Tumor necrosis factor receptor-associated periodic syndrome (TRAPS) in Japan: a review of the literature

Systemic autoinflammatory disorders

Inflammation is a physiologic defense mechanism against an out-side attack. Usually, it resolves after the removal of noxious causes, but systemic autoinflammatory disorders (SAIDs) have recurrent or repeated acute inflammation through uncontrolled gene function, which can present as gain-of-function or loss-of-function of a gene during inflammation. Most SAIDs are hereditary autoinflammatory diseases and develop by dysregulation of innate immunity through various pathways including inflammasomes, endoplasmic reticulum stress, nuclear factor-κB dysregulation, and interferon production. The clinical manifestations include periodic fever with various skin findings such as neutrophilic urticarial dermatosis, or vasculitic lesions. Some SAID cases stem from immunodeficiency or allergic reactions related to monogenic mutation. The diagnosis of SAIDs is based on clinical findings of systemic inflammation and genetic confirmation, and have to exclude infections or malignancies. Moreover, a genetic study is essential for clinical features to be suspect SAID with or without a family history. Treatment is based on understanding the immunopathology of SAID, and targeted therapy to control disease flares, reduce recurrent acute phases and prevent serious complications. Diagnosing and treating SAID requires understanding its comprehensive clinical features and pathogenesis related to genetic mutation.

Recurrent fever and arthralgia as the presentation of tumor necrosis factor receptor-associated periodic syndrome (TRAPS) in a Chinese girl: a case report and review of the literature

Tumor necrosis factor receptor-associated periodic syndrome (TRAPS) is characterized by recurrent episodes of inflammation with fever, abdominal pain, chest pain, rash, myalgia, arthralgia, conjunctivitis, and periorbital edema. This condition is a rare autosomal dominant disease that is strongly associated with heterozygous mutations in the tumor necrosis factor (TNF) receptor super family 1A (TNFRSF1A) gene. This condition is believed to be more common in Western countries than in Asian countries, and the AA amyloidosis rate for European countries is estimated to be 10%. Herein, we report the case of a 14-year-old girl with recurrent fever and arthralgia with inflammatory marker elevation for 10 years. After extensive investigation of the infectious etiology with negative results and similar phenomenon observed within her family, the diagnosis of TRAPS was made based on next-generation sequencing, which revealed a T50M mutation; she was also sensitive to corticosteroids. Although none of our TRAPS patients developed AA amyloidosis, we suggest the continual monitoring of urinalysis results and serum amyloid A concentrations during long-term follow-up. Moreover, we also reviewed the related literature and found no Asian patients who had developed AA amyloidosis.

Lung Involvement in Children with Hereditary Autoinflammatory Disorders

Short-lived systemic inflammatory reactions arising from disrupted rules in the innate immune system are the operating platforms of hereditary autoinflammatory disorders (HAIDs). Multiple organs may be involved and aseptic inflammation leading to disease-specific phenotypes defines most HAIDs. Lungs are infrequently involved in children with HAIDs: the most common pulmonary manifestation is pleuritis in familial Mediterranean fever (FMF) and tumor necrosis factor receptor-associated periodic syndrome (TRAPS), respectively caused by mutations in the MEFV and TNFRSF1A genes, while interstitial lung disease can be observed in STING-associated vasculopathy with onset in infancy (SAVI), caused by mutations in the TMEM173 gene. The specific pleuropulmonary diseases may range from sub-clinical abnormalities during inflammatory flares of FMF and TRAPS to a severe life-threatening disorder in children with SAVI.