Interpreting the clinical significance of the differential inhibition of cyclooxygenase-1 and cyclooxygenase-2

The International Consensus Meeting on the Mode of Action of COX-2 Inhibition (ICMMAC) brought together 17 international experts in arthritis, gastroenterology and pharmacology on 5 6 December 1997. The meeting was convened to provide a definition of COX-2 specificity and to consider the clinical relevance of COX-2-specific agents. These compounds are a new class of drugs that specifically inhibit the enzyme COX-2 while having no effect on COX-1 across the whole therapeutic dose range. The objectives of the meeting were to review the currently available data regarding the roles and biology of COX-1 and COX-2, and to foster a consensus definition on COX-2 specificity. At the present time, no guidelines exist for the in vitro and in vivo assessment of COX specificity, and it was felt that consensus discussion might clarify some of these issues. The meeting also reviewed recent clinical data on COX-2-specific inhibitors. The following article reflects discussion at this meeting and provides a consensus definition of COX-2-specific inhibitors.

ATP hydrolysis-dependent formation of a dynamic ternary nucleoprotein complex with MutS and MutL

Functional interactions of Escherichia coli MutS and MutL in mismatch repair are dependent on ATP. In this study, we show that MutS and MutL associate with immobilised DNA in a manner dependent on ATP hydrolysis and with an ATP concentration near the solution K m of the ATPase of MutS. After removal of MutS, MutL and ATP, much of the protein in this ternary complex is not stably associated, with MutL leaving the complex more rapidly than MutS. The rapid dissociation reveals a dynamic interaction with concurrent rapid association and dissociation of proteins from the DNA. Analysis by surface plasmon resonance showed that the DNA interacting with dynamically bound protein was more resistant to nuclease digestion than the DNA in MutS-DNA complexes. Non-hydrolysable analogs of ATP inhibit the formation of this dynamic complex, but permit formation of a second type of ternary complex with MutS and MutL stably bound to the immobilised DNA.

Disease-modifying antirheumatic drugs

Rheumatologists now seem to accept that early treatment of patients with rheumatoid arthritis with disease-modifying antirheumatic drugs is required if erosions are to be prevented. Methotrexate remains the most popular disease-modifying antirheumatic drug and is used in the most popular combination treatments, although the dose needs to be reduced in the elderly and those with renal dysfunction. The combination of sulfasalazine, methotrexate with reducing high-dose prednisolone, is demonstrated to be cost-effective in patients with rheumatoid arthritis, but although several other combinations have been reported effective in patients with rheumatoid arthritis, most trials do not have the power to provide a definitive answer as to the best combination available, if one exists.

Systemic sclerosis prevalence and mortality in Sydney 1974-88

BACKGROUND

Systemic sclerosis prevalence and mortality estimates have demonstrated wide variability. The sole Australian study published to date demonstrated high prevalence rates when compared to overseas estimates. The prevalence and mortality findings reported in this paper derive from a larger study which addressed the distribution and determinants of systemic sclerosis within Sydney.

AIMS

To determine systemic sclerosis prevalence and mortality rates within Sydney over 15 years, 1974-88.

METHODS

Cases were ascertained from multiple sources including death certificates, hospitals, physicians, vascular surgeons' and dermatologists' private practices, a systemic sclerosis self-help group and private medical laboratories.

RESULTS

Overall, 715 cases were identified. Females comprised 77% (95% CI: 74-80) of cases. Disease of the limited subtype accounted for 79% (95% CI: 76-82) of all systemic sclerosis, being relatively more frequent in living than deceased cases, and in females than males. Crude prevalence estimates appeared to rise between 1975 (4.52/100,000 95% CI:3.75-5.29/100,000) and 1988 (8.62/100,000 95% CI:7.64-9.60/100,000) as did estimates of diffuse disease. However, diffuse disease prevalence, when expressed as a proportion of total disease prevalence, showed no significant temporal change. Although crude mortality rates also showed apparent temporal increases (0.24/100,000 in 1975 to 0.80/100,000 in 1988) standardised mortality rates showed less convincing trends (0.41/100,000 in 1976 and 0.40/100,000 in 1988). Death certificate-derived mortality rates provided relatively large underestimates of total mortality. However, these underestimates were relatively constant over time.

