Iukary Takenami

Levels of Interferon-Gamma Increase after Treatment for Latent Tuberculosis Infection in a High-Transmission Setting

Objectives. We investigated IFN-γ levels before and after a six month course of isoniazid among individuals with latent tuberculosis infection (LTBI) in a high-transmission setting. Design. A total of 26 household contacts of pulmonary tuberculosis patients who were positive for LTBI by tuberculin skin test completed six months of treatment and submitted a blood sample for a follow-up examination. The IFN-γ response to Mycobacterium tuberculosis-specific antigens was measured, and the results before and after the completion of LTBI treatment were compared. Results. Of the 26 study participants, 25 (96%) showed an IFN-γ level higher than their baseline level before treatment (P ≤ 0.001). Only one individual had a decreased IFN-γ level after treatment but remained positive for LTBI. Conclusion. In a high-transmission setting, the IFN-γ level has increased after LTBI treatment. Further studies must be undertaken to understand if this elevation is transient.

Revisiting the Rich's formula: an update about granulomas in human tuberculosis

The formula proposed by Rich in 1951 explained the formation in a tuberculous lesion in a period that was unknown cellular functions, cytokines and other immunological aspects involved in granuloma formation by tuberculosis; its components are assembled conceptually to explain the pathogenic mechanisms involved in the granulomatous lesion in tuberculosis. In this manuscript, we report an update of Richs formula based on the new and old concepts about pathogenic mechanisms involved in the granulomatous lesion in tuberculosis. Current knowledge allows us to conclude that the balance between the characteristics of the bacillus and host protective response is necessary to indicate the outcome of pathogenesis, infection or active disease and the necrosis degree of the tuberculosis lesion.

Serum antiphospholipid antibody levels as biomarkers for diagnosis of pulmonary tuberculosis patients

SETTING Salvador, Bahia, Brazil. OBJECTIVE To evaluate the immunoglobulin (Ig)M and total IgG antibody response to cardiolipin (CL), phosphatidylcholine (PTC), phosphatidylethanolamine (PE), phosphatidylinositol (PI) and sulfatide (SL-I) as biosignatures that can be used to diagnose pulmonary tuberculosis (TB) and its applicability for monitoring the efficacy of anti-tuberculosis treatment. DESIGN Serum samples from 37 adult pulmonary TB patients and 48 controls (16 healthy household contacts, 19 household contacts with latent tuberculous infection [LTBI] and 13 non-TB patients with lung disease) were screened using enzyme-linked immunosorbent assays (ELISAs) for IgM and total IgG against phospholipids. RESULTS Levels of IgM response to CL, PE and PI, and IgG response to CL, PE, PI and PTC were significantly higher in TB patients than in control groups. Anti-CL IgG had the best performance characteristics, with a sensitivity and specificity of respectively 86.5% and 87.2%. This IgG anti-CL ELISA test detected 86.5% (32/37) of the TB patients, whereas the number detected using sputum smear was only 65.9% (24/37). After anti-tuberculosis treatment, the median value for all anti-phospholipid antibodies decreased significantly compared with baseline values (P < 0.05). CONCLUSION Our results suggest that the total IgG anti-CL level could be useful to complement conventional bacteriological tests for the rapid diagnosis of adult pulmonary TB.