Risk Factors for Recurrence of the Anti-Synthetase Syndrome Related Interstitial Lung Disease

This current study aimed to detect the risk factors for recurrence of the anti-synthetase syndrome related interstitial lung disease (ASSD-ILD).

Patients who were diagnosed with ASSD-ILD and achieved the improving standards after treatment at a single clinical center from January 1, 2017 to January 1, 2022 were retrospectively collected. The patients were divided into the recurrence group and non-recurrence group. We compared the baseline information, pulmonary function test, chest computed tomography/high-resolution computed tomography (CT/HRCT) images, and treatments et al between the two groups. Cox regression was performed to find risk factors for recurrence. Moreover, the Kaplan-Meier curve was conducted to estimate the recurrence-free rate.

Totally 76 ASSD-ILD patients were collected in this study. There were 24 patients in the recurrence group and 52 patients in the non-recurrence group. The recurrence rate was 31.6%. Univariate analysis showed that pyrexia of unknown origin, neutrophil percentage > 75%, non-specific interstitial pneumonia (NSIP) alone pattern, and immunosuppressants discontinuation were associated with recurrence (p < 0.05). In the primary IPTW-weighted Cox model, pyrexia of unknown origin was significantly associated with recurrence (HR = 2.70, 95% CI: 1.12-6.51, p = 0.027). In sensitivity analyses using a doubly robust IPTW-weighted Cox model, both pyrexia of unknown origin (HR = 5.17, 95% CI: 1.94-13.78, p = 0.001) and NSIP alone pattern (HR = 0.30, 95% CI: 0.11-0.80, p = 0.016) remained significantly associated with recurrence. Furthermore, the Kaplan-Meier curve demonstrated that the non-NSIP group (p = 0.039) and the pyrexia of unknown origin group (p = 0.023) had worse recurrence-free rate.

Among patients with ASSD-ILD there is a high frequency of recurrence. The results suggested that pyrexia of unknown origin was a risk factor for recurrence. A follow-up strategy, customized treatment, and early surveillance for high-risk patients who relapse were critical to enhancing patients' quality of life and prognosis.