Efficacy of plasma exchange in anti-MDA5-positive dermatomyositis with interstitial lung disease under combined immunosuppressive treatment.

ABSTRACT

OBJECTIVES: Rapidly progressive interstitial lung disease (RP-ILD) with poor prognosis often accompanies anti-melanoma differentiation-associated gene 5 (MDA5)-positive DM. Combined immunosuppressive therapy, including glucocorticoids, calcineurin inhibitors and intravenous cyclophosphamide (IVCY) is reportedly effective in DM with RP-ILD, but some patients remain resistant to therapy. We examined the utility of plasma exchange (PE) in such intractable cases and investigated the prognostic factors of the disease. METHODS: Thirty-eight anti-MDA5-positive DM-ILD patients who received the combined immunosuppressive therapy were retrospectively reviewed. Their serum cytokines were evaluated by multiplex assay before treatment. The patients were divided into two groups those who achieved remission without exacerbation of respiratory dysfunction (n = 25, group A) and those who progressed to hypoxemia during the treatment (n = 13, group B). RESULTS: PE was carried out in eight group B patients, but none of group A. Five of the eight treated with PE survived, while the five untreated patients died (P =0.04). Higher neutrophil lymphocyte ratio, higher serum ferritin, hypoxemia, high-resolution computed tomography (HRCT) score before treatment and increase of Krebs von Lungen-6 (KL-6) in the first 4 weeks of the treatment were the prognostic factors for disease progression. Serum cytokines such as IL-1, IL-6, IL-8, IL-10, IL-12p70, IL-18 and sCD163 levels were higher in group B than group A. CONCLUSION: PE should be an effective adjuvant treatment in anti-MDA5-positive DM with RP-ILD. Assessment of basal laboratory tests or monocyte/macrophage-derived cytokines and the increase of KL-6, HRCT score and hypoxemia may help us to predict intractable cases and to make early treatment decisions regarding PE in anti-MDA5-positive DM.