# P-2116. Cryptococcosis in Transplant Recipients: Predictors of Mortality and Clinical Outcome

## TL;DR

This study examines factors affecting mortality and outcomes in transplant recipients with cryptococcosis, identifying key predictors like immunosuppressive therapy and disease severity.

## Contribution

The study identifies non-tac-based immunosuppressive regimens, CNS involvement, and positive blood cultures as significant predictors of higher mortality in transplant recipients with cryptococcosis.

## Key findings

- Non-tac-based immunosuppressive therapy was associated with higher mortality at 90 and 365 days.
- CNS involvement and positive blood cultures were linked to significantly higher 30 and 90-day mortality.
- Relapses and postinfectious inflammatory response syndrome occurred in a small subset of patients.

## Abstract

Cryptococcosis (crypto) is the third most common fungal infection in solid organ transplant recipients (SOTR), remaining a significant cause of morbidity and mortality. Outcomes vary based on disease severity, timing of diagnosis, and immunosuppressive (IS) therapy. Despite advances in antifungal therapy (AFT) and transplant care, crypto remains a significant threat. We describe the demographics, clinical features, and outcomes of crypto in SOTR.

We conducted a retrospective cohort study of SOTR with crypto at a large transplant center between 1996-2023. Demographics, clinical features, IS regimen, AFT, and outcome were collected. Univariate and multivariate analyses were performed to identify factors associated with mortality. For survival analysis, patients were stratified into 4 groups based on blood and CSF cultures.

228 patients were included, mean age was 55 ±12.2 years. Kidney recipients were the most common. Most were transplanted between 2015-2023 and received tacrolimus (tac)-based IS; 40 (17.5%) received non-tac regimens. Crypto meningitis occurred in 51.8%; among these, 58% had positive CSF culture, 11 hydrocephalus, and 3 CNS mass lesions. Median durations for induction, consolidation, and suppression AFT were 14, 60, and 254d, respectively. Mortality at 30, 90, and 365d was 7%, 13%, and 23%, respectively (Table 1). Only 4% received non-fluconazole drugs following induction. Relapses occurred in 2 patients; 3 developed crypto postinfectious inflammatory response syndrome. Tac-based IS was associated with lower mortality at 90d and 365d (p < 0.01; Table 2). CNS involvement and positive blood culture were associated with significantly higher 30d and 90d mortality compared to isolated pulmonary disease (p< 0.01 and p=0.03; Table 3). Survival analysis stratified by blood and CSF cultures did not show a significant difference in overall survival (p=0.14); however, KM curves indicated that patients with positive blood and CSF cultures had higher mortality at 30 and 90d (Graphic 1).

Crypto remains a major cause of mortality in SOTR. Non-tac-based IS, CNS involvement, and positive blood culture were associated with higher mortality. Further research is needed to optimize IS strategies and identify prognostic markers in this population.

Cesar G. Berto, MD, Basilea: Grant/Research Support|Cidara: Grant/Research Support Todd P. McCarty, MD, Basilea: Grant/Research Support|Cidara: Grant/Research Support|F2G: Grant/Research Support|Mundipharma: Grant/Research Support|Pfizer: Advisor/Consultant|Scynexis: Grant/Research Support Peter G. Pappas, MD, Astellas: Grant/Research Support|Basilea: Advisor/Consultant|Basilea: Grant/Research Support|F2G: Advisor/Consultant|Gilead: Grant/Research Support|Melinta: Advisor/Consultant