COAGULATION

1. PLATELET DISORDERS
DR.N.MANJULA

2. PLATELETS
• Normal range 1.50.000 to 4.50.000 cells per
cubic mm.
• THROMBOCYTOPENIA:
• Platelet less than 1.50.000 cells per cubic mm.

3. CLASSIFICATION OF PLATELET
DISORDERS
• QUANTITATIVE
• QUALITATIVE

4. CLINICAL FEATURES OF
THROMBOCYTOPENIA
• Cutaneous bleeding –
pinpoint hemorrhage,
petechiae, ecchymoses.
• Mucosal bleeding
• Intracranial bleed – SAH,
ICH.

5. SEVERITY OF BLEEDING
• Post traumatic bleeding – platelet less than
20.000 to 50.000 cells per cubic mm.
• Spontaneous bleeding - platelet less than
20.000 cells per cubic mm.
• Intracranial bleeding - platelet less than
10.000 cells per cubic mm.

6. CLASSIFICATION OF
THROMBOCYTOPENIA

8. IMMUNE THROMBOCYTOPENIC
PURPURA
• M/C form of thrombocytopenia.
• Due to increased destruction of plateleys by
immune mechanisms.
• Mainly AUTOIMMUNE mechanism.
• Types:
• Acute ITP
• Chronic ITP

9. ACUTE ITP
• Self limited disease.
• 2 – 4 yrs.
• M = F.
• Presents 1 – 3 weeks after viral infection
(measles, rubella, EBV).
• Platelets are destroyed by antiplatelet
autoantibodies – Type II Hyspersensitivity
reaction.

10. CLINICAL FEATURES
• Sudden onset
• Petechiae
• Gum bleeding
• Epistaxis
• Spontaneously resolve with in 6 months
• Excellent prognosis

11. CHRONIC ITP
• Persistent thrombocytopenia for more than 6
months.
• Indolent
• F > M
• M/C – adults (20 – 40 yrs).

12. PATHOGENESIS
• Autoimmune disorder.
• Formation of antiplatelet antibody.
• Against platelet membrane glycoprotein.
• In 80 % it is of IgG type.
• Platelets are destroyed by mononuclear
phagocytes – spleen.

13. CLINICAL FEATURES
• Skin bleeding.
• Mucosal bleeding.
• Mennorhagia.

14. LAB FINDINGS
• CBC: reduced platelet.
• PS: platelet – reduced, giant platelets seen.
• RBC: MHC red cells – chronic bleeding and
blood loss.
• BM: hypercellular.
• Megakaryopoiesis: increase in both immature
and mature forms of platelets.
• Erythropoiesis: micronormoblastic
maturation.

16. • Bleeding time: prolonged.
• PT and PTT are normal.
• Tourniquet test: positive.
• Clotting time: normal.
• Test for platelet autoantibody: positive.