The therapeutic window of intravenous immunoglobulin (IVIG) and its correlation with clinical outcomes in Kawasaki disease: a systematic review and meta-analysis

BACKGROUND: The optimal therapeutic window to start intravenous immunoglobulin (IVIG) for Kawasaki disease (KD) is highly debatable. We aimed to summarize the existing literature to evaluate the therapeutic window of IVIG treatment and its correlation with clinical outcomes in KD patients. METHODS: We searched the databases from inception to August 26, 2022, without language restrictions. The primary outcomes were initial IVIG resistance and coronary artery lesions (CALs) in acute phase. Secondary outcome was CALs during 1–2 months of follow-up. RESULTS: 27 studies involving 41,139 patients were included in this study. Very low-quality evidence showed that the earlier IVIG treatment within 4 days had a higher IVIG-resistance rate (RR, 1.80; 95% CI, 1.50–2.15; P < .00001; I(2) = 75%) than the late treatment. Very low-quality evidence showed that IVIG treatment for more than 7 days was associated with a higher risk of CALs in acute phase(RR, 0.57; 95% CI, 0.40–0.80; P = .001; I(2) = 76%). There was a lower risk of CALs during 1–2 months follow-up for those who started IVIG administration within 10 days from the onset. CONCLUSIONS: Overall, IVIG treatment within 7 days of illness seems to be the optimal therapeutic window of IVIG. IVIG treatment within 7 days is found to be effective for reducing the risk of coronary artery lesions and cardiac sequelae in KD patients. The early IVIG treatment within 4 days should be vigilant for the IVIG resistance although large multi-center randomized trials with well design are needed. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13052-023-01451-6.