Characteristics and Outcome of Periengraftment Respiratory Distress Syndrome after Autologous Hematopoietic Cell Transplant

Pulmonary complications of bone marrow transplantation

Bone marrow transplantation, now often known as haematopoietic stem cell transplantation (HSCT), is a complex choreographed procedure used to treat both acquired and inherited disorders of the bone marrow. It has proven invaluable as therapy for haematological and immunological disorders, and more recently in the treatment of metabolic and enzyme disorders. As the number of performed transplants grows annually, and with patients enjoying improved survival, a knowledge of both early and late complications of HSCT is essential for respiratory trainees and physicians in practice. This article highlights the spectrum of respiratory complications, both infectious and non-infectious, the timeline of their likely occurrence, and the approaches used for diagnosis and treatment, keeping in mind that more than one entity may occur simultaneously. As respiratory issues are often a leading cause of short- and long-term morbidity, consideration of a combined haematology/respiratory clinic may prove useful in this patient population.

Lung Injury Prediction Model in Bone Marrow Transplantation: A Multicenter Cohort Study

Rationale: Pulmonary complications contribute significantly to nonrelapse mortality following hematopoietic stem cell transplantation (HCT). Identifying patients at high risk can help enroll such patients into clinical studies to better understand, prevent, and treat posttransplantation respiratory failure syndromes. Objectives: To develop and validate a prediction model to identify those at increased risk of acute respiratory failure after HCT. Methods: Patients underwent HCT between January 1, 2019, and December 31, 2021, at one of three institutions. Those treated in Rochester, MN, formed the derivation cohort, and those treated in Scottsdale, AZ, or Jacksonville, FL, formed the validation cohort. The primary outcome was the development of acute respiratory distress syndrome (ARDS), with secondary outcomes including the need for invasive mechanical ventilation (IMV) and/or noninvasive ventilation (NIV). Predictors were based on prior case-control studies. Measurements and Main Results: Of 2,450 patients undergoing stem cell transplantation, there were 1,718 hospitalizations (888 patients) in the training cohort and 1,005 hospitalizations (470 patients) in the test cohort. A 22-point model was developed, with 11 points from prehospital predictors and 11 points from posttransplantation or early (<24-h) in-hospital predictors. The model performed well in predicting ARDS (C-statistic, 0.905; 95% confidence interval [CI], 0.870-0.941) and the need for IMV and/or NIV (C-statistic, 0.863; 95% CI, 0.828-0.898). The test cohort differed markedly in demographic, medical, and hematologic characteristics. The model also performed well in this setting in predicting ARDS (C-statistic, 0.841; 95% CI, 0.782-0.900) and the need for IMV and/or NIV (C-statistic, 0.872; 95% CI, 0.831-0.914). Conclusions: A novel prediction model incorporating data elements from the pretransplantation, posttransplantation, and early in-hospital domains can reliably predict the development of post-HCT acute respiratory failure.

What Is Different in Acute Hematologic Malignancy-Associated ARDS? An Overview of the Literature

Background and Objectives: Acute hematologic malignancies are a group of heterogeneous blood diseases with a high mortality rate, mostly due to acute respiratory failure (ARF). Acute respiratory distress syndrome (ARDS) is one form of ARF which represents a challenging clinical condition. The paper aims to review current knowledge regarding the variable pathogenic mechanisms, as well as therapeutic options for ARDS in acute hematologic malignancy patients. Data collection: We provide an overview of ARDS in patients with acute hematologic malignancy, from an etiologic perspective. We searched databases such as PubMed or Google Scholar, including articles published until June 2022, using the following keywords: ARDS in hematologic malignancy, pneumonia in hematologic malignancy, drug-induced ARDS, leukostasis, pulmonary leukemic infiltration, pulmonary lysis syndrome, engraftment syndrome, diffuse alveolar hemorrhage, TRALI in hematologic malignancy, hematopoietic stem cell transplant ARDS, radiation pneumonitis. We included relevant research articles, case reports, and reviews published in the last 18 years. Results: The main causes of ARDS in acute hematologic malignancy are: pneumonia-associated ARDS, leukostasis, leukemic infiltration of the lung, pulmonary lysis syndrome, drug-induced ARDS, radiotherapy-induced ARDS, diffuse alveolar hemorrhage, peri-engraftment respiratory distress syndrome, hematopoietic stem cell transplantation-related ARDS, transfusion-related acute lung injury. Conclusions: The short-term prognosis of ARDS in acute hematologic malignancy relies on prompt diagnosis and treatment. Due to its etiological heterogeneity, precision-based strategies should be used to improve overall survival. Future studies should focus on identifying the relevance of such etiologic-based diagnostic strategies in ARDS secondary to acute hematologic malignancy.

Noninfectious complications of hematopoietic cell transplantation

Noninfectious lung diseases contribute to nonrelapse mortality. They constitute a spectrum of diseases that can affect the parenchyma, airways, or vascular pulmonary components and specifically exclude cardiac and renal causes. The differential diagnoses of these entities differ as a function of time after hematopoietic cell transplantation. Specific diagnosis, prognosis, and optimal treatment remain challenging, although progress has been made in recent decades.