Association Between Bone Mineral Density and Autoantibodies in Patients With Rheumatoid Arthritis

Objective

Autoantibodies, such as anti–citrullinated protein antibodies (ACPAs), have been described as inducing bone loss in rheumatoid arthritis (RA), which can also be reflected by bone mineral density (BMD). We therefore examined the association between osteoporosis and autoantibodies in two independent RA cohorts.

Methods

Dual x‐ray absorptiometry (DXA) of the lumbar spine and left hip was performed in 408 Dutch patients with early RA during 5 years of follow‐up and in 198 Swedish patients with early RA during 10 years of follow‐up. The longitudinal effect of ACPAs and other autoantibodies on several BMD measures was assessed using generalized estimating equations.

Results

In the Dutch cohort, significantly lower BMD at baseline was observed in ACPA‐positive patients compared to ACPA‐negative patients, with an estimated marginal mean BMD in the left hip of 0.92 g/cm² (95% confidence interval [95% CI] 0.91–0.93) versus 0.95 g/cm² (95% CI 0.93–0.97) (P = 0.01). In line with this, significantly lower Z scores at baseline were noted in the ACPA‐positive group compared to the ACPA‐negative group (estimated marginal mean Z score in the left hip of 0.18 [95% CI 0.08–0.29] versus 0.48 [95% CI 0.33–0.63]) (P < 0.01). However, despite clear differences at baseline, ACPA positivity was not associated with greater decrease in absolute BMD or Z scores over time. Furthermore, there was no association between BMD and higher levels of ACPAs or other autoantibodies (rheumatoid factor and anti–carbamylated protein antibodies). In the Swedish cohort, ACPA‐positive patients tended to have a higher prevalence of osteopenia at baseline (P = 0.04), but again, ACPA positivity was not associated with an increased prevalence of osteopenia or osteoporosis over time.

Conclusion

The presence of ACPAs is associated with significantly lower BMD at baseline, but not with greater BMD loss over time in treated RA patients. These results suggest that ACPAs alone do not appear to contribute to bone loss after disease onset when disease activity is well‐managed.

Changes in bone mineral density over 10 years in patients with early rheumatoid arthritis

Objectives

To investigate changes in bone mineral density (BMD) in patients with early rheumatoid arthritis (RA) over a 10-year period.

Methods

Consecutive patients with early RA (symptom duration <12 months) were followed according to a structured programme and examined with dual-energy X-ray absorptiometry (DXA) at inclusion and after 2, 5 and 10 years. Mean Z-scores over the study period were estimated using mixed linear effect models. Changes in Z-scores between follow-up visits were analysed using paired T-tests.

Results

At inclusion, 220 patients were examined with DXA. At the femoral neck, the mean Z-score over 10 years was −0.33 (95 % CI −0.57 to −0.08) in men and −0.07 (−0.22 to 0.08) in women. Men had significantly lower BMD at the femoral neck than expected by age at inclusion (intercept Z-score value −0.35; 95 % CI −0.61 to −0.09), whereas there was no such difference in women. At the lumbar spine, the mean Z-score over the study period for men was −0.05 (−0.29 to 0.19) and for women 0.06 (−0.10 to 0.21). In paired comparisons of BMD at different follow-up visits, femoral neck Z-scores for men decreased significantly from inclusion to the 5-year follow-up. After 5 years, no further reduction was seen.

Conclusions

In this observational study of a limited sample, men with early RA had reduced femoral neck BMD at diagnosis, with a further significant but marginal decline during the first 5 years. Lumbar spine BMD Z-scores were not reduced in men or women with early RA. Data on 10-year follow-up were limited.

Abatacept in rheumatoid arthritis: survival on drug, clinical outcomes, and their predictors-data from a large national quality register

BACKGROUND

There are limited data regarding efficacy of abatacept treatment for rheumatoid arthritis (RA) outside clinical trials. Quality registers have been useful for observational studies on tumor necrosis factor inhibition in clinical practice. The aim of this study was to investigate clinical efficacy and tolerability of abatacept in RA, using a national register.

METHODS

RA patients that started abatacept between 2006 and 2017 and were included in the Swedish Rheumatology Quality register (N = 2716) were investigated. Survival on drug was estimated using Kaplan-Meier analysis. The European League Against Rheumatism (EULAR) good response and Health Assessment Questionnaire (HAQ) response (improvement of ≥ 0.3) rates (LUNDEX corrected for drug survival) at 6 and at 12 months were assessed. Predictors of discontinuation were investigated by Cox regression analyses, and predictors of clinical response by logistic regression. Significance-based backward stepwise selection of variables was used for the final multivariate models.

