Intestinal fatty-acid binding protein (I-FABP) and cytokines as promising predictive biomarkers for bowel ischemic injury

Objective. To evaluate diagnostic and prognostic value of serum intestinal fatty acid-binding protein (I-FABP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) in comparison with pathomorphological assessment (Chiu score) in a rat model of intestinal ischemia-reperfusion with different duration of ischemia. Materials and methods. An experimental study enrolled 70 rats divided into three groups: control (laparotomy without ischemia, n=10), 60-minute ischemia (n=30), and 120-minute ischemia (n=30). Blood and tissue samples were collected on days 1, 7, and 21. Biomarker were determined using enzyme-linked immunosorbent assay (ELISA), and histological specimens were evaluated blindly using the Chiu score. Statistical analysis was performed using non-parametric tests (Kruskal-Wallis, Spearman correlation). Results. Serum I-FABP, IL-6 and TNF-α significantly increased on the 1st day and demonstrated a dose-dependent effect (p<0.05). I-FABP showed the most pronounced and persistent changes. This protein was significantly elevated compared to the control group at all time points, including day 21 (p=0.020). This Chiu scores and serum TNF-α became normal by that time. Strong correlations were identified between I-FABP and Chiu score (ρ=0.665), TNF-α (ρ=0.895), and IL-6 (ρ=0.851) on day 1. Conclusion. I-FABP is the most sensitive and robust marker of ischemic intestinal injury. Combination of I-FABP and IL-6 provides unique information regarding injury phase and activity of reparative processes, offering prospects for their use as prognostic biomarkers in clinical practice.