# Adaptive immune responses against common viruses are sustained and functional in end-of-life patients

## TL;DR

The immune system of patients nearing the end of life can still effectively respond to common viruses like CMV.

## Contribution

This study is the first to show that both antibody and T cell responses to viruses remain functional in end-of-life patients.

## Key findings

- Memory T cells in end-of-life patients show elevated activation markers but retain functionality.
- CMV-specific CD8+ T cells are more polyfunctional in these patients compared to controls.
- Cytotoxic T cell markers correlate with survival time in end-of-life patients.

## Abstract

Viral infections occur with increased frequency in patients in palliative care, impacting their quality of life and increasing mortality rates. Still, the function of the immune system has never been thoroughly studied at the end of life. We investigated virus-specific humoral and cellular immune responses in elderly end-of-life patients (n = 38) and controls (n = 28). Virus-specific T cell responses were characterized using high-parameter flow cytometry, after stimulation with cytomegalovirus (CMV) and human coronavirus OC43 peptides. Although some virus-specific T cells from patients exhibited elevated expression of costimulatory and coinhibitory molecules, their functional profile remained largely intact compared to controls. The expression of the cytotoxic markers Granzyme B, CD107a, and 2B4 on CMV-specific T cells correlated closely with survival time. Significantly, our data demonstrate that both humoral and cellular immunity remain responsive and functional against common viruses in end-of-life patients.

•Humoral immunity against acute and chronic viruses is sustained at the end of life•Memory T cells display elevated activation but remain functional at the end of life•CMV-specific CD8+ T cells are more polyfunctional in end-of-life patients•The cytotoxic capacity of CMV-specific T cells is linked to patients’ survival time

Humoral immunity against acute and chronic viruses is sustained at the end of life

Memory T cells display elevated activation but remain functional at the end of life

CMV-specific CD8+ T cells are more polyfunctional in end-of-life patients

The cytotoxic capacity of CMV-specific T cells is linked to patients’ survival time

Health sciences; Medicine; Medical specialty; Immunology