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

Symptomatic central nervous system infections in kidney transplant recipients: a 20-years multicenter observational study

BACKGROUND

Central nervous system (CNS) infections in kidney transplant recipients (KTRs) remain poorly characterized, with current evidence largely derived from isolated case reports over the past two decades. This multicenter study aims to systematically delineate the epidemiology, clinical profiles, and outcomes of CNS infections in a large KTR cohort.

METHODS

We conducted a retrospective analysis of 3,602 KTRs across three transplant centers in China (May 2004-July 2024). CNS infections were defined by: 1) neurological symptoms/signs, and 2) microbiological confirmation via cerebrospinal fluid (CSF) analysis, including metagenomic next-generation sequencing (mNGS) and routine microbiologic testing (bacterial and fungal cultures).

RESULTS

CNS infections were diagnosed in 0.53% of KTRs (19/3602), with symptom onset occurring 2-121 months post-transplantation. Etiologies included bacterial (47%, 9/19), viral (32%, 6/19), and fungal (21%, 4/19) pathogens. Notably, 79% of cases (15/19) were exclusively identified by mNGS, whereas conventional cultures failed detection. Presenting symptoms included headache (79%) and altered mental status (42%). Mortality reached 42% (8/19) within 9-22 days of diagnosis; among survivors, 73% (8/11) exhibited neurological sequelae.

CONCLUSIONS

CNS infections in KTRs are rare but characterized by rapid progression and high fatality rate. While the risk of CNS infections persists throughout the post-transplant period, 1-6 months after transplantation is a higher-incidence period of CNS infections. KTRs with neurological symptoms (particularly headache and elevated CSF pressure) should undergo CSF mNGS which is critical in diagnosing such infections.

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.

Late-Onset HSV-2 Encephalitis in a Kidney Transplant Recipient: A Rare Case Report

Infections are an important cause of morbidity and mortality in renal transplant recipients. Among the viral pathogens encountered in this population, herpes simplex virus (HSV), a member of the Alphaherpesvirinae subfamily, has an important place. HSV type 2 infections in this immunosuppressed population are primarily due to viral reactivation. While HSV-2 frequently presents as genital herpes or remains asymptomatic, in rare cases, it can lead to severe neurological manifestations, such as encephalitis, particularly in the early post-transplant period with a reported mortality rate of up to 40%. We present the case of a 49-year-old male who, three years after kidney transplantation, developed acute neurological symptoms, including aphasia and disorientation. Polymerase chain reaction (PCR) analysis of cerebrospinal fluid (CSF) identified HSV-2 as the causative pathogen, enabling a swift and accurate diagnosis. The patient was promptly treated with intravenous acyclovir, adjusted for renal function, resulting in complete neurological recovery and subsequent negative follow-up CSF PCR results. This case emphasizes the vital role of PCR diagnostics as the gold standard for confirming viral encephalitis, particularly in immunosuppressed patients, where atypical presentations can complicate diagnosis. It also highlights the importance of considering HSV-2 encephalitis in the differential diagnosis even beyond the immediate post-transplant period. Early recognition and management, facilitated by the multidisciplinary approach, are critical for improving outcomes in this vulnerable patient population.

Solid organ transplant-related central nervous system infections

PURPOSE OF REVIEW

Central nervous system (CNS) infections in solid organ transplant (SOT) recipients may present atypical or nonspecific symptoms. Due to a wider range of infectious agents compared with immunocompetent hosts, diagnosis is challenging. This review categorizes CNS infections in SOT recipients by cause.

RECENT FINDINGS

New studies have reported new data on the epidemiology and the risk factors associated with each specific pathogen described in this review. Additionally, we included the treatment recommendations.

SUMMARY

The latest findings give us an insight into the different pathogens causing infectious neurologic complications in SOT recipients.

Severe meningoencephalitis: epidemiology and outcomes

PURPOSE OF REVIEW

This article aims to provide an updated review on the epidemiology and outcomes of severe meningoencephalitis.

RECENT FINDINGS

Meningoencephalitis is a critical medical condition characterized by inflammation in both the meninges and brain parenchyma. Bacterial, viral, or fungal infections are common causes, although noninfectious factors, such as autoimmune causes, can also contribute. In patients requiring intensive care, meningoencephalitis is associated with a severe prognosis, including mortality rates ranging from 11 to 25% and functional disability in 15-25% of survivors. Recent multicenter studies have identified several parameters linked to poor outcomes, including older age, immunocompromised status, focal neurologic signs, abnormal brain imaging, and delayed administration of antimicrobials. The use of new multiplex PCR techniques for diagnosis has generated debate based on recent data. Investigation is still needed to determine the effectiveness of adjunctive therapies, including seizure prophylaxis, and adjunctive steroids for nonbacterial causes.

SUMMARY

Recent multicenter studies have enhanced our understanding of the current epidemiology and outcomes of severe meningoencephalitis in adult patients.