Cryptococcosis in Transplant Recipients
Cryptococcosis is one of the most significant opportunistic fungal infections in solid organ transplant (SOT) recipients. Disease presentation and principles of management of cryptococcosis in other hosts are relevant in transplant recipients. This chapter summarizes the current knowledge and topical developments in the epidemiologic characteristics, clinical manifestations, diagnosis, and management of cryptococcosis in transplant recipients. Cryptococcosis is the third most commonly occurring invasive fungal disease in SOT recipients. Most cryptococcal disease in SOT recipients is due to Cryptococcus neoformans var. grubii (serotype A), which has no particular geographic predilection. Calcineurin inhibitors are currently the mainstay of immunosuppression in SOT recipients. Cutaneous cryptococcosis can present as papular, nodular, or ulcerative lesions; cellulitis; or necrotizing fasciitis. While cutaneous lesions largely represent hematogenous dissemination, skin has also been identified as a portal of entry of Cryptococcus and a potential source of subsequent disseminated disease in SOT recipients. Rapid reduction of immunosuppressive therapy in conjunction with initiation of antifungal therapy in SOT recipients may lead to the development of immune reconstitution syndrome (IRS), the clinical manifestations of which mimic worsening disease due to cryptococcosis. Cryptococcosis occurs rarely in hematopoietic stem cell transplant (HSCT) recipients. Lipid formulations of amphotericin B are recommended in lieu of amphotericin B deoxycholate owing to the risk of nephrotoxicity when concurrently administered with a calcineurin inhibitor and owing to the significant number of transplant patients with underlying renal dysfunction at the time of diagnosis. Reduction in immunosuppressive therapy should be considered in transplant recipients diagnosed with cryptococcosis.
