Langfassung zur S2e-Leitlinie Gichtarthritis (fachärztlich): Evidenzbasierte Leitlinie der Deutschen Gesellschaft für Rheumatologie (DGRh)

[Gout (ICD 10: M10): a retrospective analysis of the data from the histopathological arthritis register of the DGORh]

BACKGROUND

Gout is considered to be the most common inflammatory arthritis worldwide. The histopathological arthritis register of the German Society for Orthopedic Rheumatology (DGORh) was founded in 2018. The aim of this register is a systematic collection of histopathological data on joint pathologies. As part of a master's thesis in medicine at the Sigmund Freud Private University (Vienna, Austria) the data on gout cases were retrospectively analyzed.

OBJECTIVE

The objective of this analysis was to determine the prevalence of gout, the localizations of gout in the musculoskeletal system and the sensitivity of clinical gout diagnostics.

MATERIAL AND METHODS

In cooperation with the Medical Treatment Center for Histology, Cytology and Molecular Diagnostics in Trier, Germany (MVZ-HZMD-Trier GmbH; Germany), tissue samples from 190 different orthopedic clinics and practices were analyzed and 7595 datasets were collected and stored in an arthritis register created by the DGORh. All gout cases stored between 1 January 2018 and 20 January 2020 were eligible for retrospective analysis (N = 102).

RESULTS

The prevalence of gout was calculated at 1.34%. Of 108 histopathologically confirmed urate crystal depositions and gout granulomas, 76 were found in the lower extremities (70.37%), 30 in the upper extremities (27.78%) and 2 in the spinal joints (1.85%). The sensitivity of clinical gout diagnostics could be determined at 73.53%.

CONCLUSION

Gout affects different anatomical regions with the first metatarsophalangeal joint being the main localization site. The sensitivity of clinical gout diagnostics was determined at 73.53%. These results emphasize the importance of histopathology in gout diagnostics.

The role of gut microbiota in gout: Is gut microbiota a potential target for gout treatment

Numerous studies have demonstrated that gut microbiota is essential for the host's health because it regulates the host's metabolism, endocrine, and immune systems. In recent years, increasing evidence has shown that gut microbiota plays a role in the onset and progression of gout. Changes in the composition and metabolism of the gut microbiota, result in abnormalities of uric acid degradation, increasing uric acid generation, releasing pro-inflammatory mediators, and intestinal barrier damage in developing gout. As a result, gout therapy that targets gut microbiota has drawn significant interest. This review summarized how the gut microbiota contributes to the pathophysiology of gout and how gout affects the gut microbiota. Additionally, this study explained how gut microbiota might serve as a unique index for the diagnosis of gout and how conventional gout treatment medicines interact with it. Finally, prospective therapeutic approaches focusing on gut microbiota for the prevention and treatment of gout were highlighted, which may represent a future avenue in gout treatment.

Differenzialdiagnose ausgedehnter ossärer Destruktionen – ein Fallbericht

Die Gicht ist die häufigste metabolische Arthropathie. Obwohl Ätiologie und Pathogenese des Krankheitsbildes gut untersucht sind, bereitet die Diagnosesicherung mittels des Nachweises von Natriumuratkristallen aus einem Gelenkpunktat oder anderen betroffenen Geweben mitunter große Schwierigkeiten. Wir berichten von einem außergewöhnlich schweren Fall einer generalisierten Gichtarthropathie mit atypischer Manifestation und kompliziertem Verlauf. Dabei sollen wichtige Differenzialdiagnosen ausgedehnter ossärer Destruktionen beleuchtet werden.

Compliance of Primary Care Providers With Gout Treatment Recommendations—Lessons to Learn: Results of a Nationwide Survey

Objectives: Gout is generally managed in the primary health care sector. Compliance of primary care physicians with gout management recommendations has been shown to be insufficient in the past. The primary aims of this study were to assess primary care providers' knowledge regarding gout and to determine if their treatment decisions are influenced by recommendations. Facing considerable variations in postgraduate training options in Austria, we secondly looked for possible knowledge differences between urban and rural areas and eastern and western parts of Austria.

Methods: We conducted a survey among 343 primary care physicians in Austria, using a questionnaire consisting of 10 questions on acute, intercritical and general gout management. Gout treatment recommendations served as the therapeutic gold standard.

