Interindividual clinical variability in the course of SARS-CoV-2 infection is immense. We report that at least 101 of 987 patients with life-threatening COVID-19 pneumonia had neutralizing IgG auto-Abs against IFN-ω (13 patients), the 13 types of IFN-α (36), or both (52), at the onset of critical disease; a few also had auto-Abs against the other three type I IFNs. The auto-Abs neutralize the ability of the corresponding type I IFNs to block SARS-CoV-2 infection in vitro. These auto-Abs were not found in 663 individuals with asymptomatic or mild SARS-CoV-2 infection and were present in only 4 of 1,227 healthy individuals. Patients with auto-Abs were aged 25 to 87 years and 95 were men. A B cell auto-immune phenocopy of inborn errors of type I IFN immunity underlies life-threatening COVID-19 pneumonia in at least 2.6% of women and 12.5% of men.

Clinical outcome upon infection with SARS-CoV-2 ranges from silent infection to lethal COVID-19. We have found an enrichment in rare variants predicted to be loss-of-function (LOF) at the 13 human loci known to govern TLR3- and IRF7-dependent type I interferon (IFN) immunity to influenza virus, in 659 patients with life-threatening COVID-19 pneumonia, relative to 534 subjects with asymptomatic or benign infection. By testing these and other rare variants at these 13 loci, we experimentally define LOF variants in 23 patients (3.5%), aged 17 to 77 years, underlying autosomal recessive or dominant deficiencies. We show that human fibroblasts with mutations affecting this pathway are vulnerable to SARS-CoV-2. Inborn errors of TLR3- and IRF7-dependent type I IFN immunity can underlie life-threatening COVID-19 pneumonia in patients with no prior severe infection.

Sarcoidosis is a systemic disease of unknown cause that is characterised by the formation of immune granulomas in various organs, mainly the lungs and the lymphatic system. Studies show that sarcoidosis might be the result of an exaggerated granulomatous reaction after exposure to unidentified antigens in individuals who are genetically susceptible. Several new insights have been made, particularly with regards to the diagnosis and care of some important manifestations of sarcoidosis. The indications for endobronchial ultrasound in diagnosis and for PET in the assessment of inflammatory activity are now better specified. Recognition of unexplained persistent disabling symptoms, fatigue, small-fibre neurological impairment, cognitive failure, and changes to health state and quality of life, has improved. Mortality in patients with sarcoidosis is higher than that of the general population, mainly due to pulmonary fibrosis. Predicted advances for the future are finding the cause of sarcoidosis, and the elucidation of relevant biomarkers, reliable endpoints, and new efficient treatments, particularly in patients with refractory sarcoidosis, lung fibrosis, and those with persistent disabling symptoms.