The clinical picture varies with the underlying TR.

While acute hemolytic TR are often characterized by fever and chills, flushing, hypotension, in severe cases dyspnea and hemoglobinuria, an allergic TR manifests without fever. In patients suffering from hypersensitivity, the most striking signs are urticaria and pruritus; flushing, hypotension, dyspnea and anxiety may be detected and may indicate imminent anaphylaxis and bronchospasm.

Febrile non-hemolytic TR are associated with fever and generally no other symptoms. However, chills, hypotension and vomiting have been occasionally observed.

TRALI symptoms are dyspnea, rales, hypoxemia, tachycardia and fever. Onset is fast; patients do not present any symptoms indicating cardiac insufficiency to account for pulmonary edema.

It is important to note that patients receiving blood transfusions are sometimes in poor overall condition and may present different comorbidities. Thus, a rapid deterioration of the patient's health may not necessarily be triggered by the current or past transfusion. This may merely be a coincidence, although it may not be a very likely one. Health care givers should consider this possibility when trying to identify the source of the problem.

• Fever

  Classic SX: abrupt onset of acute flank pain, bright red urine, fever, and often a patient's complaint that "something is wrong." Fever (body temperature elevation of greater than 1°C above normal) and chills are commonly seen. [enotes.tripod.com]

  While acute hemolytic TR are often characterized by fever and chills, flushing, hypotension, in severe cases dyspnea and hemoglobinuria, an allergic TR manifests without fever. [symptoma.com]

  Delayed hemolytic transfusion reaction should be suspected if a patient develops fever, falling hematocrit, and/or hyperbilirubinemia approximately 3 to 7 days following a blood transfusion. [bloodworksnw.org]

  Abstract We report on the case of a woman who suffered from chills and fever when she was transfused with two units of red blood cell concentrate. [ncbi.nlm.nih.gov]

  However, if you develop any complaints, such as a fever, dizziness, shortness of breath, or mild back pain, notify health staff immediately, as this could indicate a transfusion reaction. [healthline.com]

• Chills

  Abstract We report on the case of a woman who suffered from chills and fever when she was transfused with two units of red blood cell concentrate. [ncbi.nlm.nih.gov]

  Fever (body temperature elevation of greater than 1°C above normal) and chills are commonly seen. [enotes.tripod.com]

  Healthcare providers will stop the transfusion if you have any of the following: A strong feeling of dread or that something is wrong Fainting or breathing problems Fever and chills Itching, hives, or swelling Pain or burning in your abdomen, chest, or [drugs.com]

  While receiving the transfusion, she develops fever, chills, back pain, pain at the site of transfusion, and tachycardia. [polldaddy poll=8109900] Question 2 A 28-year-old man presents with a 1-day history of rectal bleeding. [foamcast.org]

• Falling

  This was accompanied by the appearance of bilirubin and urobilinogen in his urine and a fall in haemoglobin of nearly 2 g dL(-1) following the transfusion. Anti-Wr(a) was the only antibody implicated. [ncbi.nlm.nih.gov]

  Delayed hemolytic transfusion reaction should be suspected if a patient develops fever, falling hematocrit, and/or hyperbilirubinemia approximately 3 to 7 days following a blood transfusion. [bloodworksnw.org]

• Rigor

  We report an acute HTR due to anti-Wr(a) in a 58-year-old man with myelodysplastic syndrome associated with rigors, shortness of breath and a significant rise in serum bilirubin from 16 micromol L(-1) pretransfusion to 110 micromol L(-1) immediately afterwards [ncbi.nlm.nih.gov]

  The reaction will begin during the first few minutes of transfusion with the patient often complaining of feeling a sense of ‘impending doom’ as well as flushing, chills, rigors, dyspnea and abdominal pain. [ausmed.com]

  Signs Fever (rise of 1.5°C or more) and rigors. Hypotension or hypertension. Tachycardia. Respiratory distress. Oozing from wounds or puncture sites. Haemoglobinaemia. Haemoglobinuria. [patient.info]

  […] the investigation to be carried out in the laboratory including – Implicated Unit with attached giving set Repeat Group & X-match sample Blood Cultures on the patient if Temperature rise ≥ 1.5ºC above the baseline temperature together with chills or rigors [hse.ie]

