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ID PMID Title PublicationDate abstract
9227168 Quantitative magnetic resonance imaging of the knee: a method of measuring response to int 1997 Jun OBJECTIVES: To investigate the potential of quantitative magnetic resonance imaging (MRI) to differentiate between therapeutically induced changes in inflammation and synovial proliferation in rheumatoid arthritis (RA) of the knee. METHODS: MRI of the knee was performed on patients with RA before and one week after injection with corticosteroid (triamcinolone acetonide, TA group, n = 9) and before, four, and 12 weeks after injection with yttrium-90 plus TA (TA+Y group, n = 7). MRI scans were analysed by subjective visual grading by a trained observer and by computer aided quantitation for three features: synovial fluid volume, synovial pannus volume, and synovial enhancement after intravenous contrast agent. RESULTS: All TA subjects improved clinically at one week but the effects of TA+Y were more variable. TA significantly reduced synovial enhancement and effusion volume, whereas TA+Y at 12 weeks tended to increase synovial enhancement and decrease pannus volume. Quantitative MRI values agreed well with subjective assessment of scans. Comparison of calculated change on MRI scan before and immediately after aspiration with actual volume aspirated showed high correlation (r = 0.96). CONCLUSIONS: Quantitative MRI correlates with subjective visual assessment and, at least for synovial fluid, is accurate. MRI can differentiate actions of two therapeutic modalities on various pathological processes and is sensitive enough to detect change after one week. With the additional advantage of lack of observer bias, it will probably become a useful tool in the development and assessment of existing and novel treatments.
11333348 Approaches to rheumatoid arthritis in 2000. 2001 May The year 2000 was characterized by euphoria among clinicians based on the continued and consolidated success of tumor necrosis factor (TNF) inhibition but also by problems caused by the high cost of this therapy. Looking at the risks and adverse effects has only begun, and there is so far a remarkable lack of publications dealing with this topic. Leflunomide also emerges as an established disease-modifying antirheumatic drug (DMARD). Other therapies include the cyclooxygenase-2 (Cox-2) inhibitors, which are tolerated better by the gastrointestinal system but raise concerns regarding thromboembolism in patients at risk. The enthusiasm regarding Cox-2 inhibitors is somewhat tempered by recent reports of thromboembolic complications, although those have been rare. The advances in research regarding mechanisms of inflammation and pathogenesis continue to generate new therapeutic approaches, which, however, remain mostly experimental. The complexity of genetics has been emphasized by reports on susceptibility and severity relation to TNF, mannose-binding lectin, and gamma-interferon polymorphism. Epidemiologic studies focusing on prevalence, incidence and outcome continue to deliver conflicting messages. One major worry relates to chronic inflammation in RA and other rheumatic diseases as putative cause of accelerated atherosclerosis.
10328138 The role of tumor necrosis factor in health and disease. 1999 May The vast and growing array of cytokines is the subject of intense research for their potential to ameliorate a range of diseases that extends from autoimmune disorders to cancer and beyond. Among the cytokines, tumor necrosis factor-alpha (TNF-alpha) has proven to be a key ligand in triggering many intracellular processes, both physiological and pathological. Understanding its role in rheumatoid arthritis and Crohn's disease has produced effective new therapeutic agents, and there is reason to expect greater success as research proceeds. New synthetic macromolecules are effectively interfering with TNF and other ligands at and before the cellular membrane interface. This article reviews current knowledge of the molecular mechanics of TNF and the therapeutic inhibition of TNF action. Unraveling these processes has led to many insights into cytokine physiology and pathology.
11768835 Current and emerging therapies for rheumatoid arthritis, with a focus on infliximab: clini 2001 Nov BACKGROUND: Rheumatoid arthritis (RA) is a physically debilitating disease that places an enormous burden not only on individuals and their families but also on the economy. Affecting -1% of the Canadian population, RA is characterized by pain and swelling of joints. Without effective treatment, RA results in joint destruction that often requires surgery. OBJECTIVE: This review summarizes the effect of current and new RA treatments on joint damage, with a focus on infliximab. The health-economic repercussions and potential impact of arresting the joint destruction of RA are discussed. METHODS: Information for inclusion in this review was identified through searches of the MEDLINE and HealthStar databases from 1995 to 2000. Search terms included rheumatoid arthritis, treatment guidelines, economics, and individual drug names. RESULTS: Standard initial RA drug therapy has been aimed at reducing pain and inflammation, whereas use of the more potent disease-modifying antirheumatic drugs (DMARDs) has been reserved for later stages of disease. More aggressive RA treatment involves introducing DMARDs at the earliest stage. The largest single direct cost of RA involves hospital admissions for the correction of joint deformities. Among newer therapies, the anti-tumor necrosis factor-alpha agent infliximab has been shown to arrest radiographic measures of disease progression. CONCLUSIONS: With early and aggressive treatment involving new drugs and drug combinations, it may be possible to ameliorate the physical, social, and economic effects of RA.
