Objective: Circulating platelet-neutrophil aggregates play a crucial role in amplifying acute inflammation and could promote adverse effects involving vascular injury. The aim of this study was to clarify the role of platelet-neutrophil aggregates in patients with Kawasaki disease (KD).
Methods: We analyzed 40 patients with KD (30 intravenous immunoglobulin [IVIG] responders and 10 IVIG non-responders), 7 febrile patients with bacterial infections, and 9 normal volunteers. Thirty-three patients with KD were treated with IVIG alone, and remaining seven were treated with IVIG plus prednisolone. We evaluated the rate of platelet-neutrophil aggregates and measured the platelet factor 4 (PF4) and β-thromboglobulin (β-TG) levels in patients with KD.
Results: The rate of platelet-neutrophil aggregates was significantly higher in patients with KD than in both patients with bacterial infection and normal volunteers. There was a trend toward increased rate of platelet-neutrophil aggregates within 2 or 3 days after IVIG than before IVIG. The rate of platelet-neutrophil aggregates was significantly higher in patients who showed coronary artery abnormalities (CAA) than in those who showed without CAA and was correlated with PF4 and β-TG levels in patients with KD. Comparing time course analysis, the rate of platelet-neutrophil aggregates was significantly decreased in patients treated with IVIG plus prednisolone than in those treated with IVIG alone.
Conclusions: Our findings demonstrate that platelet-neutrophil aggregates play a crucial role in regulating vasculitis, and are involved in the development of CAA. Additional prednisolone treatment in the acute phase of KD might have a potential role in inhibiting amplified reciprocal inflammatory activation by suppressing platelet-neutrophil aggregates.