IDIOPATHIC THROMBOCYTOPENIA PURPURA (ITP)
| A | Platelet ADP | |
| B |
Platelet membrane cholesterol |
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| C |
Platelet membrane glycoproteins |
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| D |
Platelet membrane lipids |
Patients with ITP(Immune Thrombocytopenic Purpura) have antibodies to which of the following?
| A |
Platelet ADP |
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| B |
Platelet membrane cholesterol |
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| C |
Platelet membrane glycoproteins |
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| D |
Platelet membrane lipids |
The autoantibodies in IPT are usually directed against platelet membrane glycoproteins.
- Immune thrombocytopenic purpura (ITP; also termed idiopathic thrombocytopenic purpura) is an acquired disorder in which there is immune-mediated destruction of platelets and possibly inhibition of platelet release from the megakaryocyte.
- ITP is characterized by mucocutaneous bleeding and a low, often very low, platelet count, with an otherwise normal peripheral blood cells and smear. Patients usually present either with ecchymoses and petechiae, or with thrombocytopenia incidentally found on a routine CBC. Wet purpura (blood blisters in the mouth) and retinal hemorrhages may herald life-threatening bleeding.
| A |
Intracranial bleed is a rare complication |
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| B |
Splenomegaly is prominent |
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| C |
More common in female |
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| D |
a and c |
Ans is ‘a’ i.e., Intracranial bleed is a rare complication, ‘c’ i.e., More common in female
o Intracranial hemorrhage (Subarachnoid hemorrhage and intracerebral hemorrhage) are rare in ITP.
o Splenomegaly and lymphadenopathy are uncommon in primay ITP and their presence should lead one to consider other possible diagnosis .
o Chronic ITP occurs most commonly in adult women (Female : Male ratio is 4 : 1)
o Thrombocytopenia lasting for more than 6 months is called chronic ITP.
o Acute ITP is a self limiting condition with spontaneous remission in 80% of patients.
| A |
A significant enlargement of the spleen |
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| B |
A high reticulocyte count |
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| C |
Patients age less than five years |
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| D |
An increase in platelet count on corticosteroid therapy |
Ans is ‘d’ i.e. An increase in platelet count on corticosteroid therapy
Idiopathic thrombocytopenic purpura is associated with all of the following Except:
| A |
Splenomegaly |
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| B |
Mucosal bleeding |
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| C |
Thrombocytopenia |
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| D |
Increased megakaryocytes |
Answer is A (Splenomegaly)
Splenomegaly and lymphadenopathy are rare in primary Idiopathic Thrombocytopenic purpura and their presence should lead one to consider other possible diagnosis – Robbins
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Clinical manifestations |
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Clinical signs and symptoms of ITP are reflective of thrombocytopenia (Bleeding |
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manifestations due to decreased platelet count) |
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Characteristic Clinical Features |
Clinical features that are characteristically unusual and suggest the possibility of other diagnosis |
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Bleeding and haemorrhages from small venules or capillaries • Spontancouspetechiae • Spontaneous echymoses • Spontaneous mucosa! bleeding • Easy Bruisibility |
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• Frequent Bleeding and haemorrhages from larger veins and arteries and bleeding into joints (Suggest coagulation disorders) • Splenomegaly and Lymphadenopathy are unusual/rare and their presence should lead one to consider other diagnosis. |
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• Spleen is normal in size |
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| A |
Antibodies of IgM class |
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| B |
Autoantibodies to Gp IIb/ Ilia or IB IX |
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| C |
Increased megakaryocytes in bone marrow |
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| D |
Spleen is normal in size |
Ans. is ‘a’ i.e., Antibodies of IgM class
I dopathic thrombocytopenic purpura :‑
- There are two clinical subtypes of primary I.T.P, acute and chronic both are autoimmune disorders in which platelet destruction results from formation of antiplatelet antibodies.
Pathogenesis
- Chronic ITP is caused by the formation of autoantibodies against platelet membrane glycoproteins most often Hb-lIla or Ib-IX.
- In overwhelming majority of cases the antiplatelet antibodies are of the .IgL, class.
- The mechanism of platelet destruction is similar to that seen in autoimmune hemolytic anemias. Opsonized platelets are rendered susceptible to phagocytosis by the cells of the mononuclear phagocyte system.
- The spleen is the major site of the destruction of platelets.
Pathology
- The principal morphologic lesions of thrombocytopenic purpura are found in the spleen and bone marrow but they are not diagnostic.
- The point to stress is that despite the increased destruction of platelets in spleen, the spleen size remains normal.
- On histological examination there is congestion of the sinusoids and hyperactivity and enlargement of the splenic follicles manifested by the formation of prominent germinal centres. Sometimes scattered megakaryocytes are found within the sinuses and sinusoidal walls. This represents a very mild form of extramedullary hematopoiesis. These splenic findings are not sufficiently distinctive to be considered diagnostic.
Bone Marrow
- Bone marrow reveals a modestly increased number of megakaryocytes.
- These findings are not specific for autoimmune thrombocytopenic purpura, but merely reflect accelerated thrombopoiesis, being found in most forms of thrombocytopenia resulting from increased platelet destruction.
- The importance of bone marrow examination is to rule out thrombocytopenias resulting from bone marrow failure.
- A decrease in the number of megakaryocytes goes against the diagnosis of I.T.P.
