Primary respiratory disease in patients with systemic lupus erythematosus: data from the Spanish rheumatology society lupus registry (RELESSER) cohort

Background The purpose of this study was to assess the prevalence, associated factors, and impact on mortality of primary respiratory disease in a large systemic lupus erythematosus (SLE) retrospective cohort. Methods All adult patients in the RELESSER-TRANS (Registry of Systemic Lupus Erythematosus Patients of the Spanish Society of Rheumatology [SER], cross-sectional phase) registry were retrospectively investigated for the presence of primary pleuropulmonary manifestations. Results In total 3215 patients were included. At least one pleuropulmonary manifestation was present in 31% of patients. The most common manifestation was pleural disease (21%), followed by lupus pneumonitis (3.6%), pulmonary thromboembolism (2.9%), primary pulmonary hypertension (2.4%), diffuse interstitial lung disease (2%), alveolar hemorrhage (0.8%), and shrinking lung syndrome (0.8%). In the multivariable analysis, the variables associated with the development of pleuropulmonary manifestation were older age at disease onset (odds ratio (OR) 1.03, 95% confidence interval (CI) 1.02-1.04), higher SLEDAI (Systemic Lupus Erythematosus Disease Activity Index) scores (OR 1.03, 95% CI 1.00-1.07), the presence of Raynaud's phenomenon (OR 1.41, 95% CI 1.09-1.84), secondary antiphospholipid syndrome (OR 2.20, 95% CI 1.63-2.97), and the previous or concomitant occurrence of severe lupus nephritis, (OR 1.48, 95% CI 1.12-1.95) neuropsychiatric manifestations (OR 1.49, 95% CI 1.11-2.02), non-ischemic cardiac disease (OR 2.91, 95% CI 1.90-4.15), vasculitis (OR 1.81, 95% CI 1.25-2.62), hematological manifestations (OR 1.31, 95% CI 1.00-1.71), and gastrointestinal manifestations, excluding hepatitis (OR 2.05, 95% CI 1.14-3.66). Anti-RNP positivity had a clear tendency to significance (OR 1.32, 95% CI 1.00-1.75; P = 0.054). The development of pleuropulmonary manifestations independently contributes to a diminished survival (hazard ratio of 3.13). However, not all complications will influence the prognosis in the same way. Whereas the occurrence of pleural disease or pulmonary thromboembolism has a minimal impact on the survival of these patients, the remaining manifestations have a major impact on mortality. Conclusion Except for pleural disease, the remaining respiratory manifestations are very uncommon in SLE (