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Objectives: Hematopoietic stem cell transplant (HSCT) is the replacement of the patient's bone marrow with hematopoietic stem or progenitor cells, in order to restore immune-hematopoietic function. Pulmonary complications can occur in up to a third of hematopoietic stem cell recipients, and can lead to significant morbimortality. Usually between 20 and 42 days after the transplantation, there's a chance of occuring Idiopathic Pneumonia Syndrome, that is a noninfectious lung injury. Patients affected by this condition, in order to fit diagnosis, need to present pneumonia's symptomatology, absence of lower respiratory tract infection, or of an etiology related to cardiac dysfunction, acute renal failure, or iatrogenic fluid overload. The mortality of IPS ranges between 60-86%, which indicates that the syndrome has a poor prognosis.The objective of this review was to summarize the literature findings describing the development of Idiopathic Pneumonia Syndrome after a hematopoietic stem cell transplantation. Material and methods: The following study consists of a literature review constructed based on the comprehensive search of articles from the past 5 years in PubMed, Scielo and Embase databases. Using the keywords “Idiopathic Pneumonia Syndrome”, “Pulmonary Complications”and “Hematopoietic Stem Cell Transplantation”, combined by boolean operator “AND”, we were able to find 5 articles that fit the objective of this review. Results: Patients subjected to HSCT have an incidence of developing IPS that varies from 4% to 12%. There is a higher risk of acquiring this syndrome for patients with acute graft-versus-host disease (GvHD), and for individuals who have received intense myeloablative conditioning with high-dose total body irradiation (TBI). Advanced patient age is also a relevant risk factor for IPS. Chest computed tomography is an essential scanning tool for patients with IPS, and bilateral multilobar opacities are the predominant findings. The incidence of IPS cases that are non-responsive to corticosteroids reaches up to 85%, progressing to respiratory failure, with 90% requiring mechanical ventilation. Higher doses of TBI have major effects on the lungs, including damages to lung endothelial DNA, culminating in the death of alveolar macrophage colony-forming cells, and reducing the lung's damage repair capacity. The use of nonmyeloablative conditioning and better GvHD management suggests a possible decrease in the incidence of IPS, as long as there are continuous advances in the technique and in the knowledge associated with HSCT. Discussion: Idiopathic pneumonia syndrome (IPS) remains a significant concern for patients undergoing hematopoietic stem cell transplantation (HSCT).Although IPS tends to occur shortly after the HSCT, some studies have reported cases initiating after 3 months, which indicates the need for continuous monitoring of patients, due to the damaging nature of the disease and of its treatment's adverse effects. The damage related to the use of TBI highlights the need for the development of alternative approaches, which is also supported by the high incidence of corticosteroid resistance, which tends to lead to lung failure. Conclusions: The findings of the present review indicate the need for physicians who care for HSCT patients to remain vigilant to the possibility of IPS, in order to provide an early diagnosis and, by extension, a more favorable prognosis. |
