Plasma exchange for refractory Kawasaki disease.

Abstract

Plasma exchange was a safe, effective prophylactic measure against coronary artery lesions in children with Kawasaki disease refractory to intravenous gamma globulin therapy. Kawasaki disease (KD) is an acute, systemic vasculitis of unknown aetiology that occurs predominantly in infants and young children [2]. Studies have indicated that immune system activation elevates interleukin-1b, interferon-c and tumour necrosis factor levels [3, 4], possibly activating endothelial cells and damaging the intima. Annually, KD causes coronary artery lesions (CALs) in some 500 Japanese children, but intravenous gamma globulin (IVGG) decreases their incidence from 25% to 8% of all KD cases. We examined the efficacy and safety of plasma exchange (PE) against CALs in children with KD refractory to IVGG therapy. KD was diagnosed according to the 1984 revised criteria. Children received IVGG (400 mg/kg per day for 3 days or 1 g/kg in a single infusion) and acetylsalicylic acid (30 mg/kg per day), and non-responders received PE, all within 10 days. CALs [1] were of three types (transient dilatation (TD), which regressed to the normal range within 30 days; persistent CAL (PD) and giant aneurysms (GA), without regression at day 30, but with respective lumen diameters 38.0oC) 48 to 72 h after IVGG were intractable to the initial IVGG [5, 6]. PE was performed, after informed parental consent was received, in those 27 children not responding to the further IVGG therapy (1 g/kg) administered to 75 children. Outcomes in the 27 were compared with those in the other 48 who received a third course of IVGG. No demographic or gender differences were demonstrated between children with (group A) and without (group B) PE therapy. Although group A patients received more IVGG (P=0.0515), they were still judged refractory to IVGG. In group A, 24 had no CALs, as demonstrated by serial echocardiography. Unfortunately, three children (11.1%) developed CALs. In group B, the inflammatory changes in 25 children resolved without coronary complications after the second IVGG; however, 23 children (47.9%) developed CALs. Furthermore, the rate of development of clinically severe CALs (PD plus GA) was 2 in 27 patients (7.4%) in group A, and 10 in 48 patients (20.8%) in group B (P =0.012). Multivariate analysis demonstrated that the most advantageous characteristic was PE therapy (odds ratio 0.041, P=0.0004) (Table 1). T. Imagawa and M. Mori contributed equally to this paper.