Alveolar haemorrhage in the immunocompetent host: a scale for early diagnosis of an immune cause.

BACKGROUND Diffuse alveolar haemorrhage (DAH) is a life-threatening condition due to immune and non-immune causes. Early identification of an underlying immune disorder is essential in order to initiate appropriate treatment. OBJECTIVE The purpose of this study was to identify early predictive factors of an immune cause of DAH. METHODS We conducted a retrospective study of 76 immunocompetent patients with DAH to identify early predictive factors of immune-related DAH using clinical, radiological and routine biological data available in the first 24 h after hospital admission. RESULTS Multivariate analysis identified 4 parameters which were independently associated with immune-related DAH: (1) onset of first respiratory symptoms ≥11 days, (2) fatigue and/or weight loss during the month prior to presentation, (3) arthralgias or arthritis and (4) proteinuria ≥1 g/l. A simplified scale was constructed using these variables, with an area under the receiver operating characteristic curve of 0.913, for the diagnosis of immune-related DAH. CONCLUSIONS A simple diagnostic scale can be used to identify an immune-related cause of DAH in immunocompetent patients and may help guide treatment decisions such as initiation of steroid therapy on the day of admission.