Kawasaki Disease: Laboratory Findings and an Immunopathogenesis on the Premise of a ""Protein Homeostasis System

Lee, Kyung-Yil; Rhim, Jung-Woo; Kang, Jin-Han

Higher severity of systemic inflammation in KD is reflected by prolonged fever duration, a higher incidence of CALs, a higher or lower laboratory values, and a higher rate of IVIG non-responsiveness. In the initial periods of IVIG treatment in Japan and Korea, the score system (Harada score) for evaluation of the severity of KD (a risk of CALs) was used to decide on IVIG treatment; WBC count >12000/mm 3 , platelet count <350000/mm 3 , CRP >3+, hematocrit <35%, albumin <3.5 g/dL, age <1 year of age, and male sex. 57 KD patients who fulfill ≥4 of the 7 criteria were regarded as having severe inflammation with higher risk of (initial 2 g/kg, and the second-dose, 1 or 2 g/kg) and intravenous methylprednisolone pulse therapy (10-30 mg/kg, for 3 days). The dose of the second IVIG infusion (1 or 2 g/ kg) was assessed on a case-by-case basis. In general, the patients who failed to respond but whose WBC with neutrophil and CRP decreased following the initial IVIG treatment received a further dose of 1 g/kg, whereas those whose WBC count and/or CRP remained unchanged or increased after the initial IVIG treatment received a second IVIG dose of 2 g/kg. Those unresponsive to the second dose of IVIG received intravenous pulsed methylprednisolone (10-30 mg/kg, for 3 days), and the dose was also determined by WBC and CRP levels within 24 h after the second-dose IVIG infusion. We have experienced no patients who remained febrile after termination of this treatment schedule among more than 500 KD patients. We were able to induce defervescence within 12 days from the beginning of the illness in a majority of the IVIG non-responders (~10% of total KD patients), and only three patients were discovered to have giant aneurysms (>8 mm in diameter) after defervesccence. 58, 75 Since the change of laboratory indices after IVIG therapy appears within 2 hrs after termination of IVIG infusion 71 and the majority of IVIG responders defervesce within 24 hrs of IVIG treatment (2 g/kg), it may be possible to make a decision on commencing the next-step in treatment of IVIG non-responders, earlier than 24 h. With this, further studies in other populations should aim to optimize treatment of IVIG non-responders in KD.