CONCLUSIONS

This study has demonstrated systemic sclerosis prevalence and mortality rates comparable to overseas estimates, consistently higher prevalence and mortality rates in females than males, proportionally higher rates of diffuse disease in males than females and in deceased cases than living cases, a diffuse: limited disease ratio apparently stable over time, apparently increasing temporal prevalence and mortality rates and, by implication, rising incidence rates. The observed temporal rise in diffuse disease prevalence and the absence of a convincing fall in diffuse disease mortality suggests a rising temporal incidence rate of diffuse disease. Standardised mortality rates demonstrated less consistent trends than did crude mortality rates and failed to demonstrate convincing declines in mortality subsequent to the introduction of ACE inhibitors for management of systemic sclerosis renal disease. Death certificate-derived systemic sclerosis mortality rates considerably and consistently underestimated systemic sclerosis-all cause mortality.

Familial risk estimation in systemic sclerosis

BACKGROUND

Familial systemic sclerosis has been rarely reported. Assumptions have therefore been made implying no familial disease aggregation. This study critically challenges the assumption using a methodical population-based epidemiological approach to quantify the prevalence and characteristics of familial systemic sclerosis.

METHODS

In this retrospective cohort study the systemic sclerosis prevalence in first degree family members was compared between 715 systemic sclerosis patients (710 families) and 371 randomly ascertained age and gender group-matched general practice controls (371 families). These data, obtained by telephone questionnaire (living patients) or medical records review (deceased patients and untraceable patients of unknown living status), were validated, where necessary, and expressed in terms of relative risk, absolute risk and population point prevalence.

RESULTS

Systemic sclerosis affecting first degree members was validated in ten of 710 families. Reporting of systemic disease in another four more distant family members, and the co-occurrence of systemic and localised disease in three families was also documented. Observed and expected disease subtype concordance was 80% (44-97%) and 68% respectively and the female predominance among familial cases was similar to that for non-familial disease. The risk of disease in a subsequent first degree relative was compared to the risk in an initial first degree family member. Its estimated magnitude was wide (11-158). However, use of population prevalence data to determine the expected number of systemic sclerosis patients in the negative cohorts' families suggests the higher estimate is more realistic. Despite the high magnitude, the absolute disease risk in first degree family members remained low--approximating 1%. The population prevalence of familial systemic sclerosis approximated 1.4/million.

CONCLUSIONS

This study substantially increases the otherwise small list of documented instances of familial systemic sclerosis. More importantly, it quantifies the risk for the first time, ranking it as the disease's most powerful determinant identified to date.

Patient based methods for assessing adverse events in clinical trials in rheumatology. Progress report for the OMERACT Drug Toxicity Working Party. Outcome Measures in Rheumatology

There has been increasing recognition in recent years that the measurement of drug related toxicities in rheumatology clinical trials has been sub-optimal. The OMERACT Drug Toxicity Working Party was established to address this issue. The first task of the working party was to identify a minimum set of attributes of drug related toxicity that would be important to patients, clinicians, investigators, and policymakers. The working party then developed consensus on a standard set of properties for instruments to measure these attributes. Existing instruments in the field of rheumatology were ascertained by literature review and by contact with experts in the field. Four instruments were ascertained and evaluated using the guidelines developed by the working party. This report outlines the progress and preliminary results of these activities.

Disease-modifying antirheumatic drugs

Disease-modifying antirheumatic drug (DMARD) therapy is now clearly accepted as the primary treatment for rheumatoid arthritis, with an increasing emphasis on use of combination therapy. Data on combination therapy have highlighted the difficulties in performing these studies and the large number of patients required to produce meaningful results. Combination studies have focused on use of rapidly decreasing high-dose steroids as a part of the combination and emphasize the importance of using patients with early rheumatoid arthritis. Even with relatively aggressive use of DMARDs, the majority of patients develop erosions. Adverse reactions to DMARDs continue to concern clinicians, although evaluation of the frequency of these events has led to a reappraisal of previously accepted monitoring strategies in some cases. For example, it may not be cost-effective to subject patients on antimalarials to regular review by an ophthalmologist because of the low frequency of serious eye defects. Studies have also identified risk factors for the development of pulmonary toxicity in association with methotrexate. That DMARDs are effective in treating rheumatoid arthritis is beyond question-just how effective they are and what combinations of DMARDs will show improved efficacy will provide data for the next annual review.

