Immunology of Blood Transfusion

The body’s immune system doesn’t rest. The cells within the immune system constantly move around the body through the circulatory system. If the immune system was absent then the body would be unable to stop different types of infections. Hence, the immune system is an important concern during blood transfusion is the immunology of blood transfusion is important and blood transfusion needs to be performed with utmost care. In case incompatible blood is provided during transfusion, the immune system of the body treats donor cells as foreign invaders. Hence the immune system of the patient ends up attacking these cells. As a result, the blood transfusion is rendered useless and a rather massive clotting system and immune system activation can circulatory collapse, shock, kidney failure, or even death

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Blood transfusion meaning

Blood transfusion means a particular process in which blood products are transferred within the circulatory system of an individual intravenously. Blood transfusions are generally done in the case of patients having several specific medical conditions. It helps in replacing lost components within the blood. Previously, blood transfusion referred to the replacement of whole blood. However, recent medical facilities carry out transfusion through the changing of different components of blood such as white blood cells, red blood cells, platelets, clotting factors, and plasma. 

In this context, it should be mentioned that hemoglobin is present in Red Blood Cells which supplies the body cells with Oxygen. Generally, WBC or white blood cell is not used during transfusion. However, they are an integral part of the immune system. Next, Plasma is described as the yellowish fluid which contains proteins and other important substances and functions as a buffer, supporting the body’s overall health. Lastly, Platelets help in the clotting of blood thereby preventing the body from excessive bleeding. 

Blood transfusion reaction

Blood transfusion is carried out in patients due to several reasons. Blood transfusion is a safe process and refers to the transferring of healthy blood into the patient’s body. This is a safe process, but sometimes it can lead to some adverse effects namely. Minor symptoms of an adverse reaction include chills, itching, fever, and hives. However, more adverse symptoms involve respiratory distress, high fever, low pressure of blood, and red urine. A blood transfusion reaction can be broadly classified into two types namely acute transfusion reaction and delayed transfusion reaction. The different types of acute transfusion reactions along with their symptoms have been outlined in the following. 

• Simple Allergic reaction: Major symptoms of this reaction involve hives, itching, and rash
• Reaction due to Anaphylactic transfusion: Major symptoms include flushed skin, hives, itching, breathing difficulty, blue lips, diarrhea, vomiting, etc.
• Reaction due to Febrile non-hemolytic transfusion: Core symptoms are chills and fever with a body temperature of more than 38°C.
• Reaction hemolytic acute transfusion: Chief symptoms are back pain, low blood pressure, renal failure, and chills.
• Reaction due to septic transfusion: Common symptoms include chills, fever, and low blood pressure.
• TRALI: Common symptoms are severe breath shortness, low pressure of blood, and fever.
• TACO: Main symptoms of this reaction are coughing, high blood pressure, rapid breathing, and shortness

In addition to these, a transfusion reaction can also be delayed which has been outlined in the following.

• Reaction due to Delayed hemolytic transfusion: Major symptoms involve abdominal pain, labored breathing, dark urine, Jaundice, etc. 
• PTP (Post Transfusion purpura): Main symptoms are bleeding of the urinary and gastrointestinal tract along with chills and fever.
• TAGVHD: Symptoms of this reaction involve nausea, rash, diarrhea, fever, and abdominal pain. 

Complications of blood transfusion

The blood transfusion process is of utmost importance in the case of specific patients. Medical practitioners use healthy blood during the process of blood transfusion. However, complications of blood transfusion can arise in some specific cases. These recently known complications of blood transfusion have been provided in the following:

• Delayed and immediate hemolytic reaction
• Non–hemolytic reaction
• Acute lung injury due to transfusion
• Allergic reactions towards protein
• Air embolism
• Circulatory overload
• Hyperkalemia
• Hypothermia 
• Thrombophlebitis
• Citrate toxicity
• Clotting abnormalities

However late complications involve the transmission of different viral, bacterial, and parasitic infections and graft vs host diseases such as iron overload and immune sensitization 

Conclusion

Throughout the article, the core topic of immunology of blood transfusion has been discussed. This is an important topic in Immunology. The core topic has been discussed through assessment of several subtopics namely blood transfusion meaning, blood transfusion reaction, and complications of blood transfusion.