Incomplete immunological recovery following anti-tuberculosis.

Background & objectives: Mycobacterium tuberculosis infection has been shown to result in increased HIV replication and disease progression in HIV-infected individuals through increased immune activation. The objective of this study was to correlate plasma levels of immune activation markers with the presence of tuberculosis (TB) in HIV-infected and uninfected individuals, and to study the changes following anti-tuberculosis treatment. Methods: Plasma markers of immune activation - neopterin, beta-2-microglobulin (β2M) and soluble tumour necrosis factor alpha receptor type I (sTNFα-RI) were measured by ELISA in 42 HIV positive TB patients (HIV+TB+) undergoing a six-month course of TB chemotherapy. Thirty seven HIV+ persons without active TB, 38 TB patients without HIV infection, and 62 healthy volunteers served as controls. Results: Plasma levels of all three markers were elevated in HIV+ individuals, more so in those with active TB. When HIV+ individuals were further categorized based on CD4+ T cell counts, HIV+TB+ patients with CD4+ T cells counts < 200 cells/μl were found to have the highest levels at baseline with a steep fall in neopterin and sTNFα-RI during treatment, but in most instances the levels did not drop to normal. β2M levels remained persistently high despite completing TB treatment. Interpretation & conclusions: The fi ndings of the study suggest that both HIV and TB act synergistically to activate the host immune system. Although ATT was effective in clearing M. tuberculosis infection, a high proportion of HIV+ TB patients continued to have levels well above the normal range, indicating that underlying immune activation persists despite TB treatment. None of the markers were specific enough to be used to assess cure of TB.

Hepatitis B or hepatitis C co-infection in individuals infected with human immunodeficiency virus and effect of anti-tuberculosis drugs on liver function.

BACKGROUND: Tuberculosis (TB) and hepatitis are the two common co-infections in patients infected with human immunodeficiency virus (HIV). Anti-tuberculosis treatment (ATT) may have an effect on the liver enzymes in these co-infected HIV patients. AIMS: To determine the prevalence of Hepatitis B and C virus coinfection in HIV infected patients in Tamilnadu and assess effects of anti-tuberculosis drugs on their liver function. SETTINGS: HIV positive subjects referred to the Tuberculosis Research Centre, Chennai. MATERIALS AND METHODS: All HIV infected patients referred to the Tuberculosis Research centre, from March 2000 to May 2004, were screened for Hepatitis B surface antigen (HBsAg) & Hepatitis C virus (HCV) antibodies by enzyme linked immunoabsorbent assay (ELISA). HIV infection was confirmed using two rapid tests and one ELISA. Patients were given either short-course anti-tuberculosis treatment or preventive therapy for tuberculosis, depending on the presence or absence of active TB, if their baseline liver functions were within normal limits. None of these patients were on antiretroviral therapy during the study period. STATISTICAL ANALYSIS: Paired t-test was used to find the significance between baseline and end of treatment liver enzymes levels, while logistic regression was done for assessing various associations. RESULTS: Of the 951 HIV-infected patients, 61 patients (6.4%) were HBsAg positive, 20 (2.1%) had demonstrable anti HCV antibodies in their blood. Serial estimation of liver enzymes in 140 HIV patients (81 being co-infected with either HBV or HCV) showed that 95% did not develop any liver toxicity while they were on anti-tuberculosis treatment or prophylaxis. CONCLUSIONS: The prevalence of hepatitis B and C coinfection was fairly high in this largely heterosexually infected population supporting the use of more careful screening for these viruses in HIV positive persons in this region. Anti-tuberculosis therapy as well as TB preventive therapy can be safely employed in HIV and hepatitis coinfected patients, if baseline liver function tests are within normal limits.

T-lymphocyte subpopulations in tuberculosis.

BACKGROUND: Tuberculosis is associated with both qualitative and quantitative defects in the cell mediated immune response. The changes that occur in the lymphocyte profile in blood in children with tuberculosis are not well understood. DESIGN: Prospective study. SETTING: Referral hospitals. METHODS: Lymphocyte subpopulations were determined by flow cytometry in 17 healthy tuberculin positive children, in 22 children with newly diagnosed pulmonary tuberculosis and in 8 of these children after antituberculosis therapy. RESULTS: Absolute numbers and percentages of CD3+ and CD4+ T cells were reduced in children with tuberculosis, compared to controls. CD4+ counts increased significantly following antituberculosis treatment, compared to baseline values. In contrast, the proportion of T cells expressing the gdT cell receptor was similar in tuberculosis patients and controls. CONCLUSION: Children with tuberculosis have a systemic decrease in the proportion and number of CD3+ and CD4+ T cells which reverses during therapy.