Background Interstitial lung disease (ILD) is one of the major contributors to morbidity and mortality of polymyositis (PM) and dermatomyositis (DM) .
Objectives To study the efficacy and the safety of intravenous cyclophosphamide (IVCYC) according to the Euro-Lupus nephritis protocol  (500 mg IVCYC every other week with a minimum of 6 doses) for progressive ILD in PM and DM patients.
Methods Twelve PM/DM patients with progressive ILD (mean age 54 years ± SD 8) were treated with 500 mg IVCYC according to the Euro-Lupus nephritis protocol as first line treatment between October 2007 and December 2014. IVCYC was given in combination with oral prednisolone 0.75- 1.0 mg/kg/day for 4 weeks, then gradually tapered. At start of treatment the median disease duration was 4 months ± IQR 11.Exertional dyspnea, dry cough, need for supplemental oxygen, pulmonary function tests (PFTs), high-resolution computed tomography (HRCT), were recorded at start of treatment and after a median follow-up of 5 months ± IQR 5.
Results Before therapy, all patients had exertional dyspnea, 11 of 12 complained of dry cough and 1 required supplemental oxygen, the median values of forced vital capacity (FVC)%, forced expiratory volume in 1 second (FEV1)%, vital capacity (VC) %, total lung capacity (TLC) % and diffusion capacity of the lung for carbon monoxide (DLCO) % were 57±IQR 25, 67±IQR 20, 63±IQR 25, 64±IQR 17, 57±IQR 25, respectively. The patients received a total mean of 4.6 g ±SD 1.4 IVCYC. At follow-up, 8 of 12 patients showed regression of both exertional dyspnea and dry cough. One patient kept requiring supplemental oxygen. The median values of PFTs improved; the difference between baseline and follow-up FVC% and VC% median values was statistically significant (p=0,01 and p=0,02, respectively). Five of 12 patients showed >10% improvement of TLC% and 3 of 12 had >15% improvement of DLCO%. The HRCT showed no signs of progression in 8 of 12 patients, the extent of abnormal lesions decreased in 5 and remained unchanged in 3. No adverse events or drug toxicity were observed during the study period.
Conclusions Our preliminary data suggest that the Euro-Lupus nephritis IVCYC protocol improved PFTs and HRCT findings in PM/DM patients with progressive ILD and it was not associated with adverse events or drug toxicity. Longitudinal controlled studies are needed to confirm the efficacy and the safety of this treatment protocol.
Fathi M1, Dastmalchi M, Rasmussen E, Lundberg IE, Tornling G. Interstitial lung disease, a common manifestation of newly diagnosed polymyositis and dermatomyositis. Ann Rheum Dis. 2004 Mar;63(3):297-301.
Houssiau FA, Vasconcelos C, D'Cruz D, Sebastiani GD, de Ramon Garrido E, Danieli MG, et al. Immunosuppressive therapy in lupus nephritis: the Euro-Lupus Nephritis Trial, a randomized trial of low-dose versus high-dose intravenous cyclophosphamide. Arthritis Rheum 2002;46:2121–31.
Disclosure of Interest A. Notarnicola: None declared, M. Dastmalchi: None declared, L. Dani: None declared, I. E. Lundberg Grant/research support from: Novartis, Servier, Astra-Zeneca och Bristol-Myers Squibb