Post-traumatic stress disorder and serum cytokine and chemokine concentrations in patients with rheumatoid arthritis✰

OBJECTIVE

Although post-traumatic stress disorder (PTSD) is identified as a risk factor in the development of rheumatoid arthritis (RA), associations of PTSD with disease progression are less clear. To explore whether PTSD might influence disease-related measures of systemic inflammation in RA, we compared serum cytokine/chemokine (cytokine) concentrations in RA patients with and without PTSD.

METHODS

Participants were U.S. Veterans with RA and were categorized as having PTSD, other forms of depression/anxiety, or neither based on administrative diagnostic codes. Multiplex cytokines were measured using banked serum. Associations of PTSD with cytokine parameters (including a weighted cytokine score) were assessed using multivariable regression, stratified by anti-CCP status and adjusted for age, sex, race, and smoking status.

RESULTS

Among 1,460 RA subjects with mean (SD) age of 64 (11) years and disease duration of 11 (11) years, 91% were male, 77% anti-CCP positive, and 80% ever smokers. Of these, 11.6% had PTSD, 23.7% other depression/anxiety, and 64.7% had neither. PTSD, but not depression/anxiety, was associated with a higher cytokine score and number of high-concentration analytes in adjusted models, though this was limited to anti-CCP positive subjects. PTSD was associated with heightened expression of several individual cytokines including IL-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-10, IL-12, IL-17, IFN-γ, GM-CSF, MCP-1, and TNF-α.

CONCLUSION

Anti-CCP positive RA patients with PTSD have higher serum cytokine concentrations than those without PTSD, demonstrating that systemic inflammation characteristic of RA is heightened in the context of this relatively common psychiatric comorbidity.

Design and Rationale for the Veterans Affairs "Cooperative Study Program 594 Comparative Effectiveness in Gout: Allopurinol vs. Febuxostat" Trial

BACKGROUND

Gout patients do not routinely achieve optimal outcomes related in part to suboptimal administration of urate lowering therapy (ULT) including first-line xanthine oxidase inhibitors allopurinol or febuxostat. Studies leading to the approval of febuxostat compared this agent to allopurinol in inappropriately low, fixed doses. We will compare allopurinol with febuxostat in gout using appropriately titrated doses of both agents and a "treat-to-target" strategy congruent with specialty guidelines.

METHODS

We have planned and initiated the Veterans Affairs (VA) Cooperative Study Program (CSP) 594, Comparative Effectiveness in Gout: Allopurinol vs Febuxostat study. This large double-blind, non-inferiority trial will enroll 950 gout patients randomized to receive allopurinol or febuxostat. Patients will be followed for a total of 72 weeks encompassing 3 distinct 24-week study phases. During Phase I (0-24 weeks), participants will undergo gradual dose titration of ULT until achievement of serum uric acid (sUA) <6.0 mg/dL or <5.0 mg/dL if tophi are present. Dose escalation will not be allowed during final three study visits of Phase 2 (24-48 weeks) and during Phase 3 (48-72 weeks). The primary study outcome is the proportion of participants experiencing at least one gout flare during Phase 3. Subsequent to the 72-week study, participants will be followed passively for up to 10 years after the study to assess long-term health outcomes.

CONCLUSION

With its completion, the VA Comparative Effectiveness in Gout: Allopurinol vs Febuxostat study will demonstrate the central role of gradual ULT dose escalation and a treat-to-target strategy in gout management.

Gingival tissue, an extrasynovial source of malondialdehyde-acetaldehyde adducts, citrullinated and carbamylated proteins

BACKGROUND AND OBJECTIVE

Postranslational modification of proteins can lead to the production of autoantibodies and loss of immune tolerance. This process has been hypothesised to be a critical factor in the pathogenesis of rheumatoid arthritis. The objective of this study was to demonstrate that inflamed human gingival tissue provides an extrasynovial source of malondialdehyde-acetaldehyde adducts, citrullinated and carbamylated proteins all of which are considered to be linked to the development of rheumatoid arthritis. Identification of such modified proteins in inflamed gingiva may explain, in part, how inflammation of the periodontal tissues may influence the development of rheumatoid arthritis.

MATERIAL AND METHODS

Gingival biopsies of healthy, mild and moderate periodontitis were triple stained with antibodies against malondialdehyde-acetaldehyde adducts, citrullinated and carbamylated proteins.

