Urinary cytokines and renal Doppler study in Kawasaki disease.

OBJECTIVE

To investigate whether renal vasculitis is the sole cause or merely a contributing cause of renal inflammation in Kawasaki disease (KD).

STUDY DESIGN

This prospective study in a university medical center in Taiwan enrolled 24 children with KD between June 2004 and November 2005. All patients underwent a technetium-99 m dimercaptosuccinic acid scintigraphy single-photon emission computed tomography scan, the results of which were used to group the patients with KD as with or without renal involvement. Urine samples underwent a cytokine analysis. Renal Doppler ultrasonography was used to evaluate renal vasculitis by measuring the pulsatility index (PI) and resistance index (RI).

RESULTS

Ten of the 24 patients (42%) with renal inflammatory foci were the study group; the remainder composed the control group. Urinary interleukin (IL)-6 levels were significantly higher in the study group (496.7 +/- 310.9 vs 115.0 +/- 65.9 ng/g urinary creatinine; P < .01), as were PI values (1.85 +/- 0.70 vs 1.44 +/- 0.53; P < .05). Urinary IL-6 levels and PI values were significantly (P < .05) correlated.

CONCLUSIONS

Increased urinary IL-6 and elevated renal Doppler measures suggest that immune-mediated vasculitis is one of the mechanisms causing renal inflammation in KD.