Methods
The EDTA tube collected peripheral blood samples from 40 newly diagnosed children with COVID-19 infection in the Department of Pediatrics of the First Affiliated Hospital of Guangzhou Medical University from December 2022 to February 2023 (diagnosed by the diagnosis and treatment protocol for novel coronavirus infection (10th edition)) and 17 hospitalized children with non-COVID-19 bronchial pneumonia in the department of Pediatrics of our hospital during the same period. Baseline clinical data were collected and analyzed, including the basic information, clinical symptoms, and laboratory tests of the case group and the disease control group. The expression of angiotensin molecules (ACE, ACE2) and neuropeptide-related molecules (SP, VIP, GRP, ASCL1) in the serum of the two groups were detected by ELISA, and the correlation with white blood cell count, lactate dehydrogenase, and other substances was analyzed (approval number: 20230570).