RESULTS

Assessment of healthy gingival tissue revealed negligible staining for carbamylated, malondialdehyde-acetaldehyde (MAA), or citrullinated proteins. Mild periodontitis was positive for all three modifications. Furthermore, there was an increase in staining intensity for carbamylated, citrullinated and MAA-modified proteins in moderate periodontitis. Negative staining results were observed for the isotype controls.

CONCLUSION

This study provides evidence for the presence of citrullinated, carbamylated and MAA adduct modified proteins in inflamed periodontal tissues. The potential for these proteins to play a role in autoimmunity in a multi-system inflammatory syndromic disease model now needs to be determined.

Salivary and serum procalcitonin and C-reactive protein as biomarkers of periodontitis in United States veterans with osteoarthritis or rheumatoid arthritis

Serum procalcitonin (ProCT) is elevated in response to bacterial infections, whereas high sensitivity C-reactive protein (hsCRP) is a nonspecific inflammatory marker that is increased by excess adipose tissue. We examined the efficacy of ProCT and hsCRP as biomarkers of periodontitis in the saliva and serum of patients with arthritis, which is characterized by variable levels of systemic inflammation that potentially can confound the interpretation of inflammatory biomarkers. Blood and unstimulated whole saliva were collected from 33 patients with rheumatoid arthritis (RA) and 50 with osteoarthritis (OA). Periodontal status was assessed by full mouth examination and patients were categorized as having no/mild, moderate or severe periodontitis by standard parameters. Salivary and serum ProCT and hsCRP concentrations were compared. BMI, diabetes, anti-inflammatory medications and smoking status were ascertained from the patient records. Differences between OA and RA in proportionate numbers of patients were compared for race, gender, diabetes, adiposity and smoking status. Serum ProCT was significantly higher in arthritis patients with moderate to severe and severe periodontitis compared with no/mild periodontitis patients. There were no significant differences in salivary ProCT or salivary or serum hsCRP in RA patients related to periodontitis category. Most of the OA and RA patients were middle aged or older, 28.9% were diabetic, 78.3% were overweight or obese, and slightly more than half were either current or past smokers. The OA and RA groups differed by race, but not gender; blacks and males were predominant in both groups. The OA and RA groups did not differ in terms of controlled or uncontrolled diabetes, smoking status or BMI. The RA patients had been prescribed more anti-inflammatory medication than the OA patients. Our results demonstrate that circulating ProCT is a more discriminative biomarker for periodontitis than serum hsCRP in patients with underlying arthritis. Any elevation in salivary and serum hsCRP due to periodontitis apparently was overshadowed by differences among these patients in factors that influence CRP, such as the extent of inflammation between RA and OA, the extent of adipose tissue, the use of anti- inflammatory medications and smoking status. Although our study showed no differences in salivary ProCT related to severity of periodontitis, this biomarker also may be useful with further refinement.

Celastrol inhibits inflammatory stimuli-induced neutrophil extracellular trap formation

Neutrophil extracellular traps (NETs) are web-like structures released by activated neutrophils. Recent studies suggest that NETs play an active role in driving autoimmunity and tissue injury in diseases including rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). The purpose of this study was to investigate if celastrol, a triterpenoid compound, can inhibit NET formation induced by inflammatory stimuli associated with RA and SLE. We found that celastrol can completely inhibit neutrophil oxidative burst and NET formation induced by tumor necrosis factor alpha (TNFα) with an IC50 of 0.34 µM and by ovalbumin:anti-ovalbumin immune complexes (Ova IC) with an IC50 of 1.53 µM. Celastrol also completely inhibited neutrophil oxidative burst and NET formation induced by immunoglobulin G (IgG) purified from RA and SLE patient sera. Further investigating into the mechanisms, we found that celastrol treatment downregulated the activation of spleen tyrosine kinase (SYK) and the concomitant phosphorylation of mitogen-activated protein kinase kinase (MAPKK/MEK), extracellular-signal-regulated kinase (ERK), and NFκB inhibitor alpha (IκBα), as well as citrullination of histones. Our data reveals that celastrol potently inhibits neutrophil oxidative burst and NET formation induced by different inflammatory stimuli, possibly through downregulating the SYK-MEK-ERK-NFκB signaling cascade. These results suggest that celastrol may have therapeutic potentials for the treatment of inflammatory and autoimmune diseases involving neutrophils and NETs.

