Shrinking lung syndrome in systemic lupus erythematosus: Insights from a case series and a systematic review of the past decade

AimsShrinking lung syndrome (SLS) is a rare pulmonary manifestation of systemic lupus erythematosus (SLE) and affects approximately 0.5-1% of patients. This systematic review aimed to summarize the clinical features, imaging findings, therapeutic strategies, and outcomes of SLS in patients with SLE.MethodsThis systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies published between 2015 and 2025 were identified using the terms "shrinking lung syndrome" AND "systemic lupus erythematosus." Clinical characteristics, imaging findings, pulmonary function tests, treatments, and outcomes were analyzed.ResultsA total of 52 cases were included, comprising 44 cases from the literature and 8 from a single-center case series. The mean age was 31.5 ± 7.5 years in our cohort and 38.6 years in the literature, with a marked female predominance. All patients had a prior diagnosis of SLE. Dyspnea was present in all the patients, followed by pleuritic chest pain and dry cough. The most common imaging finding was reduced lung volume with elevated diaphragmatic domes, which was observed in all the patients in our cohort and in 77.2% of the reported cases, followed by basal atelectasis. Diaphragmatic ultrasonography, performed in half of our patients, demonstrated reduced diaphragmatic excursion. Pulmonary function tests consistently revealed a restrictive ventilatory pattern with reduced diffusing capacity for carbon monoxide (DLCO). Immunosuppressive therapy as a corticosteroid-sparing strategy was used in all patients from our cohort and was the most frequently reported treatment in the literature, with rituximab being the most commonly used agent. Improvement in pulmonary function occurred in 62.5% of our patients and 50% of the reported patients, whereas stabilization was observed in approximately one-quarter of the patients. Two cases of clinical worsening, including one death, were reported.ConclusionSLS represents a potentially severe and underrecognized pulmonary complication of SLE. Despite the lack of standardized therapy, early diagnosis and timely initiation of immunosuppressive treatment beyond corticosteroids are critical for improving clinical outcomes, as evidenced by improvement in pulmonary function tests in approximately 52% of patients and the availability of effective steroid-sparing options. Prospective studies are needed to establish standardized treatment strategies.