Indicators of unresponsiveness after initial i.v. immunoglobulin treatment in acute Kawasaki disease

Background The aim of this study was to identify the indicators of unresponsiveness to initial i.v. immunoglobulin (IVIG) treatment for Kawasaki disease (KD). Methods One hundred and forty-five patients with KD, who had received initial treatment consisting of a single IVIG dose (1 g/kg or 2 g/kg) and oral aspirin (30 mg/kg), were studied. Laboratory parameters, including C-reactive protein (CRP) and serum sodium (Na), were measured before and after IVIG treatment, and during the convalescent phase, and the laboratory data compared with regards to IVIG response. Multiple logistic regression models, which included laboratory data obtained immediately after the IVIG treatment, were constructed to determine the indicators of IVIG unresponsiveness immediately after the completion of the initial treatment. Results On logistic regression analysis, serum Na after IVIG treatment was the only independent factor related to initial IVIG unresponsiveness (beta = 0.53, P < 0.01; OR, 1.69; 95%CI: 1.15-2.49). On receiver operating characteristic curve analysis, the optimal serum Na cut-off immediately after IVIG treatment was 135.5 mEq/L with a sensitivity of 0.75, and a specificity of 0.79. Conclusions Prolonged hyponatremia after completion of the initial IVIG therapy was an indicator of the need for subsequent IVIG therapy. Treatment plans should be established for patients with acute KD that pay particular attention to prolonged hyponatremia.