Leukocyte subset variations in wheezing preschool children: distinguishing asthma from transient wheeze

More than 40% of children under 6 experience wheezing. It remains a challenge for healthcare professionals to distinguish preschool children with transient wheeze from those at high risk of asthma. An early diagnosis could improve healthcare. A specific leukocyte subset distribution may aid in differentiating this diverse group, yet our knowledge of leukocyte subset variations in preschool children is limited. This study aimed to elucidate the key differences in circulating leukocyte composition in blood of wheezing preschool children, enhancing our understanding of asthma and refining early diagnosis and treatment in young children. The study is part of the ADEM2 randomised controlled trial. Whole blood and breath samples were primarily collected at the MosaKids Children's Hospital. The blood samples underwent analysis for peripheral white blood cell count and leukocyte subset analysis using flow cytometry. Based on the breath test results using the algorithm published by Klaassens 2015, each case was classified as either ‘asthma’ or ‘transient wheeze’. Preliminary findings from a cohort of 71 wheezing preschool children showed significantly elevated levels of circulating basophils and myeloid dendritic cells (mDCs) in the children diagnosed with asthma, shown in table 1. Other leukocyte subsets did not show significant differences. The comprehensive analysis of the entire dataset, which includes 80 healthy controls, is currently in progress. <table-wrap><object-id>erj;64/suppl_68/PA3144/TB1</object-id><object-id>T1</object-id><object-id>TB1</object-id><table><colgroup><col></col><col></col><col></col><col></col></colgroup><tbody><tr><td></td><td><bold>Asthma n=18</bold><break></break><italic>Median (IQR)</italic></td><td><bold>Transient Wheeze n=53</bold><break></break><italic>Median (IQR)</italic></td><td><bold>P-value</bold></td></tr><tr><td><bold>Basophils</bold><break></break><italic>Cells/μL</italic></td><td>89 (0-107)</td><td>53 (0-84)</td><td>0.015</td></tr><tr><td><bold>mDCs</bold><break></break><italic>Cells/μL</italic></td><td>14 (10-23)</td><td>9 (7-16)</td><td>0.027</td></tr></tbody></table></table-wrap> The findings suggest that higher basophils and mDCs may support an early asthma diagnosis.