Interstitial lung disease outcomes by high-resolution computed tomography (HRCT) in Anti-Jo1 antibody-positive polymyositis patients : a single centre study and review of the literature

Interstitial lung disease (ILD) is a frequent complication of inflammatory myopathies with high rates of morbidity and mortality. Antibodies against aminoacyl-tRNA-synthetases are the strongest predictive factors in ILD. In this study, we reviewed the literature and we retrospectively analysed high-resolution computed tomography (HRCT) findings in a cohort of 131 consecutive subjects: 75 with polymyositis (PM), 43 with dermatomyositis (DM), one with amyophatic PM, two with paraneoplastic syndromes, and 10 with overlapping syndromes. The inclusion criteria were PM/DM, anti-Jo1 antibody positivity, and HRCT-assessed ILD. The effect of 12 months' treatment with cyclophosphamide (CYC) or cyclosporin A (CsA) plus steroids was assessed by comparing baseline and follow-up HRCT scans for evidence of stability, improvement or worsening. Fifteen patients (11.5%) had ILD and were Jo-1 positive. They were all women with PM, and had a mean age of 47.33 years and a median duration of symptoms of 7.26 months. At baseline, HRCT showed ground-glass attenuations in eight cases, septal thickening in seven, and honeycombing in four. Twelve months after diagnosis, ILD had worsened in nine patients (60%; exact confidence interval [ECI] 32-84) and was stable in four (two patients were lost to follow-up). Seven of the 15 patients were treated with CsA, and 12-month HRCT revealed a worsening in ILD in five cases (71%; ECI 0.29-0.96); ILD also worsened (ECI 16-84) in four of the eight patients treated with CYC pulses (50%). The evolution of the HRCT findings was not significantly different between the two groups. Our findings confirm that ILD is a common early manifestation in patients with Jo1-positive PM. Over twelve months, HRCT showed worsening ILD in most of our patients, with no difference in the HRCT changes between those treated with CYC or CsA.