  In case of non-antibody mediated AHR This does not require rigorous management. [en.wikipedia.org]

• Weakness

  The anti-A1 reacted in a wide temperature amplitude up to 37°C with A1 RBCs, while weak agglutination was observed with A2 RBCs at room temperature. [ncbi.nlm.nih.gov]

  Finally, patient 8, who had a weak D type 4, developed anti-D antibodies after receiving a single D+ unit. All previous transfusions in this patient were D-negative. [haematologica.org]

  New Test fort Detection of Weak and “Incomplete” Rh Agglutinins. Brit. J. Exper. Path. 26 : 255 (1945). Google Scholar 12. Gray, S. J., & Sterling, K. The Tagging of Red Cells and Plasma Proteins With Radio- active Chromium. J. Clin. [link.springer.com]

  Yep immunocompromised individuals are at risk If person has weak Immunity he is more prone to develop grafts immune response when transplanted tissues have high numbers of Tcells (bone marrow or liver) #12 BUMP So First Aid seems to be behind on this: [forums.studentdoctor.net]

• Hypotension

  Acute hypotensive transfusion reactions are newly characterized transfusion reactions in which hypotension is the prominent feature. [ncbi.nlm.nih.gov]

  Like anaphylactic reactions, acute hypotensive reactions happen quickly. One notable difference, however, is that most acute hypotensive reactions spontaneously resolve as soon as the transfusion is stopped. [captodayonline.com]

• Urticaria

  Urticaria with No Other Signs or Symptoms. The appearance of an itchy rash during component transfusion, frequently seen with transfusion of platelets or plasma, is a common occurrence. [enotes.tripod.com]

  Fever, chills and urticaria are the most common manifestations of transfusion reactions. [transfusion.com.au]

  While in most cases, generalized urticaria and pruritus are the main symptoms, allergic TR may rarely progress towards life-threatening anaphylaxis. [symptoma.com]

  Urticaria and erythema sometimes occur in dogs and cats. [medical-dictionary.thefreedictionary.com]

  The most common symptoms are chills, rigor, fever, dyspnea, light-headedness, urticaria, itching, and flank pain. [merckmanuals.com]

• Purpura

  — Post Transfusion Purpura — Purpura, Post-Transfusion — Posttransfusion Purpura — Posttransfusion Purpuras — Purpura, Posttransfusion [mesh.kib.ki.se]

  Delayed reactions occur days to weeks after the transfusion and include delayed haemolytic transfusion reactions, transfusion-associated graft-versus-host disease, and post-transfusion purpura. [bestpractice.bmj.com]

  Transfusion-associated graft-versus-host disease and post-transfusion purpura are rare phenomena. The former is almost exclusively observed in immunodeficient patients. [symptoma.com]

  […] reaction Alloimmunization Urticaria Platelet refractoriness TRALI = transfusion-related acute lung injury Immune modulation/suppression Acute hemolysis, Fatal acute hemolysis Delayed hemolysis Anaphylaxis Graft-versus-host disease, Post-transfusion purpura [enotes.tripod.com]

• Pruritus

  While in most cases, generalized urticaria and pruritus are the main symptoms, allergic TR may rarely progress towards life-threatening anaphylaxis. [symptoma.com]

  Allergic reactions Allergic reactions typically present as rash, urticaria, or pruritus and are indistinguishable on examination from most food or drug allergies. Allergic reactions are IgE mediated. [emedicine.medscape.com]

  Anaphylaxis Presentation/Background The incidence is estimated to be between 1/20,000-150,000 Similar in presentation to anaphylaxis from all other causes and usually occurs early on during the transfusion You know the signs and symptoms: urticaria, pruritus [nuemblog.com]

  Allergic reactions include hives, urticaria, pruritus, erythema, bronchospasm, and hypotension. Anaphylactic reactions may occur in IgA-deficient patients. [www3.mdanderson.org]

• Petechiae

  Physical exam revealed conjunctival petechiae, multiple petechiae on the bilateral fingertips and lower extremities, and an apical mid-systolic heart murmur. [path.upmc.edu]

• Withdrawn

  If febrile symptoms of moderate severity are sustained, implicated units should be returned to the laboratory for further investigation, the blood service contacted immediately so that associated components from the implicated donation can be withdrawn [patient.info]