9338926 Evaluation of bone mineral density in patients with rheumatoid arthritis. Influence of dis 1997 Jul OBJECTIVES: To study bone mass and the factors that influence bone mass in rheumatoid arthritis patients versus controls. PATIENTS AND METHODS: 85 patients (73 women) with a mean age of 57 +/- 11 years and a mean disease duration of 13 +/- 9 years were compared to 85 age- and sex-matched controls. Among the patients, 62 (76%) had positive rheumatoid factor tests and 51 (60%) were receiving steroid therapy, with a mean daily dose of 10 +/- 4 mg and a mean duration of 7 +/- 6 years. The following parameters were determined: morning stiffness duration, painful and swollen joint counts, Lee's and Ritchie's indices, Health Assessment Questionnaire score, erythrocyte sedimentation rate, and C-reactive protein. Bone mineral density was measured at the lumbar spine and femoral neck using dual-energy X-ray absorptiometry (Sophos L-XRA). RESULTS: In the nonsteroid-treated patients, bone mineral density was similar to that in controls at the lumbar spine but was decreased by 8% (95% confidence interval [CI], 1.8-14.2%) at the femoral neck (0.76 +/- 0.14 g/cm2 versus 0.83 +/- 0.15 g/cm2; P = 0.03). Decreases of 11.5% (95% CI, 8.1-14.9%) at the lumbar spine and 10.4% (95% CI, 6.4-14.4%) at the femoral neck were found in the steroid-treated patients versus the nonsteroid-treated patients. In the patient group, femoral neck bone mineral density was significantly negatively correlated with age (r = -0.5), the Heath Assessment Questionnaire score (r = -0.27), and the erythrocyte sedimentation rate (r = -0.25), whereas only the first two variables were significantly correlated with lumbar bone mineral density. A multiple linear regression model including age, glucocorticoid use, rheumatoid factor, the Health Assessment Questionnaire score, and the erythrocyte sedimentation rate was constructed and adjusted for the number of variables. This model explained 44.7% of the variance of femoral neck bone mineral density. CONCLUSION: Rheumatoid arthritis is associated with a decrease in bone mass that is most marked in patients with active and/or severe disease and in those who take glucocorticoids.
11469456 Arthroscopic synovectomy for rheumatoid arthritis using a holmium:YAG laser. 2001 Jul OBJECTIVE: To determine the usefulness of the holmium:YAG laser system in arthroscopic synovectomy (ASSX) for treating rheumatoid arthritis (RA). METHODS: ASSX was performed on 15 knees (one Larsen Grade 1, 7 Grade 2, 7 Grade 3) and 8 ankles (6 Grade 2, 2 Grade 3) of 17 female patients with RA. The average age at ASSX was 50.6 years (25-70). The average followup period was 24.4 months (10-47). RESULTS: Seven out of 8 knees with grade 1 or 2 had reduced pain and swelling, as well as decreased average serum levels of C-reactive protein (CRP) (from 3.6+/-1.1 to 1.4+/-0.3 mg/dl). However, 4 out of 7 knees with grade 3 showed recurrence of pain and swelling along with persistent average serum level of CRP (from 4.3+/-1.0 to 3.8+/-1.0 mg/dl). All 8 ankles with Grade 2 or Grade 3 experienced reduced pain and swelling, while the average serum CRP levels did not change (from 3.2+/-0.9 to 2.9+/-1.0 mg/dl). CONCLUSION: The Holmium:YAG laser was useful in ASSX for treating RA knees and ankles.
