Validation Study of Physical Measurement of Tophi

A Study to Assess a Direct Physical Measurement Method for Evaluation of Tophus Nodules in Subjects With Gout.

The purpose of this study is to determine the inter- and intra-rater reproducibility of direct physical measurement of tophus nodules in subjects with gout.

Study Overview

• Status: Completed
• Conditions: Gout
• Intervention / Treatment: Other: Measurement of Tophi to validate procedure

Detailed Description

Gout is a chronic urate crystal deposition disorder. Left untreated, gout may result in progressive disease characterized by joint and bone destruction from tophaceous deposits and renal impairment due to gouty nephropathy. Hyperuricemia, defined as a serum urate concentration greater than 7.0 milligrams per deciliter (mg/dL), is the underlying metabolic aberration leading to urate crystal deposition in gout. Gout has several clinical presentations, including: recurrent acute attacks of inflammatory arthritis; deposition of monosodium urate monohydrate crystals in joints, bones and even parenchymal organs (tophaceous gout); renal impairment; and uric acid nephrolithiasis.1 As serum urate levels increase beyond greater than 7.0 mg/dL, the risks for gouty arthritis or for renal calculi increase.

Febuxostat is a 2-aryl-thiazole derivative chemically engineered as a novel xanthine oxidase/dehydrogenase inhibitor. Febuxostat is being developed as an orally administered agent for the management of hyperuricemia in patients with gout.

Subjects with palpable tophi >10 millimeters (mm) in length and width and as round as possible will have the tophus measured on two separate visits by two different raters to assess the inter- and intra-rater reproducibility of direct physical measurement.

• Study Type: Observational
• Enrollment (Actual): 13

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 85 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Subjects with palpable tophi >10mm in length and width and as round as possible will have the tophus measured on two separate visits by two different raters to assess the inter- and intra-rater reproducibility of direct physical measurement.

Description

Inclusion Criteria:

• Must have at least 1 palpable gouty tophus nodule in the foot/ankle, hand/wrist, or elbow, confirmed as gouty by prior diagnosis according to ACR criteria.
• The tophus must be solid, round, non-tender, intact, and larger than 10mm in both length and width.
• Joints nearest and immediately adjacent to the selected tophus must not be acutely inflamed.
• Must be on stable treatment for gout with no medication changes in the past 30 days.

Exclusion Criteria:

• Must be able to return to the clinical site within 10 days.
• Must not have allergy to ink.

Study Plan

How is the study designed?

Design Details

• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Tophi Participants	Other: Measurement of Tophi to validate procedure; Intra- and Inter-rater Reproducibility measurements of the area (in mm2) of each tophus nodule.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Average Percent Difference in Area Between Visits	The rater measured length and width (mm) of the tophus at 2 visits separated by no more than 10 days. Area of the tophus was summarized using average percent difference, calculated as absolute difference of Visits 1 and 2 divided by the average of Visits 1 and 2 for the same tophus, pooled across raters.	Visit 1 (Day 1) and Visit 2 (Days 6-11)
Average Percent Difference in Area Between Raters	Each rater measured length and width (mm) of the tophus at 2 visits separated by no more than 10 days. Area of the tophus was summarized using the average percent difference, calculated as the absolute difference of Raters 1 and 2 divided by the average of Raters 1 and 2 for the same tophus, pooled across visits.	Visit 1 (Day 1 ) and Visit 2 (Day 6-11)

Collaborators and Investigators

• Sponsor: Takeda

Publications and helpful links

General Publications

• Schumacher HR Jr, Becker MA, Palo WA, Streit J, MacDonald PA, Joseph-Ridge N. Tophaceous gout: quantitative evaluation by direct physical measurement. J Rheumatol. 2005 Dec;32(12):2368-72.

Helpful Links

• Uloric Package Insert

Study record dates

Study Major Dates

• Study Start: November 1, 2002
• Primary Completion (Actual): January 1, 2003
• Study Completion (Actual): January 1, 2003

Study Registration Dates

• First Submitted: September 12, 2005
• First Submitted That Met QC Criteria: September 12, 2005
• First Posted (Estimate): September 15, 2005

Study Record Updates

• Last Update Posted (Estimate): July 27, 2010
• Last Update Submitted That Met QC Criteria: July 22, 2010
• Last Verified: July 1, 2010

More Information

Terms related to this study

• Keywords: Drug Therapy; Hyperuricemia; Tophus; Tophi
• Additional Relevant MeSH Terms: Metabolic Diseases; Genetic Diseases, Inborn; Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases; Arthritis; Metabolism, Inborn Errors; Crystal Arthropathies; Purine-Pyrimidine Metabolism, Inborn Errors; Gout
• Other Study ID Numbers: C02-019; U1111-1114-1944 (Registry Identifier: WHO)