Risk of hospitalized bacterial infections associated with biologic treatment among US veterans with rheumatoid arthritis

OBJECTIVE

The comparative risk of infection associated with non-anti-tumor necrosis factor (anti-TNF) biologic agents is not well established. Our objective was to compare risk for hospitalized infections between anti-TNF and non-anti-TNF biologic agents in US veterans with rheumatoid arthritis (RA).

METHODS

Using 1998-2011 data from the US Veterans Health Administration, we studied RA patients initiating rituximab, abatacept, or anti-TNF therapy. Exposure was based upon days supplied (injections) or usual dosing intervals (infusions). Treatment episodes were defined as new biologic agent use. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) for hospitalization for a bacterial infection were estimated from Cox proportional hazards models, adjusting for potential confounders.

RESULTS

Among 3,152 unique RA patients contributing 4,158 biologic treatment episodes to rituximab (n = 596), abatacept (n = 451), and anti-TNF agents (n = 3,111), the patient mean age was 60 years and 87% were male. The most common infections were pneumonia (37%), skin/soft tissue (22%), urinary tract (9%), and bacteremia/sepsis (7%). Hospitalized infection rates per 100 person-years were 4.4 (95% CI 3.1-6.4) for rituximab, 2.8 (95% CI 1.7-4.7) for abatacept, and 3.0 (95% CI 2.5-3.5) for anti-TNF. Compared to etanercept, the adjusted rate of hospitalized infection was not different for adalimumab (HR 1.4, 95% CI 0.9-2.2), abatacept (HR 1.1, 95% CI 0.6-2.1), or rituximab (HR 1.4, 0.8-2.6), although it was increased for infliximab (HR 2.3, 95% CI 1.3-4.0). Infection risk was greater for those taking prednisone >7.5 mg/day (HR 1.8, 95% CI 1.3-2.7) and in the highest quartile of C-reactive protein (HR 2.3, 95% CI 1.4-3.8) and erythrocyte sedimentation rate (HR 4.1, 95% CI 2.3-7.2) compared to the lowest quartile.

CONCLUSION

In older, predominantly male US veterans with RA, the risk of hospitalized bacterial infections associated with rituximab or abatacept was similar to etanercept.

Folic acid pathway single nucleotide polymorphisms associated with methotrexate significant adverse events in United States veterans with rheumatoid arthritis

OBJECTIVES

Methotrexate (MTX) is the cornerstone medication in the treatment of rheumatoid arthritis (RA). We examined whether single nucleotide polymorphisms (SNPs) in enzymes of the folic acid pathway (folylpoly-gamma-glutamate synthetase [FPGS], gamma-glutamyl hydrolase [GGH], and methylenetetrahydrofolate reductase [MTHFR]) associate with significant adverse events (SigAE).

METHODS

Patients (n=319) enrolled in the Veterans Affairs RA (VARA) registry taking MTX were genotyped for HLA-DRB1-SE and the following SNPs: FPGS (rs7033913, rs10760503, rs10106), GGH (12548933, rs7010484, rs4617146, rs719235, rs11988534), MTHFR (rs1801131, rs1801133). AE were abstracted from the medical record using a structured instrument. SigAE were defined as an AE leading to MTX discontinuation. Covariates included: age, gender, race, RA antibody status, tobacco, RA disease duration between diagnosis and MTX course, Charlson-Deyo comorbidity index, glucocorticoids, use of prior RA medications, and mean 4-variable disease activity score. Cox regression was performed to determine factors associated with time-to-SigAE. A p-value ≤ 0.005 established significance in the final model.

RESULTS

The presence of ≥ 1 copy of the minor allele in MTHFR rs1801131 was associated with an increased hazard ratio (HR) of SigAE (HR 3.05, 95% CI 1.48-6.29, p-value 0.003 and HR 3.88, 95% CI 1.62-9.28, p-value 0.002 for heterozygotes and homozygotes for the minor allele, respectively). An interaction term, between FPGS rs7033913 heterozygotes and GGH rs11988534 homozygotes for the minor allele, had a p-value <0.0001.

