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 (<4%). Pleuropulmonary manifestations independently contributed to a decreased survival in these patients.