medwireNews: Initial treatment with low-dose aspirin alongside intravenous immunoglobulin is not associated with an increased risk for recrudescent fever relative to high-dose aspirin in children with Kawasaki disease (KD), US research shows.
There was also no difference between the two treatments in the rate of coronary artery abnormalities, James Wood and colleagues from Indiana University School of Medicine in Indianapolis report in JAMA Network Open.
They say: “Given the potential advantages, low-dose aspirin is an attractive option as initial therapy for KD; however, future studies powered to detect more subtle, yet possibly clinically relevant, differences in fever recrudescence are warranted.”
The current retrospective, single-center study included 260 children (median age 2.5 years, 40% girls) treated for a first episode of KD within 10 days of symptom onset between 2007 and 2018.
Of these, 54.6% received low-dose aspirin (<10 mg/kg per day) and 45.4% received high-dose aspirin (≥10 mg/kg per day) both in combination with high-dose (2.0 g/kg) intravenous immunoglobulin.
Wood and team found that there was no significant difference in the rate of recrudescent fever, defined as an oral or rectal temperature of at least 38°C or an axillary temperature of at least 37.5°C within 14 days of initial treatment, between the two groups.
Specifically, 27.5% of children in the low-dose group and 22.0% of those in the high-dose group experienced this outcome, and the difference between the two groups remained nonsignificant after adjustment for potential confounders including an age of less than 1 year and incomplete KD.
Further analysis suggested that children with complete KD (n=167) may be at increased risk for recrudescent fever with low- versus high-dose aspirin but the results did not reach statistical significance.
The investigators also found that there was no difference between the patients who received low- or high-dose aspirin in the rate of coronary artery abnormalities at any time during follow-up (7.4 vs 9.4%) or in the median length of hospital stay (3 days for both groups).
Wood et al therefore believe that their findings “support a growing body of literature suggesting that initial treatment with low-dose aspirin may not be associated with poor outcomes in children with KD.”
They suggest that this could be because “the major anti-inflammatory effects in the initial KD treatment regimen come from intravenous immunoglobulin, which sufficiently decreases systemic inflammation regardless of aspirin dosing.”
They add: “Another possibility is that low-dose aspirin, although thought to mainly work on platelet function, has enough anti-inflammatory properties to decrease the odds of fever recrudescence similar to high-dose aspirin.”
They authors conclude: “Further investigation into the mechanisms by which intravenous immunoglobulin and aspirin work to decrease systemic inflammation in KD is needed.”
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JAMA Netw Open 2020; 3: e1918565