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 examined the expression of tissue retinol-binding protein 4 (RBP4) and its genetic variant rs3758539 in 50 patients with severe or treatment-refractory alopecia areata (AA) compared to 50 healthy controls, focusing on their response to baricitinib treatment. The TT genotype of rs3758539 was linked to a higher likelihood of severe AA, and baricitinib treatment significantly improved SALT scores for many patients. Results showed that 72% of patients achieved at least a SALT50 improvement, with 44% reaching SALT75 and 22% achieving SALT90. Elevated baseline RBP4 levels in patients decreased to levels comparable to controls after treatment. The study suggests that RBP4 expression and its genetic variants may influence AA severity and treatment response, highlighting baricitinib's potential as a therapeutic option for severe AA. However, the rs3758539 polymorphism did not predict treatment response, indicating the need for further research to validate RBP4's role as a biomarker.