Blood counts in children with Down syndrome

Abstract Background Children with Down syndrome (DS) are more likely to have hematologic and immunologic abnormalities compared to their typically developing peers, but normal ranges have not been defined. The goal of this study was to create references for complete blood counts (CBCs) in patients with DS. Methods A retrospective investigation of 355 (male = 196, 55.2%; mean age = 6.49 years, SD = 5.07) healthy pediatric patients with DS who received a CBC between 2011 and 2017 as part of their medical care at a single, large, pediatric teaching hospital. Control data on 770 healthy patients without DS were included. Descriptive statistics were performed on demographic and clinical characteristics. Kruskal–Wallis H tests, nested analysis‐of‐variance tests, and t ‐tests were run to determine the significant associations. Results Age‐related normative curves for healthy children with DS outlining 2.5th, 25th, 50th, 75th, and 97.5th percentiles are provided for total white blood count, hemoglobin concentration, hematocrit, mean corpuscular volume, and platelet, absolute neutrophil, absolute lymphocyte, eosinophil, monocyte, and basophil counts. Statistical differences were found between children with and without DS receiving care at the same hospital based on matched age/sex groups. Conclusions This study demonstrates that patients with DS have different reference ranges for multiple blood counts compared to those without DS, creating a new resource for pediatricians to refer to when evaluating CBCs in this population.