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Long COVID syndrome in children: neutrophilic granulocyte dysfunction and its correlation with disease severity
Fanni Kovács1, Tamás Posvai2, Eszter Zsáry1
1Pediatric Center, MTA Center of Excellence, Semmelweis University, Bókay Unit, Bókay János Street 53-54, 1083, Budapest, Hungary.
Insights
Pediatric long COVID syndrome (LCS) is linked to neutrophil dysfunction, impacting children's quality of life. This study reveals altered neutrophil effector functions in children with LCS, correlating with symptom severity and offering insights into disease mechanisms.
Area of Science:
- Pediatric immunology
- Infectious disease pathology
- Long COVID research
Background:
- Lingering symptoms post-COVID-19, known as long COVID syndrome (LCS) or Post COVID-19 Condition (PCC), affect many children.
- The prevalence, quality of life impact, and mechanisms of pediatric LCS require further elucidation.
- Neutrophilic granulocytes are crucial in COVID-19, and their persistent dysfunction may underlie immunological diseases like LCS.
Purpose of the Study:
- To investigate the prevalence and characteristics of symptoms in pediatric LCS.
- To assess the impact of LCS on children's quality of life and functioning.
- To explore the role of neutrophilic granulocyte functionality in the pathogenesis of pediatric LCS.
Main Methods:
- A study involving 129 children with LCS, 32 convalescent controls (CG+), and 8 uninfected controls (CG-).
- Online questionnaires and in-person examinations were used to evaluate symptoms and quality of life.
- Effector functions of neutrophilic granulocytes were analyzed in children with LCS and CG+.
Main Results:
- Persistent fatigue was the most common LCS symptom; anxiety was most frequent in controls.
- Children with LCS reported significantly more symptoms, negatively impacting their quality of life and functioning.
- Neutrophilic granulocyte dysfunction, including reduced superoxide production and phagocytosis, was observed in LCS children compared to controls.
- A significant correlation was found between the number of complaints in LCS children and altered neutrophil effector functions.
Conclusions:
- Neutrophil dysfunction may be integral to the pathogenesis of pediatric LCS or a contributing factor.
- This research highlights significant quality of life impairments in pediatric LCS and identifies neutrophilic granulocyte dysfunction as a key pathophysiological component.
- The correlation between clinical symptoms and neutrophil function provides deeper understanding of LCS mechanisms.
Background:
Many children suffer from lingering symptoms after COVID-19, known as long COVID syndrome (LCS), otherwise called Post COVID-19 Condition (PCC). Despite extensive research, the prevalence of symptoms, its impact on quality of life, and underlying mechanisms still need to be fully understood. As neutrophilic granulocytes play an essential role in COVID-19, and their prolonged disruption was found to cause immunological diseases, we hypothesized their ongoing disturbed functionality in LCS.
Methods:
We studied 129 children with LCS, 32 convalescent children (CG+), and 8 uninfected children (CG-). Online questionnaires and in-person examinations assessed symptoms, quality of life, and functioning (QoL-F). Effector functions of neutrophilic granulocytes obtained from the venous blood of 29 LCS and 17 CG+ children were also investigated.
Results:
Persistent fatigue was the most common symptom in children with LCS, while both control groups complained about anxiety most frequently. LCS children experienced significantly more symptoms, impairing their QoL-F compared to CG+. Neutrophilic granulocyte dysfunction was found in LCS children, with decreased superoxide-producing activity and phagocytosis compared to CG+. The number of complaints of children with LCS correlated significantly with altered neutrophil effector functions.
Conclusion:
Neutrophil dysfunction in children with LCS may be part of the disease pathogenesis or a predisposing factor.
Impact:
Using online questionnaires validated during in-person medical examinations and including two different control groups, our study compellingly supports and adds to previous clinical observations in the field. Our study provides valuable insights into the prevalence and characteristics of pediatric LCS, highlighting the significant quality of life and functioning impairment compared to control groups. By detecting neutrophilic granulocyte dysfunction in children with LCS, we shed light on a previously overlooked pathophysiological component of the condition. We demonstrate a significant correlation between clinical symptoms and superoxide production, further enhancing our understanding of the underlying mechanisms of pediatric LCS.
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