Identifying CNS infections in transplantation and immunomodulatory therapy

Abstract

Opportunistic central nervous system (CNS) infections are a significant cause of morbidity and mortality in immunocompromized patients, including those undergoing transplantation and receiving immunomodulatory therapy. Particularly in these individuals, the clinical presentation of these infections may have atypical patterns, emphasizing the need to consider various diagnostic possibilities, including noninfectious conditions. Quick and accurate identification, along with prompt treatment, is crucial for improving patient outcomes. Therefore, understanding which pathogens are likely to cause infection based on factors such as timing post-transplantation, specific organ transplant, and the mechanism of action of immunomodulatory medications is essential. This review will provide a detailed description of the types of infections that may arise in the context of transplantation and immunomodulatory therapy.

Keywords: CNS infections; immunomodulatory therapy; transplantation.

Figure 1.

Timeline of pathogen occurrence following transplantation. Figure created by the authors. *Cryptococcus: Lung > liver.

Figure 2.

Imaging findings of PML on MRI. Axial brain images of a patient presenting with PML lesions, with asymmetric and bilateral hyperintensities on T2 weighted images (T2/FLAIR) in the white matter. PML, progressive multifocal leukoencephalopathy.

Figure 3.

Imaging findings of PTLD on MRI. Axial brain images of a patient presenting with CNS-PTLD. (a) T1-weighted post-gadolinium image shows a focal ring enhancing lesion in the left sub-insular region. (b) T2 weighted image (T2/FLAIR) with perilesional edema compromising the left hemisphere. CNS, central nervous system; PTLD, posttransplant lymphoproliferative disorder.