Blood test may unlock long COVID secrets

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

A/ Inclusion Criteria: * For all patients: * Age \> 18 years * Symptomatic COVID-19 diagnosed after 01JAN2021, confirmed by RT-PCR or Antigen test * Last SARS-CoV-2 infection diagnosed more than 12 weeks before inclusion * Patient covered by the French health insurance * Signature of the informed consent * For patient with Long COVID : * At least one of the following symptoms during the week preceding inclusion: abnormal fatigue, dyspnoea sine materia, abnormal pain (chest, joint, muscle, headache), unusual neurocognitive disorders (concentration disorders, "brain fog", language/memory disorders, paraesthesia) * Absence of Return to Usual Health after SARS-CoV-2 infection (patient declaration) * Absence of alternative diagnosis for the symptoms * For COVID-19 recovered patient (Control) : * None of the following symptoms in the 3 week before inclusion: abnormal fatigue, dyspnoea sine materia, abnormal pain (chest, joint, muscle, headache), unusual neurocognitive disorders (concentration disorders, "brain fog", language/memory disorders, paraesthesia) * Return to Usual Health after SARS-CoV-2 infection (patient declaration) B/ Exclusion Criteria: * History of severe COVID-19 (Hospitalization) * Symptoms caused by sequelae of SARS-CoV-2 infection (in particular, persistence of lung parenchymal abnormalities : pulmonary fibrosis, persistent alveolitis on CT-Scan) * Significant Depression or anxiety symptoms, as assessed by a \> 10 score on the A or D items of the Hospital anxiety and depression scale (HAD) * Presence of one of the following diseases: * Inborn errors of metabolism * estimated Glomerular filtration rate \< 30 ml/min (MDRD) * Autoimmune disease * Immunosuppressive treatment or immune deficiency * Symptomatic heart failure * Respiratory failure (COPD stage ≥ 3 or oxygen therapy) * Solid cancer or active blood disease * Severe malnutrition (albumin \< 30 g/L or weight loss ≥10% in 6 months) * Obesity with BMI ≥ 35 kg/m² * Diabetes not controlled by diet alone * Pregnant, breastfeeding or parturient women * Deprivation of liberty by judicial or administrative decision * Mandatory Psychiatric Care * Protected by decision of law * Unable to express consent