DOP31 Efficacy and safety of bone marrow-derived mesenchymal stem cells in refractory perianal fistulae in Crohn’s Disease: Results from a prospective monocentric study

Reenaers Dr, C.(1);Vieujean , S.(1);Coimbra , C.(2);Gillard , R.(3);Meunier , P.(3);Boutaffala , L.(1);Louis , E.(1);

(1)CHU Liège- Sart Tilman, Department of Gastroenterology, Liège, Belgium;(2)CHU Liège- Sart Tilman, Department of abdominal surgery, Liège, Belgium;(3)CHU Liège- Sart Tilman, Department of radiology, Liège, Belgium;

Background

Anoperianal lesions affect up to 30% of patients with Crohn’s disease (CD). Long-term fistula healing is challenging with conventional biotherapies. Although recent studies demonstrated the efficacy of local injections of adipose tissue-derived stem cells with 50 % of fistulae closure without abscess at one year, this treatment is not available in routine.

The primary aim of this study was to evaluate the safety and the feasibility of the injection of bone marrow-derived mesenchymal stem cells isolated and prepared in a local university laboratory of cell therapy for perianal fistulizing CD. The second aim was to evaluate the efficacy of this treatment and his impact on the quality of life of the patients.

Methods

A prospective observational study was performed in the CHU of Liège from October 2019 till October 2021. All CD patients with perianal fistula and seton placement for at least 6 months were eligible. PRO, clinical examination, CRP, fecal calprotectine, CDAI, Short health scale (SHS) and MRI were performed at weeks 0, 12 and 48. PDAI was calculated at inclusion and at Week 48. Efficacy was defined as closure of all treated external openings at clinical examination without abscess at MRI.

Results

Sixteen patients with a median age of 49 years old and a median duration of perianal CD of 8 years were included. Eleven (69%) patients were on anti-TNF. CDAI and PDAI at inclusion were 97,5 ± 48,8 et 5 ± 4,4 respectively. Four (25%) patients reported adverse events the week after the injection (local pain 3/16, mild bleeding 1/16), all of them quickly resolutive. Ten (63%) and 8 (50%) patients had a closure of all the external opening at week 12 and 48 respectively. Five out of 6 patients with 2 external openings had at least 1 opening closed at Week 48. One abscess was observed during the follow-up. The median PDAI was numerically lower at the end of the study (3 versus 5 at the inclusion). The quality of life improved with a regression of the SHS from 10 to 7.5 at the end of the follow-up. At MRI, MAGNIFI-CD score and Van Assche index were similar for each patients at the inclusion and at the end of the study.

Conclusion

Injection of locally prepared bone marrow-derived mesenchymal stem cells seems safe and effective in refractory perianal fistulae in Crohn’s disease with 50% of closure at 1 year. The treatment is associated with an improvement of the perianal activity scores and the quality of life scores but not with the MRI scores.