Results: Of the 343 physicians surveyed, 336 completed the questionnaire, leading to a very high return rate of 98%. 289 (86%) physicians were aware of the agreed-upon SUA target (<6 mg/dl). 323 (96.1%) reported change of therapy in case of missing this target. 112 (33.3%) physicians voted for long term ULT. No geographical differences in knowledge regarding gout or its management were revealed, except that colchicine was rated as being a safe medication significantly more often in rural areas (p = 0.035) and in western Austria (p = 0.014).

Conclusion: As opposed to former studies, gout knowledge among primary care physicians has improved - however, treatment patterns are still not fully concordant with gout recommendations. Our findings may help to better tailor future postgraduate training to improve primary care physicians' education in gout.

Effects of Conventional Uric Acid-Lowering Therapy on Monosodium Urate Crystal Deposits

OBJECTIVE

Few studies have systematically and quantitatively addressed the impact of urate-lowering therapy on monosodium urate (MSU) deposits. This study was undertaken to analyze the effect of lifestyle measures and conventional urate-lowering therapy on MSU deposits in patients with gout.

METHODS

In this prospective study, subjects with gout according to the American College of Rheumatology/European League Against Rheumatism classification criteria and presence of MSU deposits seen on dual-energy computed tomography (DECT) scans received either lifestyle intervention or conventional urate-lowering therapy for a mean period of 18 months before a follow-up DECT scan. Detected MSU deposits were quantified by volumetric measurement and validated by semiquantitative scoring, and baseline and follow-up measurements were compared.

RESULTS

Baseline and follow-up DECT scans were available for all 83 subjects. Six subjects discontinued treatment, and 77 subjects underwent a lifestyle intervention (n = 24) or were treated with allopurinol (n = 29), febuxostat (n = 22), or benzbromarone (n = 2) over the entire observation period. The mean serum uric acid (UA) level decreased from 7.2 to 5.8 mg/dl in the overall population. In patients who discontinued treatment, no change in MSU deposits or serum UA levels was observed. The burden of MSU deposits significantly decreased in patients undergoing lifestyle intervention (MSU volume P = 0.007; MSU score P = 0.001), and in patients treated with allopurinol (MSU volume and score P < 0.001) or febuxostat (MSU volume P < 0.001; MSU score P = 0.001). No significant decline in MSU deposits was noted in patients who discontinued treatment.

CONCLUSION

These data show that lifestyle intervention and xanthine oxidase inhibitors significantly decrease the MSU deposit burden. Hence, conventional gout therapy not only lowers serum UA levels, but also reduces pathologic MSU deposits.

[Dual-energy computed tomography diagnostics for gout]

BACKGROUND

Non-invasive imaging modalities are used for the morphological and functional evaluation and diagnosis of gout; however, none of these methods are sufficiently sensitive or specific for the diagnosis of gout. By the use of dual-energy computed tomography (DECT) the direct visualization of sodium urate deposition is now possible. Moreover, it is possible to show the different pathological situations, disease activity and monitoring of tophaceous gout. The positive DECT scan became one of the 2015 ACR/EULAR classification criteria for gout 2 years ago.

MATERIAL AND METHODS

The literature search from 2009-2017 in PubMed, with the search criteria "Dual Energy CT and Gout" revealed 77 publications on the DECT method.

RESULTS

The DECT technique has a high sensitivity (90-100%) and a high specificity (83-89%) for diagnosing gout. The development of a semiquantitative scoring method also enables measurement of the severity of urate deposits at specific sites.

CONCUSION

The gold standard for the diagnosis of gout is still the detection of monosodium urate monohydrate crystals by polarizing microscopy after a joint punction; however with the DECT it is possible to non-invasively visualize, measure and score urate deposition and is therefore suitable for estimating the severity and prognosis. Although not clinical validated, DECT may sometimes help to detect gout. More studies should be conducted.

Potential Dangers of Serum Urate-Lowering Therapy

In observational studies, high serum urate levels are associated with adverse outcomes, including mortality. However, the hypothesis that urate-lowering may improve nongout outcomes has not been confirmed by placebo-controlled clinical trials. On the contrary, 7 recent placebo-controlled trials of urate-lowering drugs with different mechanisms of action (uricosuric: lesinurad; xanthine oxidase inhibition: febuxostat; uricase: pegloticase) have observed higher mortality or trends to higher mortality in gout patients, with the largest decreases in serum urate. Because all urate-lowering mechanisms were implicated, this raises safety concerns about urate-lowering itself. Far from unexpected, the higher mortality associated with more intense urate-lowering is in line with the U-shaped association of urate with mortality in some observational studies. Urate accounts for most of the antioxidant capacity of plasma, and strategies to increase urate are undergoing clinical trials in neurological disease. Post hoc analysis of recent trials should explore whether the magnitude of urate-lowering is associated with adverse outcomes, and safety trials are needed before guidelines recommend lowering serum urate below certain thresholds.

