A nomogram to predict recurrence of RA patients in clinical remission within one year

Some patients with rheumatoid arthritis (RA) will recur despite they have achieved clinical remission after treatment. The subclinical synovitis detected by ultrasonography (US) may be one of the main causes of the RA recurrence. The aim of this study is to establish a nomogram for predicting the outcome of RA patients with disease in clinical remission.

One hundred and sixty-seven RA patients who achieved clinical remission and were willing to receive a 1-year follow-up were included in this study. Their demographic, clinical, and laboratory characteristics were recorded at baseline. 7-joints ultrasound (US7) synovitis score (simplified from US7 score) were evaluated at baseline and at the end of follow-up (or when RA recurrence confirmed). All patients were divided into recurrence group and non-recurrence group after the follow-up. Multivariable regression was applied to link the predictors that were significant at p < 0.05 in the univariate analysis and the recurrence of RA patients in clinical remission, which was served as the basis of the nomogram.

Fifty-one RA patients were included in the recurrence group and 116 patients in the non-recurrence group. All US7 synovitis scores in this study showed excellent reproducibility. Multivariable analysis revealed that high-titer positive anti-cyclic citrullinated peptide (anti-CCP), simplified clinical disease activity index (SDAI), baseline grayscale ultrasound (GSUS) score, and baseline power Doppler ultrasound (PDUS) score were the independent predictors for RA recurrence within 1 year. A nomogram incorporating the independent predictors was constructed to predict the risk of RA recurrence. The nomogram showed good discrimination (C-index=0.826) and good calibration.

The nomogram incorporating anti-CCP, SDAI, and subclinical synovitis helps to achieve complete remission and reduces the risk of short-term recurrence of RA patients.