Cryptococcosis in AIDS
Infection with HIV is the most common predisposing condition for developing cryptococcosis. This chapter focuses on aspects that are specific to the coinfection of HIV and Cryptococcus neoformans. These include clinical presentation, treatment regimens, alterations of the host immune response, and concerns about drug toxicities and interactions. Soon after the HIV pandemic was recognized in the United States and Europe, it became clear that cryptococcosis was an important opportunistic pathogen in patients with AIDS. C. neoformans infection in AIDS patients can either be the result of a newly acquired primary infection or alternatively constitute a reactivation of latent C. neoformans infection. Patients with AIDS who respond to highly active antiretroviral therapy (HAART) show a greatly reduced incidence of opportunistic infections such as cryptococcosis. Experimental evidence suggests that C. neoformans coinfection can affect HIV replication. Another factor that may affect HIV-infected patients' ability to mount a successful antifungal host response is the common abuse of methamphetamine. This drug exposure facilitates intracellular replication and inhibits intracellular killing of C. neoformans and thus affects pathogenesis in these patients. The most common manifestation of cryptococcosis in patients with HIV infection is meningoencephalitis, and central nervous system (CNS) involvement is found in the vast majority of patients with AIDS in whom cryptococcal infection is diagnosed. The treatment of AIDS-associated cryptococcal meningitis is usually divided into three stages: induction, consolidation, and maintenance.
