Pathogenic Autoreactive T and B Cells Cross-React with Mimotopes Expressed by a Common Human Gut Commensal to Trigger Autoimmunity.

Given the immense antigenic load present in the microbiome, we hypothesized that microbiota mimotopes can be a persistent trigger in human autoimmunity via cross-reactivity. Using antiphospholipid syndrome (APS) as a model, we demonstrate cross-reactivity between non-orthologous mimotopes expressed by a common human gut commensal, Roseburia intestinalis (R. int), and T and B cell autoepitopes in the APS autoantigen ß2-glycoprotein I (ß2GPI). Autoantigen-reactive CD4+ memory T cell clones and an APS-derived, pathogenic monoclonal antibody cross-reacted with R. int mimotopes. Core-sequence-dependent anti-R. int mimotope IgG titers were significantly elevated in APS patients and correlated with anti-ß2GPI IgG autoantibodies. R. int immunization of mice induced ß2GPI-specific lymphocytes and autoantibodies. Oral gavage of susceptible mice with R. int induced anti-human ß2GPI autoantibodies and autoimmune pathologies. Together, these data support a role for non-orthologous commensal-host cross-reactivity in the development and persistence of autoimmunity in APS, which may apply more broadly to human autoimmune disease.

Survey of Patient Insurance Status on Access to Specialty Foot and Ankle Care Under the Affordable Care Act.

BACKGROUND: The purpose of this study was to assess the effect of insurance type (Medicaid, Medicare, and private insurance) on access to foot and ankle surgeons for total ankle arthroplasty. METHODS: We called 240 foot and ankle surgeons who performed total ankle arthroplasty in 8 representative states (California, Massachusetts, Ohio, New York, Florida, Georgia, Texas, and North Carolina). The caller requested an appointment for a fictitious patient to be evaluated for a total ankle arthroplasty. Each office was called 3 times to assess the responses for Medicaid, Medicare, and BlueCross. From each call, we recorded appointment success or failure and any barriers to an appointment, such as need for a referral. RESULTS: Patients with Medicaid were less likely to receive an appointment compared to patients with Medicare (19.8% vs 92.0%, P < .0001) or BlueCross (19.8% vs 90.4%, P < .0001) and experienced more requests for referrals compared to patients with Medicare (41.9% vs 1.6%, P < .0001) or BlueCross (41.9% vs 4%, P < .0001). Waiting periods were longer for patients with Medicaid compared to those with Medicare (22.6 days vs 11.7 days, P = .004) or BlueCross (22.6 days vs 10.7 days, P = .001). Reimbursement rates did not correlate with appointment success rate or waiting period. CONCLUSION: Despite the passage of the PPACA, patients with Medicaid continue to have difficulty finding a surgeon who will provide care, increased need for a primary care referral, and longer waiting periods for appointments. LEVEL OF EVIDENCE: Level II, prognostic study.