Role of Gut Microbiota, Host Genetics in Reactive Arthritis

This article is part of Rheumatology Advisor’s 2017 in-depth coverage of ACR, which took place in San Diego, CA. Our staff will be reporting on the latest treatment advancements and research initiatives for spondyloarthritis. Click here to read more of Rheumatology Advisor‘s conference coverage.

SAN DIEGO — According to research to be presented at the 2017 American College of Rheumatology Annual Meeting, November 3-8, patients with reactive arthritis were shown to have a distinct gut microbial profile and unique host genetic factors compared with controls.

Researchers compared adults with reactive arthritis following gastrointestinal or genitourinary infection (n=32) with controls (n=32) who did not experience reactive arthritis. They also compared gut microbiota assessed by fecal DNA and human leukocyte antigen (HLA) status between the groups.

Patients with reactive arthritis had a higher abundance of enteropathogens compared with controls (71.9% vs 56.8%; P <.05). The primary enteropathogens with increased incidence were Erwinia and Pseudomonas species. Enthesitis was associated with increased Campylobacter species, uveitis with Erwinia species, and radiographic sacroiliitis with unclassified Ruminococcaceae species. Both uveitis and radiographic sacroiliitis were associated with increased numbers of Dialister species.

The researchers found that HLA status was associated with gut microbiota diversity. Co-occurring Ruminococcaceae, Rikenellaceae, and Coriobacteriaceae species were associated with HLA-A24, as were co-occuring Prevotellaceae, unclassified Sphingobacteriales, and Elusimicrobiaceae species.

No difference in gut bacterial alpha or beta diversity was noted between those with reactive arthritis and controls. Moreover, no differences in gut bacteria diversity were noted based on prior antibiotic exposure.

The study authors noted that, “this is the first culture-independent study characterizing the gut microbial community of [reactive arthritis]. Although bacterial factors correlated with disease presence and clinical features of [reactive arthritis], host genetics also appeared to be a major independent driver of intestinal community composition. Understanding of these gut microbiota host-genetic relationships may further clarify the pathogenesis of [reactive arthritis] and related spondyloarthropathies.”

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Reference

Manasson J, Shen N, Garcia Ferrer HR, et al. Gut microbiota perturbations in reactive arthritis. Presented at: 2017 ACR/ARHP Annual Meeting; November 3-8, 2017; San Diego, CA. Abstract 1574.