A Trial Comparing the Efficacy and Safety of Anakinra Versus Intravenous Immunoglobulin (IVIG) Retreatment, in Patients With Kawasaki Disease Who Failed to Respond to Initial Standard IVIG Treatment

Inclusion Criteria: * Children, male and female, from 3 months to \<18 years old * Patient ≥ 5 kg * Patient with KD according to the American Heart Association definition for complete or incomplete KD. (Fever ≥ 5 days (or at least 3 days if KD with American Heart Association criteria since the third days of fever) and ≥ 4 of 5 main clinical signs: modification of the extremities, polymorphic exanthema, and bilateral bulbar not exudative conjunctivitis, erythema of the lips or oral cavity, and cervical lymph nodes usually unilateral \> 1.5 cm in diameter. * Patients who failed to respond to the standard therapy of KD, e.g. Persistence or recrudescence of fever ≥ 38°C, 48 hours after the infusion of 2g/kg of IV Ig. Patients may be screened 24h after the end of the first infusion if they remain febrile 24h after the end of the first infusion. * Patient, parents or legal guardian's written informed consent is required * Patient with health insurance (SS or CMU). * Efficient contraception for the duration of participation in the research for childbearing aged women Exclusion Criteria: * Preterm and neonates, pregnancy, pregnancy and breast feeding * Suspicion of another diagnosis * Patient with overt concomitant bacterial, viral or fungal infection * Patient previously treated with steroids and/or another biotherapy * Patient with increased risk of tuberculosis infection * Recent tuberculosis infection or with active tuberculosis * Patient with any type of immunodeficiency or cancer * Patients with severe renal impairment (CLcr \< 30 ml/minute) * Patients with hepatic insufficiency * Patients with neutropenia (ANC\<1.5 x109/l) * Patients included in another interventional protocol * Patient under the following treatments: * Preventive Antipyretics (paracetamol, NSAIDs other than aspirin 30-50mg/kg given for purpose of KD inflammation), as long as the patient receives the study medication * Immunosuppressive medications given in a period less than twice of their half-life prior the patient receives the study medication (systemic steroids, cyclosporine, tacrolimus, azathioprine, cyclophosphamide, interferon, mycophenolate, other anti-IL-1, anti IL-6, anti CD20 and anti TNF (Tumor Necrosis Factor)), plasmapheresis) * Hypersensitivity to anakinra or excipients (citric acid, sodium chloride, disodium EDTA (Ethylene Diamine Tetra Acetic), polysorbate 80, sodium hydroxide, in water for injection) * Hypersensitivity to IV Ig, or excipients (L-proline and water for injection), hypersensitivity to human normal immunoglobulin, in particular if the patient have anti-IgA antibodies (IgA: Immunoglobulin A) * Patients with type I or II hyperprolinemia * Live vaccines within 1 month prior to enrollment * Hypersensitivity to anakinra or to immunoglobulins or to excipients of Kineret® or Privigen® or to E.coli proteins * Contraindication for administration of anakinra or IVIG listed in the Summary of Products Characteristics (SmPC) of Kineret® and Privigen® * Ongoing or recent use of any other medication Known inhibitors/inducers of cytochrome P450 as listed on the link below: http://medicine.iupui.edu/clinpharm/ddis/main-table