RESULTS

There was a significant difference in drug survival by previous biologic disease-modifying antirheumatic drug (bDMARD) exposure (p < 0.001), with longer survival in bionaïve patients. Men (hazard ratio (HR) 0.86, 95% confidence interval (CI) 0.74-0.98) and methotrexate users (HR 0.85, 95% CI 0.76-0.95) were less likely to discontinue abatacept, whereas a high pain score predicted discontinuation (HR 1.14 per standard deviation, 95% CI 1.07-1.20). The absence of previous bDMARD exposure, male sex, and a low HAQ score were independently associated with LUNDEX-corrected EULAR good response. The absence of previous bDMARD exposure also predicted LUNDEX-corrected HAQ response.

CONCLUSIONS

In this population-based study of RA, bDMARD naïve patients and male patients were more likely to remain on abatacept with a major clinical response.

Prevalence of sustained remission in rheumatoid arthritis: impact of criteria sets and disease duration, a Nationwide Study in Sweden

Objectives

The aims of this national study in Sweden of patients with RA were to: examine the prevalence of sustained remission (SR), that is, remission lasting for at least 6 months; compare the prevalence of SR in patients with early RA and established RA; study the timing of onset of and time spent in SR; and study possible predictors of SR.

Methods

Adult patients with RA included in the Swedish Rheumatology Quality registry were studied. The registry was searched for patients fulfilling remission criteria: DAS28-ESR, Clinical Disease Activity Index (CDAI), Simplified Disease Activity Index (SDAI) and ACR/EULAR remission for at least 6 months. Early RA was defined as symptom duration ⩽6 months at inclusion in the Swedish Rheumatology Quality.

Results

Of 29 084 patients, 12 193 (41.9%) reached DAS28 SR at some time point during follow-up compared with 6445 (22.2%), 6199 (21.3%) and 5087 (17.5%) for CDAI, SDAI and ACR/EULAR SR, respectively. SR was more common in early RA (P < 0.001). The median time from symptom onset to SR was 1.9, 2.4, 2.4 and 2.5 years according to DAS28, CDAI, SDAI and ACR/EULAR criteria, respectively. Lower age, male sex and milder disease characteristics were associated with SR.

Conclusion

The majority of patients in this nationwide study never reached SR. Patients with early RA are more likely to reach SR than patients with established RA.

Validity of polymyalgia rheumatica diagnoses and classification criteria in primary health care

Objectives

PMR is an inflammatory disease with prominent morning stiffness and muscular tenderness, usually diagnosed in primary health care (PHC). The objectives were to examine the validity of PMR diagnoses in PHC and to validate the use of classification criteria for PMR.

Methods

Medical records for patients with a registered PMR diagnosis at two PHC facilities were reviewed. Patients were classified according to several sets of criteria. An independent review, with assessment of the PMR diagnosis, was performed by an experienced rheumatologist.

Results

Of 188 patients, the PMR diagnosis was in agreement with the independent review in 60% overall, in 84% of those fulfilling a modified version of the ACR/EULAR classification criteria and in 52% of those who did not. The corresponding proportions for the Bird criteria were 66 and 31%, and for the Healey criteria 74 and 42%. In 74% of the medical records, documentation on morning stiffness was missing. Rheumatoid factor was tested in 22% and anti-CCP antibodies in 15%.

Conclusion

In this study of patients with PMR diagnosed in PHC, the diagnosis was supported by the independent review in 60% of the patients. Documentation on morning stiffness and testing for autoantibodies were limited. A modified version of the ACR/EULAR criteria can be used to identify patients with a valid PMR diagnosis in retrospective surveys but does not capture all PMR patients. The modified ACR/EULAR criteria may be more stringent than some of the older criteria sets.

Secular trends of sustained remission in rheumatoid arthritis, a nationwide study in Sweden

Objectives

The aim of this study of patients with RA in Sweden was to investigate secular trends in achieving sustained remission (SR), i.e. DAS28 <2.6 on at least two consecutive occasions and lasting for at least 6 months.

Methods

All adult RA patients registered in the Swedish Rheumatology Quality register through 2012, with at least three registered visits were eligible, a total of 29 084 patients. Year of symptom onset ranged from 1955, but for parts of the analysis only patients with symptom onset between 1994 and 2009 were studied. In total, 95% of patients fulfilled the ACR 1987 classification criteria for RA. Odds of reaching SR for each decade compared with the one before were calculated with logistic regression and individual years of symptom onset were compared with life table analysis.

Results

Of patients with symptom onset in the 1980s, 1990s and 2000s, 35.0, 43.0 and 45.6% reached SR, respectively (P < 0.001 for each increment), and the odds of SR were higher in every decade compared with the one before. The hazard ratio for reaching SR was 1.15 (95% CI 1.14, 1.15) for each year from 1994 to 2009 compared with the year before. Five years after symptom onset in 2009, 45.3% of patients had reached SR compared with 15.9% in 1999.

Conclusion

There is a clear secular trend towards increased incidence of SR in patients with RA in Sweden. This trend most likely reflects earlier diagnosis and treatment start, and adherence to national and international guidelines recommending the treat to target approach.

Malignancies in Giant Cell Arteritis: A Population-based Cohort Study

OBJECTIVE

To investigate the risk of cancer in patients with biopsy-proven giant cell arteritis (GCA) from a defined population in southern Sweden.

METHODS

The study cohort consisted of 830 patients (mean age at GCA diagnosis was 75.3 yrs, 74% women) diagnosed with biopsy-proven GCA between 1997 and 2010. Temporal artery biopsy results were retrieved from a regional database and reviewed to ascertain GCA diagnosis. The cohort was linked to the Swedish Cancer Registry. The patients were followed from GCA diagnosis until death or December 31, 2013. Incident malignancies registered after GCA diagnosis were studied. Based on data on the first malignancy in each organ system, age- and sex-standardized incidence ratios (SIR) with 95% CI were calculated compared to the background population.

RESULTS

One hundred seven patients (13%) were diagnosed with a total of 118 new malignancies after the onset of GCA. The overall risk for cancer after the GCA diagnosis was not increased (SIR 0.98, 95% CI 0.81-1.17). However, there was an increased risk for myeloid leukemia (2.31, 95% CI 1.06-4.39) and a reduced risk for breast cancer (0.33, 95% CI 0.12-0.72) and upper gastrointestinal tract cancer (0.16, 95% 0.004-0.91). Rates of other site-specific cancers were not different from expected.

CONCLUSION

In this Swedish population-based cohort of GCA, the overall risk for cancer was not increased compared to the background population. However, there was an increased risk for leukemia and a decreased risk for breast and upper gastrointestinal tract cancer.

Severe Extraarticular Manifestations in a Community-based Cohort of Patients with Rheumatoid Arthritis: Risk Factors and Incidence in Relation to Treatment with Tumor Necrosis Factor Inhibitors

Objective.

The aims of this study were to evaluate whether treatment with tumor necrosis factor (TNF) inhibitors in patients with rheumatoid arthritis (RA) affects the risk of developing severe extraarticular rheumatoid arthritis (ExRA) manifestations and to investigate potential predictors for developing ExRA.

Methods.

A dynamic community-based cohort of patients with RA was studied (n = 1977). Clinical records were reviewed and cases of severe ExRA were identified. Information on exposure to TNF inhibitors was obtained from a regional register. Exposure to TNF inhibitors was analyzed in a time-dependent fashion and the incidence of severe ExRA in exposed patients was compared with the incidence in unexposed patients. Cox regression models were used to assess potential predictors of severe ExRA.

Results.

During treatment with TNF inhibitors, there were 17 patients with new onset of severe ExRA in 2400 person-years at risk (PY; 0.71/100 PY, 95% CI 0.41–1.13) compared with 104 in 15,599 PY (0.67/100 PY, 95% CI 0.54–0.81) in patients without TNF inhibitors. This corresponded to an incidence rate ratio of 1.06 (95% CI 0.60–1.78). The age- and sex-adjusted HR for ExRA in anti-TNF–treated patients was 1.21 (95% CI 1.02–1.43), with similar findings in models adjusted for time-dependent Health Assessment Questionnaire and propensity for anti-TNF treatment. Male sex, positive rheumatoid factor (RF), long disease duration, and greater disability were predictors for ExRA.

Conclusion.

This study suggests that patients treated with TNF inhibitors are at a slightly increased risk of developing severe ExRA. RF-positive patients with disabling disease of long duration were more likely to develop severe ExRA.

Total cost and cost predictors in systemic lupus erythematosus - 8-years follow-up of a Swedish inception cohort

OBJECTIVE

To study the annual direct and indirect costs in systemic lupus erythematosus (SLE) and how age, disease manifestations, disease activity, and organ damage influence total costs and predicted costs for SLE.

METHODS

Clinical data on all patients with a diagnosis of SLE living in a defined area in southern Sweden during eight years were linked to health authority registries and the social insurance system which contain data on cost. Cost data on four matched population controls for each patient were also extracted. The controls were matched for age, sex, and area of residence.

RESULTS

Data from 127 patients with SLE and 508 population controls were extracted. The mean annual total cost for SLE patients was SEK 180,520 ($30,093); the highest costs were found in the subgroup with nephritis SEK 229,423 ($38,246). The total costs for the patient group were significantly higher (p < 0.05) compared to the population controls of SEK 59,985 ($10,000). Of the total costs, 72% were due to indirect costs, 3% to SLE-specific pharmaceuticals, and the remaining 25% were in- and outpatient related costs. During the study period, inpatient days decreased by 60%, while outpatient contacts increased by 25%. Age (inverse relation), increasing disease activity, and acquired organ damage were significant predictors of total costs (all p < 0.05).

CONCLUSION

The total annual costs for unselected SLE patients were found to be three times those for matched population controls. Important predictors of total costs were found.