Liam Martin

Clinical and Serological Features of Patients Referred through a Rheumatology Triage System because of Positive Antinuclear Antibodies

Background The referral of patients with positive anti-nuclear antibody (ANA) tests has been criticized as an inappropriate use of medical resources. The utility of a positive ANA test in a central triage (CT) system was studied by determining the autoantibody profiles and clinical diagnoses of patients referred to rheumatologists through a CT system because of a positive ANA test. Methods Patients that met three criteria were included: (1) referred to Rheumatology CT over a three year interval; (2) reason for referral was a “positive ANA”; (3) were evaluated by a certified rheumatologist. The CT clinical database was used to obtain demographic and clinical information and a serological database was used to retrieve specific ANA and/or extractable nuclear antigen (ENA) test results. Clinical information was extracted from the consulting rheumatologists report. Results 15,357 patients were referred through the CT system; 643 (4.1%) of these because of a positive ANA and of these 263 (40.9%) were evaluated by a certified rheumatologist. In 63/263 (24%) of ANA positive patients, the specialist provided a diagnosis of an ANA associated rheumatic disease (AARD) while 69 (26.2%) had no evidence of any disease; 102 (38.8%) had other rheumatologic diagnoses and 29 (11%) had conditions that did not meet AARD classification criteria. Of ANA positive archived sera, 15.1% were anti-DFS70 positive and 91.2% of these did not have an AARD. Conclusions This is the first study to evaluate the serological and clinical features of patients referred through a CT system because of a positive ANA. The spectrum of autoantibody specificities was wide with anti-Ro52/TRIM21 being the most common autoantibody detected. Approximately 15% of referrals had only antibodies to DFS70, the vast majority of which did not have clinical evidence for an AARD. These findings provide insight into the utility of autoantibody testing in a CT system.

Risk Factors for Infection Following Total Joint Arthroplasty in Rheumatoid Arthritis

Objectives: Determine risk factors for infection following hip or knee total joint arthroplasty in patients with rheumatoid arthritis. Methods: All rheumatoid arthritis patients with a hip or knee arthroplasty between years 2000 and 2010 were identified from population-based administrative data from the Calgary Zone of Alberta Health Services. Clinical data from patient charts during the hospital admission and during a one year follow-up period were extracted to identify incident infections. Results: We identified 381 eligible procedures performed in 259 patients (72.2% female, mean age 63.3 years, mean body mass index 27.6 kg/m2). Patient comorbidities were hypertension (43.2%), diabetes (10.4%), coronary artery disease (13.9%), smoking (10.8%) and obesity (32%). Few infectious complications occurred: surgical site infections occurred within the first year after 5 procedures (2 joint space infections, 3 deep incisional infections). Infections of non-surgical sites (urinary tract, skin or respiratory, n=4) complicated the hospital admission. The odds ratio for any post-arthroplasty infection was increased in patients using prednisone doses exceeding 15 mg/day (OR 21.0, 95%CI 3.5-127.2, p=<0.001), underweight patients (OR 6.0, 95%CI 1.2-30.9, p=0.033) and those with known coronary artery disease (OR 5.1, 95%CI 1.3-19.8, p=0.017). Types of disease-modifying therapy, age, sex, and other comorbidities were not associated with an increased risk for infection. Conclusion: Steroid doses over 15 mg/day, being underweight and having coronary artery disease were associated with significant increases in the risk of post-arthroplasty infection in rheumatoid arthritis. Maximal tapering of prednisone and comorbidity risk reduction must be addressed in the peri-operative management strategy.

Synovial Fluid Progenitors Expressing CD90+ from Normal but Not Osteoarthritic Joints Undergo Chondrogenic Differentiation without Micro-Mass Culture

