# Clinical, radiological and laboratory features and outcomes of diffuse alveolar hemorrhage

## TL;DR

This study examines the features and outcomes of diffuse alveolar hemorrhage in Colombia, finding autoimmune causes are common and hypoxemia is linked to higher mortality.

## Contribution

The study provides new regional insights into DAH in Latin America, emphasizing autoimmune etiology and risk factors for mortality.

## Key findings

- Autoimmune diseases were the most frequent cause of DAH (80%).
- In-hospital mortality was 12%, with hypoxemia at admission independently associated with mortality.
- Ground-glass opacities were observed in 94% of chest CT scans.

## Abstract

Diffuse alveolar hemorrhage (DAH) is a rare and potentially life-threatening syndrome with heterogeneous etiologies and limited regional data from Latin America. We conducted a retrospective cohort study of adults with bronchoalveolar lavage–confirmed DAH managed at two tertiary referral centers in Bogotá, Colombia, between 2019 and 2024. Clinical, radiological, laboratory characteristics, treatments and in-hospital outcomes were analyzed, and factors associated with mortality were explored using logistic regression models. A total of 95 patients were included, with a mean age of 49 ± 18 years; 51% were male. Autoimmune diseases were the most frequent etiology (80%), and ground-glass opacities were observed in 94% of chest computed tomography scans. Immunosuppressive therapy was administered to most patients. Overall, in-hospital mortality was 12%. In univariable analyses, hypoxemia, chest pain, microbiological isolation and use of blood products were associated with mortality, whereas autoimmune etiology was associated with lower risk of death. In multivariable analysis, hypoxemia at admission remained independently associated with in-hospital mortality. These findings highlight the predominance of autoimmune causes of DAH and underscore the importance of early etiological identification and assessment of respiratory severity to improve clinical outcomes.