Background Severe cases of coronavirus disease 2019 (COVID-19) among pediatric patients are more common in children less than 1 year of age. Our aim is to address the underlying role of immunity and inflammation conditions among different age groups of pediatric patients. Methods We recruited pediatric patients confirmed of moderate COVID-19 symptoms, admitted to Wuhan Children’s Hospital from January 28th to April 1st in 2020. Patients were divided into four age groups (≤ 1, 1–6, 7–10, and 11–15 years). Demographic information, clinical characteristics, laboratory results of lymphocyte subsets test, immune and inflammation related markers were all evaluated. Results Analysis included 217/241 (90.0%) of patients with moderate clinical stage disease. Average recovery time of children more than 6 years old was significantly shorter than of children younger than 6 years ( P = 0.001). Reduced neutrophils and increased lymphocytes were significantly most observed among patients under 1 year old ( P < 0.01). CD19+ B cells were the only significantly elevated immune cells, especially among patients under 1 year old (cell proportion: n = 12, 30.0%, P < 0.001; cell count: n = 13, 32.5%, P < 0.001). While, low levels of immune related makers, such as immunoglobulin (Ig) G ( P < 0.001), IgA ( P < 0.001), IgM ( P < 0.001) and serum complement C3c ( P < 0.001), were also mostly found among patients under 1 year old, together with elevated levels of inflammation related markers, such as tumor necrosis factor γ ( P = 0.007), interleukin (IL)-10 ( P = 0.011), IL-6 ( P = 0.008), lactate dehydrogenase ( P < 0.001), and procalcitonin ( P = 0.007). Conclusion The higher rate of severe cases and long course of COVID-19 among children under 1 year old may be due to the lower production of antibodies and serum complements of in this age group. Supplementary Information The online version contains supplementary material available at 10.1007/s12519-021-00440-1.
【저자키워드】 Inflammation, Coronavirus disease 2019, pediatric, immune, China, Age difference, 【초록키워드】 COVID-19, coronavirus disease, Neutrophils, IgM, Necrosis, Tumor, Coronavirus disease 2019, Lymphocytes, Immunity, Clinical characteristics, antibody, IL-6, children, neutrophil, B cells, procalcitonin, Lymphocyte subsets, complement, lactate dehydrogenase, Symptoms, Moderate COVID-19, B cell, lymphocyte, serum, tumor necrosis factor, Laboratory results, Immunoglobulin, Lymphocyte subset, IgA, Pediatric patients, Wuhan, Patient, severe cases, immune cells, age, group, demographic, information, disease, marker, Lactate, Recovery time, CD19, tumor necrosis, Children's Hospital, Pediatric patient, supplementary material, Severe case, cell count, CD19+, while, Cell, Course, Result, significantly, recruited, evaluated, elevated, condition, less, C3c, laboratory result, patients with moderate, significantly shorter, 【제목키워드】 age, group, Inflammatory response, Pediatric patient, with COVID-19,