Encephalitis in HIV-negative immunodeficient patients: a prospective multicentre study, France, 2016 to 2019

BackgroundData on infectious encephalitis in immunodeficient (ID) individuals are scarce. This population may present with atypical clinical symptoms, be infected by uncommon pathogens and develop poor outcomes.AimWe aimed to describe the epidemiology of infectious encephalitis among HIV-negative ID patients.MethodsPatients from the ENCEIF (Etude Nationale de Cohorte des Encéphalites Infectieuses en France) prospective cohort meeting criteria for infectious encephalitis between January 2016 and December 2019 were included. We compared clinical presentation, magnetic resonance imaging (MRI) results, biological results, infection causes and outcome of ID patients with immunocompetent (IC) patients using Pearson's chi-squared test and Student's t-test. We carried out logistic regression to assess the role of immunodeficiency as risk factor for poor outcome.ResultsID patients (n = 58) were older (mean 72 vs 59 years), had higher prevalence of diabetes (26% vs 12%), pre-existing neurological disorders (12% vs 5%) and higher case-fatality rate (23.6% vs 5.6%) compared to IC patients (n = 436). Varicella zoster virus was the primary cause of encephalitis in ID patients (this aetiology was more frequent in ID (25.9%) than in IC patients (11.5%)), with herpes simplex virus second (22.4% in ID patients vs 27.3% in IC patients). Immunodeficiency was an independent risk factor for death or major sequelae (odds ratio: 3.41, 95%CI: 1.70-6.85).ConclusionsVaricella zoster virus is the most frequent cause of infectious encephalitis in ID patients. Immunodeficiency is a major risk factor for poor outcome. ID encephalitis patients should benefit from stringent investigation of cause and early empiric treatment.

Latent human herpesvirus 6 is reactivated in CAR T cells

Cell therapies have yielded durable clinical benefits for patients with cancer, but the risks associated with the development of therapies from manipulated human cells are understudied. For example, we lack a comprehensive understanding of the mechanisms of toxicities observed in patients receiving T cell therapies, including recent reports of encephalitis caused by reactivation of human herpesvirus 6 (HHV-6)1. Here, through petabase-scale viral genomics mining, we examine the landscape of human latent viral reactivation and demonstrate that HHV-6B can become reactivated in cultures of human CD4+ T cells. Using single-cell sequencing, we identify a rare population of HHV-6 'super-expressors' (about 1 in 300-10,000 cells) that possess high viral transcriptional activity, among research-grade allogeneic chimeric antigen receptor (CAR) T cells. By analysing single-cell sequencing data from patients receiving cell therapy products that are approved by the US Food and Drug Administration2 or are in clinical studies3-5, we identify the presence of HHV-6-super-expressor CAR T cells in patients in vivo. Together, the findings of our study demonstrate the utility of comprehensive genomics analyses in implicating cell therapy products as a potential source contributing to the lytic HHV-6 infection that has been reported in clinical trials1,6-8 and may influence the design and production of autologous and allogeneic cell therapies.

Adrenal Crisis Presenting as Recurrent Encephalopathy Mimicking Autoimmune, Infectious Encephalitis, and Common Variable Immune Deficiency: A Case Report

INTRODUCTION

Adrenal crisis can present with life-threatening complications and mimic autoimmune or infectious encephalitis, and common variable immune deficiency (CVID). The literature regarding the neurological complications of adrenal crisis is limited and focuses on patients who present with hypotension and electrolyte abnormalities.

CASE REPORT

A 30-year-old man presented 3 times to our hospital with encephalopathy, fever, and left sided weakness with a history of multiple autoimmune diseases and prior hospitalizations for encephalopathy. During his first 2 admissions, he was normotensive and without electrolyte abnormalities. Extensive workup for infectious, paraneoplastic, seizure, metabolic, toxic, and vascular etiologies, and autoimmune encephalitis was negative. His exam returned to baseline with empiric steroid treatment, and he was discharged. He re-presented 2 months later with encephalopathy for a third admission. During this subsequent presentation, he had hyponatremia, low serum osmolality, elevated urine sodium, undetectable morning cortisol, and 21-α hydroxylase autoantibodies. A diagnosis of autoimmune adrenal insufficiency was established, he was treated with physiological doses of hydrocortisone and fludrocortisone, and improved rapidly to near baseline function. He has remained relapse-free at 4-year follow up. During all admissions, he was also found to have low immunoglobulin G levels and met criteria for CVID; however, his immunoglobin levels recovered with steroid replacement.

CONCLUSION

The reported patient demonstrated some of the neurological complications of adrenal crisis which can mimic other autoimmune conditions such as CVID. The neurologist should be aware that recurrent encephalopathy from adrenal insufficiency can occur regardless of hemodynamic or electrolyte changes on typical hospital metabolic panels.

Toxoplasmic Encephalitis with Untreated Hairy Cell Leukemia Variant

Toxoplasmic encephalitis is a rare infectious complication in patients with hematological malignancy except for allogeneic hematopoietic stem cell transplantation (HSCT). We herein report a case of possible toxoplasmic encephalitis with untreated hairy cell leukemia variant. Magnetic resonance imaging showed multiple nodules with surrounding edema in the entire cerebrum. A polymerase chain reaction analysis for Toxoplasma gondii was negative. Her signs and symptoms fully recovered by empirical therapy with sulfadiazine and pyrimethamine. Toxoplasmic encephalitis may occur in patients who undergo non-allogeneic HSCT for hematological malignancies, even in those who have not been treated.