Intestinal fatty acid-binding protein (I-FABP) as biomarker of ischemic damage in experimentally induced 12-h small bowel obstruction.

Laboratory tests have low diagnostic specificity for strangulated intestinal obstruction. The diagnostic potential of the intestinal fatty acid-binding protein (I-FABP) expressed in the tips of the intestinal villi continues to be explored. The number of white blood cells, blood plasma levels of L-lactate, C-reactive protein (CRP) and I-FABP were measured in rats with experimentally induced 12-h strangulated and non-strangulated intestinal obstruction. The results of the laboratory tests were compared with the changes in the morphology of the intestinal wall. The studied diagnostic markers, except for CRP, were elevated by 12-h L-lactate and I-FABP concentrations were significantly higher in the strangulated obstruction group than in other groups. L-lactate (cutoff value: 3.01 mmol/L) had 86.1% sensitivity and 66.7% specificity for strangulated obstruction (AUC 0.815, p < 0.001). I-FABP levels above 5.432 ng/ml indicated strangulated obstruction with 83.33% sensitivity and 88.9% specificity (AUC 0.906, p < 0.001). Villi destruction was observed at 2 h in the strangulated obstruction group. I-FABP levels peaked at 4 h and plateaued at 12 h. Functional changes were observed in the non-strangulated group; they were accompanied by a significant increase in I-FABP concentrations that lasted until 12 h. Compared with traditional diagnostic markers of strangulated intestinal obstruction, I-FABP demonstrated higher accuracy in the first 12 h, although its concentrations reached the plateau already at 4 h and did not increase thereafter. The functional changes in small bowel wall in non-strangulated obstruction were accompanied by continuous increase in I-FABP concentrations up to 12 h, which may have influenced the diagnostic accuracy of the marker.