Characteristics of Progressive Multifocal Leukoencephalopathy Associated With Sarcoidosis Without Therapeutic Immune Suppression

Antigen-Specific T Cell Receptor Discovery for Treating Progressive Multifocal Leukoencephalopathy

Background

Progressive multifocal leukoencephalopathy (PML) is a frequently fatal disease of the central nervous system caused by JC virus (JCV). Survival is dependent on early diagnosis and ability to re-establish anti-viral T cell immunity. Adoptive transfer of polyomavirus-specific T cells has shown promise; however, there are no readily available HLA-matched anti-viral T cells to facilitate rapid treatment.

Objective

Identify epitopes of the JCV major capsid protein VP1 that elicit an immune response in the context of human leukocyte antigen allele A*02:01 (HLA-A2) and isolate cognate T cell receptors (TCRs) from healthy donors. Evaluate individual VP1-specific TCRs for their capacity to be expressed in T cells and clear JCV in vitro .

Methods

PBMCs from HLA-A2+ healthy donors were stimulated with peptide libraries tiled across the JCV VP1 protein. Multiple rounds of stimulation were performed to identify the antigens that induced the largest expansion and CD8 + T cell response (measured as INF γ , TNF α , CD137, and CD69 expression). High-affinity, antigen-specific CD8 + T cells were isolated based on intensity of tetramer binding for downstream single-cell TCR sequencing. Candidate TCRs were selected based on tetramer binding affinity and activation assays. Promising TCRs were introduced into the T cell genome via viral transduction for in vitro validation including peptide-pulsed K562 cells and astrocyte cells, and JCV-infected astrocytes.

Results

Four conserved JCV VP1 epitopes (amino acids 100-108, 251-259, 253-262, and 274-283) presented by HLA-A2 were identified. VP1(100-108) consistently elicited the highest level of IFN- γ production from multiple donors and this peptide is in a highly conserved region of VP1. We next identified fourteen high avidity TCRs specific for VP1(100-108). When virally transduced into primary human T cells, seven of these TCRs demonstrated specific binding to VP1(100-108):HLA-A2 tetramers, and four showed increased IFN- γ response when incubated with peptide. Primary CD8 + T cells expressing two of these TCRs cleared both HLA-A2 positive K562 cells and HLA-A2 positive SVG astrocyte cell line presenting exogenously added VP1 peptide at a range of E:T ratios. In addition, both TCR-transduced T cell populations effectively lysed JCV-infected astrocytes.

Conclusions

We identified JCV VP1 epitopes that are immunogenic in the context of HLA-A2 MHC-I, including epitopes that have not been previously described. The VP1(100-108) epitope was used to isolate HLA-A2-restricted TCRs. When cloned into primary human CD8 + T cells, these TCRs recognized VP1 (100-108)-presenting targets, and the transduced T cells conferred cytotoxic activity and eliminated K562 and astrocyte cells displaying the VP1(100-108) peptide and not sham peptide, as well as JCV-infected astrocytes. Taken together, these data suggest that JCV VP1-specific TCRs could be appealing therapeutics for HLA-A2+ individuals with PML in whom intrinsic T cell immunity cannot be rescued.

Case report: Progressive multifocal leukoencephalopathy co-occurring with neurosarcoidosis: early brain biopsy and appropriate therapy for PML resulted in a favorable prognosis

Progressive multifocal leukoencephalopathy (PML) is a rare central nervous system disease caused by JC virus (JCV) infection. Human immunodeficiency virus (HIV) infection is the greatest risk factor for PML. Other immunological diseases, including systemic sarcoidosis, have also been reported as risk factors for PML. Herein, we report a case of PML co-occurring with neurosarcoidosis. Early diagnosis using brain biopsy and appropriate therapeutic interventions achieved favorable outcomes. PML in patients with active intracranial neurosarcoidosis is extremely rare. We believe that it is important to perform brain biopsy at an early stage to allow diagnosis, even for central nervous system involvement with a progressive parenchymal lesion in patients with sarcoidosis, if PML is possible.

