Inherited IFNAR1 Deficiency in a Child with Both Critical COVID-19 Pneumonia and Multisystem Inflammatory Syndrome
Hassan Abolhassani, Nils Landegren, Paul Bastard, Marie Materna, Mohammadreza Modaresi, Likun Du, Maribel Aranda‐Guillén, Fabian Sardh, Fanglei Zuo, Peng Zhang, Harold Marcotte, Nico Marr, Taushif Khan, Manar Ata, Fatima Alali, Rémi Pescarmona, Alexandre Bélot, Vivien Béziat, Qian Zhang, Jean‐Laurent Casanova, Olle Kämpe, Shen‐Ying Zhang, Lennart Hammarström, Qiang Pan‐Hammarström
Abstract
BACKGROUND: Inborn errors of immunity (IEI) and autoantibodies to type I interferons (IFNs) underlie critical COVID-19 pneumonia in at least 15% of the patients, while the causes of multisystem inflammatory syndrome in children (MIS-C) remain elusive. OBJECTIVES: To detect causal genetic variants in very rare cases with concomitant critical COVID-19 pneumonia and MIS-C. METHODS: Whole exome sequencing was performed, and the impact of candidate gene variants was investigated. Plasma levels of cytokines, specific antibodies against the virus, and autoantibodies against type I IFNs were also measured. RESULTS: We report a 3-year-old child who died on day 56 of SARS-CoV-2 infection with an unusual clinical presentation, combining both critical COVID-19 pneumonia and MIS-C. We identified a large, homozygous loss-of-function deletion in IFNAR1, underlying autosomal recessive IFNAR1 deficiency. CONCLUSIONS: Our findings confirm that impaired type I IFN immunity can underlie critical COVID-19 pneumonia, while suggesting that it can also unexpectedly underlie concomitant MIS-C. Our report further raises the possibility that inherited or acquired dysregulation of type I IFN immunity might contribute to MIS-C in other patients.