Protection against Mycobacterium tuberculosis infection is dependent on T cell and macrophage activation regulated by cytokines. Cytokines and chemokines produced at disease sites may be released into circulation. Data available on circulating cytokines in tuberculosis (TB) is mostly on pulmonary TB (PTB) with limited information on extrapulmonary disease (EPul-TB). We measured interferon-gamma (IFN-gamma), interkeukin-10 (IL-10), CXCL9 and CCL2 in sera of patients (n = 80) including; PTB (n = 42), EPul-TB (n = 38) and BCG vaccinated healthy endemic controls (EC, n = 42). EPul-TB patients comprised those with less severe (LNTB) or severe (SevTB) disease. Serum IFN-gamma, IL-10 and CXCL9 levels were significantly greater while CCL2 was reduced in TB patients as compared with EC. IFN-gamma was significantly greater in PTB as compared with LNTB (P = ) and SevTB (P = ). CXCL9 was greater in PTB as compared with LNTB (P = ). In contrast, CCL2 levels were reduced in PTB as compared with LNTB (P = ) and SevTB (P = ). A Spearman's rank correlation analysis determined a positive association between IFN-gamma and IL-10 (rho = , P = ) and IFN-gamma and CXCL9 (rho = , P = ) in the PTB group. However, in SevTB, only IFN-gamma and CXCL9 were positively associated (rho = , P = ). Systemic levels of cytokines are reflective of local responses at disease sites. Therefore, our data suggests that in PTB increased IFN-gamma and CXCL9 balanced by IL-10 may result in a more effective cell mediated response in the host. However, elevated inflammatory chemokines CXCL9 and CCL2 in severe EPul-TB without concomitant down modulatory cytokines may exacerbate disease related pathology and hamper restriction of M. tuberculosis infection.
Twenty-two of the 34 cases of actively caseating EBTB changed into the fibrostenotic type, and the other 12 healed without sequelae. Seven of the 11 cases of oedematous-hyperaemic EBTB changed into the fibrostenotic type, and the other four healed. Nine of the 11 cases of granular EBTB, six cases of non-specific bronchitic EBTB, and two cases of ulcerative EBTB resolved completely. However, the other two cases of granular EBTB changed into the fibrostenotic type. Seven cases of fibrostenotic EBTB did not improve despite antituberculosis chemotherapy. These various changes in bronchoscopic findings occurred within 3 months of treatment. In 10 cases of tumorous EBTB, seven progressed to the fibrostenotic type. In addition, new lesions appeared in two cases, and the size of the initial lesions increased in another two cases, even at 6 months after treatment. On chest CT findings of 26 EBTB patients, the length of bronchial involvement was measured from 10 to 55 mm. Bronchial stricture was noticed in 25 cases and the range of narrowing was from total occlusion to near normal, and there was wide variation in bronchial stricture even within same subtype of EBTB. The dominant feature of PFT in EBTB at the diagnosis was restrictive pattern.