Symmetric leukoencephalopathy associated with systemic lupus erythematosus: A systematic review of a distinctive neurorheumatologic syndrome

BACKGROUND

A symmetric leukoencephalopathy can occur in the context of systemic lupus erythematosus (SLE), often as a first manifestation of underlying rheumatologic disease. Recognition of this distinctive syndrome can prompt investigation for SLE when undiagnosed, or prompt treatment initiation when the diagnosis is already known. Earlier recognition of this syndrome could lead to more effective treatment of the disease.

METHODS

Clinical, laboratory, and radiographic features of three patients were described from an academic medical center in the United States with treatment dates between 2015 and 2022. A systematic review of literature from 1991 to 2023 yielded data for an additional 23 patients.

RESULTS

Twenty-six total patients with symmetric leukoencephalopathy were included in this study. The median age of the patients was 37 years (range 10-69), 22 patients (85 %) were female, and 4 (15 %) were male. Fourteen of 26 patients (54 %) had this as the first clinical manifestation of SLE. Contrast enhancement was present on MRI brain in 3/26 (88 %) patients. Twenty patients (77 %) were treated with pulse-dose steroids, and all but one patient received some immunomodulatory therapy. Seven patients (27 %) progressed to death. No meaningful predictive differences were found between patients who survived and those who did not.

CONCLUSIONS

In this case series and literature review patients developed symmetric leukoencephalopathy in systemic lupus erythematosus most often as the first clinical manifestation of SLE. Clinicians should consider this syndrome in any patient with acute onset of symmetric leukoencephalopathy on brain magnetic resonance imaging.

Progressive multifocal leukoencephalopathy in sarcoidosis successfully treated with pembrolizumab

Progressive multifocal leukoencephalopathy (PML) is a severe, demyelinating disease of the central nervous system caused by JC virus infection. The disease can be seen in sarcoidosis patients without additional risk factors. Here, we present an individual with PML secondary to sarcoidosis treated with 8 doses of pembrolizumab, a Programmed Cell-Death-1 (PD-1) Immune Checkpoint Inhibitor who showed significant improvement. This report illustrates the objective clinical and radiological improvement in a patient with PML due to sarcoidosis, and suggests further study of immune checkpoint inhibitors as a potential treatment for sarcoidosis patients with PML.

John Cunningham Virus and Progressive Multifocal Leukoencephalopathy: A Falsely Played Diagnosis

Progressive Multifocal Leukoencephalopathy (PML) is a possibly fatal demyelinating disease and John Cunningham Polyomavirus (JCPyV) is believed to cause this condition. The so-called JCPyV was initially reported in lymphoma and Human Immunodeficiency Virus (HIV) cases, whereas nowadays, its incidence is increasing in Multiple Sclerosis (MS) cases treated with natalizumab (Tysabri). However, there are conflicting literature data on its pathology and diagnosis, whereas some misdiagnosed reports exist, giving rise to further questions towards the topic. In reality, the so-called PML and the supposed JCPyV are not what they seem to be. In addition, novel and more frequent PML-like conditions may be reported, especially after the Coronavirus Disease 2019 (COVID-19) pandemic.

Drug-Induced Progressive Multifocal Leukoencephalopathy (PML): A Systematic Review and Meta-Analysis

INTRODUCTION

Progressive multifocal leukoencephalopathy (PML) was first described among patients affected by hematological or solid tumors. Following the human immunodeficiency virus (HIV) epidemic, people living with HIV have represented most cases for more than a decade. With the diffusion of highly active antiretroviral therapy, this group progressively decreased in favor of patients undergoing treatment with targeted therapy/immunomodulators. In this systematic review and meta-analysis, the objective was to assess which drugs are most frequently related to PML development, and report the incidence of drug-induced PML through a meta-analytic approach.

