Cyclophosphamide use in treatment of refractory Kawasaki disease with coronary artery aneurysms

BACKGROUND: Despite timely administration of IVIG, some patients with Kawasaki disease (KD) develop rapidly progressive or giant coronary artery aneurysms (CAA). CASE PRESENTATION: We describe our experience using cyclophosphamide (CYC) for the treatment of such cases as well as a review of the literature on the use of CYC in KD. Through a retrospective chart review of our KD population, we identified ten children treated for KD with intravenous CYC (10 mg/kg/dose) for one or two doses. Seven patients were male, the median age was 2.0 years (range 4 months − 5 years). All patients received initial IVIG between day 4–10 of illness. Other anti-inflammatory treatments administered before CYC included second IVIG (n = 9), corticosteroids (n = 10), infliximab (n = 4), cyclosporine (n = 2), and anakinra (n = 1). Median illness day at administration of the first CYC dose was 22.5 days (range:10–36 days). The primary indication for treatment with CYC for all patients was large or giant CAA and/or rapid progression of CAA. Three patients received a second dose of CYC (10 mg/kg) for progressively enlarging CAA. CAA did not progress after final CYC treatment. One patient with a history of neutropenia in infancy developed severe neutropenia 9 days after treatment with CYC, which recovered without intervention or complications. No patient developed infections or other serious toxicity from CYC. CONCLUSION: In KD patients with severe and progressive enlargement of CAA despite anti-inflammatory therapy, CYC seemed to arrest further dilation and was well-tolerated. Future multicenter studies are needed to confirm our findings in this subgroup of KD patients.