Red blood cells (erythrocytes) from donors contain normal hemoglobin (HbA), and transfusion of normal red blood cells into people with sickle cell disease reduces the percentage of red cells in the circulation containing the abnormal hemoglobin (HbS). [1] Although transfusion of donor red blood cells can ameliorate and even prevent complications of sickle cell disease in certain circumstances, transfusion therapy is not universally beneficial in sickle cell disease. [2]
There are two main types of transfusion, simple red cell transfusion and exchange transfusion.
Involves transfusing red blood cells without removing any of the patient’s blood. [3] It is used when the patient's hemoglobin is much lower than normal, for example an aplastic crisis. [4]
Exchange transfusion involves removal of the patient’s blood and replacement with donor red blood cells. [3] It is used to treat life-threatening complications of sickle cell disease such as stroke or acute chest crisis. [4]
There are three main benefits of an exchange transfusion compared to a simple transfusion, these relate primarily to the ability to remove hemoglobin S containing red blood cells: [5]
However, there are also potential risks associated with an exchange transfusion:
The exchange is performed using a machine (pheresis). This method rapidly and substantially reduces the concentration of sickle cells within the blood without increasing the overall hematocrit or blood viscosity.[ citation needed ]
The exchange is performed manually. It refers to manually phlebotomizing a percentage of the patient’s blood prior to or concomitantly with giving a red cell transfusion.[ citation needed ]
Red cell transfusions can be further classified as episodic or chronic. [3]
Episodic transfusion is used either acutely in response to a complication of sickle cell disease such as acute chest syndrome or to prevent complications prior to surgery. [3]
Chronic transfusion is used when sustained, low levels of HbS are needed to prevent sickle cell-related complications, most commonly stroke in children. [3]
Transfusion therapy for sickle-cell disease entails the use of red blood cell transfusions in the management of acute cases of sickle cell disease and as a prophylaxis to prevent complications by decreasing the number of red blood cells (RBC) that can sickle by adding normal red blood cells.[ citation needed ]
In children prophylactic chronic red blood cell (RBC) transfusion therapy has been shown to be efficacious to a certain extent in reducing the risk of first stroke or silent stroke when transcranial Doppler (TCD) ultrasonography shows abnormal increased cerebral blood flow velocities. In those who have sustained a prior stoke event it also reduces the risk of recurrent stroke and additional silent strokes. [6] [7] [8] There is no evidence for the use of red blood cell transfusion in adults to prevent primary stroke, although it is recommended to prevent secondary stroke. [8] [9] [10] [11]
In children and adults red blood cell transfusion to increase the hemoglobin level to 100 g/L has been shown to decrease the risk of sickle cell-related complications. [2] However, this has not been seen in all studies, and has only been demonstrated for African haplotypes of Hemoglobin SS. [12] [13]
In children who have been given transfusions to prevent stroke there was also a reduction in the number of children who developed acute chest crises. [13] There is no evidence about whether or not red cell transfusions prevent chronic lung complications. [14]
This should be suspected if there is a significant drop in the hemoglobin level compared to the patient's usual hemoglobin level which is associated with a low level of reticulocytes. This is usually due to infection with erythrovirus B19 (previously known as parvovirus B19). [11] The anemia is usually severe with an average drop in hemoglobin of 40 g/L, and is usually treated with a simple transfusion. [11]
Acute splenic and hepatic sequestration associated with severe anemia requires a simple transfusion to raise the hemoglobin. [3] [11]
Red cell transfusions are used to treat patients with acute chest crisis and respiratory compromise. [9] [2] Exchange transfusion is recommended for those patients who have a higher hemoglobin (> 90g/L), those who have not improved after a simple transfusion, or those who have severe respiratory compromise. [11]
Red cell alloimmunisation is common in people with sickle cell disease who receive transfusions in Europe and North America. [4] This is because there are ethnic differences in the frequencies of blood group antigens. [4] Blood donors are usually Caucasian whereas the blood transfusion recipients usually have an African or Afro-Caribbean ancestry. [4] [15] Extended phenotype matching of red blood cells (matching Rh and Kell blood groups as well as ABO) decreases the risk of alloimmunisation, but it still occurs. [4]
Each unit of transfused blood has approximately 250 mg of iron, with each successive transfusion, patients receiving chronic transfusion therapy accumulate iron in various tissues in the body as the body has no way to excrete the excess, this is a cause of increased morbidity and mortality. [16] The effects of iron overload are countered by chelation therapy [17] Guidelines recommend if patients are receiving regular or intermittent transfusions they should be monitored for iron overload. [4]
Non-Hodgkin lymphoma (NHL), also known as non-Hodgkin's lymphoma, is a group of blood cancers that includes all types of lymphomas except Hodgkin lymphomas. Symptoms include enlarged lymph nodes, fever, night sweats, weight loss, and tiredness. Other symptoms may include bone pain, chest pain, or itchiness. Some forms are slow-growing while others are fast-growing. Unlike Hodgkin lymphoma, which spreads contiguously, NHL is largely a systemic illness.
