Clinical and Genetic Features of Korean Patients with Recurrent Fever and Multi-System Inflammation without Infectious or Autoimmune Evidence

Autoinflammatory disease (AID) is a newly proposed category of disorders characterized by unprovoked episodes of inflammation without any infectious or autoimmune evidence. We aimed to characterize the clinical and genetic features of patients who had recurrent fever and multi-system inflammation but remain unclassified for any established AIDs. Medical records of 1,777 patients who visited our Rheumatology Clinic between March 2009 and December 2010 were reviewed to identify those who met the following criteria; 1) presence of fever, 2) inflammation in two or more organ systems, 3) recurrent nature of fever or inflammation, 4) no evidence of infection or malignancy, 5) absence of high titer autoantibodies, and 6) failure to satisfy any classification criteria for known AIDs. Genotyping was performed for common missense variants in MEFV, NOD2/CARD15, and TNFRSF1A. A small number of patients (17/1,777, 0.95%) were identified to meet the above criteria. Muco-cutaneous and musculoskeletal features were most common, but there was a considerable heterogeneity in symptom combination. Although they did not satisfy any established classification criteria for AIDs, substantial overlap was observed between the clinical spectrum of these patients and known AIDs. According to the newly proposed Eurofever criteria for periodic fevers, eleven of them were classified as TNF receptor-associated periodic syndrome and two as mevalonate kinase deficiency. However, no examined genetic variants including those in TNFRSF1A were found in these patients. A new set of classification criteria needs to be developed and validated for Asian patients with unclassified AIDs.

Clinical and Genetic Features of Korean Patients with Recurrent Fever and Multi-System Inflammation without Infectious or Autoimmune Evidence

Autoinflammatory disease (AID) is a newly proposed category of disorders characterized by unprovoked episodes of inflammation without any infectious or autoimmune evidence. We aimed to characterize the clinical and genetic features of patients who had recurrent fever and multi-system inflammation but remain unclassified for any established AIDs. Medical records of 1,777 patients who visited our Rheumatology Clinic between March 2009 and December 2010 were reviewed to identify those who met the following criteria; 1) presence of fever, 2) inflammation in two or more organ systems, 3) recurrent nature of fever or inflammation, 4) no evidence of infection or malignancy, 5) absence of high titer autoantibodies, and 6) failure to satisfy any classification criteria for known AIDs. Genotyping was performed for common missense variants in MEFV, NOD2/CARD15, and TNFRSF1A. A small number of patients (17/1,777, 0.95%) were identified to meet the above criteria. Muco-cutaneous and musculoskeletal features were most common, but there was a considerable heterogeneity in symptom combination. Although they did not satisfy any established classification criteria for AIDs, substantial overlap was observed between the clinical spectrum of these patients and known AIDs. According to the newly proposed Eurofever criteria for periodic fevers, eleven of them were classified as TNF receptor-associated periodic syndrome and two as mevalonate kinase deficiency. However, no examined genetic variants including those in TNFRSF1A were found in these patients. A new set of classification criteria needs to be developed and validated for Asian patients with unclassified AIDs.

Hereditary periodic fever syndromes

Hereditary periodic fever syndromes, comprise a group of hereditary disorders with similar clinical features of recurrent short episodes of fever associated with inflammatory manifestations. These are usually self-limited in nature and occur in the absence of infection or autoimmune reaction. Between attacks, patients feel well and regain their normal daily functions until the next episode occurs. The episodes are usually associated with elevated serum levels of acute-phase reactants [e.g., fibrinogen, serum amyloid A [SAA]], an elevated erythrocyte sedimentation rate [ESR], and leukocytosis. These illnesses represent inborn errors in the regulation of innate immunity thus substantiating the distinction from autoimmune disorders, which more directly affect the adaptive immune system. Each of these disorders has a distinct genetic defect. Most of these proteins are members of the Death Domain Superfamily and are involved in inflammation and apoptosis. These proteins mediate the regulation of nuclear factor-kB [NF-kB], cell apoptosis, and interleukin 1beta [IL-1beta] secretion through cross-regulated and common signaling pathways. Six periodic fever syndromes have been characterized. Genetic defects, pathogenesis, epidemiology and management of these fevers will be discussed