Статья, в которой показываются отличия в иммунитете детей, которые переболели ковидом и выздоровели, и детей, у которых наблюдаются постковидные симптомы- они присутствуют, и свидетельствуют о наличии воспалительной реакции и иммунопатологиях (и возможной вялотекущей хронической инфекции- тоже-повышенные количества IL6, IL1β, плазмобластов и клеток памяти).
We enrolled 12 children with PASC (long covid) and 17 that completely recovered from the acute infection (Table 1). Distinct immunologic features were detectable comparing PASC patients and children who had recovered. The group of PASC showed significantly higher levels of plasmablasts, IgD-CD27+ memory and switched IgM-IgD- B cells. On the contrary, healed children had significantly higher naïve and unswitched IgM+IgD+ and IgM+CD27-CD38dim B cell subsets (figure 1a). The T-regulatory compartment showed no significant differences (Figure 1b). Moreover, IL6 and IL1βserum levels were elevated in PASC patients and consistently higher than children who had recovered after infection (Figure 1c).
While PASC is widely recognized in adults, its existence in children is more controversial, since it has been speculated that this group may rather have psychological sequelae of social restrictions. In this study, we documented significant immunologic differences between children that completely recovered from acute infection and those with PASC, providing the first objective laboratory sign of the existence of PASC in children. Healed children restored B-cell homeostasis, by reconstituting the naïve/unswitched B-cell compartment. In PASC children, the consistent amounts o f plasmablasts, switched and memory B lymphocytes revealed the involvement of those subsets in the immunopathogenesis of chronic symptoms. Moreover, the persisting high levels of IL6 and IL1β suggest that innate immune response played a pivotal role in children with PASC. Considering their role as mediators of inflammatory responses and auto-immune processes, these findings could explain systemic persisting symptoms such as fatigue and post-exertional malaise, headache, muscle and joint pain, and tachycardia. The possibility that a low level, persistent infection after acute infection may persist in some children, contributing to the development of post-acute inflammatory conditions such as Multisystem Inflammatory Syndrome (MIS-C) or PASC has recently been suggested. The presence of persisting viral particles were recently detected by immune-histochemistry and electron microscopy in dermal vascular endothelium weeks after acute infection5. Moreover, extensive burr cells (echinocytes) have been described in the blood smears of patients with MIS-C (which typically develops weeks after acute infection), and have been linked to inflammatory conditions6. Our findings provide further evidence that a chronic inflammatory process and immune dysfunction may explain why some children develop PASC, highlighting the importance of further studies aimed to better characterize this new condition. A better understating of PASC will also provide indirect benefits for other post-infectious conditions.