In 7 KD patients, serum MMP-9 activity was measured using the MMP-9 assay kit 3 times: before and after intravenous immunoglobulin (IVIG) treatment, and during the convalescent phase. The effect of captopril on MMP-9 activity was also assessed using serum obtained before IVIG treatment.
Serum MMP-9 activity was significantly higher during the pre-treatment phase than during the post-treatment and convalescent phases. MMP-9 activity during the pre-treatment phase was dose-dependently inhibited by captopril, and the IC50 for MMP-9 was 500 nM. The potency of captopril for MMP-9 inhibition was comparable to that for ACE inhibition.
ACE inhibitor may be effective for preventing CAA formation in KD patients, especially IVIG non-responders.