High antistreptolysin O titer is associated with coronary artery lesions in patients with Kawasaki disease.

Purpose: In Kawasaki disease (KD) patients, coronary artery complications, incomplete and refractory types occur more frequently in patients with streptococcal or other bacterial/viral infections. Recently, we observed a higher incidence of coronary lesions in KD patients with high anti-streptolysin O (ASO) titer. Therefore, we hypothesized that KD patients diagnosed with concurrent streptococcal infection have poor prognosis, with respect to treatment response and development of coronary artery lesions.

Methods: A retrospective review was performed in 723 patients with KD who were admitted to 2 major hospitals between June 2010 and September 2017.

Results: Among 723 patients with KD, 11 initially showed an elevated ASO titer (>320 IU/mL) or elevated follow-up ASO titer after treatment. Of these patients, 5 showed no response to the first intravenous immunoglobulin treatment, 3 had abnormalities of the coronary arteries. This is a significantly higher proportion of patients with a high ASO titer (n=3, 27.3%) than those with a normal ASO titer (n=53, 7.4%; P=0.047). A severe clinical course was seen in 81.8% of patients in the high ASO group versus 14.5% of patients in the normal ASO group.

Conclusion: It is not certain whether acute streptococcal infection may cause KD, but this study revealed that KD with high ASO titers showed higher rates of severe clinical course. It may be helpful to analyze concurrent streptococcal infection in patients with a severe clinical course.