Abstract

OBJECTIVES: To describe the disease specificity, clinical phenotype, and cancer associations of patients with autoantibodies against cell division cycle and apoptosis regulator 1 (CCAR1).METHODS: Dermatomyositis patients from two independent cohorts, as well as several rheumatic disease and healthy control cohorts, were studied to determine the frequency of anti-CCAR1 autoantibodies measured by ELISA. Clinical features of anti-CCAR1-positive dermatomyositis patients and cancer risk compared to the general population were determined.RESULTS: Anti-CCAR1 antibodies were significantly associated with anti-TIF1-gamma-positive compared to anti-TIF1-gamma-negative dermatomyositis patients (80/252 [32%] vs 14/186 [8%], p<0.001). These antibodies were not detected in the healthy control sera assayed (0/32) and were present at very low frequencies in other rheumatic diseases: 1/44 (2.3%) in anti-HMGCR-positive necrotizing myopathy sera, 1/44 (2.3%) in inclusion body myositis sera, and 3/46 (6.5%) in systemic lupus erythematosus patient sera. Upon examining data on cancer occurrence from dermatomyositis onset onwards, the observed number of cancers diagnosed in anti-TIF1-gamma-positive patients was significantly greater than expected in both cohorts, with standardized incidence ratios (SIRs) of 3.49 (95% CI 2.39-4.92), p<0.001 for Hopkins and 4.54 (95% CI 3.04-6.52), p<0.001 for Stanford. In patients who were anti-TIF1-gamma-positive/anti-CCAR1-positive, the SIRs decreased to 1.78 (95% CI 0.77-3.51), p=0.172 and 1.61 (95% CI 0.44-4.13), p=0.48 for Hopkins and Stanford, respectively.CONCLUSIONS: Anti-CCAR1 autoantibodies are specific for anti-TIF1-gamma-positive dermatomyositis. Their presence in anti-TIF1-gamma-positive patients attenuates the risk of cancer to a level comparable to that seen in the general population.

View details for DOI 10.1002/art.42474

View details for PubMedID 36762496