Biomarkers of long COVID in children and young adults: a scoping review, 2026, Camara et al

[forestglip]

Biomarkers of long COVID in children and young adults: a scoping review

Bettina Camara, Danilo Buonsenso

Abstract
Following the SARS-CoV-2 pandemic, a significant percentage of people are now experiencing long-term symptoms, despite a continuing lack of concrete documentation of physiological and risk profiles that hinders diagnosis and treatment, particularly in pediatric contexts.

This review aims to highlight the existing evidence for measurable physiological markers for post-acute sequelae of SARS-CoV-2 infection (long COVID) in children, adolescents, and young adults. Titles providing data related to measurable biomarkers distinguishing young long COVID patients from controls were compiled and analyzed.

Results were displayed in table and diagram form for optimal qualitative evaluation of the relationship between markers and symptomatology within the context of each organ system. Only human studies published in English, Italian, Portuguese, German, and Spanish between the 5th of February 2025 and the 31st of December 2025 were considered, and no other time constraints were applied.

Following search and criteria evaluation, nine studies were included, totaling 41 occurrences identified in diseased patients with statistically significant variation from healthy controls. Markers suggest the presence of organic manifestations based on published literature, although more data and future studies will be necessary to establish clear connections.

Conclusion: The data compiled for this review adds to the body of evidence indicating a physiological manifestation of long COVID and its consequences.

Further investigation into potential risk factors, pre- and post-pubescent manifestations, and specific inflammatory and immune pathways will be necessary for a more concrete understanding of long COVID and its effects on children, adolescents, and young adults.

Web | DOI | PDF | European Journal of Pediatrics | Open Access

 

[forestglip]

Correspondence about this. I can't access the letter from Wyller et al, but the reply to it gives a good idea of what was said.

Methodological considerations for interpreting a scoping review of pediatric long COVID biomarkers
Joel Pradeepkumar Selvakumar, Vegard Bruun Bratholm Wyller
Web | DOI | European Journal of Pediatrics | Paywall

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Response to letter: Methodological considerations for interpreting a scoping review of pediatric long COVID biomarkers
Bettina Camara, Danilo Buonsenso

Snippets

Our search terms and search criteria were determined following primary searches that highlighted thousands of articles, therefore the inclusion of specific terms such as ‘biomarkers’ or ‘long COVID’, ‘Post-Acute COVID-19 Syndrome’ in tandem in order to create a more realistic body of works from which to extract the data. We realize that because of that, titles lacking reference to those specific terms may have been missed, which is a notable limitation of a small team conducting such a search. Inclusion of your valuable works would certainly improve analyses of the field in the future, and we regret that this search did not highlight them at this time, and your correspondence linked to our paper will definitely add to the evidence that the readers of European Journal of Pediatrics can gain.

In regard to the second concern, highlighting our inclusion of exclusively statistically significant results, we understand that it creates the possibility of interpretation bias, which is a limitation of compiling published works in an emerging topic in the field. However, our article was conducted as a scoping review, with the intention of providing avenues for further investigation. These constraints as well as specific objectives guided our decision to focus on significant findings.

Web | DOI | PDF | European Journal of Pediatrics | Open Access

 

[rvallee]

Inclusion of your valuable works would certainly improve analyses of the field in the future

Heh, no, no it wouldn't. But quite a diplomatic reply. Imagine the hubris of someone who has contributed nothing to a problem demanding to be included in its review. Humans are so freaking weird.

 

[Nightsong]

Second, current standards for evidence synthesis recommend reporting the full range of findings across studies. However, the authors present only statistically significant results, which risks distorting rather than synthesising the evidence base. For example, the authors report that Güven and Buluş [11] found an association between long COVID and leukocyte count—but do not acknowledge that two other studies included in their review found no such association [3, 12]. Similarly, the authors highlight associations between D-dimer and long COVID in two studies, but do not contextualise that several other studies reported null findings [6, 8, 9]. In a field vulnerable to inadequate control groups, multiple testing, and publication bias, the authors’ selective presentation of results risks amplifying rather than attenuating bias.

That is just breathtakingly hypocritical.

 

[Sean]

That is just breathtakingly hypocritical.

And proves that they do understand what robust methodology is, and hence have no excuse for not using in their own work.

They are very quick to point out deficiencies in biomed studies and hypotheses. Not so much for their own psych studies. And by not so much I mean not at all.