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

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

IVIG down-regulates nearly all inflammatory laboratory parameters except ESR including total WBC and neutrophil count, CRP, AST, ALT, CPK and LDH in IVIG responders. IVIG increases ESR artificially through interference Because incomplete KD is more common in young infants than in older children, 2,32,33 clinicians must make every effort for accurate diagnosis and timely treatment of these young patients. The American Heart Association provided an algorism for diagnosis of incomplete KD in 2004. Patients with fever lasting longer than 5 days with 2 or 3 of the diagnostic signs of KD should be evaluated for systemic inflammation daily if possible. Initially CRP (>3 mg/dL) and ESR (>40 mm/h) levels and complementary laboratory findings including albumin <3.0 g/dL, anemia for age, elevation of ALT, platelets after 7 days >450000/mm 3 , WBC count >15000/mm 3 , and urine >10 WBC/high-power field, should be reviewed. Patients who fulfill more than 3 of these complementary indices can be treated with IVIG as having incomplete KD followed by echocardiography. Although laboratory findings in KD are non-diagnostic, they may prove useful in the diagnosis of incomplete Kawasaki disease. 2 It is reported that ~25% of untreated patients and ~5% of IVIG treated patients are affected with CALs. 3,4 Therefore, we were able to determine an imaginary line for the threshold of CALs during the natural course of systemic inflammation in KD, and we assumed that IVIG could lower the peak point of the inflammation curve (Fig. 1) . CALs begin at the point where the threshold line and the curve of inflammation intersect, and more severely affected patients reach the threshold line earlier before the peak stage of inflammation (arrows in Fig. 1 ). Early and extensive treatment with IVIG (2 g/kg) and methylprednisolone pulse therapy (30 mg/kg) may not prevent CALs development in some severely affected patients, 56 and small CALs can progress to huge giant aneurysms after defervescence induced by various treatments. These findings suggest that the severity of CALs is determined in the early period, before the peak stage of KD. Therefore, early IVIG treatment before the peak stage is mandatory to reduce the risk of CALs and the progression of CALs.