Clinical Study on the Correlation between IgA, IgG, IgM and the Severity of Illness in Children with Influenza A

doi:10.16458/j.cnki.1007-0893.2025.10.020

Abstract：Objective: To investigate the correlation between immunoglobulin (Ig) A, IgG, IgM and the severity of illness in children with influenza A (hereinafter referred to as 'influenza A'). Methods: A total of 570 children with influenza A treated at Anyang People's Hospital from January 2023 to December 2023 were selected as the study subjects. Clinical data were collected, and the children were divided into five age groups: infant group (<1 year), toddler group (1-2 years), preschool group (3-5 years), school-age group (6-12 years), and adolescent group (>12 years). The infection status of influenza A in different age groups was statistically analyzed, and then the children were further grouped based on fever duration, infection condition, and involvement of other systems. Serum levels of IgA, IgG, and IgM were detected upon admission, and the levels of IgA, IgG, and IgM in each group were compared. Results: The number of children infected with influenza A in the infant group (<1 year), toddler group (1-2 years), preschool group (3-5 years), school-age group (6-12 years), and adolescent group (>12 years) were 25 (4.39%), 67 (11.75%), 180 (31.58%), 251 (44.04%), and 47 (8.25%), respectively. In the toddler group (1-2 years), school-age group (6-12 years), and adolescent group (>12 years), the serum IgA levels of children with fever lasting >7 days were higher than those with fever lasting ≤7 days, with statistically significant differences (P < 0.05). There was no statistically significant difference in serum IgG levels between children with fever lasting ≤7 days and those with fever lasting >7 days in all age groups (P > 0.05). In the school-age group (6-12 years), the serum IgM levels of children with fever lasting >7 days were higher than those with fever lasting ≤7 days, with statistically significant differences (P < 0.05). In the infant group (<1 year), preschool group (3-5 years), and school-age group (6-12 years), the serum IgA levels of children with co-infection with other pathogens were higher than those with only influenza A, with statistically significant differences (P < 0.05). In the preschool group (3-5 years) and school-age group (6-12 years), the serum IgG and IgM levels of children with co-infection with other pathogens were also higher than those with only influenza A. In all age groups, there was no statistically significant difference in serum IgA, IgG, and IgM levels between children with only respiratory system involvement and those with respiratory system involvement combined with other system involvement (P > 0.05). Conclusion: In children aged 3-5 years and 6-12 years, higher serum IgA, IgG, and IgM levels may indicate more severe illness and a higher likelihood of co-infection with multiple pathogens.