Immune Exhaustion in ME/CFS and long COVID

Gene expression analysis of RNA was performed using the commercially available NanoString® nCounter Immune Exhaustion gene expression panel (NanoString Technologies, Seattle, WA, USA). This panel contains 785 genes to elucidate mechanisms behind T cell, B cell and NK cell exhaustion in disease. Ribonucleic acid (RNA) was extracted from peripheral blood mononuclear cells (PBMCs) isolated from ME/CFS (n=14), long COVID (n=15), and healthy control (HC; n=18) participants. ME/CFS participants were included according to Canadian Consensus Criteria for ME. Long COVID participants were eligible according to the working case definition for Post COVID-19 Condition published by the World Health Organization. Raw gene expression data was normalised against positive and negative controls to account for background noise and platform-associated variation. Normalisation and analysis were performed using Rosalind Bio (San Diego, CA, USA) using geometric means of housekeeping genes (ABCF1, ALAS1, EEF1G, G6PD, GAPDH, GUSB, HPRT1, OAZ1, POLR1B, POLR2A, PPIA, RPL19, SDHA, TBP, TUBB) (Supplementary Material 1). Differential expression is reported between ME/CFS and long COVID with HC.