Antiendothelial cell antibodies in inflammatory myopathies: Distribution among clinical and serologic groups and association with interstitial lung disease

Objective. To determine the prevalence and associations of antiendothelial cell antibodies (AECA) in a well characterized cohort of patients with idio pathic inflammatory myopathies (IIM), Methods. Clinical characteristics, AECA, and myositis-specific autoantibodi es were assessed by standard methods in 56 subjects with IIM. Results. AECA were found in 20/56 patients with IIM, were seen in all the m ajor clinical and serologic IIM groups, and were found in 10/15 patients wi th interstitial lung disease (ILD) (chi squared 6.5, p < 0.01 with Yates' c orrection, relative risk 2.7, specificity 86% and sensitivity 50%). Antisyn thetase antibodies, also associated with ILD as described (chi squared = 26 .5, p < 0.001 with Yates' correction, relative risk 8.7, specificity 95%, s ensitivity 77%), did not correlate with the presence of AECA, Conclusion. AECA appear to be present in all forms of IIM and are markers f or no that are independent of anti-synthetase autoantibodies. AECA may be a useful serologic marker for ILD in IIM.