TOFACITINIB TREATMENT PREVENTS POST-OPERATIVE RECURRENCE OF CROHN’S DISEASE MODELED BY ILEOCECAL RESECTION IN HLA-B27 TRANSGENIC RATS
Authors: Blondeaux Aurélie , Speca Silvia , Valibouze Caroline , Lambin Thomas , Dubuquoy Caroline , Titecat Marie , Blanquart Helene , Neut Christel , Genin Michael , Zerbib Philippe , Foligne Benoit , Desreumaux Pierre 
Published: January 2022

Abstract

BACKGROUND
Post-operative recurrence (POR) after ileocecal resection (ICR) affects most of Crohn’s disease (CD) patients within 3-5 years after surgery. Current immunomodulatory treatments have not proven efficiency in preventing POR, except for anti-TNFα biologic agents.

AIM
To evaluate the efficacy of the Janus Kinase inhibitor Tofacitinib to prevent POR after ICR in HLA-B27 transgenic rat model (TgB27) operated on an ICR.

METHODS
Thirty-three rats (strain F344, 29 TgB27, 4 control non Tg (nTg) rats) were operated on an ICR at the 12th week of life and were sacrificed at the 18th week of life. Tofacitinib (15 mg/kg, n=17) or placebo (n=16) were daily administered by oral gavage two weeks before surgery (10th week of life) until sacrifice. Anastomotic recurrence was blindly analyzed using macroscopic (from 0 to 4) and histologic (from 0 to 6) scores. Luminal microbiome was analyzed by shotgun metagenomic sequencing (Hiseq Illumina) in 9/33 rats before (week 9) and after Tofacitinib treatment or placebo (week 12), as well as 6 weeks following surgery (week 18). STAT3 phosphorylation was quantified in ileal samples by western blotting. Data were expressed by median with IQR. Comparisons were performed using not parametric two tailed Mann-Whitney analysis for unmatched data and Wilcoxon matched-pairs test for matched data. Two tailed χ2 test was used for contingency analysis. Spearman rank correlation was used for microbiota analysis.

RESULTS
8/14 TgB27 rats receiving placebo (57%) showed signs of POR (macroscopic score ≥ 2) which were significantly prevented in 2/15 TgB27 rats (13%) treated with Tofacitinib (p= 0.013). nTg animals did not show macroscopic signs of POR. Macroscopic lesions were located 2 cm around the anastomosis in the TgB27 placebo group and consisted in ulcerations with a score of 2 (1-2.25). 11/15 TgB27 rats (73%) treated with Tofacitinib did not show macroscopic lesions and their score were significantly improved (0 (0-1), p= 0,0006). Histologic scores were significantly higher in TgB27 placebo group vs TgB27 Tofacitinib-treated rats (3 (2-4) vs 2 (1-3), p=0.036). Tofacitinib did not impact on alpha diversity and the relative abundance of bacterial taxa either before and after surgery. In contrast, surgery led to a significant 47% decrease of alpha diversity (p=0.0008) and loss of specific taxa in both TgB27 and nTg animals. No correlation was found between individual lesion scores and alpha diversity indexes. Ileal pSTAT3/STAT3 ratios were decreased by 80% in TgB27 rats treated with Tofacitinib (n=4) compared to placebo group (n=4) (0.3 ± 0,16 vs 1.58 ± 0,3, p=0,028).

CONCLUSION
We develop a reliable model of ICR in TgB27 rats mimicking the POR of CD. Tofacitinib prevents the macroscopic and histologic POR after ICR, without major modifications of the microbioma.

ACKNOWLEDGMENTS
Charity Foundation DigestScience and Pfizer SAS.