PLATELET COUNT; MEAN PLATELET VOLUME (MPV)
PLATELETS (thrombocytes) are the smallest elements circulating in the blood.
Platelets are round or oval, flattened, nonnucleated, disc-shaped structures that are formed via fragmentation of RBC's.
Platelets are necessary for clot formation, vascular integrity and vasoconstriction. Platelets are also responsible for adhesion and aggregation activity when forming platelet plugs for small breaks in artery walls.
Thrombocytes are produced in the bone marrow with a life-span of 7 days. Two-thirds of all platelets are found in the circulating blood with one-third found in the spleen.
MEAN PLATELET VOLUME indicates uniformity of size of platelet population and is used to differentially diagnosis thrombocytopenia
PLATELET COUNT
ADULTS: 140-400 x 10(3)/mm3 or 140-400 x 10 (9)/L
CHILDREN: 150-450 x 10(3)/mm3 or 140-450 x 10 (9)/L
MEAN PLATELET VOLUME
ADULTS: 7.4-10.4 um3 or fL
CHILDREN: 7.4-10.4 um3 or fL
Platelets are increased in:
1. Allergic reactions
2. Thrombocytopenia
3. Chronic myelogenous and granulocytic leukemia, myeloproliferative diseases
4. Polycythemia vera
5. Splenectomy
6. Iron deficiency anemia
7. Asphyxiation
8. Rheumatoid arthritis and other collagen diseases, SLE
9. Rapid blood regeneration caused by blood loss and hemolytic anemia
10. Acute infections
11. Hodgkin’s disease, lymphomas, and malignancies
12. Chronic pancreatitis, tuberculosis, inflammatory bowel disease
13. Renal failure
Platelets are decreased in:
1. Toxic reactions
2. Idiopathic thrombocytopenia purpura, neonatal purpura
3. Pernicious, aplastic and hemolytic anemias
4. Viral, bacterial and rickettsial infections
5. Thrombopoietin deficiency
6. Toxemia of pregnancy
7. Hypersplenism
8. Renal Insufficiency
9. Alcohol toxicity
10. HIV
11. During chemotherapy and radiation
12. Lesions of the bone marrow (leukemia, carcinoma)
Increased MPV is found in:
1. Idiopathic thrombocytopenia
2. Massive hemorrhage
3. Splenectomy
4. Myeloproliferative
5. Vasculitis
6. Megaloblastic anemia