INCREASING RATE OF INTRAVENOUS IMMUNOGLOBULIN NONRESPONDERS AMONG CHILDREN WITH ACUTE KAWASAKI SYNDROME IN SAN DIEGO COUNTY.

Abstract

Purpose To determine annual response rates to intravenous immunoglobulin (IVIG) among Kawasaki syndrome (KS) patients and to compare characteristics of IVIG responder and nonresponder patients. Methods All patients met the AHA 2004 diagnostic criteria for KS and were first treated within 10 days of illness onset. Nonresponse to IVIG was defined as a rectal or oral temperature ≥ 100.4°F at 36 hours to 7 days following the end of IVIG infusion. Coronary artery dilatation was defined as Z-score for the left anterior descending or right coronary artery ≥ 2.5. We determined annual response rates from 1998 to 2006 and compared IVIG brands and lots used to treat nonresponder and responder patients in 2006. We compared demographic and laboratory data and clinical signs between responder and nonresponder patient groups treated in 2006. Continuous variables were analyzed by Wilcoxon rank sum test and categorical variables by Fisher9s exact and chi-square as appropriate. Results The IVIG nonresponse rate was significantly higher in 2006 than in all previous years (p The percentage of patients with each of the KS clinical signs was similar between 2005 and 2006. Nonresponders in 2006 were more likely than responders to have been diagnosed earlier (median day 5 vs day 6, p = .02), have a higher percentage of neutrophils and bands (p = .04 and .01, respectively), and have a higher ALT (median 117 vs 51 IU/L, p = .03). The distribution of IVIG brands and lots was not different between nonresponder and responder groups. Conclusion The increase in IVIG nonresponders in 2006 was not due to a specific lot or brand of IVIG, nor were the patients clinically different from patients in 2005. The emergence of a high rate of IVIG nonresponse may suggest a change in the causative agent(s) of KS.