Soluble HLA-G serum levels depend on allergy type and IgE levels.

Allergic rhinitis (AR) is characterized by Th2 polarized immune response. Soluble HLA (sHLA) molecules play an immunomodulatory activity. Two different studies evidenced that both patients with seasonal AR (SAR) and patients with perennial AR (PAR) had higher sHLA-G levels than normal controls. The aim of this study was to compare sHLA-G serum levels in SAR and PAR patients, also considering allergen-specific IgE. One hundred sixty-eight AR patients were enrolled, 94 with SAR and 74 with PAR. A group of 116 healthy subjects was considered as control. sHLA-G and allergen-specific IgE serum levels were determined by immunoenzymatic method. SAR patients had significantly higher levels of sHLA-G than PAR patients (p = 0.0194). sHLA-G was moderately related to allergen-specific IgE both in SAR (r = 0.497) and in PAR patients (r = 0.584). The present study provides evidence that sHLA-G serum levels depend on the type of allergy and are related to allergen-specific IgE serum levels. These findings may suggest that sHLA-G could be a biomarker of allergic reaction.