Abstract
Objective
Evaluate pulmonary function, functional capacity, profile, and clinical aspects in systemic lupus erythematosus (SLE) with chronic pulmonary thromboembolism (CPTE) and correlate them with pulmonary perfusion defect (PPD).
Methods
A cross-sectional study from March 2018 to December 2019, with retrospective electronic data retrieval. 72 consecutive outpatients with SLE underwent chest radiography and lung perfusion (Q) scan. PPD was calculated by the Meyer et al. criteria. Data from spirometry, transthoracic echocardiography (TTE), 6-minute walk distance (6MWD) and New York Heart Association (NYHA) class results were compared with reference.
Results
Patients studied were divided into groups, PPD < 10% (n = 32; 2,3 ± 3%) and PPD ≥ 10% (n = 35; 24 ± 12%). Univariate analysis included: the ratio of forced expiratory volume in the first second (FEV1)/ forced vital capacity, FEV1, anti-RO/SSA, chronic cutaneous lupus erythematosus and lupus nephritis. Linear regression analysis showed lupus nephritis as an independent predictor inversely associated with PPD ≥ 10% (OR: 0,23; CI: 0,06 − 0,85; p = 0,02). There was no correlation between the extension of PPD and right ventricular function assessed by TTE and functional parameters (6MWD and NYHA class).
Conclusion
SLE is an important risk factor for CPTE, we found high percentage (73%) of PPD on (Q) scan in outpatients with SLE without previous lung disease. Furthermore, PPD ≥ 10% occurred in more than half of the sample (52%), which is the clinically relevant cut-off point. Lupus nephritis is a protective factor possibly related to more aggressive immunosuppressive treatment, which leads to considering an inflammatory factor in CPTE in these patients.