KIDCARE (Kawasaki Disease Comparative Effectiveness Trial)

Kawasaki disease (KD) is a self-limited illness that affects the heart blood vessels (coronary arteries) of infants and children and is now the most common cause of acquired heart disease in children. A mixture of proteins from human blood (Intravenous immunoglobulin, IVIG) is a treatment that reduces the rate of the major complication of the disease: a bulging of the wall of the coronary arteries called an aneurysm. However, 10-20% of children are resistant to this treatment and the fever returns. These children have the highest rates of aneurysm formation and thus should be treated aggressively. Unfortunately, there are no guidelines for the best secondary treatment for these resistant patients because the problem has never been adequately studied. Most physicians choose either a second infusion of IVIG or an engineered antibody called infliximab that inactivates a molecule that promotes inflammation. This trial will randomize (assign by chance like the flip of a coin) IVIG-resistant patients to receive either a second IVIG infusion or infliximab and the response to treatment will be compared to learn which treatment stops the fever the fastest. In addition, parents and caregivers will provide observations about their child's response to the different treatments.

This is a 3-year (2.75-years of enrollment), Phase III, two-arm, randomized, multi-center, superiority treatment study to compare infliximab to a second intravenous immunoglobulin (IVIG) infusion for treatment of persistent or recrudescent fever in children with KD who fail to become afebrile after the first IVIG infusion.

1. Specific aim 1 will test the hypothesis that infliximab will be superior to a second intravenous immunoglobulin (IVIG) infusion for treatment of persistent or recrudescent fever in children with KD who fail to become afebrile after the first IVIG infusion (resistant KD). Cessation of fever (\<38°C rectally or orally) within 24h of initiation of study treatment infusion will be the primary outcome measure.
2. Specific aim 2 will test the hypothesis that infliximab treatment will result in more rapid resolution of inflammation compared to second IVIG as measured by the change in white blood cell count (WBC), absolute neutrophil count (ANC), and high-sensitivity C-reactive protein (hsCRP) concentration between baseline and 24 hours and 2 weeks following study treatment.
3. Specific aim 3 will test the hypothesis that infliximab treatment will result in a reduction from baseline in coronary artery Zworst score of ≥ 0.05 standard deviation units as compared to second IVIG at 2 weeks following study treatment measured by echocardiography.

Eligibility Criteria:
Inclusion Criteria:

* Eligible subjects will be as follows:

  1. 4 weeks to 17 years of age,
  2. fulfill the American Heart Association case definition for complete or incomplete KD,
  3. have had fever (T ≥38°C) for 3 to 10 days prior to initial IVIG treatment,
  4. have fever (T ≥38°C orally or rectally) between 36 hours and 7 days after end of the first IVIG infusion without other likely cause

Exclusion Criteria:

1. Patient treated with infliximab or steroids for present illness (pts who received oral steroids as outpatients prior to KD diagnosis but who otherwise qualify for the study will not be excluded)
2. Known prior infection with tuberculosis, coccidiomycosis, or histoplasmosis.