Patient 2 was a 20-year-old woman. From around the age of 12, she had occasionally suffered from severe abdominal pain of unknown cause. Around 13 years of age, she had suffered from a recurrent fever that persisted for 3–7 days and abdominal pain with a high level of serum CRP approximately every 2 months. Serum inflammatory reactants were negative during the intermittent episodes of fever. Lower gastrointestinal endoscopy showed erosion in Peyer’s patch of the ileum. Histopathologically, this lesion showed ulcers and granulation tissue with inflammatory cell infiltration. This case was initially considered to possibly involve familial Mediterranean fever (FMF) related to the heterozygous c.329T>C (p.Leu110Pro; rs11466018) and c.442G>C (p.Glu148Gln; rs3743930) variants of MEFV. However, colchicine given for diagnostic and therapeutic purposes failed to reduce the fever attacks, while NSAIDs and PSL were also ineffective for the fever and abdominal pain. When infliximab treatment was started with methotrexate as secondary prevention, the episodes of fever and abdominal pain completely disappeared. Finally, the heterozygous c.929T>C (p.Ile310Thr; rs530310566) variant of TNFAIP3 was identified in this patient. Her mother had the same variant but lacked any symptoms.
Patient 3 was a 24-year-old woman. She had suffered from athetoid cerebral palsy due to cardiopulmonary arrest of unknown cause on postnatal day 1. She had developed epilepsy at the age of 4 years and type 1 diabetes with positive anti-glutamic acid decarboxylase antibody at the age of 12 years. At the age of 24 years, she had a fever, facial erythema, and proteinuria. She was diagnosed with systemic lupus erythematosus (SLE) with the following findings: positive antinuclear antibodies, anti-dsDNA antibodies, anti-Sm antibodies, anti-cardiolipin antibodies, hypocomplementemia, and positive direct Coombs test. She had a heterozygous c.2126A>G (p.Gln709Arg) variant of TNFAIP3. Her father had the same variant but lacked any symptoms.\nThe variant Glu192Lys was identified among 55 patients suspected of having autoinflammatory diseases analyzed at Gifu University Hospital from October 2017 to September 2020. The patients with variants Ile310Thr and Gln709Arg were recruited by personal communication with the collaborators (Nagasaki University and Tokyo Medical and Dental University).\nWritten informed consent to participate in this study was obtained from each of the patients or their parents. This study was conducted in accordance with the Declaration of Helsinki and approved by the ethics boards of Gifu University and Tokyo Medical and Dental University.