Diagnostic accuracy of plasma biomarkers for intestinal ischaemia

Objective. Intestinal ischaemia is a life-threatening condition with high mortality, and the lack of accurate and readily available diagnostic methods often results in delay in diagnosis and treatment. The aim of this study was to investigate the accuracy of different plasma biomarkers in diagnosing intestinal ischaemia. Material and methods. Prospective inclusion of patients older than 50 years with acute abdomen admitted to hospital in Karlskrona, Sweden, between 2001 and 2003. Venous blood was sampled prior to any surgery and within 24 h from onset of pain. D-lactate, alpha glutathione S-transferase, intestinal fatty acid binding protein, creatine kinase B, isoenzymes of lactate dehydrogenase (LD) and alkaline liver phosphatase (ALP) were analysed. D-dimer was analysed using four different commercially available test kits. Results. In-hospital mortalities among patients with (n=10) and without (n=61) intestinal ischaemia were 40 % and 3 %, respectively (p=0.003). D-dimer was associated with intestinal ischaemia (p=0.001) independently of which assay was used. No patient presenting with a normal D-dimer had intestinal ischaemia. D-dimer > 0.9 mg/L had a specificity, sensitivity and accuracy of 82 %, 60 % and 79 %, respectively. Total LD, isoenzymes of LD 1-4 and liver isoenzyme of ALP (ALP liver) were significantly higher in patients with intestinal ischaemia, and accuracies for LD 2 (cut-off 2.3 mu kat/L) and ALP liver (cut-off 0.7 mu kat/L) were 69 % and 66 %, respectively. Conclusions. D-dimer may be used as an exclusion test for intestinal ischaemia, but lacks specificity. The other plasma biomarkers studied had insufficient accuracy for this group of patients. Further studies are needed.