Immune Thrombocytopenic Purpura Overview

Questions and Answers

What is a primary distinction between acute and chronic Immune Thrombocytopenic Purpura (ITP)?

Acute ITP is self-limited, whereas chronic ITP involves persistent thrombocytopenia. (correct)

Acute ITP presents with numerous skin lesions, while chronic ITP does not.

Chronic ITP has a higher prevalence in children than acute ITP.

Chronic ITP typically resolves spontaneously within six months.

What mechanism leads to increased platelet destruction in Immune Thrombocytopenic Purpura (ITP)?

Platelets are overproduced in the bone marrow.

Viral infections cause a direct lysis of platelets.

Genetic mutations inhibit the production of platelets.

Autoantibodies bind to platelets, triggering their destruction. (correct)

Which symptom is commonly associated with acute ITP in children?

Fatigue and weight loss

Severe abdominal pain

Persistent joint pain

Petechiae and gum bleeding (correct)

In the case of chronic ITP, what demographic is predominantly affected?

Women aged 20-40 Signup and view all the answers

Which of the following states a potential cause of secondary ITP?

Bone marrow malignancies Signup and view all the answers

What is the typical platelet count associated with acute ITP?

Below 10,000/mm3 Signup and view all the answers

Which clinical feature is least likely to be associated with chronic ITP?

Abrupt onset of symptoms Signup and view all the answers

What type of antibody is primarily associated with the destruction of platelets in acute ITP?

IgM Signup and view all the answers

What is a distinguishing feature of acute ITP compared to chronic ITP?

Rapid onset of symptoms Signup and view all the answers

Which cytokine is commonly increased in ITP pathogenesis?

IL-2 Signup and view all the answers

What is the typical platelet count range observed in ITP?

10 - 100 x 10^9/L Signup and view all the answers

Which of the following is a common diagnostic finding in the peripheral smear of an ITP patient?

Hypochromic microcytic anemia Signup and view all the answers

What mechanism underlies the formation of antiplatelet antibodies in ITP?

Molecular mimicry and cross-reaction Signup and view all the answers

Which of the following is NOT typically associated with primary ITP?

Splenomegaly Signup and view all the answers

What is the key difference in the management of acute ITP compared to chronic ITP?

Acute ITP often resolves spontaneously within 2 to 6 months. Signup and view all the answers

Which mechanism is primarily involved in the pathogenesis of Immune Thrombocytopenic Purpura (ITP)?

Destruction of platelets due to antibodies. Signup and view all the answers

Which of these tests is likely to show a prolonged result in ITP?

Bleeding time (BT) Signup and view all the answers

What is typically observed in a peripheral blood film of a patient with ITP?

Almost total absence of platelets with large, young platelets present. Signup and view all the answers

What role do T cell tolerance failures play in ITP?

Enhance immune response against self-antigens Signup and view all the answers

What type of patient management is primarily indicated for a life-threatening hemorrhage in ITP?

Intravenous immunoglobulin (IVIg). Signup and view all the answers

Which of the following is NOT a characteristic feature of chronic ITP?

It is typically self-limited with resolution within weeks. Signup and view all the answers

What is one of the diagnostic evaluation techniques used for ITP?

Bone marrow examination for megakaryocyte count. Signup and view all the answers

Which of the following conditions could potentially lead to secondary ITP?

HIV infection. Signup and view all the answers

What role does corticosteroids play in the treatment of ITP?

First-line treatment leading to complete remission in about 80% of cases. Signup and view all the answers

Study Notes

Immune Thrombocytopenic Purpura (ITP)

Autoimmune disorder leading to low platelet count and mucocutaneous bleeding.
Characterized by the formation of antiplatelet antibodies targeting glycoproteins IIb-IIIa or Ib-IX on platelets, predominantly IgG type.
About 80% of patients present with detectable antibody/platelet complexes.
Common symptoms include easy bruisability and excess bleeding.

Types of ITP

Acute ITP:
- Typically affects children aged 2-6 years; self-limited, resolving within 2-6 months.
- Onset occurs 1-3 weeks post viral infections or vaccinations.
- Characterized by sudden platelet destruction and counts below 10,000/mm³.
- Symptoms: petechiae, gum bleeding, epistaxis, and possible intracranial hemorrhage.
Chronic ITP:
- Affects predominantly women aged 20-40 years with a ratio of 3:1 (F:M).
- Associated with persistent thrombocytopenia lasting over 6-12 months, without preceding infection.
- Characterized by relapses and remissions.

Pathogenesis

Events include recognition of self-antigens and tolerance failures in T and B cells.
Mechanisms involve altered cell communication pathways (B7/CD28, CD40/CD40L, Fas/FasL) and type-1/type-2 cytokine responses.
Notable cytokine changes: increased IL-2, IL-10, M-CSF, and low TGF-β.
Autoimmune mechanisms lead to increased platelet destruction by immune complexes.

Diagnostic Evaluation

Complete Blood Counts:
- Platelet count significantly reduced (10-100 x 10⁹/L).
- Hemoglobin levels vary, potentially leading to hypochromic microcytic anemia due to chronic blood loss.
Peripheral Smear:
- Thrombocytopenia visible with enlarged or giant platelets.
- White blood cells typically remain within normal limits.
Coagulation Studies:
- Bleeding time prolonged; PT and PTT remain normal.
Tests for Autoantibodies:
- Presence of platelet autoantibodies may be detected.

Clinical Features

Symptoms are not specific but largely due to thrombocytopenia.
Splenomegaly and lymphadenopathy are rare in primary ITP.
Associated with increased risk of severe bleeding.

Peripheral Blood Smear and Bone Marrow Findings

Peripheral blood smear shows near absence of platelets; presence of large young platelets.
Bone marrow examination reveals hypercellularity with normal or increased megakaryocytes.

Management Approach

Acute ITP:
- Generally supportive; spontaneous remission expected.
Chronic ITP:
- Aim for maintaining platelet count above thresholds for spontaneous bruising.
Emergency Treatment:
- Discontinue medications reducing platelet function and manage blood pressure.
- Corticosteroids as first-line treatment; effective in 80% of cases.
- Intravenous immunoglobulin for patients with contraindications to steroids or life-threatening hemorrhage.
- Platelet transfusion reserved for significant bleeding or urgent surgical needs.
- Antifibrinolytic medications, like tranexamic acid, used to address mucosal bleeding.
- Consider splenectomy in emergencies, with prior vaccinations if feasible.

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Description

This quiz explores Immune Thrombocytopenic Purpura (ITP), an autoimmune disorder marked by low platelet counts and increased mucocutaneous bleeding. It highlights the mechanisms of platelet destruction and symptoms associated with this condition. Test your knowledge about ITP and its implications.