Anti-Ro52 antibodies in interstitial lung disease

<bold>Background:</bold> Anti-Ro52 antibodies are often detected in connective tissu diseases (CTD) and even in non-autoimmune disorders. Because of their lack of specificity, they are not suitable diagnostic tools in CTD. However, they may participate in tissue damages such as interstitial lung diseases (ILD). <bold>Objectives:</bold> We aim to describe the characteristics of patients with ILD and positive anti-Ro52 antibodies. <bold>Methods:</bold> One handred fifty six patients with ILD were analysed retrospectively in a department of internal medicine. They were divided into positive anti-Ro52 group (group 1) and negative anti-Ro52 group (group 2). <bold>Results:</bold> Our study included 156 patients (70% women), with a mean age at diagnosis of ILD of 60 years. Positive anti-Ro52 concerned 26 cases (16%). The presence of anti-Ro52 was positively and significantly correlated to extra-pulmonary manifestations (96%, p=0,001), subjective xerostomia (58%, p=0,012), muscular involvement (19%, p=0,012), and focus score≥1 in the salivary glands biopsy (52%, p=0,005). Positive anti-Ro52 was also significantly associated with nonidiopathic forms of ILD (96%, p=0), to CTD (88,5%, p=0), Sjögren disease (42%, p=0,001), and inflammatory myopathy (38,5%, p=0). This antibody is also correlated to the use of systemic steroids (88,5%, p=0) and immunosuppressive drugs (57,7%, p=0,001). Within the group 1, half of the patients had positive antinuclear antibodies, 30% had positive anti-SSA-60, 11% had positive anti-SSB, and 15% had positive rheumatoid factor. The most frequent scannographic patterns were nonspecificic interstitial pneumonia (NSIP) (38%), and usual interstitial pneumonia (27%). NSIP was fibrotic in half of the cases. <bold>Conclusions:</bold> Anti-Ro52 positivity was an indicator of CTD in ILD.