CONCLUSIONS

RA subjects taking MTX may have decreased time-to-SigAE with ≥ 1 copy of the minor allele in MTHFR rs1801131. Further investigation is warranted, as these SNPs may indicate susceptibility to MTX toxicity.

Supervised machine learning and logistic regression identifies novel epistatic risk factors with PTPN22 for rheumatoid arthritis

Investigating genetic interactions (epistasis) has proven difficult despite the recent advances of both laboratory methods and statistical developments. With no 'best' statistical approach available, combining several analytical methods may be optimal for detecting epistatic interactions. Using a multi-stage analysis that incorporated supervised machine learning and methods of association testing, we investigated epistatic interactions with a well-established genetic factor (PTPN22 1858T) in a complex autoimmune disease (rheumatoid arthritis (RA)). Our analysis consisted of four principal stages: Stage I (data reduction)-identifying candidate chromosomal regions in 292 affected sibling pairs, by predicting PTPN22 concordance using multipoint identity-by-descent probabilities and a supervised machine learning algorithm (Random Forests); Stage II (extension analysis)-testing detailed genetic data within candidate chromosomal regions for epistasis with PTPN22 1858T in 677 cases and 750 controls using logistic regression; Stage III (replication analysis)-confirmation of epistatic interactions in 947 cases and 1756 controls; Stage IV (combined analysis)-a pooled analysis including all 1624 RA cases and 2506 control subjects for final estimates of effect size. A total of seven replicating epistatic interactions were identified. SNP variants within CDH13, MYO3A, CEP72 and near WFDC1 showed significant evidence for interaction with PTPN22, affecting susceptibility to RA.

Skeletal health among African Americans with recent-onset rheumatoid arthritis

OBJECTIVE

African Americans with rheumatoid arthritis (RA) may be at increased fracture risk. We applied the World Health Organization (WHO) Fracture Risk Assessment Tool (FRAX) and National Osteoporosis Foundation (NOF) guidelines to a cohort of African Americans with early RA to identify which patients were recommended for osteoporosis treatment.

METHODS

Risk factors and bone mineral density (BMD) were assessed in a cohort of African Americans with RA. The WHO FRAX tool estimated 10-year fracture risk. Patients were risk stratified using FRAX without BMD to identify which individuals might be most efficiently targeted for BMD testing.

RESULTS

Participants (n = 324) had a mean age of 51 years and included 81% women. There were no associations of RA disease characteristics with BMD. The proportion of patients recommended for osteoporosis treatment varied from 3-86%, depending on age and body mass index (BMI). Ten-year fracture risk calculated with BMI only was generally the same or higher than fracture risk calculated with BMD; adding BMD data provided the most incremental value to risk assessment in patients 55-69 years of age with low/normal BMI, and in those > or =70 years of age with BMI > or =30 kg/m2.

CONCLUSION

A high proportion of African Americans with RA were recommended for treatment under the 2008 NOF guidelines. FRAX without BMD identified low-risk patients accurately. Systematic application of FRAX to screen high-risk groups such as patients with RA may be used to target individuals for BMD testing and reduce the use of unnecessary tests and treatments.

Poor to modest agreement between rheumatoid arthritis response measures in clinical practice

OBJECTIVE

To evaluate the agreement among several rheumatoid arthritis (RA) response measures in a clinical setting.

METHODS

529 patients with RA were seen at 2 regular visits where the following response measures were determined: ACR-20, EULAR good or moderate (EULAR-GM), Simplified Disease Activity Index moderate (SDAI-M), Clinical DAI moderate (CDAI-M), and Patient Reported Outcomes Index-M 20 (PRO-IM-20). Each measure was modified to include a "worse" response, i.e. the inverse of the respective guidelines for a positive improvement response.Introduced for comparison was the Real-time Assessment of Disease Activity in Rheumatoid Arthritis (RADARA), a response measure that registers improvement if the patient's tender and swollen joint counts and HAQ score all improve and worsening if all three increase. Contingency tables comparing the three responses (worse, no change, and improvement) along with Cohen's kappa were calculated.

