Blood platelets are very small fragments that circulate in the bloodstream along with RBCs and WBCs. The blood platelets work with clotting factors in the plasma to form blood clots in order to stop or prevent bleeding.
Plasma is the fluid portion of the blood. It comprises protein, salt, antibodies, and coagulation factors. White blood cells (WBCs) fight harmful germs and prevent infection. Red blood cells (RBCs) transport oxygen from the lungs into the tissues.
Most cases of platelet donations are given to patients who are not capable to produce sufficient amount of blood platelets in the bone marrow. For instance, patients with leukemia or any other diseases where platelets are being produced inadequately. It can also be due to a treatment process that alters the platelet formation activity.
After a major surgery or extensive personal injury, the individual may require the need for platelet transfusions to replace for blood loss brought about by the bleeding. Considering that platelets can only be stored at room temperature for a few days (shelf life is 5 days), regular and frequent donors are in great demand.
Process of Platelet Donation
During the procedure, blood is drawn from the donor’s vein and mixed with an anticoagulant in order to prevent it from clotting. The blood will be placed under a process that separates the platelets. The rest of the blood is returned, making it safer to donate platelets at a significantly higher frequency than whole blood. Platelet donors may donate every 7 days up to 24 times in a year.
Any leukocytes that remain in the separated platelet will be removed since it can cause problems in the recipient although harmless to the donor. All the tubes that the blood comes in contact with are sterile and disposable. Following standard procedures, there is almost zero risk of ‘catching’ any infection.
Upon the return of the rest of the blood to the donor, air detectors ensure that none of the sterile air is present when the collection is passed into the vein. If the detector identifies any air, the processing machine will automatically initiate a shut down but can be restarted only when the air is removed.
Platelets are needed in patients with bleeding tendencies which is possible secondary to a reduction in the amount of blood platelets or impaired platelet function. It is common in medical conditions that alter platelet processes.
The need for platelet transfusion can also be observed in the following recipients:
- Patients on chemo and radiotherapy,
- Patients who are suffering from congenital disorders of platelet function,
- Patients hypersensitive to medications,
- Patients with chronic renal failure,
- Patients who had open-heart surgery.
Congenital Disorders of Platelet Function:
Below are some cases of congenital disorders where platelets may be needed.
• Wiskott-Aldrich syndrome
It is a hereditary disorder of the immune system (immunodeficiency), which is characterized by the triad of recurrent pyogenic bacterial infections, eczema (atopic-like dermatitis) and skin hemorrhagic coagulation disorders (caused by thrombocytopenia and platelet dysfunction).
The cause is a mutation in a gene on the X chromosome (X-linked recessive disease mode of inheritance). The treatment includes bone marrow transplant, symptomatic therapy, prophylaxis of infections, immunoglobulins, corticosteroids (eczema), transfusion of blood and blood derivatives (bleeding) and gene therapy.
A hematopoietic stem cell transplant is the only current hope of cure.
• Fanconi anemia
Fanconi anemia is one of the most common rare genetic disease that usually involves the bone marrow where an impaired labor (inability to produce blood cells) is evident.
Moreover, this form of anemia is often associated with birth defects, tendency of bleeding, frequent appearance of liver tumors, short stature, myelodysplastic syndrome (blood stem cells – immature cells – do not become mature blood cells) in about 60-75% of patients.
In this form of anemia, there are possible notable anomalies like ectopic kidney, pelvic kidney, hydronephrosis and hydroureter, open ductus arteriosus, aortic stenosis, coarctation of aorta, missing lobes of the lungs, atrial septal defect, tetralogy of Fallot, pseudotruncus, and other problems in development such as Bell’s palsy, arterial malformations of brain tissue.
With over 99% of cases, the disorder is inherited in an autosomal recessive way, which means there are two copies of the abnormal gene having the disease manifested.
Statistical data indicate that Fanconi anemia occurs approximately every 300,000 people, which makes the condition quite rare. Some data show that the carriers are rather common in the general population and it is almost present in every 200 person.
The male to female ratio is 2:1, making it more common on the side of men. This disease is diagnosed usually before 7 years of age. About 9% are diagnosed in adults. The median age of onset for megaloblastic anemia (first detected abnormality) is seven years.
Symptoms of Fanconi anemia are:
- A short stature and skin pigmentation during childhood
- The first sign of blood disorders are petechiae (small red spots on the skin caused by minor bleeding from broken capillary blood vessels) and easy bruising
- A later onset is pallor, susceptibility to infections, fatigue and body malaise
- Abnormalities of the hands and forearms
- In every third patient, there are disorders of the reproductive organs and the gonads (such as hypospadias, undescended testicles, atrophic testes, azoospermia, phimosis, micropenis, in males while, bicornuate “heart-shaped” uterus, atrophy of the vagina, in females)
- Disorders of the vision occur about 20%
- Developmental disorders of the kidneys and urinary tract occurs about 20%
- About 22% displays microcephaly (reduced volume and size of the skull), some hydrocephalus; micrognathia (snoffiness)
- There may also be spina bifida (split spine), Klippel–Feil syndrome (congenital fusion of 2 cervical vertebrae), supernumerary (extra) ribs, and Sacrococcygeal sinuses
- Congenital dislocation of the hip (Perthes’ disease)
- Hearing disorder occurs about 10%
- In every tenth patient appears slow development (intellectual and development delay)
- The treatment of choice is bone marrow transplant and frequent blood transfusions.
Radiation therapy can complicate the development of thrombocytopenia.
Damage appears in the bone marrow affecting megakaryocytes prior to the circulation of blood platelets.
Thrombocytopenia usually occurs 7-10 days after radiotherapy.
This is a frequent cause for the development of thrombocytopenia in hospitalized patients that have lost a significant amount of blood.
Aggressive application of intravenous transfusion results to a drop in blood platelets.
Chronic Renal Disease:
Chronic Renal Disease, also called chronic renal failure, describe as the gradual loss of renal function. The kidneys filter waste and excess fluid from the blood, which is eventually excreted in the urine.
When a chronic kidney disease reaches an advanced stage, dangerous levels of fluid, electrolytes and waste can build up in the body. In the early stages of chronic kidney disease, there may be a couple of notable signs or symptoms.
Chronic kidney disease may not become obvious until the renal function is considerably impaired. The treatment for the medical condition focuses on slowing the progression of kidney damage, typically by controlling the cause.
Chronic kidney disease may advance into kidney failure terminal stages, which is fatal without artificial filtering (dialysis) or kidney transplant.
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