Analysis of the plasma soluble human leukocyte antigen-G and interleukin-10 levels in childhood atopic asthma.

Human leukocyte antigen-G (HLA-G) has been hypothesized to be associated with the pathogenesis of asthma; however, results remain controversial. Furthermore, HLA-G expression could be modulated by the HLA-G 14-bp insertion (+)/deletion (-) polymorphism and by interleukin-10. In this study, the 14-bp polymorphism in exon 8 of the HLA-G gene, plasma soluble HLA-G, and interleukin-10 (IL-10) levels in untreated atopic asthmatic children, and in a group of age-, gender-, and ethnicity-matched normal controls were analyzed. Data showed that HLA-G 14-bp +/- polymorphism was not significant difference between the asthmatic patients and normal controls. Plasma soluble human leukocyte antigen (sHLA)-G in atopic asthma patients (n = 72; median, 179.28 U/ml) was dramatically higher compared with that of the normal controls (n = 76; median, 35.23 U/ml; p < 0.001). Receiver operating characteristic (ROC) curve analysis showed that the area under ROC curve for sHLA-G was 0.986 (p < 0.001) in atopic asthma patients versus normal controls. IL-10 levels in the asthmatic children (n = 50; median, 5.02 pg/ml) was significantly lower than that of the normal controls (n = 48; median, 12.82 pg/ml; p < 0.001). Both HLA-G 14-bp polymorphism and IL-10 levels were unrelated to plasma sHLA-G concentration in both groups. Our findings indicated that the HLA-G 14-bp polymorphism was not a risk factor, but that sHLA-G might be considered as a biomarker for the atopic asthmatic patients. Dramatically increased sHLA-G with decreased IL-10 levels may have implications in the pathogenesis of atopic asthma.