Objective: To evaluate the significance of different mycobacterial antigens in diagnosis of tuberculosis.
Methods: The sensitivity and specificity of 5 mycobacterial recombinant proteins in diagnosis of tuberculosis were observed by using ICT-TB card and the results of ICT-TB card were compared with PPD skin test and LAM.
Results: The sensitivities of ICT-TB card, LAM and PPD skin test in diagnosis of pulmonary tuberculosis were 55.9%, 52.6% and 75.0% respectively. There was statistically significant difference between the latter and the other two (P < 0.05). The specificities of ICT-TB card, LAM and PPD skin test in diagnosis of pulmonary tuberculosis were 87.6%, 62.9% and 68.9% respectively. There was statistically significant difference between the former and the other two. The clinical positive predictive value in diagnosis of pulmonary tuberculosis was 88.5%; the clinical negative predictive value was 53.8%. The positive reactions of ICT-TB in non-tuberculosis were caused mainly by antigens 4, 5, and if antigens 4, 5 were excluded, the specificity of ICT-TB card rose to 98.9%.
Conclusions: The results suggested that measuring mycobacterial recombinant proteins was a useful supplementary tool for diagnosis of pulmonary tuberculosis.