Clinical Report: Losartan Shows Promise in Treating Fibrostenosing Crohn’s Disease
Overview
Losartan, an angiotensin receptor blocker, demonstrates significant anti-inflammatory and anti-fibrotic effects in preclinical models of Crohn’s disease (CD). It reduces intestinal fibrosis, prevents fibrosis relapse after steroid remission, and modulates key profibrogenic pathways, supporting its potential as a novel therapeutic adjunct in fibrostenosing CD.
Background
Intestinal fibrosis is a severe complication of Crohn’s disease characterized by excessive extracellular matrix deposition and muscular hypertrophy, often leading to strictures and surgery. Current treatments inadequately address fibrosis, highlighting the need for new therapeutic strategies. The renin-angiotensin system (RAS) has been implicated in fibrosis and inflammation, with angiotensin II acting via the AT1 receptor to promote fibrogenic processes. Losartan, an AT1 receptor blocker, may therefore offer a targeted approach to modulate these pathways in CD.
Reduced inflammatory infiltrates, restored villous structure, decreased collagen I and muscularis propria thickness, lowered Col1a1, Mmp9, Igf1, IL-13 expression
SAMP mice relapse model (post-steroid remission)
Prevented fibrosis reoccurrence
Significantly reduced fibrosis severity and muscularis propria thickness; marginal impact on inflammation
Key Findings
RAS dysregulation occurs in Crohn’s disease, with increased angiotensinogen and AT1 receptor expression in affected intestinal layers.
Losartan effectively suppresses pro-fibrotic mediators and fibroblast activation in vitro.
In a murine CD model, losartan reduces both intestinal inflammation and fibrosis, improving tissue architecture.
Losartan prevents fibrosis relapse after steroid-induced remission in mice, indicating potential for long-term disease modification.
Clinical retrospective studies suggest ACE inhibitors and ARBs may reduce IBD flares and surgeries, supporting translational relevance.
Losartan treatment downregulates AT1 receptor expression in intestinal tissues, suggesting a mechanistic basis for its anti-fibrotic effects.
Clinical Implications
These findings support the potential use of losartan as an adjunct therapy targeting fibrosis in Crohn’s disease, addressing a critical unmet need. Given its established safety profile and cost-effectiveness, losartan could complement existing anti-inflammatory treatments to prevent stricture formation and reduce surgical interventions. Clinical trials are warranted to validate these preclinical results and optimize therapeutic protocols.
Conclusion
Losartan demonstrates strong preclinical efficacy in reducing intestinal fibrosis and inflammation in Crohn’s disease models, positioning RAS inhibition as a promising therapeutic strategy. This approach may improve long-term outcomes for patients with fibrostenosing CD when integrated with current treatments.
References
Artone et al. 2023 -- The angiotensin receptor blocker, losartan, reduces inflammation and fibrosis in Crohn’s disease-like ileitis
Garg et al. -- Role of RAS inhibitors in IBD outcomes
Mantaka et al. -- Angiotensin II and IBD pathogenesis
Wengrower et al. -- ACE inhibitors prevent colonic fibrosis in experimental colitis
Additional study on ACE2 expression and anti-cytokine therapy in IBD
