Association of antinuclear antibody status with clinical features and malignancy risk in adult-onset dermatomyositis.

Background: The clinical significance of antinuclear antibody (ANA) status in adults with dermatomyositis (DM) has yet to be fully defined.

Objective: We compared the incidence of amyopathic disease, risk of malignancy, and clinical findings in ANA and ANA patients with adult-onset DM.

Methods: This was a retrospective cohort study of patients with ANA or ANA adult-onset DM determined by enzyme-linked immunosorbent assay.

Results: Of 231 patients, 140 (61%) were ANA and 91 (39%) were ANA. Compared with the ANA patients, the ANA patients had a lower frequency of dysphagia (15% vs 26% [P = .033]) and heliotrope rash (38% vs 53% [P = .026]). In all, 54 patients (23%) developed malignancy within 3 years of diagnosis of their DM; 11% of the ANA patients developed malignancy versus 43% of the ANA patients (P < .001). There was a strong association between ANA positivity and lower likelihood of malignancy in multivariable analysis (odds ratio, 0.16; P < .001). Conversely, ANA positivity was not associated with amyopathic disease (odds ratio, 0.94; P = .87).

Limitations: The retrospective nature of the study was a limitation.

Conclusion: In patients with adult-onset DM, ANA negativity is associated with increased likelihood of development of malignancy within 3 years of diagnosis of their DM. Particularly close follow-up and frequent malignancy screening may be warranted in ANA individuals with DM.