Tumor necrosis factor receptor-associated periodic syndrome mimicking systemic juvenile idiopathic arthritis.
BACKGROUND
We report two cases of tumor necrosis factor receptor-associated periodic syndrome (TRAPS) in patients in whom systemic juvenile idiopathic arthritis (JIA) had initially been diagnosed or suspected. One patient, given a diagnosis of systemic JIA, was a 10-year-old boy who had presented with recurrent episodes of spike-fever, skin rash, arthritis, and myalgia. The other patient was his 7-year-old sister, who presented with similar symptoms and was suspected of having systemic JIA.


METHODS
Serum levels of soluble tumor necrosis factor receptor super family 1A (TNFRSF1A), TNF-alpha, Interleukin (IL) -6, and C-reactive protein (CRP) were measured in two siblings and JIA patients. In addition, DNA sequencing of the TNFRSF1A gene in two siblings was also performed.


RESULTS
A detailed family history showed that their mother had an episode of recurrent fever, arthritis, and myalgia with an increased serum CRP after the delivery of a daughter. Both siblings had serum levels of soluble TNFRSF1A that were below the normal reference range, and that did not reach a level corresponding to that of systemic JIA. On TNFRSF1A gene analysis, a single missense mutation resulting in C30Y was found in both siblings.


CONCLUSIONS
Based on the clinical features and the TNFRSF1A mutation, both siblings were given a diagnosis of TRAPS. The serum levels of soluble TNFRSF1A, measured along with the CRP level, may be a useful screening marker for differentiating TRAPS from systemic JIA.
Manki
Akira
A
Department of Pediatrics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan. akmanki@md.okayama-u.ac.jp
Nishikomori
Ryuta
R
Nakata-Hizume
Mami
M
Kunitomi
Taiji
T
Takei
Syuji
S
Urakami
Tomoko
T
Morishima
Tsuneo
T
D001171:Arthritis, Juvenile / Q000209:etiology / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D002097:C-Reactive Protein / Q000378:metabolism; D002648:Child; D003937:Diagnosis, Differential; D010505:Familial Mediterranean Fever / Q000097:blood / Q000175:diagnosis* / Q000276:immunology*; D005260:Female; D006801:Humans; D008297:Male; D010375:Pedigree; D018124:Receptors, Tumor Necrosis Factor / Q000097:blood* / Q000235:genetics; D013577:Syndrome
D018124:Receptors, Tumor Necrosis Factor; D002097:C-Reactive Protein