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

Abstract

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.