Plasminogen Activator Inhibitor 1 Is a Novel Faecal Biomarker for Monitoring Disease Activity and Therapeutic Response in Inflammatory Bowel Diseases

BACKGROUND AND AIMS

Crohn's disease [CD] and ulcerative colitis [UC] require lifelong treatment and patient monitoring. Current biomarkers have several limitations; therefore, there is an unmet need to identify novel biomarkers in inflammatory bowel disease [IBD]. Previously, the role of plasminogen activator inhibitor 1 [PAI-1] was established in the pathogenesis of IBD and suggested as a potential biomarker. Therefore, we aimed to comprehensively analyse the selectivity of PAI-1 in IBD, its correlation with disease activity, and its potential to predict therapeutic response.

METHODS

Blood, colon biopsy, organoid cultures [OC], and faecal samples were used from active and inactive IBD patients and control subjects. Serpin E1 gene expressions and PAI-1 protein levels and localisation in serum, biopsy, and faecal samples were evaluated by qRT-PCR, ELISA, and immunostaining, respectively.

RESULTS

The study population comprised 132 IBD patients [56 CD and 76 UC] and 40 non-IBD patients. We demonstrated that the serum, mucosal, and faecal PAI-1 concentrations are elevated in IBD patients, showing clinical and endoscopic activity. In responders [decrease of eMayo ≥3 in UC; or SES-CD  50% in CD], the initial PAI-1 level decreased significantly upon successful therapy. OCs derived from active IBD patients produced higher concentrations of PAI-1 than the controls, suggesting that epithelial cells could be a source of PAI-1. Moreover, faecal PAI-1 selectively increases in active IBD but not in other organic gastrointestinal diseases.

CONCLUSIONS

The serum, mucosal, and faecal PAI-1 concentration correlates with disease activity and therapeutic response in IBD, suggesting that PAI-1 could be used as a novel, non-invasive, disease-specific, faecal biomarker in patient follow-up.

Faecal calprotectin and lactoferrin as markers for monitoring disease activity and predicting clinical recurrence in patients with Crohn's disease after ileocolonic resection: A prospective pilot study

BACKGROUND

Several studies have reported that faecal calprotectin and lactoferrin showed a close correlation with endoscopic inflammation in patients with inflammatory bowel disease. However, the clinical significance of faecal calprotectin or lactoferrin in postoperative Crohn's disease (CD) is not fully evaluated. This prospective study was to investigate the relationship between endoscopic activity, and faecal calprotectin and lactoferrin, and assess the predictive value of these markers for future recurrence.

METHODS

Twenty patients who remained in remission during 6-12 months after ileocolonic resection for CD were included. All patients underwent ileocolonoscopy for assessing endoscopic activity (Rutgeerts score) in the neo-terminal ileum. A stool sample was collected for measurement of calprotectin and lactoferrin. All patients were then followed up for 12 months, and clinical recurrence was defined as a CDAI >150 with an increase of ≥70 points.

RESULTS

The mean time between surgery and the endoscopic examination at entry was 7.2 months. The endoscopic scores were i0 or i1 in 10 patients, i2 in six patients, i3 in three patients, and i4 in one patient. Both calprotectin and lactoferrin positively correlated with the endoscopic scores (p = 0.0001 and p = 0.038, respectively). Six patients developed clinical recurrence during the 12-month follow-up. Both calprotectin and lactoferrin levels were significantly higher in patients with clinical recurrence than those in remission (p = 0.0007 and p = 0.025, respectively). A cutoff value of 170 µg/g for calprotectin had a sensitivity of 83% and a specificity of 93% to predict a risk of clinical recurrence, while a cutoff value of 140 µg/g for lactoferrin had a sensitivity of 67% and a specificity of 71%.

CONCLUSIONS

Both calprotectin and lactoferrin levels correlate well with endoscopic activity after ileocolonic resection for CD. Calprotectin and lactoferrin could be clinically relevant biomarkers for predicting postoperative recurrence. Further well-designed large trials should strengthen the findings of the present investigation.