9068803 Focal segmental necrotizing glomerulonephritis in rheumatoid arthritis. 1997 Feb We report ten patients with rheumatoid arthritis (RA) who developed a focal segmental necrotizing glomerulonephritis (FSNGN) and extracapillary proliferation typical of vasculitic glomerulonephritis. Five patients also had extrarenal vasculitis. Renal presentation was with renal impairment (n = 9) (median creatinine 726 mumol/l, range 230-1592 mumol/l), microscopic haematuria (n = 8) and proteinuria (n = 10). Nine patients were seropositive for rheumatoid factor and nine had bone erosions. Serum from four of five patients tested by indirect immunofluorescence was positive for antineutrophil cytoplasmic antibody (ANCA) with perinuclear staining. Only three patients had penicillamine or gold therapy. Treatment was with prednisolone and cyclophosphamide (six patients, two of whom were also plasma-exchanged), prednisolone and azathioprine (two patients) and prednisolone alone (two patients). There was a marked improvement in renal function in eight patients. Two patients with dialysis-dependent renal failure recovered renal function, although in one patient this was transient and she required further dialysis 4 months later. Two other patients progressed to dialysis at 3 months and 1 year respectively. Four patients died, one remains dialysis-dependent, and four continue to have good renal function at 5 year follow-up (median creatinine 148.5 mumol/l, range 120-193 mumol/l). One patient was lost to follow-up at 5 years. FSNGN should be considered in all patients with RA and renal impairment, proteinuria and/or microscopic haematuria. This diagnosis appears to be more likely in patients with clinical extrarenal vasculitis, bone erosions or who are seropositive. In these cases, an urgent renal biopsy is indicated.
9918267 Sensitivity to change of generic quality of life instruments in patients with rheumatoid a 1999 Jan This is the initial report of the generic health OMERACT study concerned with the sensitivity to change of generic quality of life (QOL) measures. Our objective was to determine which QOL instrument is best able to show a statistically significant improvement in patients with rheumatoid arthritis (RA) demonstrating relevant improvement in a core set of disease activity and disease-specific disability measures. A multicenter controlled trial of a single group with repeated measurements at 0 (baseline), 3, and 6 months was conducted. All participating centers recruited 10 patients with RA who were about to start methotrexate therapy for the first time because of active disease. Assessments included disease activity measures, disease-specific disability measures, and generic QOL measures. To date, 40 patients have been recruited from 4 centers for the study. After 6 months of treatment many of the generic QOL measures showed a 20% improvement from baseline and medium standardized response means around 0.5. In particular, the Nottingham Health Profile (NHP) and the Rheumatoid Arthritis Quality of Life (RAQOL) measures had the largest percentage improvement (22 and 29%, respectively) and standardized response means (both with 0.54). Early results on the sensitivity of generic health QOL measures are promising, in particular for the NHP and RAQOL measures.
10719815 NRAMP1 gene polymorphisms in patients with rheumatoid arthritis in Koreans. 2000 Feb Natural resistance-associated macrophage protein 1 (Nramp1) is a genetic locus associated with innate resistance or susceptibility of murine hosts to infection with intracellular pathogens such as Salmonella, Leishmania and Mycobacterium. The human homologue of the Nramp1 gene, designated NRAMP1, has been investigated as a candidate gene for genetic susceptibility to autoimmune diseases as well as infections. This study tries to determine whether NRAMP1 polymorphisms are associated with susceptibility to rheumatoid arthritis in Koreans. The nine NRAMP1 polymorphisms (1 microsatellite, 1 variation in 3' UTR, 5 silent substitution, 2 amino acid substitution) were typed by PCR-RFLP in 74 patients with rheumatoid arthritis (RA) and 53 healthy controls in Koreans. The distribution of allele and genotype frequencies were compared between patients and controls. Three NRAMP1 polymorphisms (823C/T, D543N and 1729+55del4) were significantly associated with RA. In addition, there were significant differences in the genotype frequencies for 823C/T, D543N and 1729+ 55del4 polymorphisms between RA patients and controls. Genotypes of A/A homozygote for D543N and TGTG deletion homozygote for 1729+55del4 were only detected in the patient group. These data indicate that genetic polymorphisms of NRAMP1 might be associated with the susceptibility to rheumatoid arthritis in Koreans.
10502017 [Interferon-alpha-associated polyarthritis. Possible induction of seropositive rheumatoid 1999 Aug We describe a patient with chronic myelogenous leukemia (CML) and a patient with hairy cell leukemia being effectively treated with alpha-interferon who developed a seropositive chronic polyarthritis formally fulfilling the ACR criteria for rheumatoid arthritis. Because of its efficacy, interferon was not discontinued, and the arthritis treated with low-dose prednisolone or NSAIDS. These are the 19th and 20th case of symmetrical polyarthritis during alpha-interferon therapy fulfilling the criteria for RA. The possible mechanisms of the relatively frequent appearance of autoimmune diseases during interferon therapy are discussed.
