]> 2026-07-31T07:51:16+00:00 WBR0322 0 en Formation of IgG and IgA immune complexes that activate the complement pathway and release C3a and C5a Anaphylactic reaction, usually occurring in patients with IgA deficiency, is caused by formation of immune complexes that activate anaphylaxins, such as C3a and C5a. Patients typically present with features characteristic of anaphylaxis, such as hypotension and shock. Reaction caused primarily by the accumulation of cytokines in the platelet products during storage See explanation. Hypersensitivity reaction against foreign antigens on donor red blood cells Acute and delayed hemolytic transfusion reactions, resulting from hypersensitivity reactions against foreign antigens on donor red blood cells, manifest in jaundice, flank pain, and hemoglobinuria. Production of IgE by plasma cells following antigen exposure Following antigen exposure, allergic reaction may result from IgE production by plasma cells. The allergic reaction typically manifest with urticaria, pruritis, and wheezing. Non-immune circulatory overload due to rapidly incoming transfused blood Transfusion-associated circulatory overload (TACO) results from the rapid transfusion of blood products. TACO is a non-immune condition, which typically causes high blood pressure, peripheral edema, dyspnea, and orthopnea. Immunology A 67-year-old man presents to the physician's office with complaints of weight loss, fever, and night sweats. Following appropriate work-up,you diagnose him with acute myelogenous leukemia (AML) and start him on scheduled chemotherapy sessions. Three weeks into the treatment, you detect that patient is profoundly thrombocytopenic and requires a platelet transfusion. During the transfusion, the patient develops fever, chills, and intense flushing, but denies any itching or shortness of breath. On physical exam, you find that the patient has a temperature of 38.5 °C (101.3 °F) , heart rate of 108 bpm, respiratory rate of 18/min, and blood pressure of 128/78 mmHg. What is the most likely cause of this patient's reaction to the platelet transfusion? B Hematology 2020-10-28T00:11:07Z 2459150.5077199 WBR0322