We read with interest the recent article by Stringer et al, in which the authors analyze a cohort of patients from their center in order to determine whether the course of juvenile dermatomyositis (DM) can be predicted (Stringer E, Singh-Grewal D, Feldman BM. Predicting the course of juvenile dermatomyositis. Arthritis Rheum 2008;58:3585–92).
At present, there are no validated criteria for clinical remission and inactive disease in juvenile DM. In the study by Stringer et al, disease remission was defined as a clinical state in which rash is absent, there is no evidence of active myositis or arthritis, and the patient has not received immunosuppressive medications for a minimum of 6 months, and remission of skin disease was defined as the absence of heliotrope rash, Gottron's papules, and skin ulcers for at least 3 successive visits. We believe that using these definitions results in a significant number of patients who are classified as having “active” disease, when the standard clinical impression would be that the disease is in fact “inactive.” In particular, classifying patients in whom there is clinical disease remission (no evidence of skin, muscle, or joint inflammation), but whose medications continue to be tapered slowly, as having active disease is problematic. The clinical treatment protocol used at the authors' center would require a minimum of 30 months of treatment, with methotrexate tapered over time. When taken together, the remission definition and the methotrexate tapering protocol exaggerated the median time to remission and caused the majority of patients in the study to be classified as having a chronic disease course.
We wonder whether Stringer and colleagues might be able to provide information on patients in their study population with juvenile DM in clinical remission who were receiving treatment versus those with juvenile DM in clinical remission who were not receiving treatment, similar to the preliminary criteria for clinical remission proposed by Wallace et al for select categories of juvenile idiopathic arthritis (Wallace CA, Ruperto N, Giannini EH. Preliminary criteria for clinical remission for select categories of juvenile idiopathic arthritis. J Rheumatol 2004;31:2290–4). Such information might provide a more accurate description of the clinical course and progression to remission in patients with juvenile DM, using “real clinic” definitions.