Pathological Findings in Lung Biopsies in Patients with Clinical Suspicion of Pulmonary Graft Versus Host Disease
Lauren F Xu, Cinthia Drachenberg, E J Britt, Allen P Burke. University of Maryland Medical Center, Baltimore, MD
Background: The histopathological features of pulmonary graft versus host disease (GVHD) are not well described. Pulmonary GVHD may lead to bronchiolitis obliterans syndrome (BOS), which manifests pathologically as obliterative bronchiolitis (OB) and has a poor prognosis. We present a series of pulmonary GVHD that had not progressed to OB in order to facilitate early diagnosis and treatment.
Design: We retrospectively reviewed lung biopsies from patients with clinically suspected GVHD status post hematopoietic stem cell transplant (HSCT). Cases were retained for study if infections were excluded by culture, special stains, and immunohistochemistry and showed significant T-cell infiltrates with apoptosis in either the alveolar septa, bronchiolar mucosa, or both. Apoptosis, inflammation, and atypical reactive pneumocytes and bronchiolar epithelial cells were semiquantitated for each case. Alveolar changes were classified as acute lung injury (intra-alveolar fibrin); subacute lung injury (organizing pneumonia), or chronic interstitial pneumonia (CIP).
Results: There were 17 biopsies from 12 men (55 ± 3 years) and 5 women (54 ± 5 years) with 16 allogeneic and 1 autologous HSCT. Mean duration of transplant was 19 months (range 4-82 months). Ten patients had pathologic diagnosis of extrapulmonary GVHD. There was representative bronchiolar mucosa in 14 and alveolar parenchyma in 16 biopsies. Mean duration of transplant to time of biopsy was 6 months for patients with the acute lung injury pattern, 14 months for the subacute pattern, and 33 months for CIP. Diagnostic changes of OB were not identified in any specimens. Lymphocytic vasculitis was present in 11 biopsies. Intraepithelial bronchiolar T-cells averaged 54 ± 11 in acute and subacute alveolar injury, and 55 ± 14 in CIP. Reactive pneumocytes were present in 10 biopsies, with marked atypia in 2. Reactive bronchiolar cells showed mild atypia in 5, and marked atypia in 1, which mimics viral cytopathic effect. Alveolar eosinophils were present in 7 of 9 acute and subacute lung injury pattern, and 2 of 7 CIP. Eosinophils were present in 7 bronchiolar epithelium and prominent in 3.
Conclusions: GVHD is characterized by inflammation and apoptosis of both alveolar and bronchiolar mucosal compartments. In the former, may be associated with acute or subacute lung injury. Vasculitis is a common and helpful diagnostic feature. Recognition of patterns is essential for early diagnosis and prevention of OB.
Wednesday, March 21, 2012 9:30 AM
Poster Session V # 305, Wednesday Morning