Anemia or anaemia is a blood disorder in which the blood has a reduced ability to carry oxygen. This can be due to a lower than normal number of red blood cells, a reduction in the amount of hemoglobin available for oxygen transport, or abnormalities in hemoglobin that impair its function.
Iron deficiency, or sideropenia, is the state in which a body lacks enough iron to supply its needs. Iron is present in all cells in the human body and has several vital functions, such as carrying oxygen to the tissues from the lungs as a key component of the hemoglobin protein, acting as a transport medium for electrons within the cells in the form of cytochromes, and facilitating oxygen enzyme reactions in various tissues. Too little iron can interfere with these vital functions and lead to morbidity and death.
Thalassemias are inherited blood disorders that result in abnormal hemoglobin. Symptoms depend on the type of thalassemia and can vary from none to severe. Often there is mild to severe anemia as thalassemia can affect the production of red blood cells and also affect how long the red blood cells live. Symptoms of anemia include feeling tired and having pale skin. Other symptoms of thalassemia include bone problems, an enlarged spleen, yellowish skin, pulmonary hypertension, and dark urine. Slow growth may occur in children. Symptoms and presentations of thalassemia can change over time. Older terms included Cooley's anemia and Mediterranean anemia for beta-thalassemia. These have been superseded by the terms Transfusion-Dependent Thalassemia (TDT) and non-Transfusion-Dependent Thalassemia (NTDT). Patients with TDT require regular transfusions, typically every two to five weeks. TDTs include Beta-thalassemia major, nondeletional HbH disease, survived Hb Bart's disease, and severe HbE/beta-thalassemia.
Gastrointestinal bleeding, also called gastrointestinal hemorrhage (GIB), is all forms of bleeding in the gastrointestinal tract, from the mouth to the rectum. When there is significant blood loss over a short time, symptoms may include vomiting red blood, vomiting black blood, bloody stool, or black stool. Small amounts of bleeding over a long time may cause iron-deficiency anemia resulting in feeling tired or heart-related chest pain. Other symptoms may include abdominal pain, shortness of breath, pale skin, or passing out. Sometimes in those with small amounts of bleeding no symptoms may be present.
Alpha-thalassemia is a form of thalassemia involving the genes HBA1 and HBA2. Thalassemias are a group of inherited blood conditions which result in the impaired production of hemoglobin, the molecule that carries oxygen in the blood. Normal hemoglobin consists of two alpha chains and two beta chains; in alpha-thalassemia, there is a quantitative decrease in the amount of alpha chains, resulting in fewer normal hemoglobin molecules. Furthermore, alpha-thalassemia leads to the production of unstable beta globin molecules which cause increased red blood cell destruction. The degree of impairment is based on which clinical phenotype is present.
Platelet transfusion, also known as platelet concentrate, is used to prevent or treat bleeding in people with either a low platelet count or poor platelet function. Often this occurs in people receiving cancer chemotherapy. Preventive transfusion is often done in those with platelet levels of less than 10 x 109/L. In those who are bleeding transfusion is usually carried out at less than 50 x 109/L. Blood group matching (ABO, RhD) is typically recommended before platelets are given. Unmatched platelets, however, are often used due to the unavailability of matched platelets. They are given by injection into a vein.
Iron supplements, also known as iron salts and iron pills, are a number of iron formulations used to treat and prevent iron deficiency including iron deficiency anemia. For prevention they are only recommended in those with poor absorption, heavy menstrual periods, pregnancy, hemodialysis, or a diet low in iron. Prevention may also be used in low birth weight babies. They are taken by mouth, injection into a vein, or injection into a muscle. While benefits may be seen in days, up to two months may be required until iron levels return to normal.
Beta thalassemias are a group of inherited blood disorders. They are forms of thalassemia caused by reduced or absent synthesis of the beta chains of hemoglobin that result in variable outcomes ranging from severe anemia to clinically asymptomatic individuals. Global annual incidence is estimated at one in 100,000. Beta thalassemias occur due to malfunctions in the hemoglobin subunit beta or HBB. The severity of the disease depends on the nature of the mutation.
An exchange transfusion is a blood transfusion in which the patient's blood or components of it are exchanged with other blood or blood products. The patient's blood is removed and replaced by donated blood or blood components. This exchange transfusion can be performed manually or using a machine (apheresis).
Packed red blood cells, also known as packed cells, are red blood cells that have been separated for blood transfusion. The packed cells are typically used in anemia that is either causing symptoms or when the hemoglobin is less than usually 70–80 g/L. In adults, one unit brings up hemoglobin levels by about 10 g/L. Repeated transfusions may be required in people receiving cancer chemotherapy or who have hemoglobin disorders. Cross-matching is typically required before the blood is given. It is given by injection into a vein.
The acute chest syndrome is a vaso-occlusive crisis of the pulmonary vasculature commonly seen in people with sickle cell anemia. This condition commonly manifests with a new opacification of the lung(s) on a chest x-ray.
