Distinguishing features of Long COVID identified through immune profiling (preprint)

SARS-CoV-2 infection can result in the development of a constellation of persistent sequelae following acute disease called post-acute sequelae of COVID-19 (PASC) or Long COVID 1–3 . Individuals diagnosed with Long COVID frequently report unremitting fatigue, post-exertional malaise, and a variety of cognitive and autonomic dysfunctions 1–3 ; however, the basic biological mechanisms responsible for these debilitating symptoms are unclear. Here, 215 individuals were included in an exploratory, cross-sectional study to perform multi-dimensional immune phenotyping in conjunction with machine learning methods to identify key immunological features distinguishing Long COVID. Marked differences were noted in specific circulating myeloid and lymphocyte populations relative to matched control groups, as well as evidence of elevated humoral responses directed against SARS-CoV-2 among participants with Long COVID. Further, unexpected increases were observed in antibody responses directed against non-SARS-CoV-2 viral pathogens, particularly Epstein-Barr virus. Analysis of circulating immune mediators and various hormones also revealed pronounced differences, with levels of cortisol being uniformly lower among participants with Long COVID relative to matched control groups. Integration of immune phenotyping data into unbiased machine learning models identified significant distinguishing features critical in accurate classification of Long COVID, with decreased levels of cortisol being the most significant individual predictor. These findings will help guide additional studies into the pathobiology of Long COVID and may aid in the future development of objective biomarkers for Long COVID.

Autonomic conditioning therapy reduces fatigue and improves global impression of change in individuals with post-acute COVID-19 syndrome (preprint)

Post-acute COVID-19 syndrome (PACS) is a collection of persistent and debilitating symptoms lasting weeks to months after acute COVID-19 infection, with fatigue most commonly reported. There is controversy surrounding the role of exercise programs for this condition, due to concerns over the potential to worsen fatigue. We developed a novel physical therapy program known as Autonomic Conditioning Therapy (ACT) for PACS, and report on the preliminary patient-reported outcome (PRO) data from individuals who completed ACT for PACS, compared with those who did not. Seventy-eight (55 [71%] female, median [range] age 43 [12 to 78]) met the inclusion criteria and consented to have their data included in the analyses. A total of 31 (40%) individuals completed ACT for PACS. There was within-group improvement in fatigue in individuals who completed ACT for PACS (mean difference [95% CI] -14 [-27 to -1], p = 0.03), as well as greater between-group impression of change measured on the Patient Global Impression of Change scale (ACT for PACS median [range] 5 [1 to 7], no ACT for PACS 4 [1 to 7], p < 0.01). ACT for PACS is a novel physical therapy program that can reduce fatigue in individuals with PACS.

Post-acute COVID-19 syndrome negatively impacts health and wellbeing despite less severe acute infection (preprint)

Introduction: One of the noted features of COVID-19 is the spectrum of expressivity in symptoms among those with the disease, ranging from no or mild symptoms that may last a small number of days, to severe and/or longer lasting symptoms. It is emerging that many patients have long lasting symptoms, several months after initial infection with COVID-19. The aim of this research was to characterize post-acute COVID-19 syndrome (PACS). Methods: This was a retrospective cross-sectional observational study. Participants were patients recovering from COVID-19 infection, enrolled in Mount Sinai Hospital's COVID-19 Precision Recovery Program (PRP). Inclusion criteria were confirmed or probable (based on World Health Organization criteria) initial diagnosis of COVID-19; post-acute COVID-19 syndrome (defined as experiencing symptoms > 6 weeks since acute symptom onset) and being currently enrolled in the PRP during the months of July and August 2020. Study survey data were collected using REDCap. Demographic data, COVID-19 clinical data and patient-reported outcomes for breathlessness (Medical Research Council Breathlessness Scale), fatigue and quality of life (EuroQoL 5D-5L) were collected. Results: 84 individuals with PACS were included. Symptoms persisted at mean (range) 151 (54 to 255) days. The most prevalent persistent symptoms were fatigue (92%), loss of concentration/memory (74%), weakness (68%), headache (65%) and dizziness (64%). Most participants reported increased levels of disability associated with breathlessness, increased fatigue and reduced quality of life. Conclusions: Persistent symptoms following COVID-19 infection are prevalent, debilitating and appear to affect individuals regardless of acute infection severity or prior health status. More detailed research is required in order to identify specific symptom clusters associated with PACS, and to devise effective interventional strategies.