Early Versus Delayed Antiretroviral Therapy (ART) in the Treatment of Cryptococcal Meningitis in Africa

Overview

Cryptococcal Meningitis continues to be one of the most devastating AIDS defining illness in sub-Saharan Africa. Despite the availability of azoles such as fluconazole for treatment, mortality remains high with some studies showing 100% mortality. The investigators designed a study to determine if timing of the initiation of antiretroviral therapy (ART) in patients with cryptococcal meningitis and HIV would improve survival. The investigators hypothesis was that early initiation of ART result in improved mortality for patients with HIV and cryptococcal meningitis.

Cryptococcosis is an invasive fungal infection caused by an encapsulated yeast. Cryptococcosis in humans is almost always caused by Cryptococcus neoformans. The advent of the HIV epidemic has lead to a profound increase in the number of reported cases of cryptococcal meningoencephalitis throughout the world, particularly in sub-Saharan Africa. In Zimbabwe an analysis of the case reports at one of the major tertiary care hospitals showed an increase in the admission rate from meningitis between 1985-1995 from 78 to 523 cases per 100000 admissions with an increase in the number of those cases due to cryptococcosis from 5% to 46.2%. Cryptococcosis typically develops at a CD4 count of less than 50 cells/ mm3, and is the initial AIDS defining illness in up to 50-60% of patients. Prior to the introduction of amphotericin B, flucytosine and azoles, mortality from C neoformans meningoencephalitis was close to 100%. The introduction of amphotericin B led to a significant decrease in mortality with 60-70% of patients being successfully treated. The introduction of fluconazole prophylaxis in the 1990s lead to a significant decrease in the incidence of cryptococcosis. The use of antiretroviral therapy has also caused a significant decrease in the incidence of cryptococcal meningitis. Due to the prohibitive cost of amphotericin B and flucytosine, in many developing countries such as Zimbabwe, the mainstay of the treatment of CM is fluconazole. The current standard treatment is with fluconazole 400mg/day for 8-10 weeks, may be too low to result in adequate CNS concentration of the drug to achieve adequate killing of C. neoformans. Clinically some physicians in Zimbabwe have noted that patients are not responding adequately to this regimen and have started to treat patients with higher doses of fluconazole. Previous studies have shown that higher doses of fluconazole can be used for the treatment of CM and are well tolerated. In our proposed study, patients will be treated with high dose oral fluconazole at 800mg/day for a total 10 week period. The advent of the increased access to ART in sub-Saharan Africa provides an additional opportunity to improve morbidity and mortality in all AIDS patients. There are as yet no definitive studies to indicate if there is an advantage to immediate ART therapy in the setting of acute CM compared to deferring therapy after the first 10 weeks of intensive CM therapy. This study is designed to address this question and provide physicians in sub-Saharan Africa with evidence based guidelines for the appropriate management of HIV positive patients with acute presentation of CM.