Inflammatory markers in active pulmonary tuberculosis: association with Th1/Th2 and Tc1/Tc2 balance

Few inflammatory markers closely reflect the activity of tuberculosis and only a few surrogate markers are available. The purpose of this study was to clarify the usefulness of measuring the erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and serum amyloid A (SAA), and the association between these markers and T-cell profiles.

One hundred one patients with active pulmonary tuberculosis were enrolled in this study. The associations between ESR, CRP, and SAA values on admission and microbiological and radiological findings and T-cell profiles were assessed. Th1/Th2 and Tc1/Tc2 were determined by analyzing intracellular cytokine staining for IFN-gamma and IL-4 in blood CD4+ and CD8+ T cells using flow cytometry after stimulation with PMA and ionomycin.

There were significant correlations between ESR, CRP, and SAA, of which the correlation between CRP and SAA was strong (r = 0.88). CRP values significantly correlated with the sputum smear scale and the extent of lesions, and were higher in bilateral lesions. SAA values correlated with the sputum smear scale, whereas all markers were higher in patients with pleural effusion. Both CRP and SAA levels negatively correlated with the ratio of Th1/Th2. In contrast, ESR negatively correlated with the ratio of Tc1/Tc2.

CRP reflected the disease severity before treatment. CRP and SAA values were associated with helper T-cell proportions whereas ESR was associated with cytotoxic T-cell proportions, both being type 2 predominant.