Diagnosis: Acute Hemolytic Transfusion Reaction

Pathogenesis:

Type II hypersensitivity reaction. Intravascular hemolysis (ABO blood group incompatibility) or extravascular hemolysis (host antibody reaction against foreign antigen on donor RBCs).

Presentation:

Fever, hypotension, tachypnea, tachycardia, flank pain, hemoglobinuria (intravascular hemolysis), jaundice (extravascular). Within 1 hour.

This is acute hemolytic transfusion reaction, I believe. Type II HSR so she’s forming antibodies against the ABO groups on the blood cells. Complement is induced by antibodies.

acute hemolytic transfusion reaction (AHTR), also called immediate hemolytic transfusion reaction, is a life-threatening reaction to receiving a blood transfusion. AHTRs occur within 24 hours of the transfusion and can be triggered by a few milliliters of blood. The reaction is triggered by pre-formed host antibodies destroying donor red blood cells. AHTR typically occurs when there is an ABO blood group incompatibility, and is most severe when type A donor blood is given to a type O recipient.Antibodies against A and B blood groups (isohemagglutinins) present in the recipient's blood destroy the donor red blood cells.They also activate the coagulation cascade (blood clotting system) via factor XII, which can lead to disseminated intravascular coagulation and kidney damage. Isohemagglutinins also activate the complement cascade via C3a and C5a, which then promote inflammatory cytokine release from white blood cells. These inflammatory cytokines include IL-1, IL-6, IL-8, and TNF-alpha, which cause symptoms of low blood pressure, fever, chest pain, nausea, vomiting, and wheezing