Objective: The current study demonstrated the potential use of calcineurin inhibitor (CNI) in combination therapy for interstitial lung disease (ILD) complicated with dermatomyositis (DM) and polymyositis (PM).
Methods: Thirty DM/PM patients with ILD were enrolled in this study. Continuous intravenous administration of cyclosporine A (IV-CsA) was simultaneously started with corticosteroid in patients presenting more than two respiratory distress factors as follows: <70 mmHg of PaO2, percentage of vital capacity <70%, and/or exertional dyspnea. Other patients took CNI orally with corticosteroid. When a patient presented exacerbation of ILD, intravenous cyclophosphamide pulse therapy (IVCY) was additionally administrated. Clinical outcomes were compared with those of 21 patients who had been previously treated in our hospital before starting this study, as the historical comparison group.
Results: Seven patients underwent IV-CsA, maintaining the drug concentration in blood between 300 and 350 ng/mL, and six of them had favorable outcomes without any adverse events. Eight out of the 30 patients additionally required IVCY. Meanwhile, the frequency of death ascribable to respiratory failure was 6.7%, which was significantly lower than that of the historical comparison group (P = 0.043). Furthermore, longer survival free from exacerbation and severe adverse event was significantly shown (P = 0.029).
Conclusions: For repressing the activity of ILD in DM/PM patients, stabilizing the blood concentration of CNI immediately is a reasonable treatment as well as initiating immunosuppressive therapy in the early phase of the illness. IV-CsA may be a useful option for achieving this purpose in patients with severe ILD.