Providing concurrent anti-HIV and tuberculosis (TB) therapy, or TB treatment of greater than standard duration does not reduce the incidence of TB recurrence, according to a study conducted in Taiwan and published in the December 1st edition of the Journal of Acquired Immune Deficiency Syndromes. The investigators also found a higher recurrance rate than that found in a meta-analysis of studies published earlier this year in Clinical Infectious Diseases
Investigators conducted an observational prospective study of patients with both TB and HIV infection at a university hospital in Taiwan between 1994 and 2003. HAART was provided to individuals from early 1997, with dual nucleoside analogue (NRTI) therapy being the standard of care before then.
A total of 124 HIV-positive patients (17.6% of the cohort) developed TB. The overwhelming majority of these patients, 93%, had a CD4 cell count below 200 cells/mm3, indicating that they were highly vulnerable to opportunistic infections, and a third of patients were also diagnosed with another concurrent AIDS-defining illness. Median viral load at the point of TB diagnosis was over 250,000 copies/mL.
Anti-TB therapy was provided, based on either rifampicin or rifabutin and HAART included either indinavir or efavirenz. The mean duration of anti-TB therapy was nine months, with 84% of patients receiving over six months of rifampicin or rifabutin-based treatment. HAART was provided to 80% of patients.
A total of eight patients experienced nine episodes of TB recurrence a median of 1,065 days after the initial diagnosis of TB, providing an overall recurrence rate of 2.5 instances per 100 patient years. This compares with a recurrence rate of 1.4 cases per 100 patient years in individuals who received > 7 months of rifamycin-based TB treatment identified in a meta-analysis of studies of TB recurrence published earlier this year (Korenromp).
At the time of recurrence, median CD4 cell count was 75 cells/mm3 and viral load was a median of 400,000 copies/mL. However at the last point of follow-up, median CD4 cell count had increased to 230 cells/mm3 and median viral load was 400 copies/mL, with 70% of individuals having a viral load below 400 copies/mL.
”Our results suggest that the recurrence rate of TB may not be improved to a significant extent by concurrent treatment of TB and HIV infection with HAART and a longer duration…of rifamycin-based treatment.” The investigators note that HAART has been shown to reduce the instance of TB amongst patients with HIV, especially in individuals with advanced immune suppression.
Further information on this website
Tuberculosis - overview
Combing ARVs with treatment for TB HATIP#3
Tuberculosis - factsheet
Hung C-C et al. Recurrence of tuberculosis in HIV-1-infected adults after rifamycin-based treatment and highly active antiretroviral therapy. JAIDS 34: 437 – 438, 2003.
Korenromp E et al. Effects of human immunodeficiency virus infection on recurrance of tuberculosis after rifampin-based treatment: an analytical review. Clinical Infectious Diseases 37: 101 - 112, 2003.