RESULTS

The mean (SD) baseline characteristics of the patients included: age 66.5 (10.7) years, RA duration 12.9 (11.0) years, 91.3% male, 84.1% rheumatoid factor positive, and a Disease Activity Score-28 of 3.5 (1.3). The percentage of patients who improved/worsened were as follows: ACR-20 4.7/9.1, EULAR-GM 23.4/26.3, SDAI-M 16.1/20.6, CDAI-M 16.3/20.0, PRO-IM-20 22.5/34.4, and RADARA 7.0/11.5. Agreement (kappa) was poor to slight (</= 0.4) between most of the response measures with the exception of RADARA/ACR-20 which showed substantial agreement (0.67) and SDAI/EULAR-GM and CDAI/EULAR-GM, which showed moderate agreement (0.54 and 0.52, respectively).

CONCLUSION

RA response measures can be made more informative by the addition of a "worse" response, although even in this case the agreement in the clinic setting is primarily poor to moderate.

Cigarette smoking, disease severity and autoantibody expression in African Americans with recent-onset rheumatoid arthritis

OBJECTIVE

To examine the association of smoking with clinical and serological features in African Americans with recent-onset rheumatoid arthritis (RA) and to explore whether this association is dependent on the presence of the HLA-DRB1 shared epitope (SE).

METHODS

In African Americans with recent-onset RA (n = 300), we examined the association of cigarette smoking (current versus past versus never and pack-years of exposure) with anti-cyclic citrullinated peptide antibody, rheumatoid factor (RF) (IgM and IgA), rheumatoid nodules and baseline radiographic erosions using logistic and cumulative logistic regression (adjusting for SE status). We also examined for evidence of interaction between smoking status and SE for all outcomes.

RESULTS

Although there was no association with RF-IgA seropositivity, current smokers were approximately twice as likely as never smokers to have higher IgA-RF concentrations (based on tertiles; OR = 1.74; 95% CI 1.05 to 2.88) and nodules (OR = 2.43; 95% CI 1.13 to 5.22). These associations were most pronounced in those with more than 20 pack-years of exposure. There was no association of smoking status or cumulative tobacco exposure with anti-cyclic citrullinated peptide antibody, IgM-RF or radiographic erosions. There was also no evidence of a biological or statistical SE-smoking interaction for any of the outcomes examined.

CONCLUSIONS

This is the first study to systematically examine the association of cigarette smoking with RA-related features in African Americans. Cigarette smoking is associated with both subcutaneous nodules and higher serum concentrations of IgA-RF in African Americans with RA, associations that may have important implications for long-term outcomes in this population.

Quality of care in gout: from measurement to improvement

Gout is a growing health problem, affecting approximately 7% of men and 3% of women over the age of 65 years. Although effective therapies for gout management exist, quality in gout care has been too frequently characterized as being "suboptimal." This review examines issues pertinent to quality of care in gouty arthritis with a focus on initial reports examining suboptimal care, subsequent efforts to develop quality of care indicators for gout management, more recently published evidence-based recommendations for gout diagnosis and treatment, and an ongoing international initiative to develop core outcome measures for acute and chronic gout. "If you can not measure it, you can not improve it" - Lord Kelvin.

Smoking interacts with genetic risk factors in the development of rheumatoid arthritis among older Caucasian women

OBJECTIVE

To determine whether the impact of tobacco exposure on rheumatoid arthritis (RA) risk is influenced by polymorphisms at the HLA-DRB1 and glutathione S-transferase M1 (GSTM1) loci.

METHODS

Subjects were participants from a case-control study nested within the Iowa Women's Health Study, a population based, prospective cohort study of postmenopausal women. Incident RA cases (n = 115) were identified and medical records reviewed to confirm RA diagnosis. Controls without RA (n = 466) were matched with RA cases by age and ethnic background. HLA-DRB1 typing classified subjects according to the presence of alleles encoding the RA "shared epitope" (SE) sequence. GSTM1 was genotyped using a multiplex polymerase chain reaction assay. Conditional logistic regression was used to estimate the odds ratios (ORs) and 95% confidence intervals.

RESULTS

Strong positive associations of smoking (OR = 6.0, p = 0.004), SE positivity (OR = 4.6, p = 0.0006), and GSTM1 null genotype (OR = 3.4, p = 0.007) with risk of RA, and significant gene-environment interactions (smoking by SE interaction p = 0.034; smoking by GSTM1 interaction p = 0.047) were observed. Stratified analyses indicated that exposure to tobacco smoke primarily increased the risk of RA among subjects who lacked genetic risk factors for the disease (that is, SE negative or GSTM1 present).

