Detection of serum surfactant protein A and D levels in serum of patients with interstitial lung disease associated with rheumatoid arthritis / 中华风湿病学杂志

ABSTRACT

Objective To measure serum surfactant protein (SP) A and D levels in patients with interstitial lung disease associated with rheumatoid arthritis (RA).Methods Serum SP-A and SP-D levels of RA,RA-ILD patients and healthy controls were assessed using a sensitive enzyme-linked immunosorbent assay (ELISA).The relationship between SP-A and SP-D and RA-ILD was analyzed.The serum SP-A and SP-Dpositive rate was calculated for the three groups.The correlation between SP-A and SP-D with RF,anti-CCP,antinuclear antibody,antikeratin antibody,anti-perinuclear factor,C-reactive protein,erythrocyte sedimentation rate,were analyzed.Mean value of groups were compared with variance analysis,Spearmam rank correlation test was used for correlation analysis.Results The levels of serum SP-A in RA-ILD patients and RA patients as well as in healthy controls were [ (51.2±9.2),(25.9±2.6),( 15A±0.3 ) μg/L] respectively.The level of serum SP-D of the three groups was [ ( 42.5 ±8.1 ),(20.8 ± 1.5 ),( 16.6±0.8 ) μg/L ] respectively.The levels of serum SP-A and SP-D in patients with RA complicated with ILD were higher than those simple RA patients and healthy controls (P＜0.05).The levels of serum SP-A and SP-D in patients with RA were not significantly higher than those in healthy controls (P＞0.05).The positive rate of serum SP-A and SP-D in RA-ILD patients were significantly higher than those in simple RA patients and healthy controls.The positive rate of serum SP-D of RA-ILD patients was higher than that of SP-A.The levels of serum SP-A and SP-D in patients with RA complicated with ILD were correlated positively with age,C-reactive protein.The level of serum SP-D was correlated positively with RF,anti-CCP,antikeratin antibody.There was no correlation between the level of serum SP-A and SP-D with RA-ILD and antinuclear antibody,antiperinuclear factor,erythrocyte sedimentation rate.Conclusion The levels of serum SP-A and SP-D are correlated with RA-ILD and may be useful markers for ILD in patients with RA.These two paramenters may be helpful to early diagnosis of RA-ILD.The Serum SP-D levels are more sensitive in predicting the development of RA-ILD than other parameters and can help in assessing the severity of lung damage.