Background The recent ACR/EULAR classification (1) classify gout in patients with at least 8 out of maximum 23 points, but presence of monosodium urate crystals in a symptomatic joint/tophus alone is sufficient for gout classification without need for further scoring. It is not known how in crystal-proven patients with increased serum urate (sUA) the whole range of classification points distribute.
Objectives To determine the distribution along the spectrum of ACR/EULAR criteria in crystal-proven patients with insufficiently treated sUA levels, and if disease factors in gout are associated with high classification scores.
Methods Baseline data from a prospective observational study were used from patients with crystal-proven gout who presented after a recent gout flare. Included patients had at baseline insufficiently treated sUA level (>360 μmol/L [>6 mg/dl]). Demographic, clinical data and sUA levels were collected from September 2015 to December 2016 in one rheumatology department. Ultrasound of joints was assessed with one total score for double contour sign, tophus, and aggregates in several joints and tendons/entheses. The score for ACR/EULAR criteria for gout was calculated.
Results 89 patients were included, with baseline mean (SD) age 56.0 (14.8) years, 92% males, 88% Caucasians, disease duration 7.9 (7.3) years, presence of palpable tophi 19%, ultrasound score 19.9 (13.8), serum urate 486 (90) μmol/L, creatinine 78 (18) ml/min, creatinine clearance 78 (18) ml/min, ESR 14 (14) mm/h, body mass index 29.4 (4.9) kg/m2, comorbidity score [SCQ] 3.5 (3.2), and physical function [HAQ] 0.34 (0.51). All patients satisfied clearly the scoring arm of the classification criteria with a median (range) 19 (11 – 23) of 23 possible points (Figure 1). Patients with a median and higher score above the median (≥19 points) vs. lower score reported more gout flares during the last 12 months (p<0.001), had longer disease duration (9.2 vs. 6.2 yrs, p=0.05), and a higher ultrasound score (23.9 vs. 14.9, p=0.001). The groups with high and low scores were similar for age, gender, ethnicity, level of education, BMI, physical function, comorbidity score, sUA level and kidney function.
Conclusions As expected, patients seen in the clinic with crystal-proven gout and at least slightly increased sUA also satisfy the scoring arm of the new classification criteria for gout, supporting their clinical use. Patients with classification points above the median had more flares in the preceding year, and a higher urate burden assessed by ultrasound, but did not have other indicators for a more severe disease.
Neogi T et al. Ann Rheum Dis 2015;74:1789–98.
Disclosure of Interest T. Uhlig: None declared, L. F. Karoliussen: None declared, E. A. Haavardsholm: None declared, T. K. Kvien Consultant for: Fees for speaking and/or consulting from AbbVie, Biogen, BMS, Boehringer Ingelheim, Celltrion, Eli Lilly, Epirus, Janssen, Merck-Serono, MSD, Mundipharma, Novartis, Oktal, Orion Pharma, Hospira/Pfizer, Roche, Sandoz and UCB, H. B. Hammer: None declared