[Clinical characteristics of 25 patients with type Ⅰ interferonopathies]

Objective: To summarize the clinical characteristics of type I interferonopathies and provide clues for early identification and diagnosis. Methods: Clinical data of 20 patients admitted to Department of Pediatrics, Peking Union Medical College Hospital and 5 patients admitted to Department of Rheumatology and Immunology, Shenzhen Children's Hospital from January 2016 to September 2021 were retrospectively analyzed. The data included gene results, clinical manifestations and auxiliary examination results. Results: Of the 25 cases, 12 were males and 13 were females. Age of onset ranged from 1 day to 11 years. And 84% of them had the onset before the age of 3 years. The cases consisted of 14 cases of Aicardi-Goutières syndrome (AGS), 6 cases of adenosine deaminase 2 deficiency (DADA2), 3 cases of stimulator of interferon genes (STING)-associated vasculopathy with onset in infancy (SAVI), and 2 cases of Spondyloenchondrodysplasia with immune dysregulation (SPENCDI). Eighteen patients (72%) experienced neurologic disorder, among whom 16 (64%) showed intracranial calcification, 11 (44%) had dystonia, 10 (40%) had leukodystrophy, 6 (24%) had epilepsy, 5 (20%) had brain atrophy and 5 (20%) had early-onset cerebrovascular events. Skin involvement occurred in 15 cases (60%), among whom 8 cases (32%) had chilblain-like rash, 4 cases (16%) had livedo reticularis, 3 cases (12%) had erythema, 2 cases (8%) had erythema nodosum and 2 cases (8%) had Raynaud's phenomenon. In addition, 12 cases (48%) had positive autoimmune antibodies, 10 cases (40%) manifested as developmental retardation, 8 cases (32%) experienced lung interstitial lesions, and 7 cases (28%) demonstrated thyroid dysfunction. And 1 died (4%) at 11 years of age. Conclusions: Type Ⅰinterferonopathies can involve multiple organs, and share the characteristics of systemic inflammatory and autoimmune diseases. The early-onset neurological symptoms (early-onset cerebrovascular events, intracranial calcification, leukodystrophy and cerebral atrophy), rashes (chilblain-like rash, livedo reticularis and erythema), positive autoimmune antibodies, developmental delay, interstitial lung disease and thyroid dysfunction may indicate type Ⅰ interferonopathies.