Treatment Options for Gout

BACKGROUND

1-2% of adults in Germany suffer from gout. Gout is one of the few rheumatological diseases that can be cured. It arises through the deposition of uric acid crystals in joints as a result of hyperuricemia. Painful redness and swelling of the affected joints are typical findings. Multiple pertinent guidelines and treatment recommendations have been published, but there is reason to believe that patients with gout are not always treated accordingly.

METHODS

This review is based on relevant publications from the years 2000-2016 that were retrieved by a selective search in the Cochrane and PubMed databases.

RESULTS

In a person with normal renal function, asymptomatic hyperuricemia is not an indication for treatment to lower the serum uric acid level. The drugs of first choice for acute gouty arthritis are nonsteroidal antiinflammatory drugs (NSAID), corticosteroids, and colchicine. Treatment with xanthine oxidase inhibitors (XOI) or uricosuric drugs is indicated for patients with a recurrent or severe course; the target uric acid value is <6 mg/dL. Long-term treatment should be initiated only after resolution of the acute attack. For patients with refractory gout, lesinurad (approved in February 2016) in combination with XOI is a new treatment option that can be considered. Comprehensive patient education and counseling is an important component of the treatment of patients with gout. Regular laboratory follow-up is necessary as well.

CONCLUSION

The prevalence of gout is rising around the world. Patients with gout could benefit greatly from consistent implementation of the existing treatment guidelines and recommendations. In the future, controlled trials should be conducted to determine the best time to start treatment and the optimal target level for the serum uric acid concentration in terms of a risk/benefit analysis.

What Is the Evidence for Treat-to-Target Serum Urate in Gout?

PURPOSE OF REVIEW

Most current clinical guidelines for gout management advocate a treat-to-target serum urate approach, although notable differences exist. Serum urate is a rational target for gout treatment given the central role of urate in disease causality, its association with key outcomes and its practicality of use in clinical practice. This review analyses the evidence for this strategy in gout.

RECENT FINDINGS

Recent studies have confirmed the efficacy of urate-lowering therapy in achieving serum urate targets, both in trials using fixed doses and those applying a treat-to-target strategy. In a limited number of long-term studies (> 12-month duration), interventions that incorporate a treat-to-target serum urate approach have been shown to promote regression of tophi, reduce the frequency of gout flares and improve MRI-detected synovitis. A strong case can be made for a treat-to-target serum urate strategy in gout, supported by existing knowledge of disease pathophysiology, outcomes from urate-lowering therapy studies and emerging results of randomised strategy trials of sufficient duration.

[Evidence-based recommendations for diagnostics and treatment of gouty arthritis in the specialist sector : S2e guidelines of the German Society of Rheumatology in cooperation with the AWMF]

Due to the increasing prevalence of gout, particularly in old age, the disease is becoming of increasing importance in Germany. Gout is one of the most common forms of recurrent inflammatory arthritis and is induced by the deposition of monosodium urate crystals in synovial fluid and other tissues. The principal goals of therapy in chronic gout are the symptomatic treatment of the acute joint inflammation and the causal treatment of the underlying metabolic cause, the hyperuricemia. Only a consistent and permanent reduction of the serum uric acid level ultimately results in an efficient avoidance of further gout attacks and therefore the prevention of structural damage. Due to an often inadequate treatment of gout, the target of healing the disease is often not achieved. A correct and timely diagnosis and adequate assessment of comorbidities associated with gout are, however, of substantial importance for patient and physician to achieve remission of the disease. In order to create a solid basis for a timely and effective treatment of affected patients, in 2016 the German Society of Rheumatology (DGRh) initiated the development of S2e guidelines on gouty arthritis for specialists. This article summarizes these S2e guidelines on the management of gouty arthritis in the specialist sector.

[Methodological approaches in the development of clinical guidelines]

Practical guidelines assist the clinical decision-making process in modern medicine. In rheumatology the number of practical guidelines dealing with diagnostics and therapy of rheumatic diseases is also constantly increasing. Methodological standards for guidelines ensure adequate development under consideration of precisely defined structures. Expert recommendations for action (S1) are distinguished from consensus (S2k) or evidence-based (S2e) as well as consensus and evidence-based (S3) guidelines. Levels of evidence categorize available studies by study design. Parameters for the evaluation of guidelines are summarized in the German instrument for the assessment of guidelines (DELBI).