5 Questions About the G-CAN Consensus Statement on New Gout Terminology

The Gout, Hyperuricemia and Crystal-Associated Disease Network (G-CAN) has developed a consensus statement regarding the labels and definitions used for disease states of gout. G-CAN sought to overcome deficiencies in the consistency, accuracy, and clarity of the terminology used by clinicians and researchers.

After a content analysis of 5 years’ worth of journals, an exercise using the Delphi method, and a face-to-face consensus meeting, gout experts have agreed on the labels and definitions of 8 gout disease states, including gout itself.

David Bursill, MD, from the Department of Health and Medical Sciences at the University of Adelaide in Australia, and lead author of the consensus statement, along with other members of the international G-CAN, recommend that clinicians and researchers use these labels and definitions moving forward.

Rheumatology Consultant caught up with Dr Bursill to ask how the consensus statement will impact research and clinical practice, as well as how practitioners can expect the recommended terminology to begin working its way into everyday practice.

RHEUM CON: Can you provide a brief overview of the standardized terminology for gout itself?

DB: Going into the project, there was no standard definition of gout with widespread acceptance. Because of advanced imaging modalities, such as musculoskeletal ultrasonography and dual-energy computed tomography scanning, there has been increased detection of monosodium urate (MSU) crystal deposition in the absence of clinical features of gout. Therefore, there has arisen the issue of whether “gout” refers to the pathophysiological process of MSU crystal deposition in the setting of hyperuricemia or whether it refers to the clinical consequences of this pathology. Through the Delphi exercise, it became clear that participants had a preference for gout to be used only if there are clinical manifestations of MSU crystal deposition; this motion was passed unanimously in the subsequent face-to-face meeting. This is consistent with most existing management guidelines for gout, which state that urate-lowering therapy (ULT) should only be used if there are clinical features of gout, such as gout flares or subcutaneous tophi.

RHEUM CON: Do you anticipate any barriers to the widespread implementation of the agreed-upon labels and definitions?

DB: Gout terminology has not been guided by any consensus statements in the past, and so the popularity of existing terms that are discouraged by the current statement, such as acute gout or chronic gout, will take some time to be replaced. However, much thought has been given to develop a nomenclature that is concise, accurate, and meaningful. G-CAN members—of whom there are more than 100 worldwide—have been encouraged to use the new terms and definitions in their work, which will hopefully help disseminate the new nomenclature.

RHEUM CON: In what ways do you think the consensus statement will impact clinical practice?

DB: The main impact will be to have a consistent nomenclature in the scientific literature on gout and in communications between clinicians and researchers in this area. For example, we have provided a comprehensive nomenclature for the preclinical disease elements of gout, which includes not only the well-known label asymptomatic hyperuricemia, but also asymptomatic MSU crystal deposition and asymptomatic hyperuricemia with MSU crystal deposition. As the implications of the preclinical states are better understood through ongoing research, it will be important to have a standardized approach to the labels and definitions of these states. I hope that these labels will also promote a better understanding of gout in clinical practice and improve management of the disease by avoiding confusing or ambiguous terms.

RHEUM CON: Of the 13 identified unique disease states, there was consensus agreement on the labels and definitions for 8 of them. How do you recommend clinicians describe the remaining 5 moving forward, even though there are no recommended standardized labels?

DB: The 13 unique disease states were identified through the content analysis of the literature as being potentially meaningful. The subsequent group consensus exercises were to determine if the participants in the project actually thought there were meaningful. The disease states that were dropped from the final nomenclature were thought to be vague and not to have implications for disease prognosis or management. The most notable was severe gout; this was rejected because there is no clear way of defining severe, despite this term being used in international gout-management guidelines. It was also thought that using the label severe gout may suggest that other states of gout were not severe and do not require management with ULT. The latter point is important, as the uptake of ULT for gout in the community is suboptimal.

RHEUM CON: What did the analysis and consensus discussions show you about the current management of gout? Are there any knowledge gaps or areas that need improvement?

DB: Although not part of the scope of this project, the management of gout is currently suboptimal, with poor rates of the uptake and effective titration of ULT. However, we have excellent evidence that gout can be well-treated to avoid adverse consequences, including recurrent gout flares and erosive gout. Probably the biggest challenge is in the implementation of ULT strategies. Having a standardized nomenclature will hopefully improve gout-related communication, which will contribute to disease management.

Reference:

Bursill D, Taylor WJ, Terkeltaub R, et al. Gout, Hyperuricaemia and Crystal-Associated Disease Network (G-CAN) consensus statement regarding labels and definitions of disease states of gout. Ann Rheum Dis. 2019;78(11):1592-1600. doi:10.1136/annrheumdis-2019-215933.