From the Guidelines
Pulmonary manifestations of bone marrow transplant present in several distinct patterns based on timing after transplantation, with early complications including pulmonary edema and infections, intermediate complications including cytomegalovirus pneumonia, and late complications including bronchiolitis obliterans syndrome and cryptogenic organizing pneumonia. The timing of these complications can be broken down into:
- Early phase (within 30 days): patients commonly develop pulmonary edema, diffuse alveolar hemorrhage, and infections (bacterial, fungal, and viral) 1.
- Intermediate phase (30-100 days): cytomegalovirus pneumonia and Pneumocystis jirovecii pneumonia are prevalent, presenting with progressive dyspnea, dry cough, and fever 1.
- Late complications (beyond 100 days): include bronchiolitis obliterans syndrome, characterized by progressive airflow obstruction, and cryptogenic organizing pneumonia, presenting with cough, dyspnea, and patchy consolidations 1. Some key points to consider in the management of these complications include:
- Regular pulmonary function testing and chest imaging are essential for early detection of these complications in transplant recipients 1.
- Management depends on the specific complication but often includes antimicrobials for infections, corticosteroids for inflammatory conditions, and supportive care 1.
- Idiopathic pneumonia syndrome may occur at any time, manifesting as diffuse lung injury without identifiable infection, and pulmonary veno-occlusive disease presents with progressive dyspnea and pulmonary hypertension 1. However, the most recent and highest quality study 1 suggests that bronchiolitis obliterans syndrome is a major concern in pediatric hematopoietic stem cell transplantation, and that early detection and management are crucial to prevent long-term pulmonary complications.
From the Research
Pulmonary Manifestations of Bone Marrow Transplant
Pulmonary complications occur in 40% to 60% of recipients of bone marrow transplants, accounting for more than 90% of mortality 2. These complications can be categorized into three phases:
- Phase 1 (Days 1-30): characterized by pulmonary edema, diffuse alveolar hemorrhage, and various bacterial, fungal, and viral infections 2
- Phase 2 (Days 31-100): typically involves distinguishing between cytomegalovirus pneumonitis and idiopathic pneumonia syndrome 2
- Phase 3 (Day 100+): includes complications due to chronic graft-versus-host disease and associated bronchiolitis obliterans 2
Causes of Respiratory Distress
Respiratory distress is a common complication in children who receive bone marrow transplants, with up to 60% of patients developing this condition 3. The causes of respiratory distress can be related to:
- Infections, such as bacterial, fungal, and viral infections 2, 3
- Non-infectious causes, such as pulmonary edema, diffuse alveolar hemorrhage, and drug reactions 2, 4
Diagnosis and Treatment
Diagnosing pulmonary complications in bone marrow transplant recipients can be challenging due to the non-specific nature of high-resolution CT findings 4. However, considering the time elapsed after bone marrow transplantation can help narrow down diagnostic options 4. Treatment approaches vary depending on the specific complication and may involve antimicrobial therapy, supportive care, and other interventions 2, 5
Risk Factors for Respiratory Failure
Several risk factors have been identified for respiratory failure after nonmyeloablative related haploidentical blood or marrow transplantation, including: