title: Diffuse Alveolar Hemorrhage Secondary to Antineutrophil Cytoplasmic Antibody-Associated Vasculitis: Predictors of Respiratory Failure and Clinical Outcomes.
abstract: To identify predictors of respiratory failure and to evaluate the therapeutic efficacy of plasma exchange (PE) and of rituximab versus cyclophosphamide in a cohort of patients with diffuse alveolar hemorrhage (DAH) secondary to antineutrophil cytoplasmic antibody-associated vasculitis (AAV) with or without respiratory failure.
  
  
  
  We performed a single-center historical cohort study of all consecutive patients with AAV-associated DAH who were evaluated over a 16-year period. Logistic regression models were developed to examine the predictive role of the baseline clinical characteristics for the development of respiratory failure, and for the effect of PE and remission induction therapy on the main outcome (complete remission at 6 months).
  
  
  
  Seventy-three patients with DAH were identified, and 34 of them experienced respiratory failure. The degree of hypoxemia upon initial presentation, a higher percentage of neutrophils in the bronchoalveolar lavage fluid cell count, and higher C-reactive protein levels were independently associated with the development of respiratory failure. PE was not associated with achieving complete remission at 6 months, with an odds ratio (OR) of 0.49 (95% confidence interval [95% CI] 0.12-1.95) (P = 0.32). Rituximab treatment was independently associated with achieving complete remission at 6 months (OR 6.45 [95% CI 1.78-29], P = 0.003).
  
  
  
  Our findings indicate that the most important predictor of respiratory failure in patients with DAH secondary to AAV is the degree of hypoxemia upon presentation. No clear benefit of the addition of PE to standard remission induction therapy was demonstrated. Complete remission by 6 months was achieved at a higher rate with rituximab than with cyclophosphamide in patients with DAH secondary to AAV, including those needing mechanical ventilation.
authors.affiliation: Mayo Clinic, Rochester, Minnesota.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Cartin-Ceba
authors.affiliation: Macon Lung Center, Macon, Georgia.
authors.forename: Luis
authors.initials: L
authors.lastname: Diaz-Caballero
authors.affiliation: Brown University, Providence, Rhode Island.
authors.forename: Mazen O
authors.initials: MO
authors.lastname: Al-Qadi
authors.affiliation: Thessaloniki General Hospital, Thessaloniki, Greece.
authors.forename: Stavros
authors.initials: S
authors.lastname: Tryfon
authors.affiliation: Mayo Clinic, Rochester, Minnesota.
authors.forename: Fernando C
authors.initials: FC
authors.lastname: Fervenza
authors.affiliation: Mayo Clinic, Rochester, Minnesota.
authors.forename: Steven R
authors.initials: SR
authors.lastname: Ytterberg
authors.affiliation: Mayo Clinic, Rochester, Minnesota.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Specks
mesh_terms: D000368:Aged; D056648:Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis / Q000150:complications*; D015331:Cohort Studies; D003520:Cyclophosphamide / Q000627:therapeutic use*; D005260:Female; D006470:Hemorrhage / Q000209:etiology* / Q000628:therapy*; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use*; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D008171:Lung Diseases / Q000209:etiology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010951:Plasma Exchange; D011650:Pulmonary Alveoli; D012074:Remission Induction; D012131:Respiratory Insufficiency / Q000209:etiology* / Q000628:therapy*; D000069283:Rituximab / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D007155:Immunologic Factors; D007166:Immunosuppressive Agents; D000069283:Rituximab; D003520:Cyclophosphamide