Wang Pingping, Yao Jin, Li Yaqiong, Zhang Zhanjun, Zhang Ruiling, Lu Shouting, Sun Meixia, Huang Xiaorong
Department of Medical Laboratory, Luoyang Maternal and Child Health Hospital, 206 Tongqu Road, Luolong District, Luoyang City, Henan Province, China.
Department of Infection and Public Health Management, The Second Affiliated Hospital of Henan University of Science and Technology, No. 80 Jinguyuan Road, Xigong District, Luoyang City, Henan Province, China.
BMC Infect Dis. 2025 Jan 28;25(1):134. doi: 10.1186/s12879-025-10534-0.
The COVID-19 (SARS-CoV-2) epidemic has posed a major challenge to global public health, especially in children. Some children may experience secondary infection with Mycoplasma pneumoniae after SARS-CoV-2 infection, which has attracted widespread attention. Studies have shown that eosinophils play an important role in respiratory tract infections and are involved in regulating immune responses and inflammatory processes. However, there is a lack of systematic research on the specific manifestations and mechanisms of eosinophils in secondary infection with Mycoplasma pneumoniae after SARS-CoV-2 infection.
This study aims to explore the characteristics of immune response in children with SARS-CoV-2 infection and Mycoplasma pneumoniae infection, focusing on the changes in immune indicators such as eosinophils (EOS), immunoglobulin E (IgE), interleukin-6 (IL-6), C-reactive protein (CRP), and procalcitonin (PCT).
This study is a retrospective observational study, and a total of pediatric patients who were treated in our hospital from January 2023 to December 2023 were included. The study group included children who were diagnosed with SARS-CoV-2 infection and further infected with Mycoplasma pneumoniae, and the control group included children who were only infected with SARS-CoV-2 and had no other pathogens. The clinical data of the two groups of patients, including absolute eosinophil value, IgE quantification, IL-6, CRP and PCT levels, were collected and analyzed, and statistical comparisons were performed.
A total of 134 children were included, including 79 in the study group and 55 in the control group. The absolute eosinophil value [0.17 (0.09, 0.31) vs. 0.09 (0.06, 0.23), P < 0.01] and IgE level [59.28 (37.54, 256.88) vs. 22.00 (11.00, 113.10) P < 0.01] of the children in the study group were significantly higher than those in the control group, while IL-6 [16.81(4.72,31.86) vs. 9.5(3,57.3), P = 0.602], CRP [2.82(1.10,6.13) vs. 1.94(0.50,8.94), P = 0.528] and PCT[0.12(0.08,0.20) vs. 0.12(0.10,0.24), P = 0.329] were no significant difference between the two groups. Binary logistic regression analysis showed that the absolute value of eosinophils and IgE were independent risk factors for secondary infection of Mycoplasma pneumoniae after SARS-CoV-2 infection.
This study shows that after SARS-CoV-2 infection, the increase in eosinophils and the increase in related immune indicators IgE may be closely related to secondary infection with Mycoplasma pneumoniae. This study provides an important basis for understanding the immune response of children after SARS-CoV-2 infection and its related clinical management, suggesting that clinicians should closely monitor the eosinophil count and IgE level of children after SARS-CoV-2 infection, especially for children at risk of secondary infection, so as to take timely intervention measures to prevent secondary infection with Mycoplasma pneumoniae and improve the prognosis of children.
新型冠状病毒肺炎（SARS-CoV-2）疫情给全球公共卫生带来了重大挑战，尤其是对儿童。一些儿童在感染SARS-CoV-2后可能继发肺炎支原体感染，这引起了广泛关注。研究表明，嗜酸性粒细胞在呼吸道感染中起重要作用，并参与调节免疫反应和炎症过程。然而，对于SARS-CoV-2感染后肺炎支原体继发感染中嗜酸性粒细胞的具体表现及机制缺乏系统研究。
本研究旨在探讨感染SARS-CoV-2和肺炎支原体的儿童的免疫反应特征，重点关注嗜酸性粒细胞（EOS）、免疫球蛋白E（IgE）、白细胞介素-6（IL-6）、C反应蛋白（CRP）和降钙素原（PCT）等免疫指标的变化。
本研究为回顾性观察性研究，纳入2023年1月至2023年12月在我院治疗的儿科患者。研究组包括诊断为SARS-CoV-2感染并继发肺炎支原体感染的儿童，对照组包括仅感染SARS-CoV-2且无其他病原体的儿童。收集并分析两组患者的临床资料，包括嗜酸性粒细胞绝对值、IgE定量、IL-6、CRP和PCT水平，并进行统计学比较。
共纳入134例儿童，研究组79例，对照组55例。研究组儿童的嗜酸性粒细胞绝对值[0.17（0.09，0.31）对0.09（0.06，0.23），P＜0.01]和IgE水平[59.28（37.54，256.88）对22.00（11.00，113.10），P＜0.01]显著高于对照组，而IL-6[16.81（4.72，31.86）对9.5（3，57.3），P = 0.602]、CRP[2.82（1.10，6.13）对1.94（0.50，8.94），P = 0.528]和PCT[0.12（0.08，0.20）对0.12（0.10，0.24），P = 0.329]两组间无显著差异。二元logistic回归分析显示，嗜酸性粒细胞绝对值和IgE是SARS-CoV-2感染后肺炎支原体继发感染的独立危险因素。
本研究表明，SARS-CoV-2感染后，嗜酸性粒细胞增多及相关免疫指标IgE升高可能与肺炎支原体继发感染密切相关。本研究为了解SARS-CoV-2感染后儿童的免疫反应及其相关临床管理提供了重要依据，提示临床医生应密切监测SARS-CoV-2感染后儿童的嗜酸性粒细胞计数和IgE水平，尤其是对于有继发感染风险的儿童，以便及时采取干预措施，预防肺炎支原体继发感染，改善儿童预后。
