Clinical and imaging features of 60 cases of antisynthase syndrome with different anti-aminoacyl- tRNA synthetase antibodies

Abstract

Objective To investigate the clinical, serological and imaging features of antisynthetase syndrome (ASS) patients with different positive anti-aminoacyl-tRNA synthase (ARS) antibodies. Methods The demographic characteristics, major clinical data, serological parameters, high resolution CT (HRCT) imaging features and pulmonary function characteristics in 60 cases of ASS[including 42 cases with positive anti-histidine tRNA synthetase (Jo-1) antibody, and 7 cases with positive anti-threonyl tRNA synthetase (PL-7) antibody, 5 cases with positive anti-alanyl tRNA synthetase(PL-12) antibody, 3 cases with positive anti-glycyl tRNA synthetase (EJ) antibody and 3 cases with positive anti-leucyl tRNA synthetase(OJ) antibody] were collected. The differences in ASS patients with different positive ARS antibodies were analyzed by the χ2 test and Fisher exact test. Results ① The ASS with different positive ARS antibodies was common in patients with DM/PM, [60% (36/60), 28% (17/60)], and also appeared in patients with other connective tissue diseases, such as RA(5%, 3/60), SS(3%, 2/60), SLE(2%, 1/60), etc. With ASS diagnosed, ILD complicated with myositis was the most common clinical features (63%, 38/60). Typical clinical triad syndrome (myositis, ILD and arthritis) in 52%(31/60) patients, and myositis complicated with ILD, and mechanics hands accounted for 38%(23/60) respectively. Some patients were complicated with isolated arthritis (25%, 15/60), myositis (23%, 14/60) and ILD (13%, 8/60). The typical triad syndrome (myositis, ILD and arthritis) only accounted for 5%(3/60). The incidence of Jo-1, EJ and OJ antibodies [71%(30/42), 100%(3/3), 100%(3/3)] was significantly higher than that of PL-12 antibody (20%, 1/5). There was a statistically significant difference (χ2=5.263, P 0.05). ③ The ILD incidence of different positive antibodies had no significant difference in 82%(49/60) ASS patients with ILD. The lung function in patients with ASS-ILD showed restrictive ventilation and diffused dysfunction. Grid shadow (76%, 37/49) and grind glass (35%, 17/49) were the most common signs of HRCT. Nonspecific interstitial pneumonia (NSIP) (78%, 38/49) was the most common subtype of ILD. The incidence of traction bronchiectasis in ASS patients with PL-12 antibody (75%, 3/4) was higher than that in ASS patients with Jo-1 antibody (22%, 8/36). The incidence of pleural effusion in ASS patients with OJ antibody (100%, 2/2) was significantly higher than that in ASS patients with Jo-1 antibody (17%, 6/36). The incidence of pericardial effusion in ASS patients with PL-7 antibody (75%, 3/4) was significantly higher than that in ASS patients with Jo-1 antibody (19.4%, 7/36). All the differences were statistically significant (χ2=5.26, P 0.05). Conclusion The ASS with different positive ARS antibodies is very common in patients with DM/PM, and is also observed in patients with other connective tissue diseases. ILD and myositis are the most common clinical features of ASS, followed by the typical triad syndrome (myositis, ILD and arthritis). Myositis is commonly observed in ASS patients with Jo-1, EJ and OJ antibodies, while is rarely observed in ASS patients with PL-12 antibody. The diagnosis of ASS should be alert to the onset of isolated arthritis or ILD. Anti-SSA-52 antibody may be related to ASS. NSIP is the most common HRCT pattern in ASS-ILD patients. There are some differences in signs among various subtypes, indicating that the difference of fibrosis in the lung and inflammatory reactions in the body being correlated with the ASS specificities. Key words: Lung diseases, interstitial; Antisynthetase syndrome; Anti-aminoacyl-tRNA synthetase antibody