In a prospective imaging study involving patients with systemic lupus erythematosus, infection was the most common thoracic finding, identified in more than half of the cases followed by pulmonary arterial hypertension.
In the cross-sectional observational study, conducted over 18 months from November 2022 to April 2024, researchers enrolled 60 adult patients with systemic lupus erythematosus (SLE) who underwent chest computed tomography (CT) based on clinical indications. Imaging modalities included high-resolution CT, contrast-enhanced CT, and CT pulmonary angiography. The primary outcome was the spectrum and frequency of thoracic manifestations in SLE identified on imaging alongside associated extrathoracic findings.
The cohort had a mean age of 31.8 years and predominantly identified as female (83%). High-resolution CT was the most frequently used modality (n = 52/60).
Infection was identified in about 53% (n = 32) of the patients, with bacterial infections accounting for 45% (n = 27) of the cases. Less common infectious etiologies included polymicrobial and fungal infections (each 3%) and tuberculosis (2%). Pulmonary arterial hypertension was observed in 50% (n = 30) of the patients, while pulmonary edema occurred in 18% (n = 11) of the patients.
Interstitial lung disease (ILD) and serositis were each reported in 10% (n = 6) of the patients. Within the ILD subgroup, nonspecific interstitial pneumonia was the predominant pattern in 7% (n = 4) of the patients followed by organizing pneumonia in 3% (n = 2) of the patients. Additional thoracic findings included pulmonary thromboembolism in 5% (n = 3) of the patients, lupus pneumonitis in 3% (n = 2) of the patients, and diffuse alveolar hemorrhage in 3% (n.= 2) of the patients. No cases of shrinking lung syndrome or neoplastic involvement were identified in the study population.
Extrathoracic findings were also common. Splenomegaly was present in 52% (n = 31) of the patients followed by vascular calcifications (23%) and patulous esophagus (22%). Among the patients with SLE, additional findings included lymph node involvement; renal abnormalities such as enlarged kidneys and kidney stones; and hepatobiliary changes including fatty liver, hepatomegaly, and gallstones.
The researchers reported that distinguishing among infectious pneumonia, lupus pneumonitis, and organizing pneumonia can be difficult as a result of similar imaging and clinical features, and requires integration of clinical findings, laboratory data, microbiological evaluation, and treatment response.
The study was limited by its relatively small sample size, which may have affected generalizability.
“[CT] proved invaluable in detecting subtle and coexisting thoracic abnormalities. […] A pattern-based CT approach aids in differentiating disease-related manifestations from secondary complications,” wrote lead study author Sankeerth Kendyala, MD, MBBS, of Radiodiagnosis at Nizam's Institute of Medical Sciences in India, and colleagues.
The study authors reported no conflicts of interest. The study received funding from the Indian Council of Medical Research through its thesis grant program.
Source: Cureus
