Lung involvement in rheumatic diseases is a major determinant of patient morbidity and mortality; however, its diagnosis depends on the detection methods used. We compared the incidence of pulmonary involvement in newly diagnosed treatment-naive patients with rheumatic diseases, as assessed by pulmonary function tests (PFTs) and chest high-resolution computed tomography (HRCT). This retrospective study reviewed the symptoms, spirometry results, and HRCT scans of 22 newly diagnosed, treatment-naïve patients and age-matched controls from the University General Hospital “Attikon”, Athens, Greece, between January 2021 and December 2023. Correlations between clinical findings and spirometry parameters were tested. HRCT scans revealed lung abnormalities in all patients, including peribronchial wall thickening (61.5%), ground glass opacities (59.1%), parenchymal bands (54.5%), air-trapping (50%), reticular patterns (45.5%), bronchiectatic changes (40.9%), and parenchymal opacities (31.8%). PFTs, performed in 17/22 (77.3%) patients, revealed definite pathology in 5 patients (restrictive: N=4; obstructive: N=1). No association was found between spirometric indices and clinical parameters. The results indicate a higher prevalence of abnormal chest CT than of PFT abnormalities, suggesting that HRCT is more sensitive in detecting early lung involvement in pediatric patients with rheumatic disease and should be considered in the routine evaluation of these patients.

Introduction: Lung involvement in pediatric rheumatic diseases significantly impacts morbidity and mortality. High-resolution computed tomography (HRCT) is a sensitive diagnostic tool for detecting lung involvement; however, it raises concerns regarding radiation exposure. Spirometry, a non-invasive and widely accessible test, is often used to assess pulmonary function, but its accuracy in identifying lung disease in children with newly diagnosed rheumatic conditions remains uncertain. This study evaluates the reliability of spirometry, using HRCT as the reference standard, in detecting early lung involvement in this population. Methods: At our institution, all patients suspected of having lung involvement—either due to respiratory symptoms or the high prevalence of respiratory involvement associated with their specific disease—underwent an HRCT scan and pulmonary assessment. A retrospective review of HRCT scans was conducted for 22 pediatric patients diagnosed with rheumatic disease between January 2021 and December 2023, all of whom exhibited pathological findings in their HRCT scans. HRCT scans were conducted with a paired end-inspiratory and forced-expiratory protocol using 1-mm collimation. Radiological findings, including parenchymal opacities, ground-glass opacities (GGOs), reticular patterns, honeycombing, parenchymal bands, bronchiectasis, peribronchial wall thickening, and air trapping were assessed. Spirometric values, including percent predicted values for Forced Expiratory Volume in 1 second (ppFEV1), Forced Vital Capacity (ppFVC), and the FEV1/FVC ratio, were collected for all patients who had an acceptable flow-volume curve Results: Of the 22 patients enrolled, 17 (77.3%) had technically acceptable spirometry results. Using HRCT as the reference standard, spirometry yielded a sensitivity of 29.4%. Conclusion: Although spirometry demonstrated excellent positive predictive value, its low sensitivity indicates that it may miss early lung involvement in children with newly diagnosed rheumatic diseases. These findings reinforce HRCT as the preferred diagnostic tool in this population, despite concerns about radiation exposure, to ensure accurate detection and management of lung involvement.