Objective Mesenchymal progenitor cells (MPCs) can differentiate into osteoblasts, adipocytes, and chondrocytes, and are in part responsible for maintaining tissue integrity. Recently, a progenitor cell population has been found within the synovial fluid that shares many similarities with bone marrow MPCs. These synovial fluid MPCs (sfMPCs) share the ability to differentiate into bone and fat, with a bias for cartilage differentiation. In this study, sfMPCs were isolated from human and canine synovial fluid collected from normal individuals and those with osteoarthritis (human: clinician-diagnosed, canine: experimental) to compare the differentiation potential of CD90+ vs. CD90− sfMPCs, and to determine if CD90 (Thy-1) is a predictive marker of synovial fluid progenitors with chondrogenic capacity in vitro. Methods sfMPCs were derived from synovial fluid from normal and OA knee joints. These cells were induced to differentiate into chondrocytes and analyzed using quantitative PCR, immunofluorescence, and electron microscopy. Results The CD90+ subpopulation of sfMPCs had increased chondrogenic potential compared to the CD90− population. Furthermore, sfMPCs derived from healthy joints did not require a micro-mass step for efficient chondrogenesis. Whereas sfMPCs from OA synovial fluid retain the ability to undergo chondrogenic differentiation, they require micro-mass culture conditions. Conclusions Overall, this study has demonstrated an increased chondrogenic potential within the CD90+ fraction of human and canine sfMPCs and that this population of cells derived from healthy normal joints do not require a micro-mass step for efficient chondrogenesis, while sfMPCs obtained from OA knee joints do not differentiate efficiently into chondrocytes without the micro-mass procedure. These results reveal a fundamental shift in the chondrogenic ability of cells isolated from arthritic joint fluids, and we speculate that the mechanism behind this change of cell behavior is exposure to the altered milieu of the OA joint fluid, which will be examined in further studies.

Healthcare service utilisation costs are reduced when rheumatoid arthritis patients achieve sustained remission

Objective Determine healthcare service utilisation costs among patients using biological therapies for rheumatoid arthritis (RA), considering the magnitude and duration of patient response achieved. Methods Clinical data from the Alberta Biologics Pharmacosurveillance Program (ABioPharm) was linked with provincial physician billing claims, outpatient visits and hospitalisations. The annual mean healthcare service utilisation costs (total, RA-attributable, non-RA attributable) were estimated for patients during the best disease activity level reached during treatment. Results Of 1086 patients: 16% achieved DAS28 remission >1 year, 37% had a DAS28 remission period <1 year, 13% had a low disease activity (LDA) period <1 year and 31% had persistent moderate or high disease activity. Mean annual healthcare service utilisation cost savings for those in sustained remission was

Matrix metalloproteinase protein expression profiles cannot distinguish between normal and early osteoarthritic synovial fluid

2391 (95% CI 1437 to 3909, p<0.001) and

Development of Cardiovascular Quality Indicators for Rheumatoid Arthritis: Results from an International Expert Panel Using a Novel Online Process

2104 (95% CI 838 to 3512, p<0.001) for those with non-sustained LDA, relative to the persistent disease activity group. Savings were also observed for those in sustained remission compared to non-sustained remission (annual savings

Identification of a subset of patients with scleroderma with severe pulmonary and vascular disease by the presence of autoantibodies to centromere and histone.

1422, 95% CI 564 to 2796, p<0.001). RA-related costs were consistent across disease activity and cost categories; the majority of costs were attributable to non-RA related hospitalisations. Conclusions We provide evidence of economic benefits to the healthcare system when RA patients achieve persistent good disease control. Benefits from brief periods of remission and LDA are also observed. Coupled with an expected increase in productivity from improved disease control, there is societal benefit to the utilisation of biologics in RA management to achieve treatment goals.

Intraarticular and Systemic Inflammatory Profiles May Identify Patients with Osteoarthritis