Use and benefits of nonsteroidal anti-inflammatory drugs

Nonsteroidal anti-inflammatory drugs (NSAIDs) continue to be used very widely in the community. Their use reflects the significant burden of rheumatic disease on the general population, and they form a basis for the treatment of inflammation in and around the joint. Furthermore, NSAIDs are also being used increasingly for nonrheumatic conditions, including acute and chronic pain, biliary and ureteric colic, and dysmenorrhea. Recent studies in osteoarthritis have suggested that a significant number of patients previously maintained on NSAIDs can be equally well treated using analgesic agents, such as paracetamol. In noninflammatory rheumatic diseases, analgesics and physical therapies should be the initial treatment of choice and, even in inflammatory rheumatic diseases, NSAID use may be reduced by the addition of pure analgesics to the treatment regimen. A large number of NSAIDs now exist, and there is variability in clinical response to NSAIDs among individual patients. Concern over the widespread use of NSAIDs is largely related to their side-effects. These include adverse reactions in the gastrointestinal tract, kidney, liver, dermis, and central nervous system, as well as hematologic problems. The potential for drug interactions with NSAIDs is also large, as they are often administered to a population with significant co-morbidities. NSAIDs play a major role in the management of acute and chronic rheumatic diseases, but their use needs to be tempered with the realization that they can cause potentially serious adverse reactions. These side-effects can be reduced by careful attention to the dose and duration of therapy, concomitant risk factors, and the combined use of more specific drugs to reduce disease activity. Furthermore, the gastrointestinal side-effects of NSAIDs may be treated and prevented by using appropriate therapy in combination with NSAIDs.

Systemic sclerosis in DRw52-positive silica-exposed males: a case report

The aims of this paper were to describe clinical and laboratory details of 4 siblings, of whom 2 have systemic sclerosis and to describe this family in the context of reported cases of familial systemic sclerosis. The proband and his affected male sibling share the tissue typing antigens: HLA11, B57, DR13, DRw52,- and DQ2,6. Both were concordant for gender, silica exposure, marital status, migration history and antinuclear factor status but discordant for systemic sclerosis subtype, age at disease onset and ENA status. One non-affected sibling had no disease despite concordance for gender, HLA status, silica exposure, marital status, and migration history.

Pharmacotherapy and osteoarthritis

Therapy for osteoarthritis (OA) is aimed at relieving symptoms and at maximizing function. Therapies can be considered as either symptom modifying OA drugs (SMOADs) or as disease modifying OA drugs (DMOADs). Currently available agents fall into the category of SMOADs. Analgesic medications, particularly paracetamol and capsaicin, have proven efficacy in OA and are recommended first line therapies. Non-steroidal anti-inflammatory drugs (NSAIDs) do appear to provide extra symptomatic benefit for some patients but have greater toxicity. Newer generation NSAIDs may have safety advantages which remain to be confirmed in practice. Further therapies are being developed which aim to prevent cartilage damage and/or aid cartilage restoration, but these DMOADs remain in the experimental stage.

Allogeneic bone marrow transplantation from a donor with severe active rheumatoid arthritis not resulting in adoptive transfer of disease to recipient

We report a patient who underwent allogeneic bone marrow transplantation from a sibling with longstanding untreated severe active rheumatoid arthritis. After 4 years of follow-up there is no evidence of adoptive transfer of rheumatoid arthritis to the recipient. This case, along with another recently reported case, provides reassurance that haemopoietic stem cell transplantation from a donor with systemic autoimmune disease may not necessarily result in adoptive transfer of the disease. All previous reports of transfer of autoimmunity in humans have been of organ-specific autoimmune diseases and we speculate that pathophysiological differences might account for why systemic autoimmune disease is not transferred.

The association between external weather conditions and pain and stiffness in women with rheumatoid arthritis

OBJECTIVE

To determine the self-reported prevalence of weather sensitivity in a sample of female patients with rheumatoid arthritis (RA), and to determine if there is objective evidence of associations between weather and pain and stiffness in female patients with RA.

METHODS

Fifty-three female patients residing in the Sydney metropolitan area participated in a study on the psychological determinants of disability from 1985 to 1987. During the study, subjects recorded pain on a visual analog scale and duration of morning stiffness for 14 day periods at 3-4 monthly intervals over 1-3 years (X = 15.7 months). After completion of the study, data on weather conditions were collected from the Bureau of Meteorology for the days that pain and stiffness records were made. Descriptive statistics and autoregression were used to analyze the data.

