Serum CA72-4 Levels Predict Risk for Gout Flares During ULT Initiation

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.