Bronchiolitis obliterans after allogeneic hematopoietic stem cell transplantation

Abstract

With improvements in supportive care, both long-term survival following allogeneic hematopoietic stem cell transplantations (HSCTs) and the indications for this procedure have increased. As a result, the number of patients living with long-term toxic effects due to HSCT has increased. A once rare condition of the donor immune cells attacking healthy host tissues, termed chronic graft-vs-host disease, has become a more common phenomenon. When chronic graft-vs-host disease affects the lung tissue, bronchiolitis obliterans syndrome ensues. Recent data suggest that bronchiolitis obliterans syndrome may affect up to 6% of HSCT recipients and dramatically alters survival, with overall survival of only 13% at 5 years. These statistics have not improved since the first presentation of this disease over 20 years ago. Challenges to the progress of medical management of bronchiolitis obliterans syndrome include difficulties and delays in diagnosis and a paucity of data on pathogenesis to direct new therapies. This article critically evaluates the current diagnostic criteria for bronchiolitis obliterans syndrome and reviews the epidemiology, pathogenesis, and available treatments. Improvements in survival will likely require early disease recognition, allowing for therapeutic modulation of disease prior to the development of irreversible airway obliteration.

Figures

Figure 1.. Pulmonary Function Test of FEV1 Over Time After Hematopoietic Stem Cell Transplantation

FEV1 indicates forced expiratory volume in the first second of expiration.

Figure 2.. Biopsy of Case Patienťs Lung Tissue

A, Obliteration of bronchiolar lumen (hematoxylin-eosin, original magnification ×400). B, Inflammation between the epithelium and the smooth muscle (hematoxylin-eosin, original magnification ×400).

Figure 3.. Hypothetical Spirogram and Flow Volume Curves for Bronchiolitis Obliterans Syndrome

The pulmonary function test pattern shown for patients with scleroderma and obstructive lung disease has been observed in patients with sclerotic graft-vs-host disease. FEV1 indicates forced expiratory volume in the first second of expiration; FVC, forced vital capacity; RV, residual volume; SVC, slow vital capacity; TLC, total lung capacity.

Figure 4.. Chest Computed Tomography Scans for Bronchiolitis Obliterans (BO) Syndrome

A, Arrowheads indicate areas of air trapping. B, Dark areas show large areas of air trapping. Image contrast in panel A has been increased to accentuate areas of air trapping. FEV1 indicates forced expiratory volume in the first second of expiration.