Background and aim: Intestinal fatty acid-binding protein (I-FABP) is a useful marker in the detection of intestinal ischemia. However, more insight into the test characteristics of I-FABP release is needed. This study aimed to investigate the relationship between plasma I-FABP levels and the severity of ischemic mucosal injury, and define the clinical usefulness of systemic I-FABP following ischemia.
Methods: In a human experimental model, 6 cm of the jejunum, to be removed for surgical reasons, was selectively exposed to either 15, 30, or 60 minutes of ischemia (I) followed by 30 and 120 minutes of reperfusion (R). Blood and tissue was sampled at all time points. Arteriovenous (V-A) concentration differences of I-FABP were measured. Tissue sections were stained with hematoxylin/eosin, and villus height was measured to score epithelial damage.
Results: Histologic analysis showed only minor reversible intestinal damage following 15 I and 30 I; however, severe irreversible epithelial damage was observed in the jejunum exposed to 60 I. I-FABP V-A differences paralleled the degree of tissue damage over time [7.79 (± 1.8) ng/mL, 128.6 (± 44.2) ng/mL, 463.3 (± 139.8) ng/mL for 15 I, 30 I and 60 I, respectively]. A good correlation was found between histologic epithelial damage and V-A I-FABP (r=-0.82, P<0.001). Interestingly, systemic I-FABP levels were significantly increased after 60 I of this short small intestinal segment.
Conclusions: This study demonstrates the relationship between the duration of ischemia and the extent of tissue damage, which is reflected by I-FABP V-A plasma levels. In addition, systemic I-FABP levels appear valuable in detecting irreversible intestinal ischemia-reperfusion damage.