Long COVID pathophysiology

A number of research studies have investigated long COVID or Post-Acute Sequelae of COVID-19 (PASC), the long term health problems that occur in a significant minority of people who remained ill for an extended time after developing COVID-19.

Infection and immunity
A range of antibodies have been found in patients with persistent post-acute COVID symptoms. Elevated G-protein coupled receptor autoantibodies have been found. One study founded elevated antinuclear antibody (ANA) titles in 43.6% of long COVID patients twelve months after symptom onset.

Long COVID may be associated herpesvirus reactivation such as Epstein-Barr Virus, which has been shown to cause elevations of certain G-protein coupled receptor autoantibody types.

Pulmonary
In a single cardiopulmonary exercise test, Post-COVID-19 patients exhibited markedly reduced peak exercise aerobic capacity (VO2) compared to controls and impaired oxygen extraction, even in those without cardiopulmonary disease.

Notable studies

 * 2021, 18F-FDG brain PET hypometabolism in patients with long COVID (Full text)
 * 2021, Postural orthostatic tachycardia syndrome (POTS) and other autonomic disorders after COVID-19 infection: a case series of 20 patients (Full text)
 * 2021, Corneal confocal microscopy identifies corneal nerve fibre loss and increased dendritic cells in patients with long COVID (Full text)
 * 2021, Gut microbiota composition reflects disease severity and dysfunctional immune responses in patients with COVID-19 (Full text) - Pre-print
 * 2021, Persistent clotting protein pathology in Long COVID/ Post-Acute Sequelae of COVID-19 (PASC) is accompanied by increased levels of antiplasmin (Full text) - Pre-print
 * 2021, Immunological dysfunction persists for 8 months following initial mild-moderate SARS-CoV-2 infection (Full text) - Pre-print
 * 2021, Clinical characterization of dysautonomia in long COVID-19 patients (Full text)
 * 2021, Persistent Exertional Intolerance after COVID-19: Insights from Invasive Cardiopulmonary Exercise Testing (Full text)
 * 2021, Persistent Endotheliopathy in the Pathogenesis of Long COVID Syndrome (Full text)
 * 2021, Long COVID or Post-acute Sequelae of COVID-19 (PASC): An Overview of Biological Factors That May Contribute to Persistent Symptoms (Full text)
 * 2020, Long COVID-19: Challenges in the diagnosis and proposed diagnostic criteria (Full text)
 * 2020, Multi-organ impairment in low-risk individuals with long COVID (Full text) - Pre-print
 * 2020, Living with covid-19. A dynamic review of the evidence around ongoing covid-19 symptoms (often called long covid) (Full text)

News and articles

 * Aug 2021, When it comes to breakthrough cases, are we ignoring long Covid once again? - Hannah Davis, The Guardian

Learn more

 * Long COVID Resource Hub (database of Long COVID research)