Rheumatic diseases associated with alveolar hemorrhage: analysis of the national inpatient sample

OBJECTIVE: Diffuse alveolar hemorrhage (DAH) is a severe pulmonary complication of numerous diseases, including rheumatic conditions. We have conducted an observational study using inpatient data from the National Inpatient Sample to study the relationship of DAH with rheumatic conditions along with their descriptive characteristics. METHODS: An observational study was conducted on hospitalizations in 2016–2018 with a principal diagnosis of DAH from the United States National Inpatient Sample database. A multivariate logistic regression analysis was performed to calculate adjusted odds ratios (OR(adj)) for risk factors of DAH. RESULTS: A total of 5420 DAH hospitalizations were identified among 90 million hospitalizations. Mortality in this group was found to be 24.3%. Majority of patients admitted with DAH were white and male, with a mean age of 61.8 years and a mean LOS of 10.6 days. Multivariate analysis showed that multiple rheumatic diseases were associated with DAH, including anti-neutrophil cytoplasmic antibody–associated vasculitis (AAV) (OR(adj) 72.56) (95% C.I. 50.607–104.043), antiphospholipid antibody syndrome (APLS) (OR(adj) 6.51) (95% C.I. 3.734–11.366), eosinophilic granulomatosis with polyangiitis (EGPA) (OR(adj) 7.13) (95% C.I. 1.886–26.926), Goodpasture’s (OR(adj) 30.58) (95% C.I. 16.360–57.176), rheumatoid arthritis (RA) (OR(adj) 1.60) (95% C.I. 1.158–2.212), sarcoidosis (OR(adj) 3.99) (95% C.I. 2.300–6.926), and systemic lupus (SLE) (OR(adj) 5.82) (95% C.I. 3.993–8.481). CONCLUSION: Although DAH is a relatively rare entity, it carries a very high mortality. Multiple rheumatic diseases were associated with DAH hospitalizations including AAV, APLS, EGPA, Goodpasture’s, RA, sarcoidosis, and SLE.