BackgroundOsteoarthritis (OA) and Rheumatoid arthritis (RA) are diseases which result in the degeneration of the joint surface articular cartilage. Matrix Metalloproteinases (MMPs) are enzymes that aid in the natural remodelling of tissues throughout the body including cartilage. However, some MMPs have been implicated in the progression of OA and RA as their expression levels and activation states can change dramatically with the onset of disease. Yet, it remains unknown if normal and arthritic joints demonstrate unique MMPs expression profiles, and if so, can the MMP expression profile be used to identify patients with early OA. In this study, the synovial fluid protein expression levels for MMPs 1, 2, 3, 7, 8, 9, 12 & 13, as well as those for the Tissue Inhibitors of MMPs (TIMPs) 1, 2, 3, & 4 were examined in highly characterized normal knee joints, and knee joints with clinically diagnosed OA (early and advanced) or RA. The purpose of this study was to determine if normal, OA, and RA patients exhibit unique expression profiles for a sub-set of MMPs, and if early OA patients have a unique MMP expression profile that could be used as an early diagnostic marker.MethodsSynovial fluid was aspirated from stringently characterized normal knee joints, and in joints diagnosed with either OA (early and advanced) or RA. Multiplexing technology was employed to quantify protein expression levels for 8 MMPs and 4 TIMPs in the synovial fluid of 12 patients with early OA, 17 patients diagnosed with advanced OA, 15 with RA and 25 normal knee joints. Principle component analysis (PCA) was used to reveal which MMPs were most influential in the distinction between treatment groups. K – means clustering was used to verify the visual grouping of subjects via PCA.ResultsSignificant differences in the expression levels of MMPs and TIMPs were observed between normal and arthritic synovial fluids (with the exception of MMP 12). PCA demonstrated that MMPs 2, 8 & 9 can be used to effectively separate individuals diagnosed with advanced arthritis from early osteoarthritic and normal individuals, however, these MMP profiles do not separate early OA from normal synovial fluid. An apparent separation between advanced OA and RA subjects was also revealed through PCA. K-means clustering verified the presence of 3 clusters: normal joints clustered with early OA, and separate clusters of advanced OA or RA.ConclusionsThis study demonstrates that unique MMP and TIMP expression profiles are present within normal, advanced OA and RA synovial fluid. These MMP profiles can be used to distinguish advanced OA & RA synovial fluid from early OA & normal synovial fluid, and even between synovial fluid samples from OA and RA joints. Although this methodology cannot be used for the diagnosis of early OA, high throughput multiplex technology of MMPs and TIMPs in synovial fluid may prove useful in determining the severity of the disease state, and/or quantifying the response of individuals to disease interventions.

The Effect of Different Remission Definitions on Identification of Predictors of Both Point and Sustained Remission in Rheumatoid Arthritis Treated with Anti-TNF Therapy

Objective. Patients with rheumatoid arthritis (RA) have a high risk of premature cardiovascular disease (CVD). We developed CVD quality indicators (QI) for screening and use in rheumatology clinics. Methods. A systematic review was conducted of the literature on CVD risk reduction in RA and the general population. Based on the best practices identified from this review, a draft set of 12 candidate QI were presented to a Canadian panel of rheumatologists and cardiologists (n = 6) from 3 academic centers to achieve consensus on the QI specifications. The resulting 11 QI were then evaluated by an online modified-Delphi panel of multidisciplinary health professionals and patients (n = 43) to determine their relevance, validity, and feasibility in 3 rounds of online voting and threaded discussion using a modified RAND/University of California, Los Angeles Appropriateness Methodology. Results. Response rates for the online panel were 86%. All 11 QI were rated as highly relevant, valid, and feasible (median rating ≥ 7 on a 1–9 scale), with no significant disagreement. The final QI set addresses the following themes: communication to primary care about increased CV risk in RA; CV risk assessment; defining smoking status and providing cessation counseling; screening and addressing hypertension, dyslipidemia, and diabetes; exercise recommendations; body mass index screening and lifestyle counseling; minimizing corticosteroid use; and communicating to patients at high risk of CVD about the risks/benefits of nonsteroidal antiinflammatory drugs. Conclusion. Eleven QI for CVD care in patients with RA have been developed and are rated as highly relevant, valid, and feasible by an international multidisciplinary panel.

Canadian Estimates of Health Care Utilization Costs for Rheumatoid Arthritis Patients With and Without Therapy With Biologic Agents

OBJECTIVES--The role of autoantibodies in the investigation and management of rheumatic diseases is well recognised. The objective of this study was to determine the clinical significance of the co-occurrence of antibodies to centromere and histone in serum samples from patients investigated for systemic rheumatic diseases. METHODS--Serum samples from 1316 consecutive patients were screened for antinuclear antibodies and the clinical findings in patients with antibodies to centromere alone were compared with those with antibodies to both centromere and histone. RESULTS--Twenty six patients had antibodies to centromere. Fourteen patients had antibodies to centromere alone and 12 patients had antibodies to centromere and histone. Four of the 12 patients with antibodies to centromere and histone had diffuse scleroderma with severe pulmonary or vascular disease. CONCLUSIONS--A subset of patients with scleroderma with antibodies to centromere and histone has been identified retrospectively, who have severe pulmonary or vascular disease. It will be of interest to follow up the clinical course of other patients with scleroderma who have both antibodies for the development of pulmonary or vascular disease.