Correlation of IFABP levels with inflammatory markers in children with COVID-19

Background. The purpose was to study the relationship between intestinal fatty acid-binding protein (IFABP) levels and markers of inflammation and severity to the children with COVID-19. Materials and methods. We conducted a cohort, observational, retrospective study involving 88 patients aged 1 month to 18 years with laboratory-confirmed COVID-19. The children were hospitalized in Kyiv City Children’s Clinical Infectious Disease Hospital (Kyiv, Ukraine). They were divided into the study and control groups according to the course of the disease: the study group included 42 patients with complicated COVID-19, and the control group consisted of 46 participants with uncomplicated disease. During a comprehensive examination on the first day of hospitalization, we collected blood serum for further study of IFABP by enzyme-linked immunosorbent assay using the Human IFABP/FABP2 (Intestinal Fatty Acid Binding Protein) ELISA Kit (FineTest, China) with a working measurement range of 0.156–10 ng/ml and a sensitivity of 0.094 ng/ml. The study was performed according to the principles of the Declaration of Helsinki and in compliance with modern principles of evidence-based medicine and bioethics in accordance with the principles of good clinical practice. The study was approved by the Local Ethics Committee of the hospital. Informed consent of parents and children was obtained. Diagnostic measures carried out during this study were not accompanied by risks. We used statistical, analytical methods and the method of empirical research. To calculate the results obtained, we used the statistical software EZR v. 1.54. Results. According to the calculations, IFABP in the control group was 15.1 ± 3.1 ng/ml, while in the study group it was higher, amounting to 21.7 ± 5.5 ng/ml (p = 0.01). The results of the study demonstrated a correlation between IFABP level and an increased level of leukocytes (r = 0.284, p < 0.001), erythrocyte sedimentation rate (r = 0.56, p < 0.001), D-dimer (r = 0.259, p < 0.001), C-reactive protein (ρ = 0.225, p = 0.03) and radiological changes in the lungs (ρ = 0.355, p < 0.001). Conclusions. We have found a correlation between IFABP level and the COVID-19 inflammation and severity markers in children.