PLT, one of the blood tests most often desired, is an abbreviation of Platelet term and reported in the CBC test.
What is PLT ?
The platelet test is a very useful parameter for monitoring the response to diagnosis and treatment of bleeding disorders such as uremia (renal failure), thrombocytopenia, liver diseases, cancers and bone marrow diseases.
Thrombocytes are now the smallest shaped cells in the blood that are counted automatically in cbc analyzer nowadays.
Their volume is normally 7-11 fl, 1-3 microns in diameter.
Thrombocytes with a diameter of 3 microns and larger are called macrotrombocytes. In a normal individual, 3 % of thrombocytes are larger than normal.
They are involved in blood coagulation, vascular integrity and vasoconstriction.
They are made mainly in the bone marrow, they are destroyed in the spleen, the average life span is 7 – 10 days.
On average, 66 % of all platelets are circulate in the blood and the remaining 34 % are in the spleen.
What Does High PLT Mean in Blood Tests ?
Myeloproliferative Diseases (characterized by an increase in the number of cells, usually due to an increase in mature cells, with cellular proliferation in one or more of the hematopoietic cells Chronic myeloid leukemia, polycythemia vera, essential thrombocythemia, agnogenic myeloid metaplasia ..)
Splenectomy (removal of the spleen)
Iron Deficiency Anemia
Collagen Tissue Diseases (RA, SLE, Sjögren’s syndrome …)
Acute Blood Loss and Hemolytic Anemia
Acute Infections and Inflammations
Inflammatory Bowel Diseases
Bone Marrow Failure
Hemolytic Reactions (inappropriate blood transfusions, drugs-infection and chemistry related, autoimmune, burns, prosthetic heart valves ..)
At High Altitudes (like mountains)
When using Oral Contraceptives
Due to a lot of Drugs
If Leukocytes are Fragmented
In the presence of severe Microcytosis
If there is Erythrocyte Fragmentation
In the presence of Cryoglobulin
In Winter, the thrombocytes are liable to lie high.
Malignancy is present in about 50% of patients who unexpectedly have elevated platelets (> 1 million in general).
Bleeding may occur, usually due to abnormal platelet function, when the number of platelets is very high (> 1 million), such as myeloproliferative diseases.
What Does Low PLT in Blood Test Mean ?
If the platelet count is too low, the blood will begin to appear in the form of a collective needle.
In many diseases, plt may fall, often causing platelet thrombosis and platelet thrombosis in the tub when the blood is usually taken in small falls.
Causes of Low Platelets ;
ITP (idiopathic thrombocytopenic purpura)
TTP (thrombotic thrombocytopenic purpura)
DIC (disseminated intravascular coagulopathy)
Pernicious – Aplastic – Hemolytic anemia
After Blood transfusion (dilution effect)
Viral – Bacterial – Rickettsial infections
Congestive Heart Failure
Congenital Heart Diseases
Chemotherapy and Radiotherapy, exposure to DDT and other chemical substances
Hereditary Diseases (Chediak-Higashi syndrome, Bernard-Soulier syndrome, May-Hegglin anomaly, Wiskott-Aldrich syndrome, Fanconi syndrome)
Bone Marrow Deficiency (leukemia, lymphomas, myeloproliferative diseases …)
Pregnancy Toxemia, Eklampsi
Toxic Thrombocytopenia (usually due to drugs)
Waited blood (platelets are broken down)
In Platelet Satelism
In the Platelet Aggregation (EDTA antibodies may accumulate platelets)
A large number of Drugs can cause low PLT levels.
How to Perform PLT Test ?
The blood drawn from the card is placed in the CBC tube and given to the device.
The sample should be taken on an empty stomach if possible and no hemolysis should occur.
Blood should be taken up to the marking level of the tube and immediately gently lowered / topped 5 times.
What are the Normal (Reference) Values for PLT ?
The reference intervals vary depending on the device used in each laboratory, the kit, the age of the person, and the gender.
For this reason, the reference values given in each laboratory may show slight variations.
But for platelets, the reference values are the same everywhere;
Adults: 150.000 – 400.000 /mm3
Children: between 150.000 and 450.000 /mm3.
What are Panic Values for Platelets ?
20.000 / mm3 and below : Spontaneous Hemorrhage, Bleeding time extension, Petechiae and Ecchymoses.
50.000 / mm3 or more : Usually no spontaneous Hemorrhage.
800.000 / mm3 and above : Thrombosis, Blood vessel obstruction, Paralysis risk.