Diffuse alveolar damage - Uncommon manifestation of pulmonary involvement in patients with connective tissue diseases

Background: Diffuse alveolar damage (DAD) is a relatively common finding on surgical lung biopsy and can result from a variety of causes. Methods: We studied nine consecutive patients with connective tissue disease (CTD) and DAD diagnosed on surgical lung biopsy to examine this association and clinical implications. Results: The median age was 63 years (range, 35 to 76 years), and seven of the patients were women (78%). Underlying CTDs included rheumatoid arthritis in five patients, polymyositis in two patients, and one patient each with systemic sclerosis and mixed CTD. In seven patients (78%), CTD had been diagnosed before the onset of DAD; six of these patients had a preexisting interstitial lung disease (ILD) related to their CTD. DAD was the presenting manifestation leading to a new CTD diagnosis in two patients (22%). CT of the chest revealed ground-glass opacities and/or consolidation bilaterally with or without honeycombing. In all patients, surgical lung biopsy revealed DAD for which no cause could be identified other than the underlying CTD. Seven patients (78%) were receiving mechanical ventilatory support at the time of the surgical lung biopsy. Four patients (44%) survived to hospital discharge and included one patient with preexisting ILD and all three patients without chronic ILD. Conclusion: We conclude that DAD can complicate the clinical course of patients with CTD-related chronic ILD, or can occasionally occur as a presenting manifestation of CTDs. When DAD occurs in patients with CTDs, the outcome appears to be worse for those with preexisting chronic ILD compared to those without ILD.