The changing face of AIDS-related opportunism: cryptococcosis in the highly active antiretroviral therapy (HAART) era. Case reports and literature review.

Only nine cases of AIDS-related cryptococcosis have been reported until now in patients receiving highly active antiretroviral therapy (HAART), all of them with abnormal clinical features. Two HIV-infected patients who experienced an atypical relapse of cryptococcosis shortly after the start of HAART and despite maintenance antifungal treatment, are described. Six different relapses of cryptococcal meningitis were observed in a 28-month period in a patient who obtained a poor immune recovery after HAART (as shown by a CD4+ lymphocyte count ranging from 78 to 149 cells/microL, opposed to a baseline level of 98 cells/microL). On the other hand, a patient with favorable immunological response to HAART (as expressed by a CD4+ count growing from 7 to 186 cells/microL), experienced isolated multiple indolent cryptococcal abscesses involving head, neck, the anterior thoracic wall, and regional lymph nodes, with repeatedly negative cultures, and diagnosis obtained by both histopathologic study and positive serum antigen assay. Both our case reports are representative of novel correlations between opportunistic pathogens and immune reactivity, descending from the introduction of HAART. The first episode describes an exceedingly elevated number of disease relapses despite HAART and antifungal maintenance treatment, which may descend from an incomplete immune response to antiretroviral therapy, possibly responsible for failure in obtaining eradication of yeasts, but also for lack of disease dissemination (usually leading to a lethal multivisceral involvement in the pre-HAART era). The abnormal disease course and localization of second reported patient well depicts an "immune reconstitution syndrome" probably representing a flare-up of a latent fungal infection, caused by a rapidly effective HAART. In patients treated with HAART, AIDS-related cryptococcosis cannot therefore be ruled out by the absence of neurological involvement, and by persistingly negative cultures.