[Analysis of clinical features of ruccrent interstitial lung disease in patients with anti-EJ positive antisynthetase syndrome]

Objective: To summarize the clinical characteristics of 57 patients diagnosed with anti-glycyl tRNA synthetase (anti-EJ) positive antisynthetase syndrome (ASS), a subtype of anti-glycyl tRNA positive ASS, complicated by interstitial lung disease (ILD), and to investigate the factors asso-ciated with ILD recurrence.

Methods: A retrospective analysis was conducted on the clinical data of 57 anti-EJ positive ASS patientswho were treated at the First Affiliated Hospital of Nanjing Medical University from January 1, 2020 to June 30, 2024. The data collected included demographic information, clinical characteristics, laboratory test results, chest CT findings, and pulmonary function tests. The characteristics of ILD recurrence were also analyzed.

Results: All the 57 patients with anti-EJ positive ASS were diagnosed with ILD. The mean age at disease onset was (58.18±10.27) years, with a mean disease duration of 3.00 (2.00, 16.00) months. Among the patients, 70. 18% were female, 87.72% experienced a cough, 70. 18% had expectoration, 89.47% reported respiratory difficulties, and 14.04% developed respiratory failure. The results of pulmonary function test showed that the percentage of forced vital capacity (FVC) in the normal predicted value (FVC%), the percentage of forced expiratory volume in the first second (FEV1) in the normal predicted value (FEV1%) and the percentage of diffusion lung carbon monoxide (DLCO) in the normal predicted value (DLCO%) were 59.36±21.41, 58.34±19.46 and 58.17±27.95, respectively. The oxygenation index was (363.24±99.42) mmHg. Chest CT imaging showed that nonspecific interstitial pneumonia (NSIP) was the most common radiographic pattern. Among the 46 patients who completed a follow-up of more than 12 months, 21 cases (45.65%) showed recurrence of ILD. The average age of onset for the recurrence group was (61.38±8.63) years, while that for the non-recurrence group was (55.28±11.85) years, with a difference approaching statistical significance (P=0.056). Further analysis showed that the ESR (erythrocyte sedimentation rate) level was significantly higher in the recurrence group than in the non-recurrence group [(50.48±29.64) mm/h vs. 30.28±23.97) mm/h, P=0.025], and the IgM (immune globulin M) level was also significantly higher in the recurrence group (P=0.042). Moreover, the CD8+T proportion was significantly higher in the recurrence group than in the non-recurrence group (25.48±11.81 vs. 18.59± 8.53, P=0.027). Despite the fact that the recurrence group had a higher baseline age, higher ESR, IgM, and CD8+T proportion, multivariate binary logistic regression analysis showed that these indicators were not independent risk factors for ILD recurrence.

Conclusion: ILD is the most common clinical manifestation in patients with anti-EJ positive ASS, with a significant impact on pulmonary function. Although the patients responded well to a combination of glucocorticoid and immunosuppressive therapies, the recurrence rate remains high, particularly in those with increased sputum production, and elevated ESR. Close monitoring and early intervention for high-risk patients are essential to improving long-term outcomes.