Mild COVID-19 in an APECED Patient with Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) and High Titer of Type 1 IFN-Abs: A Case Report

Autoimmune-Poly-Endocrinopathy-Candidiasis-Ectodermal Dystrophy (APECED), caused by mutations in the Autoimmune Regulator (AIRE) gene, is an autosomal recessive multi-organ autoimmunity syndrome usually defined by high serum titers of type I Interferon Autoantibodies (Type 1 IFN-Abs). These antibodies have recently been found in individuals in the general population who develop life-threatening Coronavirus Disease 2019 (COVID-19), but the significance of pre-existing Type 1 IFN-Abs in APECED patients with COVID-19 remains unclear. Previous reports of COVID-19 outcomes in APECED patients have been divergent, and protective roles have been proposed for female sex, age <26 years, and immunomodulatory medications including intravenous immunoglobulin (IVIg). We report the case of a 30-year-old male APECED patient who experienced a Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection with mild symptoms of fatigue and headache without respiratory distress and did not require hospitalization. He received a stress dose of hydrocortisone for adrenal insufficiency and continued on his baseline medications, including subcutaneous administration of Immunoglobulins (SCIgs) for chronic inflammatory demyelinating polyneuropathy (CIDP). Mild COVID-19 in a 30-year-old male patient with APECED and pre-existing Type 1 IFN-Abs was unexpected. Younger age and management of autoimmunity may have played a role.