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

Unusual late presentation of cryptococcal meningitis with simultaneous CMV antigenemia in a kidney transplant recipient

Cryptococcosis is the third most common invasive fungal infection in solid-organ transplant (SOT) recipients after candidiasis and aspergillosis. These patients are at risk of disseminated cryptococcosis because of immuosuppressive therapy. The median time to disease onset after kidney transplantation is approximately 35 months and it rarely occurs more than 10 years after transplantation. Herein, we report a case of 64-year-old kidney transplant recipient suffering from coexisting disseminated cryptococcosis with brain and skin involvement, together with cytomegalovirus (CMV) antigenemia more than 20 years after transplant. She presented with frontal headache and bilateral hand tremor, in addition to multiple nodular lesions over bilateral lower limbs. The diagnosis was made after lumbar puncture and skin biopsy. She was successfully treated with a course of anti-fungal and anti-CMV regimen without any relapse of central nervous system infection. Our case illustrates that disseminated cryptococcosis can occur very late after organ transplant. It is thus important to watch out for late-onset opportunistic infections and strike the balance between risks of infections and rejections in SOT patients.

Central Nervous System Infections in Recipients of Solid Organ Transplant

BACKGROUND

Central nervous system (CNS) infections are severe and life-threatening complications that can occur in solid organ transplant (SOT) recipients. We describe the epidemiology, clinical presentation, diagnosis, disease course, and outcome of CNS infections in SOT.

METHODS

We analyzed data of patients who underwent transplantation from September 2012 to February 2023, diagnosed and treated for CNS infections at our institution in Houston, TX. Data were retrospectively collected from medical charts.

RESULTS

Of 1,345 patients who received a SOT, 30 (2.23%) were diagnosed with CNS infection, with a median age of 63 years, 60% were male. Time to CNS infection onset after transplant in 53.3% of the cases was after the first year. There were 15/30 (50%) cases of fungal infection, 8/30(26.7%) of viral infection, 7/30 (23.3%) of bacterial infection. There were no unknown causes. The most common etiologies were Cryptococcus neoformans 14/30(46.6%), and nocardiosis 3/30 (10%). On presentation, 22 (73.4%) patients had normal mental status, but 21 (70%) reported headaches, and 18 (60%) were febrile. Abnormal neuroimaging was found in 5 cases (16.6%) on computed tomography (CT)-scans and 10 cases (33.3%) on magnetic resonance imaging (MRI) scans. An adverse clinical outcome on discharge was noticed in 33%, and 6.7% died. Fever was associated with an increased risk of adverse clinical outcomes (OR 11; P = .018).

CONCLUSION

The incidence of CNS infections in SOT recipients is low but associated with substantial adverse clinical outcomes. The most common causes are fungal, with no unknown etiologies seen in this study.

Fungal Infections in Kidney Transplant Recipients: A Comprehensive Narrative Review

BACKGROUND

Despite kidney transplantation being a life-saving procedure, patients experience a high risk of developing fungal infections (FIs), with an increased risk of both morbidity and mortality, especially during the first year after transplant.

METHODS

We herein conducted a narrative review of the most common FIs in kidney transplant recipients (KTRs), with a focus on prevalence, risk factors, mortality, and prevention strategies.

RESULTS

The most common fungal pathogens in KTRs include Candida species (up to 70% of the overall FIs), Aspergillus species, Pneumocystis jiroveci, and Cryptococcus species. Fungal colonization, diabetes mellitus, chronic liver disease, malnutrition, and pre-existing lung conditions should all be acknowledged as possible predisposing risk factors. The mortality rate can vary from 25 to 50% and according to different settings and the types of FIs. Preventive strategies are critical for reducing the incidence of FIs in this population. These include antifungal prophylaxis, environmental precautions, and infection control measures. The use of novel tools (such as PCR-based molecular assays and NGS) for rapid and accurate diagnosis may play an important role.

CONCLUSIONS

Early recognition, the appropriate use of antifungal therapy, and preventive strategies are essential for improving graft loss and fatal outcomes in this vulnerable population. Future research is needed to optimize diagnostic tools, identify novel antifungal agents, and develop better prophylactic strategies for high-risk transplant recipients.

Deciphering prognostic indicators in non-HIV cryptococcal meningitis: Constructing and validating a predictive Nomogram model