• Dark Urine

  She complained of severe back pain and dark urine. In addition, she became hypertensive, tachycardic, and jaundiced. The DAT indicated the presence of IgG on the patient's RBCs. Anti-Fy3 was identified in the serum and eluate. [ncbi.nlm.nih.gov]

  Transfusion reaction symptoms include: back pain dark urine chills fainting or dizziness fever flank pain skin flushing shortness of breath itching In some instances, however, transfusion reactions take place days after the transfusion. [healthline.com]

  Abdominal distention, jaundice, dark urine, reticulocytosis. If reticulocytosis occurs, it suggests some other associated problem (for example, a deficiency in glucose-6 phosphate dehydrogenase [G6PD]). [pearsonitcertification.com]

  She is rushed to the operating room, and while she is being prepped for an exploratory laparotomy, she is found to have a temperature of 101.8°F and has dark urine draining from her Foley catheter. [intechopen.com]

  urine, uncontrolled bleeding due to DIC. [rch.org.au]

If possible, anamnestic data regarding previous transfusions and possible TR should be provided before starting to transfuse any blood products. In some cases, however, this might not be possible.

Hemolytic reactions may be recognizable by visual inspection of the patient's plasma and urine. Both are probably reddish. As has been mentioned above, if the mistake that lead to mistransfusion can be cleared up, it will be a lot easier to comprehend what is happening between recipient's and donor's blood components. If a simple confusion can be ruled out, Coombs testing may confirm incompatibility and both types of erythrocytes should be retyped [11]. If erythrocytes have indeed been typed wrong, other patients may be at risk of similar incidents. Of note, delayed hemolytic TR are also diagnosed by proving incompatibility, but fresh samples of the recipient's blood, i.e., after the delayed hemolytic TR has taken place, should be used for testing.

Allergic TR do neither cause hemolysis nor hemoglobinuria and this also applies to anaphylactic reactions. If a hemogram is established, eosinophil granulocyte counts are usually not elevated. As its name indicates, a febrile non-hemolytic reaction is not associated with hemolysis or hemoglobinuria either [12]. The clinical presentation is helpful to distinguish all these acute TR.

With regards to TRALI, symptoms should prompt a strong suspicion for this serious TR. Differentiation between TRALI and cardiogenic pulmonary edema may require further diagnostic measures. Serum brain natriuretic peptide levels may be useful to that end and will not be elevated in TRALI patients.

In general, transfusions should be stopped if a TR is suspected. The intravenous access should, however, be maintained to allow for fast responds.

The first therapeutic measure is to cease the transfusion. If necessary, subsequent transfusions should consist of blood products of other suitable donors. Ideally, transfusion therapy will not be continued until the cause of the TR is identified.

Fluid resuscitation with crystalloid solutions is indicated after diagnosing an acute hemolytic TR in order to prevent circulatory and renal failure. Forced diuresis may be a second option if fluid therapy is not sufficient to increase urine output. Adequate hydration is a prerequisite for diuresis. Renal failure may require dialysis. If hemolysis triggers considerable hypoxia, additional therapeutic measures such as respiratory support should be considered. Delayed hemolytic TR may be treated similarly, but are usually less severe and do seldom require extensive therapy.

While mild allergic TR are usually self-limiting, but antihistamine application is often recommended. Corticosteroids may provide additional benefit. Moderate cases of allergic TR may progress to anaphylaxis and urgent attention is needed by a patient suffering an anaphylactic reaction: Epinephrine should be administered immediately and may needed to be utilized repeatedly [13]. If intramuscular injections don't yield the desired response, the drug should be applied intravenously. Although bronchospasms may be resolved with bronchodilators, patients should be intubated for safety reasons. Patients may benefit from antihistamines and, in cases of prolonged anaphylaxis, from corticosteroids.

Febrile non-hemolytic TR are treated symptomatically with antipyretics, preferentially with paracetamol.

Respiratory support in any necessary form, i.e., additional oxygen supply or mechanical ventilation, if necessary, is provided to TRALI patients until symptoms subside spontaneously. Hemodynamic parameters should be monitored and circulation may possibly benefit from adequate support.

Several immunosuppressive treatments have been tried for transfusion-associated graft-versus-host disease, but none was found effective. Thus, only symptomatic treatment can be recommended.

High-dose immunoglobulin therapy has been found effective to treat post-transfusion purpura associated thrombocytopenia [14].