11740068 Relationship between bone mineral density and radiologic scores of hands in rheumatoid art 2001 Fall This study proposed to assess the relationship between hand bone mineral density (BMD) and radiographic scoring methods, important measures to assess the course of rheumatoid arthritis. Hand, spine, and femur BMD of 49 patients with rheumatoid arthritis and 34 age- and sex-matched healthy control subjects were measured using dual X-ray absorptiometry and the results were compared. Standard hand films of patients were scored according to five different scoring methods--Larsen method, modified Larsen method, Sharp/van der Heijde modified method, carpo:metacarpal ratio, and simple erosion narrowing score (SENS)--and were correlated with hand BMD. There was a moderate relationship between hand BMD measurements and radiologic scores. SENS was the method that correlated significantly with the highest correlation coefficient. Hand BMD correlated significantly with disease duration and c-reactive protein levels. Hand BMD in patients with rheumatoid arthritis was significantly lower than in control subjects, whereas there was no significant difference in axial BMD measurements. The advantages and disadvantages of hand BMD and radiographic scoring methods were determined. Our results indicate that hand BMD measurements may be as useful is assessing the course of rheumatoid arthritis as radiologic scoring methods. However to prove this, a well-designed reference population for hand BMD and longitudinal studies are required.
9581011 Rheumatoid arthritis and metal compounds--perspectives on the role of oxygen radical detox 1998 Jan Rheumatoid arthritis (RA) is characterised by migration of activated phagocytes and other leukocytes into synovial and periarticular tissue. Activated oxygen species and other mediating substances from triggered phagocytes appear to exacerbate and perpetuate the rheumatoid condition. Iron excesses are capable of aggravating the arthritic inflammation, probably through their pro-oxidant potentials. In contrast, therapeutically given gold salts, through a lysosomal loading of the metal, inhibit the triggered cells, thereby reducing the toxic oxygen production. Pharmacological doses of zinc also may immobilise macrophages. Furthermore, the copper-zinc-containing enzyme SOD (superoxide dismutase) can act as a scavenger of toxic oxygen in the tissues. Therapeutic remission of RA has been obtained following intraarticular administration of SOD. Intramuscular administration of copper complexes has induced remission in about 60% of RA patients in open studies. Another drug, penicillamine, that protects cellular membranes against toxic oxygen in vitro, is presumed to act as an antirheumatic via the SOD mimetic activity of its copper complex. Thiomalate and other thiols may possess similar activities. Selenium compounds also may act as oxygen radical scavengers. A significant alleviation of articular pain and morning stiffness was obtained following selenium and vitamin E supplementation in a double-blind study on RA patients. The observations reviewed here indicate that metal compounds and other antioxidants can reduce the rheumatic inflammation by reducing the cellular production and/or concentration of toxic oxygen species.
9972955 Paucity of radiographic progression in rheumatoid arthritis treated with methotrexate as t 1999 Feb OBJECTIVE: To determine disease progression in patients with rheumatoid arthritis (RA) using methotrexate (MTX) as the first disease modifying antirheumatic drug (DMARD). METHODS: Patients with RA treated with MTX as their first DMARD and in whom hand/wrist radiographs prior to MTX administration had been obtained and who had received MTX for at least 10 months were evaluated radiographically for disease progression. Coded radiographs were read for erosions by 2 experienced readers using the modified method of Sharp. Erosion scores and rate of progression (per month) were calculated. RESULTS: Of 24 patients studied, baseline radiographs showed erosions (one or more) in 11 and none in 13. Patients with and without erosions at baseline had comparable demographic and clinical features, although patients with erosions had longer disease duration and higher rheumatoid factor positivity than those without erosions (statistically nonsignificant, however). Half of all patients showed no progression; 73% of those patients with erosions at baseline but only 31% of those without erosions at baseline progressed (p = 0.049); progression rates were 0.017 (+/-0.033) and 0.049 (+/-0.078) for the 2 groups (p = 0.040). CONCLUSION: Patients with RA starting MTX before erosions have occurred are less likely to develop them; these patients also experienced a lesser degree of disease progression than patients who started MTX with erosions already present.