CONCLUSIONS

Although these findings require confirmation in other groups, the results support the importance of considering both genetic and environmental factors, and also their interaction, in studies of complex diseases like RA.

Sex differences in gout epidemiology: evaluation and treatment

BACKGROUND

Little is known about the characteristics, evaluation and treatment of women with gout.

OBJECTIVE

To examine the epidemiological differences and differences in treatment between men and women in a large patient population.

METHODS

The data from approximately 1.4 million people who were members of seven managed care plans in the USA for at least 1 year between 1 January 1999 and 31 December 2003 were examined. Adult members who had pharmacy benefits and at least two ambulatory claims specifying a diagnosis of gout were identified. In addition, men and women who were new users of urate-lowering drugs (ULDs) were identified to assess adherence with recommended surveillance of serum urate levels within 6 months of initiating urate-lowering treatment.

RESULTS

A total of 6133 people (4975 men and 1158 women) with two or more International Classification of Disease-9 codes for gout were identified. As compared with men with gout, women were older (mean age 70 (SD 13) v 58 (SD 14), p<0.001) and had comorbidities and received diuretics more often (77% v 40%; p<0.001). Only 37% of new users of urate-lowering treatment had appropriate surveillance of serum urate levels post-initiation of urate-lowering treatment. After controlling for age, comorbidities, gout treatments, number of ULD dispensings and health plan, women were more likely (odds ratio 1.36, 95% confidence interval 1.11 to 1.67) to receive the recommended serum urate level testing.

CONCLUSIONS

Women with gout were older, had greater comorbidities and more often used diuretics and received appropriate surveillance of serum urate levels, suggesting that the factors leading to gout as well as monitoring of treatment are very different in women and men.

Suboptimal physician adherence to quality indicators for the management of gout and asymptomatic hyperuricaemia: results from the UK General Practice Research Database (GPRD)

OBJECTIVES

: To examine adherence to validated quality indicators assessing the quality of allopurinol use in the treatment of gout and asymptomatic hyperuricaemia.

METHODS

We determined physician adherence in the UK General Practice Research Database (GPRD) to three validated quality indicators developed to assess the quality of allopurinol prescribing practices. These indicators were developed to assess: (i) dosing in renal impairment; (ii) concomitant use with azathioprine or 6-mercaptopurine; and (iii) use in the treatment of asymptomatic hyperuricaemia. We also examined the association of patient-level factors (sociodemographics, comorbidity, follow-up duration and concomitant medicine use) with the treatment of asymptomatic hyperuricaemia using multivariable logistic regression.

RESULTS

Of the 63 105 gout patients, 185 (0.3%) were eligible for Quality Indicator 1 and 52 (0.1%) were eligible for Quality Indicator 2. There were an additional 471 patients with asymptomatic hyperuricaemia eligible for Quality Indicator 3. Rates of practice deviation for the three individual quality indicators ranged from 25 to 57%. Male sex, older age, a history of chronic renal failure, and a greater number of concomitant medications were significantly associated with increased odds of inappropriate treatment for asymptomatic hyperuricaemia. Hypertension and diuretic use were associated with lower odds of this practice.

CONCLUSIONS

One-quarter to one-half of all patients eligible for at least one of the validated quality of care indicators were subject to possible allopurinol prescribing error, suggesting that inappropriate prescribing practices are widespread with this agent. Future interventions aimed at reducing inappropriate allopurinol use are needed and should be targeted towards high-risk groups, including older men and those receiving multiple concomitant medications.

Gout epidemiology: results from the UK General Practice Research Database, 1990-1999

OBJECTIVE

To examine the epidemiology of gout and gout treatment in the United Kingdom using a large national practice based population.

METHODS

Data from the UK General Practice Research Database from 1990 to 1999 were examined. Physician diagnoses and drug codes were used, and trends in gout incidence and treatment examined. Additionally, disease prevalence for the year 1999 was assessed. To examine the association of gout with comorbid disease, the prevalence of select health conditions and drug use was compared with the corresponding prevalences seen in osteoarthritis, adjusting for both age and sex.