RESULTS

Sixty percent of subjects reported that they were sensitive to weather. Six weather variables made a statistically significant contribution to daily pain score (p < 0.0001). However, they accounted for only 2.5% of the variance. Two weather variables contributed to duration of morning stiffness (p < 0.0001), but again these variables accounted for only a small portion of the variance (1.1%). A separate analysis for pain was carried out on the data from subjects who reported being weather sensitive. The results were consistent with those of the other analyses, with 2 variables accounting for only 1.7% of the variance (p < 0.0001).

CONCLUSION

On the basis of these results it appears that weather makes only a minimal contribution to pain and stiffness in women with RA. The study may have been limited by its use of static measures of weather variables and pain. Further research using dynamic measures of pain and weather and a more extensive range of weather variables is needed.

Disease-modifying antirheumatic drugs

The case for early intervention with disease-modifying antirheumatic drugs is strengthened by published reports during the past year. These drugs include methotrexate, gold sulfasalazine, and antimalarial agents. The American College of Rheumatology issued guidelines for the management of rheumatoid arthritis and for monitoring the toxicity of antirheumatic drugs. Studies on the mechanisms of action of disease-modifying antirheumatic drugs focused on their effects on cytokines and their receptors. The toxic effects of disease-modifying antirheumatic drugs remained an important issue, especially the adverse pulmonary effects of methotrexate. An important trial demonstrated a beneficial effect of triple disease-modifying antirheumatic drug therapy (methotrexate, sulfasalazine, and hydroxychloroquine) over individual agents.

Recommendations for a core set of outcome measures for future phase III clinical trials in knee, hip, and hand osteoarthritis. Consensus development at OMERACT III

Significant progress has been made in outcome measurement procedures for osteoarthritis (OA) clinical trials, and guidelines have been established by the US Food and Drug Administration, European League Against Rheumatism, the World Health Organization/International League of Associations for Rheumatology, and the Group for the Respect of Ethics and Excellence in Science. However, there remains a need for further international harmonization of measurement procedures used to establish beneficial effects in Phase III clinical trials. A key objective of the OMERACT III conference was to establish a core set of outcome measures for future phase III clinical trials. During the conference, using a combination of discussion and polling procedures, a consensus was reached by at least 90% of participants that the following 4 domains should be evaluated in future phase III trials of knee, hip, and hand OA: pain, physical function, patient global assessment, and, for studies of one year or longer, joint imaging (using standardized methods for taking and rating radiographs, or any demonstrably superior imaging technique). These evidence based preferences, achieved with a high degree of consensus, establish an international standard for future phase III trials and will also facilitate metaanalysis and Cochrane Collaborative Project goals.

Psoriatic arthritis: a quantitative overview of therapeutic options. The Psoriatic Arthritis Meta-Analysis Study Group

The objective of this study was to use the technique of meta-analysis to undertake a systematic review of published and unpublished randomized controlled trials of pharmacological agents to determine their relative efficacy and toxicity in the treatment of psoriatic arthritis. The main outcome measure was the change in pooled disease index with component variables derived from OMERACT. Nineteen randomized trials were identified, of which 12 were included in the quantitative analysis with data from 792 subjects. Although all agents were better than placebo, parenteral high-dose methotrexate, salazopyrin, azathioprine and etretinate were the agents that achieved statistical significance (although it should be noted that only one component variable was available for azathioprine and only one trial with a high dropout rate was available for etretinate suggesting some caution is necessary in interpreting these results). In all trials, the placebo group improved over baseline (pooled improvement 0.43 disease index (DI) units, 95% CI 0.28-0.59). There were insufficient data to examine toxicity. In conclusion, parenteral high-dose methotrexate and salazopyrin are the only two agents with well-demonstrated published efficacy in psoriatic arthritis. The magnitude of the effect seen with etretinate, oral low-dose methotrexate, azathioprine and perhaps colchicine suggests that they may be effective, but that further multicentre clinical trials are required to establish their efficacy. Furthermore, the magnitude of the improvement observed in the placebo group strongly suggests that uncontrolled trials should not be used to guide management decisions in this condition.