9175935 Prevalence of low body mass in rheumatoid arthritis: association with the acute phase resp 1997 May OBJECTIVE: To ascertain the prevalence of low body mass in a rheumatoid arthritis (RA) population and to explore a possible relation with the acute phase response. METHODS: 97 patients who fulfilled the American College of Rheumatology (ACR) criteria for RA were recruited. Change in weight from initial presentation was noted. Body mass index (BMI), upper arm fat and muscle areas were recorded together with fat free mass calculated from the waist measurement. Blood samples were taken for erythrocyte sedimentation rate (ESR), C reactive protein (CRP), and serum albumin. RESULTS: 13% of the RA group fell into the lowest 5th centile for BMI for the general population. The loss of body mass was greater for lean tissue than fat, with over 50% of the RA group falling into the lowest 10th centile of a reference population for the upper arm muscle area. Female patients who lost greater than 15% of their initial weight had higher health assessment questionnaire (HAQ) results than the rest of the group (p = 0.020). In female patients there was a significant correlation between reduced fat free mass and the acute phase response (ESR p = 0.016 and CRP p = 0.003) CONCLUSIONS: There is an increased prevalence of low body mass, greatest for lean tissue, in the RA population. In the female group there was an inverse relation between the acute phase response and fat free mass. Female patients with RA who lose a significant amount of weight are more disabled as assessed by HAQ.
9584367 Ankle arthrodesis in patients with rheumatoid arthritis. 1998 Apr The results of 26 ankle arthrodeses performed for rheumatoid arthritis on 21 patients were reviewed. Tibiotalar arthrodesis was performed in 14 ankles, and tibiotalocalcaneal arthrodesis was performed in 12. External fixation was used in 20 ankles, and internal fixation was used in six. Followup was available in 24 of 26 ankles (19 patients), and averaged 5 years (range, 2-8 years). There was no pain experienced in 19 ankles; mild, occasional pain was experienced in four ankles; and moderate, daily pain was experienced in one ankle. Daily activities were limited in five patients and recreational activities were limited in 11. All patients reported some difficulty walking on uneven terrain. Nearly all patients were satisfied; two were satisfied with reservations and two were dissatisfied. Union was achieved in 25 of 26 (96%) ankles. Ankle arthrodesis is an effective operation in patients with rheumatoid arthritis. Unlike previous reports, union and complication rates in this series were comparable with rates for arthrodesis for posttraumatic and degenerative arthritis.
10503557 Cyclosporin and sulfasalazine combination in the treatment of early rheumatoid arthritis. 1999 The aim of the study was to assess the efficacy of a new formulation of cyclosporin-A (CyA) and sulfasalazine (SASP) combination treatment in preventing disability and reducing inflammatory disease activity in patients with early rheumatoid arthritis, as well as to assess the tolerability, safety, and suitability for long-term treatment. Forty five patients with early, active rheumatoid arthritis, (RA) were treated with CyA and SASP combination therapy for 12 months. The patients were evaluated by disease activity and radiologic measurements. The combined CyA and SASP therapy seems to be effective. Disease activity parameters improved within 3 months. The individual treatment response rate according to EULAR response criteria was 78% after a one year treatment period. Five patients were withdrawn due to gastrointestinal side effect and two patients because of lack of efficacy. CyA and SASP combination treatment seems to be effective in early severe RA, and with careful monitoring, side effects can be kept under control.
10882721 The generation and characterization of antagonist RNA aptamers to human oncostatin M. 2000 Sep 15 Oncostatin M (OSM) is a multifunctional member of the interleukin-6 cytokine family. OSM has been implicated as a powerful proinflammatory mediator and may represent a potentially important, novel therapeutic opportunity for treatment of established rheumatoid arthritis. To further investigate the role of OSM in inflammatory disorders, we have isolated a series of RNA aptamers that bind specifically to human OSM. The highest affinity aptamer, designated ADR58, has been characterized in a series of in vitro and cell based assays. ADR58 has an affinity of 7 nm for human OSM, and it can antagonize OSM binding to the gp130 receptor and specifically antagonize OSM mediated signaling. The aptamer has been truncated in length to 33 bases, all pyrimidine positions are substituted with 2' fluorine, and 14 of 18 purine positions have been substituted with 2' O-methyl to increase stability toward nucleases. This truncated, modified form of ADR58 retains complete affinity and functional activity for OSM. This aptamer may be used as a tool to further investigate the role of OSM in inflammatory disorders and may also have role as a therapeutic agent.
