Interstitial lung disease common in dermatomyositis patients
MedWire News: Interstitial lung disease (ILD) and isolated low diffusing capacity for carbon monoxide (DLCO) reductions are common in dermatology patients with classic or skin-predominant dermatomyositis, say researchers.
They suggest that due to the inexpensive and accurate nature of the technique for detecting pulmonary disease, serial DLCO measurements may be appropriate for all patients with dermatomyositis to try and detect and treat ILD before irreversible fibrosis occurs.
Victoria Werth (University of Pennsylvania, Philadelphia, USA) and co-workers report the results of a retrospective cohort study of 71 patients with adult-onset dermatomyositis - 36 classic and 35 skin-predominant - seen in a dermatology clinic between 2006 and 2009.
The researchers tested for pulmonary abnormalities in the participants using thin slice chest computed tomography (CT) scans and DLCO testing. In total, 37 had CT and DLCO testing, four had CT alone, and 30 participants had DLCO alone.
Of the patients who had CT and DLCO testing, 16 (23% of the cohort) had ILD diagnosed from the CT results and all had reduced DLCO.
A further 18 (25% of the cohort) of these patients had low DLCO in the absence of CT findings, which the researchers say may represent an early stage of ILD or pulmonary hypertension.
Of note, the prevalence of ILD was not significantly different between patients with classic and skin-predominant dermatomyositis, at 17% and 29%, respectively.
Patients with classic dermatomyositis had a 6% and 13% prevalence rate of skin cancer and general internal malignancies, respectively. The corresponding rates in skin-predominant dermatomyositis patients were much lower, at 2% and 0%.
"Multicenter prospective studies of patients with dermatomyositis are needed to more accurately characterize the prevalence and course of ILD, the natural history of an isolated reduction in DLCO, and the effect of immunosuppressants on this history," say the authors.
"An ideal observational study would include serial pulmonary function tests with DLCO and high-resolution CT of the chest, functional pulmonary studies (eg, the 6-minute walk), systematic assessment of skin disease activity and pulmonary symptoms, and documentation of pulmonary artery systolic pressure and hemoglobin level," they explain.
The results of this study are published in the Archives of Dermatology.
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By Helen Albert