Evolution of laboratory values in patients with Kawasaki disease.

BACKGROUND: As outlined in the 2004 American Heart Association guidelines, the diagnosis of Kawasaki disease (KD) is supported by results of clinical laboratory studies. However, detailed information regarding the evolution of these results during illness has not been previously reported. The goals of this project were to characterize the evolution of clinical laboratory values in KD before and after treatment with intravenous immunoglobulin (IVIG).
METHODS: Laboratory values from 380 unselected, consecutive KD patients were analyzed at 3 times: acute (illness day, 2-10; illness day 1 = first day of fever and before IVIG), subacute (illness day, 11-21), and convalescent (illness day, 22-60). Results were stratified by IVIG response and coronary artery outcome.
RESULTS: Although white blood cell count, percentage bands, erythrocyte sedimentation rate, and C-reactive protein values were highest and age-adjusted hemoglobin was lowest in the acute phase before IVIG, platelet count was highest in the subacute phase, and percentage lymphocytes and eosinophils were highest in the convalescent phase after IVIG. KD patients with coronary artery aneurysms had a higher white blood cell count in the subacute phase and higher erythrocyte sedimentation rate in the subacute and convalescent phases compared with those with dilated or normal coronary arteries.
CONCLUSIONS: A consistent evolution of laboratory values is associated with KD before and after treatment. Understanding the dynamic changes in laboratory values can assist physicians in using laboratory criteria to diagnose KD following the American Heart Association guidelines.