Cryptococcus neoformans meningitis in kidney transplant recipients: A diagnostic and therapeutic challenge.

Cryptococcosis is the third most common invasive fungal infection in solid organ transplant recipients. We describe three cases of neuro-meningeal cryptococcosis occurring among kidney transplant (KT) patients, and discuss the diagnostic and therapeutic challenges in this context. Median time from KT to infection was 6 months [range: 3-9]. The most common clinical manifestations at diagnosis were fever (2/3), headache (2/3), and confusion (2/3); none had extra-neurological involvement. CrAg was positive in all cases at diagnosis both in serum and cerebrospinal fluid (CSF). For two patients, analysis of previous samples showed that CrAg was detected in plasma up to 4 weeks before diagnosis. All patients received induction treatment with liposomal amphotericin-B (L-AmB) and flucytosine for a median duration of 10 days [range: 7-14], followed by fluconazole maintenance therapy. Acute kidney injury secondary to L-AmB therapy was observed in only one case, but all patients had a tacrolimus overdose following initiation of maintenance therapy due to drug-drug interactions between fluconazole and tacrolimus. Among KTR, early detection of Cryptococcus meningitis using serum CrAg is possible. Close monitoring of renal function during treatment is essential due to the nephrotoxicity of L-AmB, but also drug-drug interactions between fluconazole and calcineurin inhibitors.