Idiopathic thrombocytopenic purpura

ITP

1. IDIOPATHIC THROMBOCYTOPENIC PURPURA DR.T.ARIVAZHAGAN POST GRADUATE DEPARTMENT OF PATHOLOGY

2. THROMBOCYTOPENIA Isolated thrombocytopenia is associated with a bleeding tendency and normal coagulation tests . Generally < 150000 Spontaneous bleeding 20000 to 50000 Bleeding from small vessels < 20000

3. results from Increased peripheral destruction of platelets Decreased production of platelets in bone marrow Dilutional thrombocytopenia Sequestration in enlarged spleen

4. INTRODUCTION Also known as Immune Thrombocytopenic Purpura A bleeding disorder that involves immunologically mediated destruction of the platelets Commonest bleeding disorder presenting in children Usually presents between 1 and 7 yr of age Acute ITP: Thrombocytopenia < 6 months- children's Self imitated , after viral infections Chronic ITP: Thrombocytopenia > 6 months – 20 & 40 years

5. Etio-pathogenesis Acute ITP Chronic ITP Viral antigens & viral antibodies binds to Fc receptors on platelet Immune destruction of platelets by macrophages Autoantibodies predominantly IgG type Antibodies direct against specific platelet glycoproteins GpIIb / IIIa or Gp1b/IX Antibody coated platelets recognized by Fc receptors on macrophages & destroyed mainly in the spleen

6. Clinical features - symptoms Sudden appearance of bruises and mucosal bleeding Epistaxis Menorrhagia Prolonged bleeds with superficial trauma Symptoms appear often 1-2 weeks after a self-limited viral illness, Purpuric spots Ecchymosis Hematuria

7. Physical examination Petechiae, purpura, ecchymosis Splenomegaly , lymphadenopathy, bone pain are unusual and if present , other causes of thrombocytopenia should be thought of like leukemia

8. Parameters Acute ITP Chronic ITP Age Childhood Young adults Sex No sex preference Females > males H/O preceding viral infection Present Absent Onset of bleeding Sudden Insidious Degree of thrombocytopenia Severe Moderate Duration of disease Self limited ( 2-6months) Many years Spontaneous remission Usual Rare

9. investigations Peripheral blood: Blood loss – anemia Lymphocyte , eosinophils increased in case of children's Platelet count – reduced < 20000 Platelets are large in size

10. Bone marrow : Megakaryocytes normal or increased in number Hypo granularity of cytoplasm Vacuolization Lack of platelet budding Hypolobulation Dense nuclear chromatin

11. Coagulation profile : Prolonged bleeding time Platelet antibodies: Platelet associated immunoglobulins are raised

12. diagnosis Mucocutaneous type of bleeding with abrupt onset Other abnormalities on physical examination Presence of isolated thrombocytopenia with no other abnormality on complete blood count Bone marrow examination is normal

13. treatment Goal of therapy: Minimizing the risk of hemorrhage and decreasing the long-term side effects of treatment

14. Acute ITP: 1. Close observation for platelet count >20,000/ uL 2. IVIG 1 g/kg/day for 1-2 days 3. Corticosteroids: Prednisone 1-4 mg/kg/day for 2-4 weeks and then tapered 4. Intravenous anti-D immunoglobulin 50-75 mg/kg in Rh + ve children 5. If severe hemorrhage occurs, platelet transfusion under the cover of steroids Chronic ITP: 1. Low dose Prednisone on alternate days 2. Rituximab (anti-CD20 monoclonal antibody) 3. Cyclosporine 4. Azathioprine 5. Thrombopoietin receptor-binding agents ( Eltrombopag , Romiplostim )

15. Surgical management: Splenectomy Indications: 1. Child >4 yr , severe ITP for >1 yr i.e. chronic ITP 2. Symptoms not controlled with medical therapy 3. When life-threatening hemorrhage (intracranial hemorrhage) complicates Acute ITP and platelet count cannot be corrected rapidly with transfusion of platelets and administration of IVIG and corticosteroids Complications : 1. Lifelong risk of overwhelming post-splenectomy infection by encapsulated organisms 2. Increased risk of thrombosis 3. Potential development of pulmonary HTN in adulthood