9794048 Cervical lesions related to the systemic progression in rheumatoid arthritis. 1998 Oct 1 STUDY DESIGN: Cross-sectional study of cervical involvement in rheumatoid arthritis. OBJECTIVES: To clarify the correlation between the deterioration of cervical lesions and the systemic progression of rheumatoid arthritis. SUMMARY OF BACKGROUND DATA: The natural course of cervical lesions varies. To date, no systemic parameter has been clarified to predict the progression. METHODS: One hundred seventy-three patients with rheumatoid arthritis participated in this study. The authors studied the progression of cervical lesions and investigated the relation between the types of cervical subluxation at the end of study and the following four variables: the serum level of C-reactive protein, the number of joints with erosion, carpal height ratio, and disease subset (least erosive subset, more erosive subset, and mutilating disease subset). RESULTS: Of the 173 patients, 55 already had cervical subluxation before entering the study. During the follow-up period, 44 patients deteriorated radiographically, and 77 (45%) had cervical involvement, including involvement of upper cervical lesions in 65 patients, upper lesions combined with subaxial subluxation in 10, and subaxial subluxation alone in 2. The upper cervical subluxation progressed in the order of anterior atlantoaxial subluxation, atlantoaxial subluxation combined with vertical subluxation, and vertical subluxation alone. Deterioration of upper cervical lesion and occurrence of subaxial subluxation were closely correlated with an elevation of serum C-reactive protein level, an increase in the number of joints with erosion, and a decrease in the carpal height ratio. The incidence of cervical involvement and the extent of deterioration were different among the disease subsets. CONCLUSIONS: The serum level of C-reactive protein, the number of joints with erosion, and the carpal height ratio correlated closely with the extent of the cervical subluxation. The average C-reactive protein values during the follow-up period correlated with progression of the cervical lesions. The classification of rheumatoid disease subset was useful for predicting the terminal feature of the cervical lesions.
10798357 Identification of 142 single nucleotide polymorphisms in 41 candidate genes for rheumatoid 2000 Mar Single-nucleotide polymorphisms (SNPs) can make an important contribution to our understanding of genetic backgrounds that may influence medical conditions and ethnic diversity. We undertook a systematic survey of genomic DNA for SNPs located not only in coding sequences but also in non-coding regions (e.g., introns and 5' flanking regions) of selected genes. Using DNA samples from 48 Japanese patients with rheumatoid arthritis (RA) as templates, we surveyed 41 genes that represent candidates for RA, screening a total of 104 kb of DNA (30 kb of coding sequences and 74 kb of non-coding DNA). Within this 104 kb of genomic sequences we identified 163 polymorphisms (1 per 638 bases on average), of which 142 were single-nucleotide substitutions and the remainder, insertions or deletions. Of the coding SNPs, 52% were non-synonymous substitutions, and non-conservative amino acid changes were observed in a quarter of those. Sixty-nine polymorphisms showed high frequencies for minor alleles (more than 15%) and 20 revealed low frequencies (<5%). Our results indicated a greater average distance between SNPs than others have reported, but this disparity may reflect the type of genes surveyed and/or the relative ethnic homogeneity of our test population.
9365083 Blood transfusion, smoking, and obesity as risk factors for the development of rheumatoid 1997 Nov OBJECTIVE: To examine a range of demographic, social, and clinical risk factors for the development of rheumatoid arthritis (RA). METHODS: Population-based case-control study in Norfolk, England, involving adult patients, ages 18-70, with an inflammatory polyarthritis of <12 months' duration who were recruited from the Norfolk Arthritis Register. Controls, matched for sex and date of birth, were selected from the primary care register of the Norwich Health Authority. Both cases and controls completed identical self-administered questionnaires. Matched analysis of the 165 case-control sets was conducted for the whole group and for the subset in which the cases satisfied the 1987 American College of Rheumatology criteria for RA. RESULTS: The controls were of higher socioeconomic status than the cases. This was probably due to response bias. Having a body mass index > or =30 was associated with an adjusted odds ratio (OR) of 3.74 for developing RA (95% confidence interval [95% CI] 1.14-12.27). RA was also associated with a history of blood transfusion (OR 4.83, 95% CI 1.29-18.07). Even after correcting for social class, a history of having ever smoked was associated with a higher risk of developing RA (OR 1.66, 95% CI 0.95-3.06). There was no difference between cases and controls in previous exposure to childhood infections, certain surgical procedures, or reproductive history variables. CONCLUSION: RA has a number of potential environmental triggers, including smoking, obesity, and blood transfusion.