Ferritin levels in children with juvenile idiopathic arthritis of systemic onset and children with other causes of fever of unknown origin: A multicenter study of diagnostic tests.

Introduction: There are no sensitive or specific tests available to diagnose systemic juvenile idiopathic arthritis (sJIA). Objective: To assess the utility as diagnostic tests of total ferritin (TF) levels greater than 5 times the normal value (TF>5N) and the decreased percentage (less than or equal to 20% of TF) of glycosylated ferritin (GF≤20%) for the diagnosis of sJIA in patients with fever of unknown origin evaluated by pediatric rheumatology. Materials and methods: We conducted an observational, cross-sectional study of diagnostic tests in children under 16 years of age hospitalized between 2010 and 2014.

A novel pathogenic variant in PRF1 associated with hemophagocytic lymphohistiocytosis.

Familial Hemophagocytic Lymphohistiocytosis type 2 (FHL2) results from mutations in PRF1. We described two unrelated individuals who presented with FHL, in whom severely impaired NK cytotoxicity and decrease perforin expression was observed. DNA sequencing of PRF1 demonstrated that both were not only heterozygous for the p.

[Kikuchi-Fujimoto disease: pediatric case presentation].

Kikuchi-Fujimoto disease or histiocytic necrotizing lymphadenitis is a rare, benign condition, usually self-limited to a six-month period. Classic clinical presentation is characterized by cervical lymphadenopathy, leukopenia and prolonged fever. It affects principally young, Asiatic adult women, although a few cases in the pediatric population have been reported.