PURPOSE: Evidence supports that elevations of circulating RA-specific autoantibodies are present prior to the development of symptomatic joint disease. Lung disease is common in RA, even in early disease, and may be caused by immune-mediated injury. As such, the lung may be affected in this preclinical period of RA development. Therefore, the objective of this study was to determine if lung abnormalities in patients with established, early RA are similar to findings in subjects with RA-related autoimmunity without arthritis, supporting a hypothesis that the lung may be a site of RA-related injury in absence of symptomatic articular disease.
METHODS: Seven subjects with established RA <1 year from onset of symptoms underwent pulmonary evaluation including high-resolution computed tomography (HRCT). All RA cases were positive for rheumatoid factor [RF] and anti-cyclic citrullinated peptide [anti-CCP] antibody. Additionally, 6 subjects with elevations of RF and/or anti-CCP but without arthritis as well as 12 autoantibody negative subjects underwent similar pulmonary evaluation. These latter subjects were selected from a study of the natural history of RA.
RESULTS: Participant mean ages (% female) were as follows: early RA, 42 (71%); autoantibody positive/no arthritis, 56 (83%); controls, 51 (83%). Smoking prevalence (ever): early RA, 57%; autoantibody positive/no arthritis, 33%; controls, 17%. Airways disease, including bronchial wall thickening, bronchiectasis, centrilobular nodules and air trapping, was noted on HRCT in 100% of early RA cases, compared to 83% in autoantibody positive/no arthritis cases, and 33% of controls (P <0.01, Kruskal-Wallis testing).
CONCLUSIONS: Airways disease is highly prevalent in both early RA and in autoantibody positive/arthritis negative subjects. This suggests that airways disease may be a continuum from preclinical to established articular RA. Further studies on the role of the lung in the pathogenesis of RA using BAL and sputum analyses in both preclinical and early established RA patients are underway.
CLINICAL IMPLICATIONS: Understanding the role of the lung in the pathogenesis of RA may lead to improved therapies for RA and RA-related lung disease.
DISCLOSURE: The following authors have nothing to disclose: Annie Harrington, Isabel Pedraza, Michael Weisman, Peter Sachs, David Lynch, Lezlie Derber, Jill Norris, Michael Holers, Kevin Deane
No Product/Research Disclosure Information