UG2 CD8 encephalitis in HIV: a review of this emerging entity

Abstract

Introduction

Encephalitis is a life-threatening neurological condition. CD8 Encephalitis (CD8E) is a newly recognised condition in the setting of Human Immunodeficiency Virus (HIV) infection which can present acutely with classical radiological findings and brain parenchymal infiltration of CD8+ T-cells. This review attempted to clarify symptomatology and determinants of this condition.

Methods

A literature review was conducted, utilising PubMed and Google Scholar databases, reviewing papers published between 2006–2022. Eighteen papers, totalling 57 patients, were identified and analysed. Statistical analysis was undertaken using Chi-squared and Wilcoxon rank-sum tests, with p<0.05 deemed significant.

Results

Among the cohort, a female (61%) and Black African (70%) preponderance was identified. Headache was commoner in females (p=0.006) and in those who died (p=0.02). There was no statistically significant association between baseline CD4 count (p=0.079) and viral load (p=0.72) with mortality. Overall, 77% of patients had classical radiological findings of gadolinium-enhancing punctate and perivascular white matter lesions, with many requiring a brain biopsy to confirm the diagnosis. CSF analysis typically showed lymphocytic pleocytosis, demonstrating CD8+ predominance in 90% of where the lymphocyte subset was tested. Corticosteroids were commonly prescribed (64%) and demonstrated mortality benefit, with an overall survival in this group of 71% (p=0.0008). In those who died, the median survival was 5.5 months.

Discussion

Amongst symptoms, headache appeared more common in females and was significantly associated with death. CD8E is likely under-diagnosed, possibly due to overlapping features with other illnesses and lack of physician experience. Corticosteroids demonstrated a mortality benefit, but more studies should determine their optimal dosing, duration, and use of steroid-sparing agents. Further research should better identify risk factors and non-invasive biomarkers to predict poor prognosis and disease recurrence.