Prevalence of Novel Myositis Autoantibodies in a Large Cohort of Patients with Interstitial Lung Disease

Abstract

Connective tissue diseases (CTDs) are an important secondary cause of interstitial lung disease (ILD). If a CTD is suspected, clinicians are recommended to perform autoantibody testing, including for myositis autoantibodies. In this study, the prevalence and clinical associations of novel myositis autoantibodies in ILD are presented. A total of 1194 patients with ILD and 116 healthy subjects were tested for antibodies specific for Ks, Ha, Zoα, and cN1A with a line-blot assay on serum available at the time of diagnosis. Autoantibodies were demonstrated in 63 (5.3%) patients and one (0.9%) healthy control (p = 0.035). Autoantibodies were found more frequently in females (p = 0.042) and patients without a histological and/or radiological usual interstitial pneumonia (UIP; p = 0.010) and a trend towards CTD-ILDs (8.4%) was seen compared with other ILDs (4.9%; p = 0.090). The prevalence of antibodies specific for Ks, Ha, Zoα, and cN1A was, respectively, 1.3%, 2.0%, 1.4%, and 0.9% in ILD. Anti-Ha and Anti-Ks were observed in males with unclassifiable idiopathic interstitial pneumonia (unclassifiable IIP), hypersensitivity pneumonitis (HP), and various CTD-ILDs, whereas anti-cN1A was seen in females with antisynthetase syndrome (ASS), HP, and idiopathic pulmonary fibrosis (IPF). Anti-Zoα was associated with CTD-ILD (OR 2.5; 95%CI 1.11–5.61; p = 0.027). In conclusion, a relatively high prevalence of previously unknown myositis autoantibodies was found in a large cohort of various ILDs. Our results contribute to the awareness that circulating autoantibodies can be found in ILDs with or without established CTD. Whether these antibodies have to be added to the standard set of autoantibodies analysed in conventional myositis blot assays for diagnostic purposes in clinical ILD care requires further study.

Aminoacyl-tRNA Synthetases: On Anti-Synthetase Syndrome and Beyond

“…Moreover, two-thirds of the patients had autoantibodies against anti-Ro52, which has been previously reported to co-exist with other antisynthetase autoantibodies and more severe ILD (135,136). A more recent study reported the prevalence of anti-Zo autoantibodies as 1.4% in patients with ILD and novel associations of anti-Zo with connective tissue-disease related ILD (CTD-ILD) and idiopathic pneumonias (45).…”

“…The first report of autoantibodies against TyrRS referred to as anti-YRS or anti-HA was published in 2005 in a patient with ASSD features (17). The prevalence of anti-HA autoantibodies in a large cohort of patients with ILD (n = 1,194) was 2% (45).…”

Autoantigenic properties of the aminoacyl tRNA synthetase family in idiopathic inflammatory myopathies

“…The fact that we used population controls that might have other autoimmune diseases could explain some of the reactivities. Recent studies reported a relatively high prevalence of anti-Zo, -KS, and -HA in a broad spectrum of ILD patterns [42], and ILD has been reported as the primary clinical feature of anti-KS patients [43]. In our cohort, ten patients with IIM were identified with these autoantibodies, and ILD was reported only in three.…”

Prevalence of myositis specific and associated antibodies in a cohort of patients affected by idiopathic NSIP and no hint of inflammatory myopathies

“…anti-Zo, Ks and Ha, has contributed to shed a new light in the comprehension of ASS. ILD seems to be one of the most common feature in anti-Ks and anti-Ha positive patients [ 18 , 19 ], in whom lung involvement may be the sole manifestation of ASS and present with NSIP pattern and long-term stabilization of lung functionality [ 20 ]. Conversely, in case of anti-Zo, ILD, arthritis and myositis are reported in similar percentage [ 21 , 22 ], but data are restricted to a dozen of patients [ 21 – 24 ].…”