Abstract: “Recessive or dominant inborn errors of type I interferon (IFN) immunity can underlie critical COVID-19 pneumonia in unvaccinated adults. The risk of COVID-19 pneumonia in unvaccinated children, which is much lower than in unvaccinated adults, remains unexplained. In an international cohort of 112 children (<16 yr old) hospitalized for COVID-19 pneumonia, we report 12 children (10.7%) aged 1.5-13 yr with critical (7 children), severe (3), and moderate (2) pneumonia and 4 of the 15 known clinically recessive and biochemically complete inborn errors of type I IFN immunity: X-linked recessive TLR7 deficiency (7 children) and autosomal recessive IFNAR1 (1), STAT2 (1), or TYK2 (3) deficiencies. Fibroblasts deficient for IFNAR1, STAT2, or TYK2 are highly vulnerable to SARS-CoV-2. These 15 deficiencies were not found in 1,224 children and adults with benign SARS-CoV-2 infection without pneumonia (P = 1.2 × 10-11) and with overlapping age, sex, consanguinity, and ethnicity characteristics. Recessive complete deficiencies of type I IFN immunity may underlie ∼10% of hospitalizations for COVID-19 pneumonia in children.”
Zhang Q, Matuozzo D, Le Pen J, Lee D, Moens L, Asano T, Bohlen J, Liu Z, Moncada-Velez M, Kendir-Demirkol Y, Jing H, Bizien L, Marchal A, Abolhassani H, Delafontaine S, Bucciol G; COVID Human Genetic Effort, Bayhan GI, Keles S, Kiykim A, Hancerli S, Haerynck F, Florkin B, Hatipoglu N, Ozcelik T, Morelle G, Zatz M, Ng LFP, Lye DC, Young BE, Leo YS, Dalgard CL, Lifton RP, Renia L, Meyts I, Jouanguy E, Hammarström L, Pan-Hammarström Q, Boisson B, Bastard P, Su HC, Boisson-Dupuis S, Abel L, Rice CM, Zhang SY, Cobat A, Casanova JL. Recessive inborn errors of type I IFN immunity in children with COVID-19 pneumonia. J Exp Med. 2022 Aug 1;219(8):e20220131. doi: 10.1084/jem.20220131. Epub 2022 Jun 16. PMID: 35708626; PMCID: PMC9206114.
https://pubmed.ncbi.nlm.nih.gov/35708626/
and see also:
Shih HP, Ding JY, Sotolongo Bellón J, Lo YF, Chung PH, Ting HT, Peng JJ, Wu TY, Lin CH, Lo CC, Lin YN, Yeh CF, Chen JB, Wu TS, Liu YM, Kuo CY, Wang SY, Tu KH, Ng CY, Lei WT, Tsai YH, Chen JH, Chuang YT, Huang JY, Rey FA, Chen HK, Chang TW, Piehler J, Chi CY, Ku CL. Pathogenic autoantibodies to IFN-γ act through the impedance of receptor assembly and Fc-mediated response. J Exp Med. 2022 Sep 5;219(9):e20212126. doi: 10.1084/jem.20212126. Epub 2022 Jul 14. PMID: 35833912; PMCID: PMC9287643.
Abstract: “Anti-interferon (IFN)-γ autoantibodies (AIGAs) are a pathogenic factor in late-onset immunodeficiency with disseminated mycobacterial and other opportunistic infections. AIGAs block IFN-γ function, but their effects on IFN-γ signaling are unknown. Using a single-cell capture method, we isolated 19 IFN-γ-reactive monoclonal antibodies (mAbs) from patients with AIGAs. All displayed high-affinity (KD < 10-9 M) binding to IFN-γ, but only eight neutralized IFN-γ-STAT1 signaling and HLA-DR expression. Signal blockade and binding affinity were correlated and attributed to somatic hypermutations. Cross-competition assays identified three nonoverlapping binding sites (I-III) for AIGAs on IFN-γ. We found that site I mAb neutralized IFN-γ by blocking its binding to IFN-γR1. Site II and III mAbs bound the receptor-bound IFN-γ on the cell surface, abolishing IFN-γR1-IFN-γR2 heterodimerization and preventing downstream signaling. Site III mAbs mediated antibody-dependent cellular cytotoxicity, probably through antibody-IFN-γ complexes on cells. Pathogenic AIGAs underlie mycobacterial infections by the dual blockade of IFN-γ signaling and by eliminating IFN-γ-responsive cells.”
