Autoinflammatory phenotypes in Aicardi-Goutières syndrome with interferon upregulation and serological autoimmune features

To the Editor: Recent advances in molecular genetics have revealed that polymorphisms in the genes implicated in innate immunity via nucleic acid metabolism and type I IFN production underlie a subgroup of autoimmune diseases, such as systemic lupus erythematosus.1 In addition, mutations in the same genes cause several systemic inflammatory syndromes accompanied by type I IFN upregulation and autoimmune features, termed type I interferonopathies, such as Aicardi-Goutières syndrome (AGS [MIM 225750]).2 AGS is an early-onset genetic encephalopathy characterized by microcephaly with basal ganglia calcification and severe developmental delay. Clinical symptoms, serological abnormalities, or both, analogous to those of systemic lupus erythematosus, are frequently observed; however, autoinflammatory disease-like phenotypes have rarely been reported.3 Here, we report a patient with AGS with an IFIH1 mutation who had periodic sterile pyrexia responsive to oral cimetidine therapy, that is, an interesting therapeutic alternative in another uncommon autoinflammatory disease, periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome. [...]the present case illustrates autoinflammatory phenotypes in AGS, which have previously been poorly described compared with autoimmune phenotypes.