Sickle cell disease (SCD), also simply called sickle cell, is a group of hemoglobin-related blood disorders typically inherited. The most common type is known as sickle cell anemia. It results in an abnormality in the oxygen-carrying protein haemoglobin found in red blood cells. This leads to a rigid, sickle-like shape under certain circumstances. Problems in sickle cell disease typically begin around 5 to 6 months of age. A number of health problems may develop, such as attacks of pain in joints, anemia, swelling in the hands and feet, bacterial infections, dizziness and stroke. Long-term pain may develop as people get older. The average life expectancy in the developed world is 40 to 60 years. It often gets worse with age. All the major organs are affected by sickle cell disease. The liver, heart, kidneys, gallbladder, eyes, bones, and joints also can suffer damage from the abnormal functions of the sickle cells, and their inability to flow through the small blood vessels correctly.
Patient Blood Management (PBM) is a set of medical practices designed to optimise the care of patients who might need a blood transfusion. Patient blood management programs use an organized framework to improve blood health, thus increasing patient safety and quality of life, reducing costs, and improving clinical outcomes. Some strategies to accomplish this include ensuring that anemia is treated prior to a surgical operation, using surgical techniques that limit blood loss, and returning blood lost during surgery to the patient via intraoperative blood salvage.
Sickle cell nephropathy is a type of kidney disease associated with sickle cell disease which causes kidney complications as a result of sickling of red blood cells in the small blood vessels. The hypertonic and relatively hypoxic environment of the renal medulla, coupled with the slow blood flow in the vasa recta, favors sickling of red blood cells, with resultant local infarction. Functional tubule defects in patients with sickle cell disease are likely the result of partial ischemic injury to the renal tubules.
Treatment of the inherited blood disorder thalassemia depends upon the level of severity. For mild forms of the condition, advice and counseling are often all that are necessary. For more severe forms, treatment may consist in blood transfusion; chelation therapy to reverse iron overload, using drugs such as deferoxamine, deferiprone, or deferasirox; medication with the antioxidant indicaxanthin to prevent the breakdown of hemoglobin; or a bone marrow transplant using material from a compatible donor, or from the patient's mother. Removal of the spleen (splenectomy) could theoretically help to reduce the need for blood transfusions in people with thalassaemia major or intermedia but there is currently no reliable evidence from clinical trials about its effects. Population screening has had some success as a preventive measure.
Anemia is a condition in which blood has a lower-than-normal amount of red blood cells or hemoglobin. Anemia in pregnancy is a decrease in the total red blood cells (RBCs) or hemoglobin in the blood during pregnancy. Anemia is an extremely common condition in pregnancy world-wide, conferring a number of health risks to mother and child. While anemia in pregnancy may be pathologic, in normal pregnancies, the increase in RBC mass is smaller than the increase in plasma volume, leading to a mild decrease in hemoglobin concentration referred to as physiologic anemia. Maternal signs and symptoms are usually non-specific, but can include: fatigue, pallor, dyspnea, palpitations, and dizziness. There are numerous well-known maternal consequences of anemia including: maternal cardiovascular strain, reduced physical and mental performance, reduced peripartum blood reserves, increased risk for peripartum blood product transfusion, and increased risk for maternal mortality.
Transfusion-dependent anemia is a form of anemia characterized by the need for continuous blood transfusion. It is a condition that results from various diseases, and is associated with decreased survival rates. Regular transfusion is required to reduce the symptoms of anemia by increasing functional red blood cells and hemoglobin count. Symptoms may vary based on the severity of the condition and the most common symptom is fatigue. Various diseases can lead to transfusion-dependent anemia, most notably myelodysplastic syndromes (MDS) and thalassemia. Due to the number of diseases that can cause transfusion-dependent anemia, diagnosing it is more complicated. Transfusion dependence occurs when an average of more than 2 units of blood transfused every 28 days is required over a period of at least 3 months. Myelodysplastic syndromes is often only diagnosed when patients become anemic, and transfusion-dependent thalassemia is diagnosed based on gene mutations. Screening for heterozygosity in the thalassemia gene is an option for early detection.
A granulocyte transfusion is a medical procedure in which granulocytes are infused into a person's blood. Granulocyte transfusions were historically used to prevent and treat infections in people with neutropenia, but the practice declined in popularity in the 1980s. Interest in the procedure increased in the 1990s due to the development of more effective methods for harvesting granulocytes and a growing population of people with severe neutropenia from chemotherapy. However, the treatment's efficacy remains poorly understood and its use is controversial.
Sickle cell retinopathy can be defined as retinal changes due to blood vessel damage in the eye of a person with a background of sickle cell disease. It can likely progress to loss of vision in late stages due to vitreous hemorrhage or retinal detachment. Sickle cell disease is a structural red blood cell disorder leading to consequences in multiple systems. It is characterized by chronic red blood cell destruction, vascular injury, and tissue ischemia causing damage to the brain, eyes, heart, lungs, kidneys, spleen, and musculoskeletal system.