Biomarkers of exposure to airborne formaldehyde in children with allergic pathologies

Introduction. Formaldehyde (FA) is a wide-spread pollutant and allergen. It is believed to create elevated risks of diseases associated with the immune system. Allergy-associated phenotypes of T-lymphocytes are known to prevail significantly in blood of people who are permanently exposed to FA.

Materials and methods. Seventy four 7 to 13 years children living near the sanitary protection zone of a metalworking enterprise, where the concentrations of formaldehyde in the atmospheric air correspond to 0.6 MPC_a.d. (34 of whom are children with allergic diseases). Immunological indices were measured using flow cytometry and enzyme immunoassay. The genetic analysis was performed using real-time polymerase chain reaction (PCR).

Results. In the children of the main group, the FA blood level was significantly higher than in the comparison group (p < 0.05). Comparative analysis of cell differentiation clusters in the examined groups established in the test group authentic hyperexpression of some regulatory mediators including CD277⁺, CD284⁺, and IgЕ specific to FA. Their levels were 1.2–3.4 times higher than in the reference group. Our analysis of cause-effect relations showed a positive correlation between FA blood levels and CD277⁺ hyperexpression as a co-stimulating factor able to cause allergic and autoimmune diseases. We also assessed a relative risk of allergic reactions under formaldehyde contamination; as a result, we detected a risk of excessive expression of CD284⁺, which participates in the development of allergy.

Limitations. The sample was limited to the number of examined children.

Conclusion. Low-level exposure to airborne FA creates its elevated levels in biological media; is accompanied with general sensitization in a child’s body as well as specific one to the analyzed toxicant; is associated with CD277⁺ and CD284⁺ hyperexpression. The latter, with rs713041 polymorphism of the GPx4 C718T gene in the background, indicates an elevated risk that allergic pathology may develop in a genetically randomized sample under formaldehyde contamination.

Compliance with ethical standards. The study was conducted in accordance with the ethical principles of the Helsinki Declaration, as well as the National Standard of the Russian Federation GOST-R 52379–2005, which is based on the recommendations on good clinical practice (ICH E6 GCP) The World Medical Association. Following the meeting of the Commission, the conclusion of the Local Ethics Committee was prepared, created on the basis of the Federal State Budgetary Institution “Federal Scientific Center for Medical and Preventive Health Risk management Technologies of the Federal Service for Surveillance over Consumer Rights Protection and Human Wellbeing “ (Protocol No. 8 of 03/14/2023). All participants (or their legal representatives) gave informed voluntary written consent to participate in the study.

Contributions:
Alikina I.N. – data collection and analysis, writing and editing the text;
Dolgikh O.V. – study concept and design, writing, and editing the text.
All authors are responsible for the integrity of all parts of the manuscript and the approval of the final version of the article.

Conflict of interest. The authors declare no conflict of interest.

Acknowledgement. The study had no sponsorship.

Received: September 9, 2024 / Accepted: November 19, 2024 / Published: December 17, 2024