Prevalence of pulmonary diseases among patients newly diagnosed with systemic lupus erythematosus: A cross-sectional case-series introducing thoracic ultrasound and diaphragmatic ultrasound

Background and Objectives Pulmonary diseases (PD) are common in Systemic Lupus Erythematosus (SLE) and associated with increased mortality and decreased health-related quality of life, but no study has so far addressed PD in newly diagnosed patients with SLE. Our objectives were among newly diagnosed patients with SLE to investigate: Primarily, if PD and subtypes of PD are present, and secondarily characterise the patients by means of (i) lung physiology, (ii) radiology, (iii) thoracic ultrasound (TUS) and diaphragmatic ultrasound (DUS). Methods Patients newly diagnosed with SLE from 1st July 2023 to 31st July 2024 at Odense University Hospital, Odense, Denmark, underwent a dedicated clinical evaluation for PD, including pulmonary function tests (PFT), chest high-resolution computed tomography or computed tomography scan alongside with TUS and DUS. Subsequently, PD were diagnosed, and subtype was categorised on a multidisciplinary discussion. Results Ten participants were included in average 3 months after SLE diagnosis, and six out of ten had PD. PD included one case of shrinking lung syndrome (SLS) and two cases of interstitial lung disease. All participants exhibited at least one abnormal PFT measure, with some showing severely reduced pulmonary function. TUS was associated with diseases of the lung parenchyma and pleura and DUS with SLS. Conclusion We found PD among newly diagnosed patients with SLE and in some cases associated with severely affected pulmonary function. TUS and DUS may contribute with information in diagnosing SLE related PD, but further studies are needed.