Serum CA72-4 is an independent predictor of gout flares during urate-lowering therapy (ULT) initiation, according to study findings published in Rheumatology. Among patients with gout initiating ULT, elevated CA72-4 levels were associated with increased likelihood of flares.
Researchers conducted a prospective cohort study at Qingdao University in Qingdao, China, between 2021 and 2022. Eligible patients were adult men with gout who had experienced at least 1 flare in the prior 12 months. Patients also received serum CA72-4 measurements at least 3 times during the preceding 6 months. Enrolled participants received low-dose febuxostat daily for 24 weeks.
Patients with CA72-4 levels of greater than 6.9 U/mL at baseline were assigned to the “high” CA72-4 group; patients with measurements lower than 6.9 U/mL were assigned to the “normal” CA72-4 group. Patients were followed-up with every 4 weeks for the presence of flares.
A total of 193 patients (79 with high and 114 with normal CA72-4 levels) completed the study. Mean age in the total cohort was 45.3 (SD, 12.4) years; median gout duration was 7.0 years.
During the study, the cumulative incidence of gout flares was 62.1% in the high CA72-4 group and 38.4% in the normal CA72-4 group (P =.001). Patients with recurrent (≥2) gout flares were more common in the high vs normal CA72-54 group (47.1% vs 23.2%; P <.001).
In logistic regression models, independent risk factors for gout flares included high CA72-4 levels (odds ratio [OR], 2.34; 95% CI, 1.14-4.82), longer disease duration (OR, 1.08; 95% CI, 1.01-1.16), larger intra-articular tophus size (OR, 1.97; 95% CI, 1.19-3.24), and increasing erythrocyte sedimentation rate (OR, 1.06; 95% CI, 1.01-1.12). High CA72-4 levels alone predicted recurrent gout flares with an AUC of 0.63 (95% CI, 0.54-0.71), with a sensitivity and specificity of 0.58 and 0.68, respectively. When combined with other independent variables, the predictive capacity increased to 0.78 (95% CI, 0.71-0.85).
One of the main limitations of the study was that the cohort only included Chinese men.
“Monitoring the dynamic changes of CA72-4 may have potential to identify which patients may benefit from gout flare prophylaxis during ULT initiation,” the study authors concluded.
Hu S, Sun M, Li M, et al. Elevated serum CA72-4 predicts gout flares during urate lowering therapy initiation: a prospective cohort study. Rheumatology (Oxford). Published online November 21, 2022. doi:10.1093/rheumatology/keac656