As patients with early onset gout (EOG) present with severe disease and are more resistant to urate-lowering therapy, they may benefit from early rheumatology referral and urate-lowering via a treat-to-target approach, according to results of a systematic review published in Rheumatology & Therapy.
While nearly 600,000 Americans have been diagnosed with EOG, data on disease specific characteristics in this younger population are lacking. To address this gap, researchers conducted a systematic literature review to assess the clinical features, comorbidities, and treatment response among patients diagnosed with EOG.
Investigators searched PubMed, as well as the American College of Rheumatology (ACR) and European Alliance of the Associations for Rheumatology (EULAR) abstract archives, for articles on EOG published from 2016 to 2022. To differentiate between EOG and common gout (CG), CG was defined as diagnosis occurring among patients aged more than 40 years.
In total, 12 full-length publications and 5 abstracts were included in the review. Of the 17 publications that were included, 6 focused on the genetic aspects of EOG, while 10 centered on the clinical aspects. A single publication included aspects of both genetic and clinical factors.
EOG was defined as the first instance of gout diagnosis or acute gout flare occurring prior to the age of 40 years in 7 studies, and before the age of 30 years in 4 studies. Gout was defined based on ACR/EULAR criteria in 5 studies.
Among patients with EOG, average age of the first gout flare or diagnosis was between 23.5 to 32.8 years. For CG patients, average age was between 47.8 to 61.0 years. While both the EOG and CG cohorts were comprised of mostly men, the EOG group had a consistently higher proportion of men across all studies (96.7%-100%) compared with the CG group (71.0%-97.3%).
Patients with EOG experienced more severe and difficult to treat disease vs those with CG. This was indicated by a higher frequency of flare-ups, involvement of multiple joints, and/or elevated levels of uric acid that were less responsive to oral medication.
At the time of diagnosis, patients with EOG had a lower number of cardiometabolic comorbidities compared with patients in the CG group.
Researchers noted that anomalies in renal urate transporters may contribute to the development of EOG. Specifically, mutations in the ABCG2 transporter may affect its function and the body’s ability to excrete urate.
Patients with EOG were found to have higher serum urate (SU) levels overall and were less likely to reach target SU levels during urate-lowering therapy. This could be due to genetic mutations that are associated with gout, making this population less responsive to xanthine oxidase inhibitors.
This study was limited by the small number of publications meeting inclusion criteria and inconsistency in the definition of EOG across studies. These limitations could result in overlapping groups and a non-homogeneous population.
Study authors concluded, “Early rheumatology referral and gout management may benefit EOG patients due to a potential ‘window of opportunity’ where proper SU control may prevent gout-related suffering and health burden in young EOG patients who will live with gout and its consequences for decades.”
Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Amatucci AJ, Padnick-Silver L, LaMoreaux B. et al. Comparison between early-onset and common gout: a systematic literature review. Rheumatol Ther. Published online June 19, 2023. doi:10.1007/s40744-023-00565-x