Clinical implications of gallbladder enlargement in Kawasaki disease

Background: Kawasaki disease (KD) presents with gallbladder enlargement (GBE) or hydrops in the acute phase. Although GBE is highly specific to KD, epidemiological data on GBE have not been updated. In this study we evaluated the occurrence rate of GBE in KD and characterized the clinical features of patients who developed GBE.Methods: The present study was a prospective, observational study. The maximum longitudinal area of the gallbladder and the common bile duct diameter in KD patients were measured by ultrasonography at the start of initial intravenous immunoglobulin (IVIG) therapy (day 0) and on days 7, 30, and 60 of therapy. The primary outcome was the complication rate of GBE (z-score =2.0) on day 0. The secondary outcome was the association of GBE with cholestasis, unresponsiveness to IVIG, and coronary artery lesions (CAL).Results: Gallbladder enlargement occurred in 35% (35/101) of patients on day 0. Cholestasis and severe patients (Kobayashi score [KS] =5) were more common in the GBE group (20.6% vs. 1.6%, p = 0.002, and 54.3% vs. 15.2%, p < 0.001, respectively). In patients with a KS of =4, the non-responder rate was higher in the GBE group (44% vs. 20%, p = 0.0495) but did not differ in those with a KS of =5 (21% vs. 20%, p = 0.95). The rate of CAL occurrence did not differ significantly between the groups (8.6% vs. 6.1%, p = 0.64).Conclusions: Gallbladder enlargement occurred in 35% of KD patients and was associated with cholestasis. Gallbladder enlargement may not only be a diagnostic finding, but also a severity marker in KD patients.