METHODS

The electronic databases MEDLINE, EMBASE, ClinicalTrials.gov, Web of Science and the Canadian Agency for Drugs and Technologies in Health Database (CADTH) were searched up to May 10, 2022. Articles that reported the risk of PML development after treatment with immunomodulatory drugs, including patients of both sexes under the age of 80 years, affected by any pathology except HIV, primary immunodeficiencies or malignancies, were included in the review. The incidence of drug-induced PML was calculated based on PML cases and total number of patients observed per 100 persons and the observation time. Random-effect metanalyses were conducted for each drug reporting pooled incidence with 95% confidence intervals (CI) and median (interquartile range [IQR]) of the observation time. Heterogeneity was measured by I2 statistics. Publication bias was examined through funnel plots and Egger's test.

RESULTS

A total of 103 studies were included in the systematic review. In our analysis, we found no includible study reporting cases of PML during the course of treatment with ocrelizumab, vedolizumab, abrilumab, ontamalimab, teriflunomide, daclizumab, inebilizumab, basiliximab, tacrolimus, belimumab, infliximab, firategrast, disulone, azathioprine or danazole. Dalfampridine, glatiramer acetate, dimethyl fumarate and fingolimod show a relatively safe profile, although some cases of PML have been reported. The meta-analysis showed an incidence of PML cases among patients undergoing rituximab treatment for multiple sclerosis (MS) of 0.01 cases/100 persons (95% CI - 0.08 to 0.09; I2 = 20.4%; p = 0.25) for a median observation period of 23.5 months (IQR 22.1-42.1). Treatment of MS with natalizumab carried a PML risk of 0.33 cases/100 persons (95% CI 0.29-0.37; I2 = 50%; p = 0.003) for a median observation period of 44.1 months (IQR 28.4-60) and a mean number of doses of 36.3 (standard deviation [SD] ± 20.7). When comparing data about patients treated with standard interval dosing (SID) and extended interval dosing (EID), the latter appears to carry a smaller risk of PML, that is, 0.08 cases/100 persons (95% CI 0.0-0.15) for EID versus 0.3 cases/100 persons (95% CI 0.25-0.34) for SID.

CONCLUSIONS

A higher risk of drug-related PML in patients whose immune system is not additionally depressed by means of neoplasms, HIV or concomitant medications is found in the neurological field. This risk is higher in MS treatment, and specifically during long-term natalizumab therapy. While this drug is still routinely prescribed in this field, considering the efficacy in reducing MS relapses, in other areas it could play a smaller role, and be gradually replaced by other safer and more recently approved agents.

Infectious Complications of Pulmonary Sarcoidosis

In this review, the infectious complications observed in sarcoidosis are considered from a practical point of view to help the clinician not to overlook them in a difficult context, as pulmonary sarcoidosis makes the recognition of superinfections more difficult. An increased incidence of community-acquired pneumonia and of opportunistic pneumonia has been reported, especially in immunosuppressed patients. Pulmonary destructive lesions of advanced sarcoidosis increase the incidence of chronic pulmonary aspergillosis and infection by other agents. Screening and treatment of latent tuberculosis infection are crucial to prevent severe tuberculosis. Severity in COVID-19 appears to be increased by comorbidities rather than by sarcoidosis per se. The diagnosis of infectious complications can be challenging and should be considered as a potential differential diagnosis when the exacerbation of sarcoidosis is suspected. These complications not only increase the need for hospitalizations, but also increase the risk of death. This aspect must be carefully considered when assessing the overall health burden associated with sarcoidosis. The impact of immune dysregulation on infectious risk is unclear except in exceptional cases. In the absence of evidence-based studies on immunosuppressants in the specific context of pulmonary sarcoidosis, it is recommended to apply guidelines used in areas outside sarcoidosis. Preventive measures are essential, beginning with an appropriate use of immunosuppressants and the avoidance of unjustified treatments and doses. This approach should take into account the risk of tuberculosis, especially in highly endemic countries. Additionally, parallel emphasis should be placed on vaccinations, especially against COVID-19.