Cryptococcal meningitis in a kidney transplant recipient: Navigating diagnostic and management challenges. A case report

Cryptococcal meningitis is a rare but serious opportunistic infection in solid organ transplant recipients, characterised by high mortality in the context of chronic immunosuppression. We report a 69-year-old renal transplant recipient who presented with a one-month history of non-specific constitutional symptoms without classical features of meningitis, resulting in a delayed clinical diagnosis. Cerebrospinal fluid direct smear was positive for capsulated, budding yeast cells, and culture grew Cryptococcus species. The Cryptococcal antigen test was positive. Management was promptly initiated with induction therapy using liposomal amphotericin B and fluconazole, along with a reduction in overall immunosuppression.  Management was complicated by a significant tacrolimus-fluconazole interaction, which required frequent tacrolimus dose adjustments, as well as amphotericin-related hypokalaemia and hypomagnesemia. He also developed complications of cryptococcal immune reconstitution inflammatory syndrome (C-IRIS), which were managed with a modest increase in the steroid dose. Treatment doses and duration were guided by improvement of clinical symptoms and repeated CSF evaluation. The duration of the induction phase was extended to 4 weeks, and the fluconazole dose was increased due to persistent CSF abnormalities. The patient was later transitioned to the consolidation and then maintenance phases of fluconazole treatment due to a good treatment response. This case highlights the importance of maintaining a high index of suspicion for CM as well as the therapeutic complexities in its management in kidney transplant recipients.