Objective To analyze the levels of serum solute carrier family 7 member 11 (SLC7A11) and platelet-derived growth factor BB (PDGFBB) in children with bronchial asthma and their correlations with disease severity.

Methods A total of 80 children with acute asthma were enrolled in acute asthma group, and divided into severe asthma group (40 cases) and mild asthma group (40 cases) according to severity of the disease. Additionally, 80 children with asthma in remission during the same period were enrolled in remission group, and 80 healthy children undergoing physical examination during the same period were enrolled in control group. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of serum SLC7A11 and PDGFBB in children from each group. Pearson correlation analysis was conducted to assess the correlation between serum levels of SLC7A11 and PDGFBB and lung function indicators peak expiratory flow (PEF) and forced expiratory volume in one second as percentage of predicted (FEV₁%pred) in asthmatic children. Multivariate Logistic regression analysis was performed to explore the relationships ofn serum levels of SLC7A11 and PDGFBB with disease severity in asthmatic children. Receiver operating characteristic (ROC) curves were plotted to evaluate the diagnostic efficacy of serum SLC7A11 and PDGFBB levels for severe asthma.

Results The serum SLC7A11 levels and PEF, FEV₁%pred in the acute asthma group were lower than those in the remission group and control group, while the PDGFBB levels were higher than those in the remission group and control group (P < 0.05). The serum SLC7A11 levels and PEF, FEV₁%pred in the remission group were lower than those in the control group, while the PDGFBB levels were higher than those in the control group (P < 0.05). The serum SLC7A11 levels in asthmatic children were positively correlated with PEF and FEV₁%pred (P < 0.05), while the serum PDGFBB levels were negatively correlated with PEF and FEV₁%pred (P < 0.05). The serum SLC7A11 levels and PEF, FEV₁%pred in the severe asthma group were lower than those in the mild asthma group, while the PDGFBB levels were higher than those in the mild asthma group (P < 0.05). High PEF, high FEV₁%pred, and high SLC7A11 were independent protective factors for severe asthma (P < 0.05), while high PDGFBB was an independent risk factor (P < 0.05). The area under the ROC curve for the combined diagnosis of severe asthma using serum SLC7A11 and PDGFBB levels was 0.851, significantly larger than the areas under the ROC curves for the individual diagnosis using SLC7A11(0.790) and PDGFBB (0.785) alone (P < 0.05).

Conclusion Decreased serum SLC7A11 levels and increased serum PDGFBB levels in asthmatic children are closely related to decreased lung function and increased disease severity. The combined detection of these two biomarkers has high diagnostic value for severe asthma.