Is Short-Term Exposure to PM2.5 Relevant to Childhood Kawasaki Disease?

Abstract

Background: Kawasaki disease (KD) is an acute febrile vascular disease of unknown cause that affects the whole body. KD typically occurs in infants under the age of five and is found mainly in East Asian countries. Few studies have reported on the relationship between the pollutant PM2.5 and KD, and the evidence remains irrelevant or insufficient. Objectives: We investigated the relationship between short-term exposure to PM2.5 and KD hospitalizations using data from Ewha Womans University Mokdong Hospital, 2006 to 2016. Methods: We obtained data from the hospital EMR (electronic medical records) system. We evaluated the relationship between short-term exposure to PM2.5 and KD hospitalizations using a case-crossover design. We considered exposures to PM2.5 two weeks before the date of KD hospitalization. We analyzed the data using a conditional logistic regression adjusted for temperature and humidity. The effect size was calculated as a 10 μg/m3 increase in PM2.5 concentration. We performed a subgroup analysis by sex, season, age group, and region. In the two-pollutants model, we adjusted SO2, NO2, CO, and O3, but the effect size did not change. Results: A total of 771 KD cases were included in this study. We did not find any statistically significant relationship between PM2.5 and children’s KD hospitalization (two-day moving average: odds ratio (OR) = 1.01, 95% confidence intervals (CI) = 0.95, 1.06; seven-day moving average: OR = 0.98, CI = 0.91, 1.06; 14-day moving average: OR = 0.93, CI = 0.82, 1.05). A subgroup analysis and two pollutant analysis also found no significant results. Conclusion: We did not find a statistically significant relationship between PM2.5 and children’s KD hospitalizations. More research is needed to clarify the association between air pollution, including PM2.5, and KD.

Ambient Air Pollution and Kawasaki Disease in Korean Children: A Study of the National Health Insurance Claim Data

“… 23 Similarly, a recent single‐center cohort study of 711 KD cases in South Korea showed the null association between KD and ambient PM 2.5 without adjusting for weather conditions. 40 Inconsistencies between the previous studies and our current findings could result from a difference in sample size, variation in the concentration of air pollutants, and adjustment of confounders. For example, the study in North America had the mean concentration of PM 2.5 ranged from 7.0 to 17.2 μg/m 3 , which is much lower than those of our study population.…”

Incidence and seasonality of Kawasaki disease in children in the Philippines, and its association with ambient air temperature

“…These disparities in seasonality indicate that not only climate, but also other factors such as large-scale tropospheric wind patterns, environmental exposures, and host genetics, can influence the seasonality of KD ( 11 ). Specifically, the seasonal patterns of KD are influenced by airborne triggers carried by wind currents from central Asia ( 47 ), exposure to infectious agents or allergens in the environment leading to KD occurrence based on the child's genetic background and susceptibility ( 9 , 10 , 48 ), variations in infectious disease activity in each season ( 49 , 50 ), dynamic population activity exposing the vulnerable to the infectious agents in the environment ( 8 ), and effect of meteorological factors such as large-scale tropospheric wind patterns and ambient temperature ( 11 , 47 , 51 ). Nonetheless, these theories are yet to be directly confirmed in several studies.…”

“…Several mechanisms have been postulated to explain this increased risk of developing KD in higher temperature ( 50 , 57 ). These include enhanced spread of infectious agents such as fungi and bacteria in high ambient temperature, increased exposure to infectious agents due to children spending more time outside during summertime, efficient release of inflammatory mediators upon exposure to high temperature causing systemic inflammatory response and vascular endothelial dysfunction, and increased incubation of infectious agents in the environment during hot weather ( 8 , 50 , 57 , 58 ). In contrast, studies conducted in Japan, San Diego, and Michigan have shown that there is an inverse relationship between daily average temperature and the number of admissions for KD ( 17 , 19 , 59 , 60 ).…”

“…However, further studies are needed to elucidate the genetic and immunologic factors influencing these findings in this population ( 6 ). Recent research efforts have intensified, focusing on infectious triggers and environmental stressors that may potentially activate an immune response in genetically susceptible children ( 8 , 9 ).…”

Study of the relationship between occurrence of Kawasaki disease and air pollution in Chengdu by parametric and semi-parametric models

“…In order to analysis the association between KD and prenatal exposure to ambient and industrial air pollution, a population-based cohort study has been conducted and a positive correlation has been found (Buteau et al 2020). Besides, a small number of studies examined the correlation between short-term pollution exposure in childhood and the incidence of KD, but no signi cant environmental indexes have been found (Zeft et al 2016;Lin et al 2017;Yorifuji et al 2018;Oh et al 2021). It is worth noting that the odds ratio (OR) of children exposed to suspended particulate matter density greater than 25μg/m 3 to the density lower than 20μg/m 3 getting KD is 1.41, but the con dence interval is too wide to be signi cant (Yorifuji et al 2018).…”