Soluble HLA-G and HLA-A,-B,-C serum levels in patients with allergic rhinitis

Background: Allergic rhinitis (AR) is characterized by Th2‐polarized immune response. Soluble HLA (sHLA) molecules play an immunomodulatory activity. So far, however, no study investigated them in AR. Objective: The aim of this study was to evaluate sHLA‐G and sHLA‐A,‐B,‐C serum levels in AR patients with pollen allergy and in a group of healthy controls. Methods: Forty‐nine AR patients were enrolled. A group of healthy nonallergic subjects was considered as control. sHLA‐G and sHLA‐A,‐B,‐C serum levels were determined by immunoenzymatic method. The study was conducted during the winter, such as outside the pollen season. Results: Allergic patients had significantly higher levels of both sHLA‐G (P < 0.0001) and sHLA‐A,‐B,‐C (P = 0.011) molecules than normal controls. Moreover, there was a significant relationship between these two soluble molecules (r = 0.69) in allergic patients. Conclusion: The present study provides the first evidence that both sHLA‐G and sHLA‐A,‐B,‐C serum levels are significantly increased in AR patients with pollen allergy.