Response to therapy in patients with cryptococcosis and AIDS: Association with in vitro susceptibility to fluconazole.

Background: The implications of the Cryptococcus neoformans resistance to fluconazole on patient therapy have not been fully elucidated due to the discordant results found in published studies.

Aims: To establish the influence of C. neoformans resistance to fluconazole in the therapy of individuals with cryptococcosis and AIDS.

Methods: This study retrospectively compared the clinical course of patients with cryptococcosis according to the level of fluconazole resistance of their C. neoformans isolates.

Results: This study included 71 episodes of cryptococcosis, defined as those isolates of C. neoformans obtained from patients with mycosis, of which 36 isolates were sensitive to fluconazole, 20 susceptible dose-dependent (SDD), and 15 were resistant. There were 5 treatment failures in the consolidation phase; two occurred in patients who had a susceptible strain, 2 in patients who had SDD strains, and one in a patient who had a resistant strain. During the maintenance treatment, relapses occurred in 4 of 33 patients (12%), seen during the follow-up period, none of which occurred in the group with resistant isolates. There were no significant differences in survival time free of treatment failure (p=0.65) or survival time free of failure or relapse (p=0.38). These results were not affected when tested in a Cox model that included age, CD4T lymphocyte counts, and use of antiretroviral therapy.

Conclusions: In HIV patients with cryptococcosis, the resistance of C. neoformans appeared not to increase the risk of failure or relapse during treatment.