ALT Preprint posted on Aug 20, 2024 to medRxiv: "Soluble IL-2R impairs muscle cell mitochondrial respiration in fatigued individuals with post-acute sequelae of COVID-19." Abstract: "...This study aimed to investigate the underlying mechanisms of PASC-related fatigue by examining skeletal muscle function and circulating factors in affected individuals. We conducted a cross-sectional case-control study of patients with fatigue-associated PASC who had experienced mild to moderate COVID-19 without hospitalization. Skeletal muscle biopsies revealed reduced mitochondrial respiration and content in PASC participants compared to healthy controls. This lower respiratory capacity was accompanied by markedly elevated circulating levels of soluble IL-2 receptor alpha subunit (sIL2R), a T cell-specific receptor. ...These findings suggest a mechanism linking systemic immune dysregulation to muscle-specific mitochondrial dysfunction in PASC."