A62-06 Pft’s and Psle: Pulmonary Function Abnormalities in Pediatric Systemic Lupus Erythematosus

Pediatric Systemic Lupus Erythematosus (pSLE) is a rare, heterogeneous multisystem disease with diverse clinical outcomes. When compared to adult-onset SLE, pSLE is more severe, requiring higher levels of immunosuppression.1 The prevalence of interstitial lung disease in patients with pSLE varies from 8%-14%, and subacute disease on pulmonary function tests (PFTs) in approximately 50% of adult patients.2,3 PFTs are non-invasive, inexpensive, and sensitive studies that can detect subtle declines in lung function and diffusing capacity even before the onset of respiratory symptoms. Despite its common use in patients with rheumatological diseases, there are currently no validated guidelines that exist regarding the use of pulmonary function monitoring in pSLE. This study aims to describe the patterns of PFT results in children with pSLE, as well as provider practices in the screening and monitoring of lung function in pSLE at Children’s Hospital Los Angeles (CHLA). We analyzed 148 PFTs completed by individual patients with pSLE from 2022-2025 during routine clinical care. PFT type ranged from spirometry only to complete with maximal inspiratory and expiratory pressures. Data was analyzed using descriptive statistics with JMP Pro. The median age at the time of PFT was 16 years (IQR 14-17). Providers ordered 47% of first-time PFTs in the first 12 months of diagnosis. The most identified PFT abnormalities were elevated RV/TLC (13%), decreased FEV1 (16%), and decreased TLC (19%) (Table 1). There were no significant differences in PFT abnormalities by sex or age. Time since lupus diagnosis was statistically associated with higher odds of abnormal FEV1/FVC (p = 0.03) and RV (p = 0.02). This study illuminates the frequency of abnormal PFTs in the pSLE population at CHLA who underwent pulmonary function testing, with up to 16% of results falling in the abnormal category for various PFT metrics when following race-neutral percent predicted values. Interestingly, metrics associated with obstructive disease (RV, FEV1/FVC ratio) were the most abnormal and associated with longer duration of disease. Our results only consider pSLE patients who have completed PFTS, and there are approximately double the number of patients who have not performed PFTs in this population at CHLA. Finally, this highlights a provider trend of obtaining PFTs near the time of diagnosis with a tapering of PFT monitoring as time goes on - perhaps due to lack of guidelines or reliance on clinical signs or symptoms alone. Additional studies are required to further investigate the cohort of pSLE patients with abnormal PFT findings and provider practice.