Prevalence of Myositis-Specific Antibodies in Idiopathic Interstitial Pneumonias

Although included in the serological domain of the 'interstitial pneumonia with auto-immune features' (IPAF) research statement, the search for myositis-specific antibodies (MSA) is not incorporated in routine clinical practice. The objective of the study was to evaluate MSA prevalence in an idiopathic interstitial pneumonia (IIP) cohort (n = 68) with suggestive morphological interstitial lung disease patterns. Twelve of 68 patients (17.6%) carried MSA, whereof only two were anti-nuclear antibody-positive. Besides female gender, no demographic or pulmonary function parameter was predictive for MSA positivity. MSA were present in 32.4% of IPAF patients (n = 37), being essential for IPAF diagnosis in four of them (10.8%).