Diffuse alveolar hemorrhage in immunocompetent patients: etiologies and prognosis revisited

Diffuse alveolar hemorrhage (DAH) represents a diagnostic challenge of acute respiratory failure. Prompt identification of the underlying cause of DAH and initiation of appropriate treatment are required in order to prevent acute respiratory failure and irreversible loss of renal function. More than 100 causes of DAH have been reported. However, the relative frequency and the differential presentation of those causes have been poorly documented, as well as their respective prognosis.

We retrospectively reviewed the charts of 112 consecutive patients hospitalized for DAH in a tertiary referral center over a 30-year period.

Twenty-four causes of DAH were classified into four etiologic groups: immune (n = 39), congestive heart failure (CHF; n = 33), miscellaneous (n = 26), and idiopathic DAH (n = 14). Based on this classification, clinical and laboratory features of DAH differed on hospital admission. Patients with immune DAH had more frequent pulmonary-renal syndrome (p < 0.001), extra-pulmonary symptoms (p < 0.01), and lower blood hemoglobin level than others (p < 0.001). Patients with CHF-related DAH were older and received more anticoagulant treatments than others (p < 0.05). Those with miscellaneous causes of DAH exhibited a shorter prodromal phase (p < 0.001) and had more frequent hemoptysis >200 mL (p < 0.05). Patients with idiopathic DAH had more bronchoalveolar lavage siderophages (p < 0.01). In-hospital mortality was 24.1%, ranging from 7.1% in patients with idiopathic DAH to 36.4% in those with CHF.

Arbitrary classification of DAH in four etiologic groups gives the opportunity to underline distinct presentations and outcomes of various causes of DAH.