Prognosis varies considerably with the specific type of TR and its severity. In this context, most acute hemolytic TR, delayed hemolytic TR, most allergic TR, febrile non-hemolytic TR an post-transfusion purpura are generally associated with an very good prognosis. Many of such reactions are mild and self-limiting. However, if greater amounts of incompatible blood cause acute hemolytic TR or if an allergic TR progresses to anaphylaxis, they may be lethal [9]. TRALI is a potentially life-threatening TR with high mortality [6]. Transfusion-associated graft-versus-host disease is most often fatal [10].

Although in general, TR are adverse reactions of the patient's immune system towards transfused blood products, they may be triggered by a variety of incompatibilities. These may affect distinct cell types or other blood components, antigens and antibodies may be provided by donor and recipient or vice versa, and different organs may suffer from TR in the patient's body.

If erythrocytes of an AB0 incompatible donor are transfused, the recipient's IgM antibodies will mediate hemolysis of the transfused red blood cells. This acute hemolytic TR is the result of mistransfusion after unintended errors. If other, non-AB0 antigens on erythrocytes cause TR, particularly if the recipient's immune system only starts antibody production upon receiving the transfusion, hemolytic TR may occur as delayed reactions. Such is the case when Rhesus antigens are transferred to a recipient who is negative for this antigen.

Any potential allergen transfused with blood components may trigger an acute allergic TR, a hypersensitivity reaction.
Other types of acute TR are transfusion-related acute lung injury (TRALI) and acute febrile non-hemolytic TR. The former is presumably mediated by activated neutrophil granulocytes that subsequently trigger severe damage to the endothelium of pulmonary vessels and life-threatening pulmonary edema. With regards to acute febrile non-hemolytic TR, the etiology of this reaction is not yet understood.

Immunodeficient patients are particularly susceptible to transfusion-associated graft-versus-host disease, a type of delayed TR. Here, transfused lymphocytes initiate an immune reaction against the recipient's tissue. Such events are prevented by the recipient's immune system in immunocompetent patients.

Post-transfusion purpura is another type of delayed TR and is associated with thrombocytopenia. Possibly, in this case, cross reactive antibodies produced against transfused antigens mediate lysis of the recipient's thrombocytes.

The overall incidence of TR has significantly decreased since leukoreduction has been adopted as a standard safety procedure.

Acute hemolytic TR, usually the result of confusion and subsequent transfusion of the "wrong" blood bag, has been repeatedly estimated to happen once or twice per 10,000 transfusions [3]. These accidents may be lethal in approximately 2% of such cases. Delayed hemolytic TR are observed in about 4 per 10,000 transfusions.

Allergic TR range among the most frequent TR and are reported for up to 30 per 10,000 transfusions [4]. Anaphylactic reactions account for about 1% of these cases.

Febrile non-hemolytic TR occurs more frequently than acute hemolytic TR, but less often than allergic TR. Incidence rates have been estimated to up to 19 per 10,000 red blood cell transfusions and up to 15 per 10,000 platelet transfusions. Interestingly, numbers available for transfusions carried out without prior leukoreduction show that incidence rates for febrile non-hemolytic TR were 2-fold and 14-fold increased for erythrocytes and thrombocytes, respectively [5].

The incidence of TRALI has been estimated to be about 10 per 10,000 transfusions. It is the type of TR associated with the highest mortality [6].

Transfusion-associated graft-versus-host disease and post-transfusion purpura are rare phenomena. The former is almost exclusively observed in immunodeficient patients.

Acute hemolytic TR result from an immune reaction between the recipient's IgM antibodies against AB0-antigens of the transfused erythrocytes. Presence of antibodies against other red blood cell antigens of the donor may also trigger an acute hemolytic TR, but such a reaction is usually considerably less severe than that against AB0-antigens. In rare cases, an acute hemolytic TR may result from transfusion of previously damaged erythrocytes and subsequent hemolysis. Here, no immune reaction is taking place and the patient is not presenting symptoms of a typical acute hemolytic TR.

While acute hemolytic TR are typically mediated by IgM, IgE accounts for hypersensitivity and an allergic TR. Causative allergens are usually soluble allergens against which the recipient has already been sensitized. Also, genetic disorders seem to play a role in susceptibility for allergic TR [7].

