RESUMEN
Crohn's disease (CD) in humans and Johne's disease (JD) in ruminants share numerous clinical and pathologic similarities. As Mycobacteria avium subspecies paratuberculosis (MAP) is known to fulfill Koch's postulates as the cause of JD, there has been considerable debate over the past century about whether MAP also plays a role in CD. With recent advances in MAP identification techniques, we can now demonstrate a higher presence of MAP in CD patients compared to the general population. However, it remains unclear if MAP is playing a bystander role or is directly pathogenic in these patients. Studies have shown that there may be an immune response targeting MAP in these patients, which may underlie a pathologic role in CD. Clinical studies have yielded conflicting results as to whether anti-MAP therapy improves clinical outcomes in CD, leading to the lack of its inclusion within evidence-based clinical guidelines. Additionally, many of these studies have been small case series, with only a few randomized controlled trials published to date. In this article, we will discuss the historical context of MAP in CD, review clinical and laboratory data surrounding detection of MAP and possible pathogenesis in human disease, and suggest future directions which may finally provide some clarity to this debate.
RESUMEN
BACKGROUND: The co-occurrence of autoimmune diseases is well recognized. Though studies have suggested that eosinophilic esophagitis (EoE) is more common in patients with inflammatory bowel diseases (IBD), whether co-occurrence of EoE modifies natural history of IBD is unknown. METHODS: This was a retrospective case-control study at a referral center. Cases consisted of patients with IBD and EoE, with both diseases diagnosed using established criteria. Controls comprised patients with IBD without concomitant EoE. Two controls were selected per case and were matched for duration of IBD. Relevant covariates regarding disease presentation and natural history were extracted from the medical record and compared between the 2 groups. RESULTS: A total of 95 IBD-EoE cases and 190 IBD controls were included in our study. The IBD-EoE group was diagnosed with IBD at a younger age than those with IBD alone (22.3 years vs 29.0 years; P < 0.001) and were more likely to be male (80.0% vs 45.8%; P < 0.001). There were no differences in medical or surgical therapy for IBD between the 2 groups. Among those with IBD-EoE, patients for whom IBD was diagnosed first presented more commonly with dysphagia (50.8% vs 26.9%; P = 0.04) and endoscopically had evidence of esophageal rings (50.0% vs 23.1%; P = 0.02) when compared with those where EoE was diagnosed first. CONCLUSION: Patients with concurrent IBD-EoE are diagnosed at a younger age and more likely to be males but have similar natural history as those without EoE. There were differences in EoE phenotype based on whether the EoE or IBD was diagnosed first.