Hypotensive transfusion reaction
Encyclopedia
A Hypotensive transfusion reaction or HTR is a rare condition that presents with hypotension
associated with administration of blood product
s. The hypotension quickly resolves when the transfusion
is stopped.
HTRs are caused by the production of bradykinin
produced through Factor XII activation by negatively charged surfaces such as filters. When mechanisms for the degradation of bradykinin are impaired, the peptide
builds up and causes hypotension. Angiotensin converting enzyme or ACE is primarily responsible for its degradation (75%) but can be inhibited by administration of blood pressure
medications called ACE inhibitor
s. Polymorphisms
in ACE or aminopeptidase P (APP), another enzyme responsible for bradykinin degradation (20%) may also contribute to HTRs.
Hypotension
In physiology and medicine, hypotension is abnormally low blood pressure, especially in the arteries of the systemic circulation. It is best understood as a physiologic state, rather than a disease. It is often associated with shock, though not necessarily indicative of it. Hypotension is the...
associated with administration of blood product
Blood product
A blood product is any component of the blood which is collected from a donor for use in a blood transfusion. Whole blood is uncommonly used in transfusion medicine at present; most blood products consist of specific processed components such as red blood cells, blood plasma, or platelets.-Relation...
s. The hypotension quickly resolves when the 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...
is stopped.
HTRs are caused by the production of bradykinin
Bradykinin
Bradykinin is a peptide that causes blood vessels to dilate , and therefore causes blood pressure to lower. A class of drugs called ACE inhibitors, which are used to lower blood pressure, increase bradykinin further lowering blood pressure...
produced through Factor XII activation by negatively charged surfaces such as filters. When mechanisms for the degradation of bradykinin are impaired, the peptide
Peptide
Peptides are short polymers of amino acid monomers linked by peptide bonds. They are distinguished from proteins on the basis of size, typically containing less than 50 monomer units. The shortest peptides are dipeptides, consisting of two amino acids joined by a single peptide bond...
builds up and causes hypotension. Angiotensin converting enzyme or ACE is primarily responsible for its degradation (75%) but can be inhibited by administration of blood pressure
Blood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
medications called ACE inhibitor
ACE inhibitor
ACE inhibitors or angiotensin-converting enzyme inhibitors are a group of drugs used primarily for the treatment of hypertension and congestive heart failure...
s. Polymorphisms
Polymorphism (biology)
Polymorphism in biology occurs when two or more clearly different phenotypes exist in the same population of a species — in other words, the occurrence of more than one form or morph...
in ACE or aminopeptidase P (APP), another enzyme responsible for bradykinin degradation (20%) may also contribute to HTRs.