A novel Asp344Val substitution in the fibrinogen gamma chain (fibrinogen Caen) causes dysfibrinogenemia associated with thrombosis.

A 5-year-old boy was hospitalized for acute appendicitis. Routine preoperative hemostasis screening resulted in a diagnosis of dysfibrinogenemia. Fifteen days after the operation the patient was re-hospitalized for deep vein thrombosis. Genetic analysis of the fibrinogen genes revealed a novel missense mutation in exon 8 of fibrinogen gamma-chain gene (FGG): c.1031A>T, p.Asp344Val (p.Asp318Val in the mature chain) in heterozygosity. Interestingly, this same residue in the fibrinogen gamma chain was previously found to be mutated to a glycine (fibrinogen Giessen IV) in another young dysfibrinogenemia patient with thrombosis. The side chain of Asp344 (or Asp318) in the gamma chain is directly involved in binding to calcium. Abnormal polymerization of fibrin in fibrinogen Giessen IV and in the novel fibrinogen Caen described here could lead to the formation of abnormal clots leading to thrombosis, in addition to abnormal thrombin binding and decreased fibrinolysis.

Efficacy of etanercept for the treatment of juvenile idiopathic arthritis according to the onset type.

OBJECTIVE: To assess the efficacy of etanercept in patients with juvenile idiopathic arthritis (JIA), and to assess the tolerance of these patients to etanercept. METHODS: All JIA patients with active chronic polyarthritis, who were first treated with etanercept between November 1999 and June 2001 in 18 French centers because of poor response or intolerance to methotrexate, were included in this open-label, prospective, multicenter study. A standardized questionnaire was sent to the treating physicians. We assessed the validated international core-set score for JIA activity every 3 months and performed an intent-to-treat analysis. We also compared the risk of treatment failure in patients defined as having systemic-onset, oligoarticular-onset, or polyarticular-onset JIA. RESULTS: Sixty-one patients were enrolled and were followed up for a median of 13 months. Treatment had to be stopped in 1 patient who became pregnant and in 12 patients due to severe side effects, including neurologic or psychiatric disorders, retrobulbar optic neuropathy, major weight gain, severe infection, cutaneous vasculitis with systemic symptoms, hemorrhagic diarrhea, uveitis flare, and pancytopenia. All of these side effects disappeared after discontinuation of etanercept. Crohn's disease was subsequently diagnosed in 1 child. Scores improved by > or =30% in 73% of patients after 3 months, but this proportion decreased to 39% after 12 months. The response rate was significantly lower in patients with systemic-onset JIA than in those with oligoarticular- or polyarticular-onset JIA. CONCLUSION: Treatment of JIA with etanercept may be associated with a wide spectrum of severe side effects. Although most patients initially respond to etanercept, this initial response is not always followed by sustained improvement over longer periods of time. In addition, the higher rate of treatment failure in the group with systemic-onset JIA indicates that these patients in particular may require alternative treatments.