotide sequence of rs2076530 allele in exon 5 of BTNL2 gene was compared among the paraffin-embedded blocks of 34 patients with a histologic diagnosis of sarcoidosis, 14 patients with skin sarcoidal reaction (tattoo, foreign body), and 27 patients with normal skin (excised during cosmetic surgery) using polymerase chain reaction. Results: There was no statistically significant difference in the frequency of 3 genotypes of AA, AG, and GG in rs2076530 allele among skin sarcoidosis, skin sarcoidal reaction, and normal skin. Conclusion: The expression of rs2076530 allele of BTNL2 gene in skin sarcoidosis or sarcoidal reaction does not differ with its expression in the normal skin.