https://orcid.org/0000-0002-2331-3961
Organizing pneumonia (OP) is a known non-infectious pulmonary complication following allogeneic hematopoietic cell transplant (HCT) and represents a significant risk factor for non-relapse mortality in HCT recipients. Unlike bronchiolitis obliterans syndrome, it is not universally acknowledged as a distinctive pulmonary manifestation of chronic-graft-versus-host disease (cGVHD) and therefore, its diagnostic criteria and management approach is lacking. Given it shared similar clinical features, radiological and histological findings to OP in non-HCT population, the diagnostic approach and treatment strategy for OP in HCT recipient is largely adapted from the non-HCT population. In this paper, we aim to enhance the understanding of OP within the context of cGVHD following HCT, distinguish its clinical features and treatment strategy from non-HCT counterpart, thereby reinforcing its recognition as a pulmonary manifestation of GVHD. We will propose the diagnostic criteria and outline our approach in diagnosis and treatment strategy, highlighting the potential challenges that may arise in each process. Finally, we will discuss knowledge gaps in this field and identify the area of need for future research.
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Review Article|
June 12, 2024
How I diagnose and treat organizing pneumonia in hematopoietic cell transplant recipients
Husham Sharifi
Husham Sharifi
Stanford University School of Medicine, Stanford, California, United States
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Joe L Hsu
Stanford University School of Medicine, Palo Alto, California, United States
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Blood blood.2023023249.
Article history
Submitted:
February 2, 2024
Revision Received:
May 7, 2024
Accepted:
May 27, 2024
Comments
Reply to: How I diagnose and treat organizing pneumonia in hematopoietic cell transplant recipients
Pulmonary complications after HCT persist in up to 30–60% of HCT recipients despite improvements in supportive care and remain fatal. Among non-infectious complications, idiopathic pneumonia syndrome (IPS), diffuse alveolar haemorrhage (DAH), peri-engraftment respiratory distress syndrome, nonspecific interstitial pneumonia (NSIP), lymphoid interstitial pneumonia (LIP), and OP2 can occur. These conditions can inherently exhibit clinical features like both infectious and other non-infectious conditions, often requiring a lung biopsy for definitive diagnosis3, so doing to avoid improper therapy.
We believe it is important to emphasize that, particularly in atypical presentation cases where the clinical, radiological findings do not allow for a highly confident diagnosis of OP, lung biopsy should be included in the diagnostic workup. In fact, in these specific cases, prolonged corticosteroid therapy or immunosuppression therapy may be more harmful for the patient than undergoing a lung biopsy.
Transbronchial lung cryobiopsy (TBLC) has recently been recognized as a valid and less invasive alternative to SLB for diagnosing interstitial lung diseases (ILDs). TBLC allows for the collection of larger and higher-quality lung tissue samples without the crush artifacts typically associated with conventional transbronchial lung biopsy performed with flexible forceps4.
Moreover, recent randomized clinical trials have demonstrated an acceptable safety profile for TBLC when performed even in intensive care unit settings, both in terms of haemorrhage and pneumothorax, particularly when conducted by experienced pulmonologists5.
References
1. Cherian SV, Patel D, Machnicki S, et al. Algorithmic Approach to the Diagnosis of Organizing Pneumonia: A Correlation of Clinical, Radiologic, and Pathologic Features. Chest. 2022 Jul;162(1):156-178. doi: 10.1016/j.chest.2021.12.659.
2. Bondeelle L, Bergeron A. Managing pulmonary complications in allogeneic hematopoietic stem cell transplantation. Expert Rev Respir Med. 2019;13(1):105-119. doi:10.1080/17476348.2019.1557049
3. Patel SS, Ahn KW, Khanal M, et al. Noninfectious Pulmonary Toxicity after Allogeneic Hematopoietic Cell Transplantation. Transplantation and Cellular Therapy, Official Publication of the American Society for Transplantation and Cellular Therapy. 2022;28(6):310-320. doi:10.1016/j.jtct.2022.03.015
4. Ravaglia C, Poletti V. Transbronchial lung cryobiopsy for the diagnosis of interstitial lung diseases. Curr Opin Pulm Med. 2022;28(1):9-16. doi:10.1097/MCP.0000000000000848
5. Loor K, Culebras M, Sansano I, et al. Lung allograft transbronchial cryobiopsy for critical ventilated patients: a randomised trial. European Respiratory Journal. 2023;61(1). doi:10.1183/13993003.02354-2021