RESULTS

From 1 January 1990 to 31 December 1999 overall gout incidence remained relatively stable, ranging from a low of 11.9 cases (95% confidence interval (CI) 11.5 to 12.3) in 1991 to a high of 18.0 cases (95% CI 17.6 to 18.4) per 10 000 patient-years in 1994. Gout prevalence in 1999 was 1.4% with rates approaching 7% in men over the age of 65. Drugs used for the treatment of gout remained constant in prevalent cases with the exception of a significant decline in non-steroidal anti-inflammatory drug use over the 10 year follow up. Compared with patients with osteoarthritis, patients with gout were significantly more likely to have cardiovascular disease, hypertension, diabetes, and chronic renal failure, and were more likely to have used diuretics or ciclosporin, or both.

CONCLUSION

Although gout is common in the UK, particularly among older men, the incidence of the disease seems to have remained stable during the 1990s.

Association of rheumatoid arthritis treatment response and disease duration with declines in serum levels of IgM rheumatoid factor and anti-cyclic citrullinated peptide antibody

OBJECTIVE

To examine the association of treatment response and disease duration with changes in rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) antibody levels among patients with rheumatoid arthritis (RA).

METHODS

The study sample included 66 RA patients who completed double-blind, randomized clinical protocols and for whom baseline and followup serum samples were available. Anti-CCP and RF levels were measured using commercially available assay kits. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to describe the association of response and disease duration with declines in antibody levels.

RESULTS

Patients had a mean +/- SD age of 49.9 +/- 12.0 years and were predominantly female (n = 51; 77%). The mean +/- SD duration between the times at which the baseline and followup serum samples were obtained was 13.7 +/- 8.6 months. Among the 64 subjects with positive antibody at baseline, 33 (52%) experienced a > or =25% reduction in the anti-CCP antibody level during the course of treatment, and 35 patients (55%) had a > or =25% reduction in RF. After adjustment for the baseline anti-CCP antibody level, only a shorter disease duration (< or =12 months) was significantly associated with a decline in the level of anti-CCP antibody (OR 3.0, 95% CI 1.0-8.8), and no association with treatment response was observed. Conversely, treatment response was the only significant determinant of a decrease in RF levels (OR 3.6, 95% CI 1.2-10.4).

CONCLUSION

Shorter disease duration predicts greater declines in anti-CCP antibody levels with treatment in RA. Although treatment response is a robust determinant of a decrease in RF, it does not appear to be associated with declines in the anti-CCP antibody level.

Incidence of hip osteonecrosis among renal transplantation recipients: a prospective study

AIM

To investigate whether a lessened glucocorticoid cumulative dose would lead to a decreased incidence of femoral head osteonecrosis.

METHODS

Newly transplanted in-patients (n = 49) underwent hip radiographs and magnetic resonance imaging (MRI) a mean of 17.0+/-4.3 (range 8-29) days after renal transplantation. For the 48 patients without evidence of prevalent osteonecrosis, imaging at a mean of 5.9+/-0.8 (range 4.8-8.7) months after renal transplantation was graded for presence/absence of femoral head osteonecrosis by two blinded radiologists. Sociodemographic and disease characteristics of patients were compared to identify potential associations with incident osteonecrosis.

RESULTS

At 6-month follow-up, only two patients (4%) had osteonecrosis of the femoral head (three hips). The two primary radiologists had excellent agreement between osteonecrosis diagnosis (kappa coefficient=0.78). Both cases of a definite MRI diagnosis of osteonecrosis occurred in patients who were in the highest tertile of glucocorticoid dosage.

CONCLUSION

Osteonecrosis was uncommon among a prospective cohort of renal transplant recipients within 6 months after engraftment.

Early rheumatoid arthritis in African-Americans: the CLEAR Registry

African-Americans have been under-represented in genetic studies of rheumatoid arthritis (RA) susceptibility and severity. Genetic and non-genetic factors influencing the radiographic severity of RA and its response to treatment are poorly understood, particularly in African-Americans. The Consortium for the Longitudinal Evaluation of African-Americans with early RA (CLEAR) Registry, a collaborative effort among four institutions in the southeast USA, will hopefully provide a useful resource to study these issues.

Mortality risk associated with rheumatoid arthritis in a prospective cohort of older women: results from the Iowa Women's Health Study

OBJECTIVE

To determine whether rheumatoid arthritis (RA) is associated with excess mortality among older women.

