Increased plasma soluble human leukocyte antigen-G in persistent wheezy infants.

BACKGROUND

Human leukocyte antigen (HLA)-G is a non-classical major histocompatibility complex class I antigen characterized by limited polymorphism in its coding region, unique tissue expression pattern in physiologic conditions and immunomodulatory properties. Recently, the level of soluble (s)HLA-G was found to be higher in atopic asthma and allergic rhinitis, but this remains to be clarified in wheezy infants. The aim of the present study was therefore to investigate sHLA-G in wheezy infants.

METHODS

The subjects consisted of infants with persistent wheezing and positive modified asthma predictive index (mAPI; n = 30; persistent group) and those with transient wheezing and negative mAPI (n = 17; transient group). sHLA-G was measured in plasma using enzyme-linked immunosorbent assay. Total immunoglobulin E (IgE) and eosinophil count were measured, and skin testing was performed with a battery of 13 antigens with appropriate positive and negative controls.

RESULTS

sHLA-G was significantly higher in the persistent wheezing (positive mAPI) group compared with the transient wheezing (negative mAPI) group (P = 0.008). There was no significant difference in peripheral blood eosinophil count and total IgE between the groups.

CONCLUSIONS

The increased sHLA-G in infants with persistent wheeze suggests that sHLA-G may be able to be used to distinguish persistent from transient wheeze. Further comprehensive studies are needed on this topic.