Posts Tagged ‘blood’

Low blood platelets

Tuesday, October 4th, 2011

Blood cells are produced in the bone marrow. The three main components of blood are the red blood cells which carry oxygen, white blood cells or leukocytes which fight infection and platelets also called thrombocytes which assist in the formation of blood clot.

When a blood vessel is damaged platelets adhere to the surface of damaged vessel wall and release chemicals. The chemicals attract more platelets as well as red blood cells in order to form a clot or thrombus. As the clot grows the blood vessel narrows, thereby decreasing the blood loss. This process is called coagulation.

Normal platelet counts are in the range of 150, 000 to 350, 000 platelets per micro liter. Thrombocytopenia or low blood platelets are the disorders in which there are not enough platelets in the blood. When the platelet count is decreased the body is unable to form blood clots and is therefore unable to control the bleeding. Bruising and bleeding can occur from relatively little trauma. When the platelets count gets below 10, 000 platelets per micro liter, bleeding can develop even without significant trauma.

Chemotherapy induced thrombocytopenia is a disorder that develops as an adverse effect of chemotherapy. Cancer drugs not only kill cancer cells, they can also damage the platelet forming cells in the bone marrow. The severity of this disorder depends on the type of chemotherapy and the duration of treatment. Fortunately chemotherapy induced thrombocytopenia or low blood platelets can be managed with platelet transfusions, additional medications such as blood cell growth factors or with blood stem cell transplants.

Other common causes of thrombocytopenia or low blood platelets are ITP (immune thrombocytopenic purpura) and heparin induced thrombocytopenia. In immune thrombocytopenic purpura, anti platelet antibodies coat the platelets and destroy them, while heparin induced thrombocytopenia is caused by the formation of abnormal antibodies that activates platelets.

Impact-R has evolved as a blessing in disguise for the thrombocytopenia hit populations as it provides a very effective screening test for the timely detection of the patients suffering from thrombocytopenia. It has markedly decreased the morbidity and mortality associated with this disorder.

Causes of low blood platelets

Tuesday, October 4th, 2011

Before discussing the causes of low blood platelets or thrombocytopenia, I feel necessary to mention the grave consequences associated with low blood platelets. The dominant features of thrombocytopenia include petechial cutaneous bleeding, intracranial bleeding and oozing from mucosal surfaces.

Causes can be divided into three main groups;

  • Decreased production
  • Increased destruction
  • Un replaced loss or dilution of platelets

The characteristic findings of thrombocytopenia are decreased platelet count and prolonged bleeding time. Bone marrow aspiration is helpful in the cases of thrombocytopenia. It reveals decreased megakaryocytes (immature form of platelets) when caused by decreased platelet production and increased megakaryocytes when caused by increased platelet destruction.

Now I would like to discuss few common causes of low blood platelets;

  • Irradiation, exposure to drugs or chemical causes decreased production of the platelets.
  • Acute leukemia in which there is decreased platelet production due to replacement of bone marrow by blast cells.
  • Myelophthisis results in low blood platelets because the bone marrow is replaced by tumor cells.
  • Aplastic anemia can also be the cause of low blood platelets. It may be caused by exposure to toxic agents like benzene or due to autoimmune destruction by cytotoxic T cells.
  • Circulating blood platelets are lost or destroyed when they are sequestered by spleen, thus decreasing the blood platelet count.
  • Dilution of platelets occurs in multiple transfusions, where there is relatively deficiency of platelets and thus low blood platelets.
  • Disseminated intravascular coagulation, commonly known as consumptive coagulopathy results in consumption of almost all the platelets in the blood.
  • Low blood platelets can be secondary to other disease such as acquired immunodeficiency syndrome or systemic lupus erythematosus.
  • Immune thrombocytopenic purpura is a very common autoimmune disorder of the platelets occurring due to formation of anti platelet antibodies in the blood, which damage the platelets and decreases their count.

All the above mentioned causes of thrombocytopenia can be diagnosed well before time by the use of Impact-R platelet analyzer. This kit uses the very basic principles of platelet aggregation and adhesion and can be used to screen the cases of thrombocytopenia due to any cause.

Blood platelets

Tuesday, October 4th, 2011

Blood platelets commonly called megakaryocytes are one of the three tiny cellular components of the blood which helps in the stoppage of bleeding.. Other cellular components of blood are the red blood cells and white blood cells. All the cellular components bathe in the plasma.

Nearly half a billion blood platelets are being formed in the bone marrow every day. These play a primary role in the formation of blood clot. Here I would like to define the two common terms related to the platelet plug formation when the blood vessel in injured.

*  Adhesion means sticking of blood platelets with the wall of the bleeding vessel.

*  Aggregation means sticking of the platelets with each other.

Normally, in the circulating blood, platelets keep on flowing without any adhesion or aggregation. However, injury to the wall of blood vessel is the point when blood platelets start clinging to the injured part of the vessel wall. At the same time the platelets aggregate with one another and completely seal the opening which helps in arresting the bleeding from the specific site. We call these aggregates as ‘haemostatic plugs’.

Blood platelets can also be activated in the presence of atherosclerosis where the disease itself damages the intimal layer of the blood vessel. So, platelets cling to this damaged layer of the vessel wall and results in the formation of platelet plug by the process of adhesion and aggregation. Eventually thrombus is formed when the coagulation factors come into play. So, blood platelets are responsible for most of the cardiovascular and cerebrovascular events occurring in the human body.

Anti platelets drugs are used as blood thinners in the high risk patients. Their basic role is to decrease the activity of the platelets in the circulating blood.

While using anti platelet drugs, role of Impact-R cannot be ignored because it monitors the response to the anti platelet drugs with high accuracy and is very sensitive in all such tests. So, over treatment or under treatment can be easily detected and dealt with accordingly. Presently it is being used for the research purposes but can be used clinically also.

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