METHODS

RA associated mortality was examined in a prospective cohort study that was started in 1986, and included 31 336 women aged 55-69 years without a history of RA at baseline. Up to 1997, 158 cases of RA were identified and validated against medical records. The relative risk (RR) and 95% confidence interval (CI) were calculated as measures of association between RA onset and subsequent mortality (overall and cause-specific) using Cox proportional hazards regression.

RESULTS

Compared with non-cases, women developing RA during follow up had a significantly increased mortality risk (RR=1.52; 95% CI 1.05 to 2.20). Mortality was higher among rheumatoid factor (RF) positive cases (RR=1.90; 95% CI 1.24 to 2.92) than among RF negative cases (RR=1.00; 95% CI 0.45 to 1.99). There were trends towards increased proportions of RA related deaths from infection (RR=3.61; 95% CI 0.89-14.69) and circulatory disease (RR=1.46; 95% CI 0.76 to 2.81) but not malignancy (RR=0.97; 95% CI 0.46 to 2.04).

CONCLUSIONS

RA was associated with significantly increased mortality in a cohort of older women, and the association appeared to be restricted to those with RF positive disease.

Samarium-153-EDTMP in the treatment of refractory rheumatoid arthritis

We examined the preliminary safety and efficacy of intravenous samarium-153-EDTMP (Sm-153) in the treatment of refractory rheumatoid arthritis (RA). In an open-label sequential group comparison of 0.5, 1.0, and 2.0 mCi/kg, Sm-153 was administered as a single intravenous infusion to 24 patients with refractory disease. Across treatment doses, the frequency of American College of Rheumatology (ACR) 20% responses was 25%, 29%, 25%, and 33% at 2, 4, 8, and 12 weeks, respectively. Expected significant declines in absolute neutrophil count, hemoglobin, and platelet counts were observed with nadirs seen between 2-4 weeks. Sm-153, at doses of 0.5 and 1.0 mCi/kg, is well tolerated but minimally effective in the treatment of refractory RA as measured using ACR response criteria.

Comorbidity in rheumatoid arthritis

It is increasingly clear that coexistent disease plays a pivotal role in RA outcome and that efforts aimed at specifically addressing these comorbidities need to be aggressively sought, investigated, and implemented once proven effective. RA-associated costs are currently increasing at twice the rate of the medical care index. Comorbidity in the setting of RA independently predicts disease-associated disability (a major cost component) and mortality, underscoring the need for a more comprehensive approach to RA, one that adequately addresses disease-specific comorbidities. At present, many primary and secondary preventative measures (Table 1) for RA-specific comorbidities remain largely unproved and require rigorous investigation in a randomized prospective fashion. Despite this ongoing need, advances are being made in our understanding of the underlying pathogenesis of these comorbid conditions and their relation with RA. This improved understanding should translate into further effective interventions. Bisphosphonates, for instance, have been shown to be effective in the prevention of GIOP and associated fractures. The past several years have seen other exciting therapeutic advances in RA. DMARD combinations have been shown to be more effective and no more toxic than MTX monotherapy. In addition to the recent release of COX-2 NSAIDs, three new disease-modifying agents (leflunomide, etanercept, and infliximab) have been added to the therapeutic armamentarium; these are options that have markedly changed the treatment landscape in RA. Although these important advances have generated much deserved optimism, the precise effect that these agents may have on RA-specific comorbidity remains to be seen. The next decade should prove to be an exciting time in RA management. Better identification, understanding, and management of RA comorbidities have great potential to improve quality of life and survival among our patients with RA.

TNF blockade in the treatment of rheumatoid arthritis: infliximab versus etanercept

There is accumulating evidence that tumour necrosis factor (TNF) plays a major role in the pathogenesis of rheumatoid arthritis (RA). Recent biotechnological advances have allowed for the development of agents that directly target TNF, a pro-inflammatory cytokine. In the last 2 years, the US FDA and the EU's Commission of the European Communities have approved two biological agents for the treatment of refractory RA, etanercept and infliximab. Etanercept is a fusion protein, composed of the Fc portion of IgG1 and the extracellular domain of the TNF receptor (p75). Infliximab is a chimeric monoclonal antibody (mAb) composed of murine variable and human constant regions. In placebo-controlled trials, both agents have proven to be effective and well-tolerated in RA patients. This review evaluates the available TNF inhibitors, summarises pertinent clinical trials and underscores differences between the two agents in terms of molecular structure, efficacy, safety data, antigenicity and pharmacokinetics.