Tissue Retinol-Binding Protein 4 Expression and Its Genetic Variants (rs3758539) in Patients With Severe and Treatment-Refractory Alopecia Areata: Association With Response to Baricitinib

This study investigated the role of tissue Retinol‐Binding Protein 4 (RBP4) and its genetic variant rs3758539 in patients with severe alopecia areata (AA) and their response to baricitinib treatment. The study included 50 patients with severe AA and 50 healthy controls. Results showed that baseline tissue RBP4 levels were significantly higher in patients compared to controls and decreased significantly after baricitinib treatment, especially in responders. Elevated RBP4 levels were associated with higher disease severity. The TT genotype and T allele of rs3758539 were linked to increased susceptibility to severe AA, but this polymorphism did not affect the response to baricitinib treatment.