From the Guidelines
Yes, there are pulmonary manifestations of graft versus host disease (GVHD), with bronchiolitis obliterans syndrome (BOS) being a common chronic pulmonary complication. GVHD can affect the lungs in both acute and chronic forms, with the latter being more common. In acute pulmonary GVHD, patients may develop idiopathic pneumonia syndrome within the first 100 days after transplantation, characterized by diffuse alveolar damage, interstitial pneumonitis, and respiratory failure. Chronic pulmonary GVHD typically presents as BOS, which involves fibrotic narrowing of the small airways leading to progressive airflow obstruction.
Key Features of BOS
- Relative decline of FEV1 percent predicted, compared to pre-HSCT baseline, by 15% which persists on two tests at least 2 wk apart
- Supporting features, such as FEV 1/VC below lower limit of normal, evidence of air trapping on expiratory CT, or evidence of air trapping on plethysmography 1
- Clinical symptoms, such as wheeze, shortness of breath with activity, in children who cannot perform spirometry 1 Patients with pulmonary GVHD often experience dyspnea, dry cough, wheezing, and declining lung function tests showing an obstructive pattern.
Treatment of Pulmonary GVHD
- Systemic corticosteroids, such as prednisone 1-2 mg/kg/day initially, then tapered 1
- Calcineurin inhibitors, like tacrolimus or cyclosporine
- Additional immunosuppressants, such as mycophenolate mofetil or sirolimus
- Inhaled corticosteroids, bronchodilators, and macrolide antibiotics, like azithromycin (250-500 mg three times weekly), for their anti-inflammatory properties 1 Early recognition is crucial as pulmonary GVHD can significantly impact quality of life and survival, with lung function monitoring through pulmonary function tests being an essential component of post-transplant care. According to the most recent guidelines, the diagnosis of BOS should be based on a combination of clinical symptoms, pulmonary function tests, and imaging studies, as outlined in the American Journal of Respiratory and Critical Care Medicine 1.
From the Research
Pulmonary Manifestations of Graft-Versus-Host Disease (GVHD)
The pulmonary manifestations of GVHD can be severe and life-threatening. Some of the key pulmonary manifestations include:
- Bronchiolitis obliterans syndrome (BOS), which is considered the only diagnostic manifestation of pulmonary GVHD 2, 3
- Bronchiolitis obliterans organizing pneumonia (BOOP) 4
- Diffuse alveolar damage 5
- Lymphocytic interstitial pneumonia 5
- Non-specific interstitial pneumonia (NSIP) 5
- Lymphocytic bronchiolitis/bronchitis 5
Incidence and Prevalence
The incidence of BOS after allogeneic hematopoietic stem cell transplantation (HSCT) is estimated to be around 2-3% 3. However, the true incidence may be higher due to the lack of uniform diagnostic criteria and the inability to detect the syndrome at a reversible stage.
Diagnosis and Treatment
Diagnosing pulmonary GVHD can be challenging due to the non-specific symptoms and the complexity of the disease pathophysiology 2, 3. Treatment options include immunosuppressive agents, such as prednisone, cyclosporin-A, and mycophenolate mofetil, as well as extracorporeal photopheresis (ECP) 4. Early treatment is crucial to reduce disease morbidity and mortality 2.