Successful discontinuation of therapy for disseminated Mycobacterium avium complex infection after effective antiretroviral therapy

Background: Highly active antiretroviral therapy (HAART) is associated with improvement or resolution of several HIV-associated opportunistic infections. Although prophylaxis against disseminated Mycobacterium avium complex infection may be successfully discontinued after a favorable response to HAART, the 1999 guidelines from the U.S. Public Health Service/Infectious Diseases Society of America recommend continuing therapy for disseminated M. avium complex infection, regardless of the response to HAART. Objective: To examine the outcome among patients with disseminated M. avium complex infection whose antimycobacterial therapy was discontinued after a favorable response to HAART. Design: Retrospective chart review between May 2000 and May 2001. Setting: 13 Canadian HIV clinics. Patients: 52 HIV-infected adults (43 men; mean age, 37.3 years) in whom successful antimycobacterial therapy for disseminated M. avium complex infection was discontinued after a favorable virologic response to HAART. Measurements: Survival, survival free of disseminated M. avium complex infection, and CD4⁺ cell count responses. Results: At the time of diagnosis of disseminated M. avium complex infection, the median CD4⁺ cell count was 0.016 × 10⁹ cells/L, and the median plasma HIV RNA level was 90 000 copies/mL (plasma HIV RNA levels were available for only 21 patients). The patients received a median of 32 months of antimycobacterial therapy that included ethambutol plus either clarithromycin or azithromycin. When antimycobacterial therapy was discontinued, the median CD4⁺ cell count was 0.23 × 10⁹ cells/L and the median plasma HIV RNA level was less than 50 copies/mL. A median of 20 months after discontinuation of antimycobacterial therapy, only 1 patient had developed recurrent M. avium complex disease (37 months after stopping antimycobacterial therapy). This patient had stopped HAART 2 months earlier because of uncontrolled HIV viremia. Twenty months after stopping antimycobacterial therapy, the other 51 patients had a median CD4⁺ cell count of 0.288 × 10⁹ cells/L; 34 (67%) had undetectable plasma HIV RNA levels, and 8 (15%) had plasma HIV RNA levels of 50 to 1000 copies/mL. Conclusions: Discontinuation of successful disseminated M. avium complex therapy after a successful response to HAART is safe and reduces patients' pill burdens, potential drug adverse effects, drug interactions, and costs of therapy.