Cryptococcal meningitis (CM) is a well-recognized fungal infection, with substantial mortality in individuals infected with the human immunodeficiency virus (HIV). However, the incidence, risk factors, and outcomes in non-HIV adults remain poorly understood. This study aims to investigate the characteristics and prognostic indicators of CM in non-HIV adult patients, integrating a novel predictive model to guide clinical decision-making. A retrospective cohort of 64 non-HIV adult CM patients, including 51 patients from previous studies and 13 from the First Hospital of Shanxi Medical University, was analyzed. We assessed demographic features, underlying diseases, intracranial pressure, cerebrospinal fluid characteristics, and brain imaging. Using the least absolute shrinkage and selection operator (LASSO) method, and multivariate logistic regression, we identified significant variables and constructed a Nomogram prediction model. The model's calibration, discrimination, and clinical value were evaluated using the Bootstrap method, calibration curve, C index, goodness-of-fit test, receiver operating characteristic (ROC) analysis, and decision curve analysis. Age, brain imaging showing parenchymal involvement, meningeal and ventricular involvement, and previous use of immunosuppressive agents were identified as significant variables. The Nomogram prediction model displayed satisfactory performance with an akaike information criterion (AIC) value of 72.326, C index of 0.723 (0.592-0.854), and area under the curve (AUC) of 0.723, goodness-of-fit test P = 0.995. This study summarizes the clinical and imaging features of adult non-HIV CM and introduces a tailored Nomogram prediction model to aid in patient management. The identification of predictive factors and the development of the nomogram enhance our understanding and capacity to treat this patient population. The insights derived have potential clinical implications, contributing to personalized care and improved patient outcomes.

Cryptococcal meningitis in a non-HIV patient with solid organ transplantation

Cryptococcal meningitis (CM) is often associated with human immunodeficiency virus (HIV). Recently, this microorganism has been increasingly identified in HIV-negative patients. CM cases are encountered in HIV-negative individuals, especially secondary to liver disease, solid organ transplantation (SOT), tuberculosis, lymphoproliferative diseases with T-cell-mediated immunological disorders, long-term corticosteroid use, malignancies, diabetes mellitus, and sarcoidosis. Our patient is an HIV-negative, SOT case with CM. It should be considered that CM can also occur in HIV-negative patients. As in our case, patients receiving long-term immunosuppressive therapy should be evaluated for CM, and renal functions should be closely monitored during treatment. There is a need for more case reports on the subject, especially in CM detected HIV-negative patients, due to the different treatment protocols and challenging clinical conditions compared to HIV-positive cases.

Specificities of Meningitis and Meningo-Encephalitis After Kidney Transplantation: A French Retrospective Cohort Study

Kidney transplant recipients develop atypical infections in their epidemiology, presentation and outcome. Among these, meningitis and meningoencephalitis require urgent and adapted anti-infectious therapy, but published data is scarce in KTRs. The aim of this study was to describe their epidemiology, presentation and outcome, in order to improve their diagnostic and management. We performed a retrospective, multicentric cohort study in 15 French hospitals that included all 199 cases of M/ME in KTRs between 2007 and 2018 (0.9 case per 1,000 KTRs annually). Epidemiology was different from that in the general population: 20% were due to Cryptococcus neoformans, 13.5% to varicella-zoster virus, 5.5% to Mycobacterium tuberculosis, and 4.5% to Enterobacteria (half of which produced extended spectrum beta-lactamases), and 5% were Post Transplant Lymphoproliferative Disorders. Microorganisms causing M/ME in the general population were infrequent (2%, for Streptococcus pneumoniae) or absent (Neisseria meningitidis). M/ME caused by Enterobacteria, Staphylococci or filamentous fungi were associated with high and early mortality (50%-70% at 1 year). Graft survival was not associated with the etiology of M/ME, nor was impacted by immunosuppression reduction. Based on these results, we suggest international studies to adapt guidelines in order to improve the diagnosis and the probabilistic treatment of M/ME in SOTRs.

Cryptococcus neoformans Presenting as a Lung Mass in an Immunocompromised Patient

BACKGROUND Pulmonary cryptococcosis is an uncommon infection mainly affecting immunocompromised individuals. Presentation of cryptococcal disease ranges from asymptomatic pulmonary colonization to severe pneumonia. It can progress to acute respiratory failure and life-threatening meningoencephalitis. CASE REPORT A 55-year-old woman with a history of a kidney transplant, on immunosuppressive therapy, presented to the hospital with persistent low-grade fever, headache, weight loss, and fatigue for 2 weeks. On arrival, she was tachycardic, normotensive, and saturating 99% on room air. Her chest X-ray showed right middle lung opacity measuring 1.9×2.8 cm. She was admitted and started on broad-spectrum antibiotics for suspected pneumonia. Her chest computed tomography (CT) scan showed a 3.0×1.7 cm hypo-dense opacity at the right upper lobe. Overnight, she developed a severe headache and neck stiffness. Her serum cryptococcal antigen and cerebrospinal fluid culture results were positive. The patient was started on intravenous liposomal amphotericin B plus flucytosine. A CT-guided lung biopsy was performed to rule out malignancy. Cultures came back positive for Cryptococcus neoformans. She completed a 2-week course of amphotericin and flucytosine and was switched to oral fluconazole to complete an 8-week course. CONCLUSIONS Prompt diagnosis and effective management of the cryptococcal disease can decrease morbidity and mortality. Diagnosis requires CT-guided lung biopsy, with culture growing mucoid colonies of Cryptococcus neoformans. Antifungal therapy with intravenous liposomal amphotericin B plus flucytosine is the mainstay of treatment. Clinicians should be aware of the various presentations of pulmonary cryptococcosis, especially in immunocompromised patients.