Study on the relationship between serum surfactant protein and interstitial lung disease in systemic lupus erythematosus / 中华风湿病学杂志

ABSTRACT

Objective To investigate the relationship between serum surfactant protein-A (SP-A) and -D (SP-D) in patients with systemic lupus erythematosus (SLE) complicated with interstitial lung disease.(SLE-ILD) and its clinical significance.Methods Serum SP-A and SP-D levels of SLE patients and controis were assessed using a sensitive enzyme-linked immunosorbent assay (ELISA).The relationship between SP-A and SP-D and SLE-ILD,the correlation between SP-A and SP-D with age,disease activity index,pulmonary function test and high-resolution computed tomography (HRCT) score were analyzed.Results The level of serum SP-A and SP-D in patients with SLE is higher than that in healthy controls(P＜0.05).The level of serum SP-A and SP-D in patients with SLE complicated with ILD was higher than that in patients without ILD and healthy controls (P＜0.05).The level of serum SP-D in patients with SLE-ILD was correlated positively with HRCT score (r=0.508,P=0.004) and interstitial score (r=0.468,P=0.009),and it correlated inversely with vital capacity (%VC) (r=-0.590,P=0.001 ) and diffusing capacity of carbon monoxide (%DLCO)(r=-0.588,P=0.001 ).There was no correlation between the level of serum SP-A with SLE-ILD and HRCT score,%VC and %DLCO.The level of serum SP-D in patients with SLE-ILD correlated positively with serum IgG (r=0.376,P=0.040),and the level of serum SP-A in patients with SLE-ILD correlated positively with serum C reactive protein (CRP)(r=0.403,P=0.027).There was a positive correlation between the level of serum SP-D in patients with SLE and age (r=0.352,P=O.001 ).Conclusion The levels of serum SP-A and SP-D may be useful markers for ILD in patients with SLE.There is correlation between the level of serum SPD and HRCT score,pulmonary function test,and it is positively correlated with age and disease activity index.