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.