Transfusion related acute lung injury
Encyclopedia
Medicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....
, transfusion related acute lung injury (TRALI) is a serious blood transfusion
Blood transfusion
Blood transfusion is the process of receiving blood products into one's circulation intravenously. Transfusions are used in a variety of medical conditions to replace lost components of the blood...
complication
Complication (medicine)
Complication, in medicine, is an unfavorable evolution of a disease, a health condition or a medical treatment. The disease can become worse in its severity or show a higher number of signs, symptoms or new pathological changes, become widespread throughout the body or affect other organ systems. A...
characterized by the acute onset of non-cardiogenic pulmonary edema
Pulmonary edema
Pulmonary edema , or oedema , is fluid accumulation in the air spaces and parenchyma of the lungs. It leads to impaired gas exchange and may cause respiratory failure...
following transfusion of blood products.
TRALI is the leading cause (around 50% of cases) of transfusion-related fatalities in the United States.
Definition
TRALI is defined as an acute lung injuryAcute lung injury
Acute lung injury is a diffuse heterogeneous lung injury characterized by hypoxemia, non cardiogenic pulmonary edema, low lung compliance and widespread capillary leakage...
that is temporally related to a blood transfusion; specifically, it must occur within the first six hours following a transfusion.
It is typically associated with plasma components such as platelets and Fresh Frozen Plasma
Fresh frozen plasma
The term fresh frozen plasma refers to the liquid portion of human blood that has been frozen and preserved after a blood donation and will be used for blood transfusion...
, though cases have been reported with packed red blood cells
Packed red blood cells
In transfusion medicine, packed red blood cells are red blood cells that have been separated from whole blood for transfusion purposes. The product is typically abbreviated RBC or PRBC, and sometimes LRBC for leukoreduced products...
since there is some residual plasma in the packed cells. The blood component transfused is not part of the case definition.
Etiology and Risk Factors
The etiology of TRALI is currently not fully understood. TRALI is thought to be immuneImmune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
mediated. Antibodies directed toward Human Leukocyte Antigens (HLA) or Human Neutrophil Antigens (HNA) have been implicated. Women who are multiparous (have had more than one child) develop these antibodies through exposure to fetal blood; transfusion of blood components obtained from these donors is thought to carry a higher risk of inducing immune-mediated TRALI. Previous transfusion or transplantation can also lead to donor sensitization. To be at risk of TRALI via this mechanism, the blood recipient must express the specific HLA or neutrophil receptors to which the implicated donor has formed antibodies. A two-hit hypothesis has been suggested wherein pre-existing pulmonary pathology (ie, the first-hit) leads to localization of neutrophils to the pulmonary microvasculature. The second hit occurs when the aforementioned antibodies are transfused and attach to and activate neutrophils, leading to release of cytokines and vasoactive substances that induce non-cardiac pulmonary edema.
A non-immune mechanism has been studied and proposed by Silliman, involving the accumulation of bioactive lipids in stored blood components (red cells, platelets, plasma) that possess neutrophil priming capabilities.
TRALI is typically associated with plasma products such as FFP
Fresh frozen plasma
The term fresh frozen plasma refers to the liquid portion of human blood that has been frozen and preserved after a blood donation and will be used for blood transfusion...
, but can also occur in recipients of packed red blood cells
Packed red blood cells
In transfusion medicine, packed red blood cells are red blood cells that have been separated from whole blood for transfusion purposes. The product is typically abbreviated RBC or PRBC, and sometimes LRBC for leukoreduced products...
due to the residual plasma present in the unit. The AABB
AABB
The AABB is a United States-based professional body and standards organization that was founded in 1947 as the American Association of Blood Banks. The organization is now international with members in 80 countries and has taken on a broader scope to include all of transfusion medicine as well as...
(formerly the American Association of Blood Banks) recommended on 11/03/2006 in association bulletin 06-07 that blood banks use high plasma volume components from female donors for further manufacturing instead of transfusion due to the higher risk of TRALI.
Mortality & morbidity
The immune mediated form of TRALI occurs approximately once every 5000 transfusions and has a mortality of 6-9%.Treatment
Treatment for TRALI is primarily supportive measures. Many patients with TRALI need mechanical ventilationMechanical ventilation
In medicine, mechanical ventilation is a method to mechanically assist or replace spontaneous breathing. This may involve a machine called a ventilator or the breathing may be assisted by a physician, respiratory therapist or other suitable person compressing a bag or set of bellows...
. TRALI is associated with microvascular damage and not fluid overload, so diuretics are not recommended. There are tests that can be performed on apheresis platelet donors after donation but before transfusion to determine if the donor contains HLA antibodies thought to be involved with development of this complicaton.
External links
- Transfusion Related Acute Lung Injury - US Food and Drug AdministrationFood and Drug AdministrationThe Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...
(FDA). - Neutrophil Antigens and Antibodies - American Society of Histocompatibility and Immunogenetics.
- TRALI (ABBA)