Nine separate projects related to outcomes of patients with rheumatic diseases are included in this report. The first project, Genetic determinants of ankylosing spondylitis severity, is a prospective observational study of subjects with ankylosing spondylitis (AS) that seeks to identify genetic determinants of AS susceptibility and severity. This project will test genotype-phenotype correlations in a large sample. Over 1200 subjects have been enrolled at five centers including the NIH Clinical Center, and genetic testing and data analysis are underway. Radiographic data have been analyzed in 801 patients. Findings include 26 new genes associated with susceptibility to AS, gene-gene interaction between HLA-B27 and ERAP1 in risk of AS, lack of association of bone metabolism candidate genes with radiographic severity, impact of hip arthritis on physical functioning, lessening of association between radiographic damage and functional impairment with more prolonged AS, and association of ESR and CRP with axial impairments. Collaborators include Drs. J. Reveille, M. Brown, M. Weisman, J. Davis, T. Learch, and J. Malley. Ongoing work will test fine mapping and additional susceptibility markers in larger samples, as well as associations between medication use and spine fusion. The second project, Progression of spinal fusion in ankylosing spondylitis, is a developmental study to test a measure of spinal fusion in AS based on quantification of calcification of the lumbar intervertebral discs by computed tomography. Fifty-five subjects have been enrolled. Computerized semi-automatic algorithms for measuring syndesmophyte volume and height have been optimized to maximize reliability. Based on the three-dimensional information provided by these scans, we have discovered that syndesmophytes are preferentially formed at the posteriolateral vertebral rim. This localization coincides with areas of high mechanical stress and suggests that biomechanics are likely under-recognized factors in syndesmophyte development. We have tested this hypothesis using finite element analysis on longitudinal data. We have also extended the imaging to include the thoracic spine in addition to the lumbar spine. Collaborators on this project are Drs. J. Flynn, L. Yao, Y. Yao, and S. Tan. The third project, Clinically important changes in rheumatoid arthritis, is a prospective observational study of clinically important changes in rheumatoid arthritis (RA) activity. Current criteria for improvement in RA have not emphasized the patients perspective. The goals of this project are to identify benchmarks of important improvement in pain, functioning, and global arthritis status in RA based on the self-assessment by patients of changes in their symptoms. Based on longitudinal data on 250 patients, criteria for improvement have been determined for pain, physical functioning, patient global assessment, and four composite measures of RA activity, as well as for SF-36 scales. We also determined that clinical trial response criteria, such as the ACR20, are sensitive but not specific measures of improvement. We have also determined that correlates of the patient global assessment differ with the level of RA activity, and that patient-physician discrepancies are due in part to use of different standards of reference. We are currently using these data to validate health transition questions. The fourth project, Outcomes in patients with RA, uses secondary data to examine risks of mortality, malignancy and cardiovascular disease between patients with RA and those without RA. We have found the perioperative risk of cardiovascular events and mortality not to be increased among persons with rheumatoid arthritis. The goals of the fifth project, Clinical epidemiology of systemic lupus erythematosus, are to investigate health disparities among patients with SLE, and to identify clinical features and health care practices that are associated with health outcomes. We have completed a systematic literature review and Bayesian meta-analysis of end-stage renal disease risk in patients with lupus nephritis, which document improved outcomes between 1970 and 1995, but no subsequent improvement in risk of end-stage renal disease, along with a slight increase recently. We are currently extending these methods to a study of trends in mortality among patients with SLE over time. We have also recently determined that among patients with end-stage renal disease, the survival advantage of blacks on dialysis relative to whites on dialysis is due to differential use of transplantation and withdrawal of dialysis. The goal of the sixth project, Outcomes in Orthopedics, is to investigate associations between processes and outcomes of orthopedic care. Risk of atypical hip fractures was associated with degree of compliance with bisphosphonate treatment among Medicare beneficiaries. In an observational study we found no difference in subtrochanteric beaking and chronic bisphosphonate use, indicating that this bone change is not an inevitable consequence of bisphosphnate treatment. The seventh project examines the frequency and complications of orthopedic procedures among Medicare beneficiaries. Specifically we will investigate: 1) rates of joint arthroplasty from 1996 to 2010 among patients with RA and AS, and if these rates differ by treatment with TNF inhibitors; 2) infection and other complications following surgery in patients with RA by use of TNF inhibitors; 3) regional variations in surgeries for low back pain and knee or hip arthroplasty, and their relationship to variations in risk factors for osteoarthritis; 4) postoperative complications associated with either warfarin or heparinoid anticoagulation; 5) outcomes of treatment of femoral neck fractures with either hemiarthroplasty or total hip replacement. We have found that initial treatment of hip fracture with hemiarthroplasty is equally effective as total hip replacement. The goal of the eight project is to test whether patients with RA in clinical remission can safely be withdrawn from treatment with TNF inhibitors without relapse of their arthritis. We have initiated a multicenter double-blind placebo-controlled withdrawal trial to test this hypothesis in 300 patients with RA in remission. This study will also provide data on clinical, imaging (joint ultrasound and magnetic resonance imaging), and immunological predictors of relapse. Patient enrollment is underway. The ninth project is a study of the etiology of melorheostosis, a progressive bone-forming disease, which is testing the hypothesis that somatic mutations in affected bone are responsible for the condition. Bone biopsies and extensive clinical and radiographic assessments are underway.
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