Immunoglobulin G Values before Treatment Are Correlated With the Responsiveness to Initial Intravenous Immunoglobulin Therapy for Kawasaki Disease.

Background: Low levels of serum immunoglobulin G (IgG) before intravenous immunoglobulin (IVIG) therapy for Kawasaki disease (KD) have been reported as one of the risk factors for coronary artery abnormalities (CAAs). This risk factor needs to be re-evaluated because the dosage of IVIG has changed from 0.2-0.4 g/kg/day for 5 days to a single high dose of 2 g/kg. Methods: We reviewed the clinical records of KD patients admitted to our hospital from January 2001 to August 2011. Patients who were given a single high dose of IVIG within 7 days of illness, and who had blood collected for serum immunoglobulin values before treatment, were selected. The serum immunoglobulin levels and coronary artery diameters measured by echocardiogram were transformed to z-scores. Results: The subjects were 197 KD patients, including 22 IVIG nonresponders and 16 patients with CAAs. Of these, 150 (76%) had a z-score for IgG (IgGz) of ≤0. There were no differences in IgGz values between patients with CAAs and those without CAAs. However, nonresponders had higher IgGz values than responders (median, 25th percentile and 75th percentile: −0.26, −0.83 and 0.34 vs. −0.79, −1.40 and −0.03; p = 0.020). Logistic regression analysis showed that the IgGz value was an independent risk factor for resistance to IVIG (OR 1.36, 95% CI 1.002-1.849; p = 0.048). Conclusions: Low IgGz values were not a risk factor for CAAs in this study. However, KD patients with relatively high IgGz values before treatment may have an increased risk of resistance to initial IVIG therapy. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]