Cryptococcosis in Renal Transplant Recipients: A Single-Center Experience

In solid organ transplant patients, 8% of invasive fungal infections are attributed to Cryptococcus. The aim of this study was to determine the frequency, risk factors, clinical characteristics, and outcome of kidney transplant recipients (TR) infected with Cryptococcus.

Between 2007 and 2014, a total of 500 kidney transplantations were performed at São João Hospital, in Porto, Portugal. Six infections by C. neoformans were reported, an incidence of 1.2% (3 disseminated, 2 meningeal, and 1 cutaneous). Patients were 65-72 years of age and 4 of 6 were male, compared with all kidney TR, among whom the mean age was 51.1 years and 60% were male. Three cases of crytococcosis occurred within the first 6 months after transplantation; 3 patients had cytomegalovirus infection and leukopenia, and 2 patients' immunosuppression had been increased in the last 6 months. Meningitis presented with headache, fever, and acute mental confusion; pulmonary involvement presented with respiratory insufficiency and infiltrative or nodular lung lesions; and cutaneous infections presented as cellulitis or skin abscess. Blood cultures for C. neoformans were positive in 3 cases; all of these patients had positive cryptococcal antigen of 1:128 to 1:8192. Five patients received liposomal amphotericin B for 9-21 days, followed by fluconazole. Four patients lost their grafts, and one patients died after a persistent vegetative state due to cryptococcal meningitis.

This small case series led to suspicion of an association between cryptococcosis and older age, renal dysfunction, cytomegalovirus infection, and intensification of immunosuppression after rejection episodes. In our series, cryptococcosis was associated with poor graft outcome.