Acute febrile non-hemolytic TR are little understood. It has been suggested that transfused leukocytic cytokines trigger this type of TR.

With regards to TRALI, there are different hypotheses as to the pathogenesis of this severe reaction. One assumes that antibodies transfused with blood components activate neutrophil granulocytes that subsequently mediate endothelial damage and cause increased vascular permeability. Of note, transfused neutrophil antibodies may trigger different reactions, not all of them leading to pulmonary edema as in TRALI [8]. The alternative hypothesis also concentrates on neutrophil granulocytes, suggests, however, that these immune cells are primed previous to transfusion. Thus, no antibodies need to be transfused. Blood components are merely the straw that breaks the camel's back.

In general, the medical history of the patient, focused on previous transfusions and pregnancies, may reveal important information to avoid TR and should be attentively studied.

Severe acute hemolytic TR may be avoided by careful management and assignment of transfusion bags.

Pretreatment of blood and blood products may be required before certain patients, e.g., immunocompromised patients in risk of transfusion-associated graft-versus-host disease, may be transfused.

Transfusion reaction (TR) is a general term and may refer to any adverse immune response towards previously donated blood products. With regards to symptom onset, acute can be distinguished from delayed TR.

Symptoms of acute TR can manifest as early as transfusion is carried out, but any adverse signs occurring in between 24 hours after transfusion are considered acute reactions. Typically, patients experience fever and chills as well as generalized pruritus and urticaria. In most cases, symptoms are mild and subside spontaneously within a short period of time. Here, no special treatment is required. However, if patients present high fever, dyspnea, hemoglobinuria and reduced consciousness, these are serious indicators of a potentially life-threatening immune reaction [1] [2].

TR may occur days or even weeks after the transfusion. Such delay may, for instance, be caused by the fact that antibodies are not present in the patient's body at the time of transfusion, but have to be produced first.

Any TR should prompt clinical and laboratory investigations as to the nature of the reaction. In some cases, the explanation may be as easy as an error that occurred while someone provided a transfusion bag prepared for another patient. If no such obvious mistake happened, samples of the recipient's and donor's blood should be gathered for further analysis.

Transfusion reaction (TR) is a general term referring to any immune mediated adverse event occurring after receiving blood or blood products. There is a variety of different types of TR and they happen due to distinct causes, they neither manifest in the same way nor require the same treatment:

• Acute hemolytic TR. Human may have different blood types and the most common classification of blood types is the A, B, AB and 0 system. A patient with blood type A, for instance, possesses A-antigens and B-antibodies. Since they have neither A-antibodies nor B-antigens, nothing happens. If this person does, however, receive a blood type B transfusion, there will suddenly be B-antigens. This triggers an immune reaction and destruction of red blood cells. Acute hemolytic TR usually result from errors upon assignation of transfusion bags, from simple confusion. This confusion may indeed have severe consequences and patients may require fluid therapy, renal and maybe even respiratory support.
• Delayed hemolytic TR. There are a lot more antigens and antibodies in human blood. Similarly to the reaction described above, other molecules of recipient's and donor's blood may react. In some cases, antibody production only starts upon transfusion and the hemolytic TR will occur days later. Delayed hemolytic TR are often less severe than acute hemolytic TR and only require minimal therapy.
• Allergic TR. Allergens may cause hay fever and a lot of other diseases. The patient's body may react comparably, albeit much more severely to allergens administered with blood transfusions. While in most cases, generalized urticaria and pruritus are the main symptoms, allergic TR may rarely progress towards life-threatening anaphylaxis. This condition may involve bronchospasm, circulatory failure and shock and requires urgent medical attention.
• Febrile non-hemolytic TR. The mechanisms behind this mild reaction are not yet completely understood. It manifests mainly with fever and is usually treated symptomatically.
• Transfusion-associated graft-versus-host disease. This reaction is almost exclusively observed in immunodeficient patients. Their immune system is unable to eliminate lymphocytes transferred with blood transfusions and these lymphocytes start to attack the recipient's tissues. Transfusion-associated graft-versus-host disease is mostly lethal.
• Post-transfusion purpura. Here, platelet counts drop significantly after receiving blood products. This may be caused by another antigen-antibody reaction. This condition has a very good prognosis and is treated with immunoglobulins.

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