TY - JOUR T1 - Dr. Mahler replies JF - The Journal of Rheumatology JO - J Rheumatol SP - 94 LP - 94 DO - 10.3899/jrheum.121234 VL - 40 IS - 1 AU - MICHAEL MAHLER Y1 - 2013/01/01 UR - http://www.jrheum.org/content/40/1/94.abstract N2 - To the Editor:We thank Dr. Muro and colleagues for the thoughtful analysis1 of our study on anti-DFS70 (anti-dense fine speckled 70) antibodies in systemic autoimmune rheumatic diseases (SARD), disease controls, and apparently healthy individuals as measured by a novel chemiluminescent immunoassay (CIA). The data on patients with dermatomyositis (DM) presented by Muro, et al are interesting and complement our findings2. Anti-DFS70 antibodies were found in 7/116 (6.4%) patients with DM. Although the prevalence in DM was not directly compared to a cohort of healthy individuals, based on previous data of 597 healthy hospital workers3, Muro and colleagues concluded that anti-DFS70 antibodies are less prevalent in persons with DM compared to healthy individuals (6.4% vs 10.7%, respectively). It is important to point out that the 2 cohorts were tested with 2 different ELISA systems, the DM cohort with a commercial ELISA and the healthy individuals with a research assay. Of high interest, the prevalence of isolated anti-DFS70 antibodies (with no other SARD-related autoantibody) was even lower. In the DM cohort, 2/116 … Address correspondence to Dr. Mahler; E-mail: mmahler{at}inovadx.com ER -