Abstract:

Objective      To investigate the change of serum surfactant protein-D(SP-D) in pulmonary tuberculosis patients, observe its relation with gender, age and other factors, and explore value of diagnosis for pulmonary tuberculosis. MethodsThe level of SP-D in the serum was detected by ELISA in 101 cases of pulmonary tuberculosis, 30 cases of chronic obstructive pulmonary disease(COPD) and 85 healthy people. Leucocyte count, neutrophilic granulocyte percentage and lymphocyte percentage were detected with the electric resistance method, erythrocyte sedimentation rates by the sedimentation process, tubercle bacillus antibodies by ELISA, purified protein derivative(PPD) trial by the Mantoux method, and count of tubercle bacilli by acidfast stain. Results    The level of SP-D in the serum from pulmonary tuberculosis patients was significantly higher than that of the healthy，while it was significantly lower than that of COPD patients（P＜0.05）. The cutoff value of SP-D was 0.26 determined by the ROC curve drawn according to the measured values. The sensitivity, specificity and accuracy of detection of SP-D in the serum were 72.30%,  91.00%, and 80.65% respectively in the diagnosis of pulmonary tuberculosis. There were no obvious differences in SP-D levels in different conditions of gender, age, leukocyte count, neutrophilic granulocyte percentage, lymphocyte percentage, sedimentation process and count of tubercle bacilli in the sputum and hollow in the lung, however, there were  correlations of SP-D level with tubercle bacillus antibodies and PPD trial（values of  were 8.44 and 17.08 respectively，P＜0.01）. Conclusions     Detection of SP-D in serum is of great significance in the diagnosis of pulmonary tuberculosis, may become a new diagnostic method, and is worth exploring.

Key words: Tuberculosis, pulmonary; Serologic tests; Surfactant protein-D; Diagnosis