Causes of Thrombocytopeniain pediatrics other

than ITPPrepared by-:

Asmaa Rabie Abdel Monem A 5th grade med student

Alexandria University Faculty of Medicine

 

Causes of thrombocytopenia increased destruction Immune mechanism Iodopathic (ITP) Secodary to infection, drugs, SLE Non-immune mechanism platelet consumption DIC ,HUS microangiopathic hemolytic

anemia platelet destruction Hypersplenism , drugs Prothetic heart valve sequesteration Large spleen

Decreased production

Bone marrow depression Hereditary Fanconi anemia TAR syndrome Acquired Drugs , chemotherapy Inefction,

hepatitis ,HIV ,EBV Bone marrow infiltration Leukemia ,neuroblastoma Storage disease

Secondary immune mechanismDrug-Induced Thrombocytopenia

•A number of drugs are associated with immune thrombocytopenia as

the result of either an immune process or a megakaryocyte injury .

Heparin-induced hrombocytopenia (and rarely thrombosis) is seldom seen in pediatrics but occurs when, after exposure to heparin, the patient develops

an antibody directed against the heparin/ platelet factor IV complex .

Non immune Platelet Destructionincrease platelet consumption

DIC

hemolytic-uremic syndrome

thrombotic thrombocytopenic purpura

The syndromes of DIC, hemolytic-uremic syndrome, and thrombotic thrombocytopenic purpura share the hematologic picture of

The microangiopathic hemolytic anemia is characterized by the presence of RBC fragments, including helmet cells, schistocytes, spherocytes, and burr cells.

Hemolytic-Uremic Syndrome (HUS)

Abnormal red cell morphology

Normal numbers of megakaryocytes.

Combined Platelet and Fibrinogen Consumption Syndromes Kasabach-Merritt Syndrome

Hemangioma

platelet trapping and activation of coagulation with fibrinogen

consumption and generation of fibrin(ogen)

Non immune Platelet Destruction Sequestration

•Individuals with massive splenomegaly

develop thrombocytopenia, since the spleen acts as a sponge for platelets

and sequesters large numbers .•Most such patients will also have mild

leukopenia and anemia on the CBC. Individuals who have thrombocytopenia caused by splenic sequestration should undergo a work-

up to diagnose the etiology of splenomegaly, including infectious, infiltrative, neoplastic, obstructive,

and hemolytic causes .

Thrombocytopenia - Underproduction

Marrow failure: myelodysplasia, aplastic anemia, vitamin deficiencies.

Marrow infiltration: tumor, granulomatous diseases, fibrosis, leukemias, lymphomasMarrow toxins: drugs, radiation, infections (CMV, HIV), alcohol.

Congenital Thrombocytopenic Syndromes

Congenital Amegakaryocytic thrombocytopenia

Bone marrow transplant is curative.

Bone marrow failure

absence of megakaryocytes in bone marrow examination.

Thrombocytopenia–absent radius (TAR)

The thrombocytopenia of TAR syndrome frequently remits over the first few years of life .

Fanconi anemia

Aplastic anemia not present at birth, develops about 6 yr of age; fatal without bone marrow transplant; chromosomal breakage challenge test available for early diagnosis.

Wiskott-Aldrich syndrome (WAS)

Microthrombocytopenia

Eczema

Recurrent infections

X-linked

Normal number of megakaryocytes

Successful bone marrow

transplantation cures WAS .

Microthrombocytes

Refrences

1 .Nelson textbook of pediatrics 19th edition, Chapter 476.

2 .Dan L. Longo, HARRISON’S Hematology and Oncology ;

3 .Childhood idiopathic thrombocytopenic purpura (itp): over 40 year of experiences; Medical Journal of Islamic World Academy of Sciences 19:4, 151-160, 2011.4 .

:// . . / /http www uptodate com contents clinica- - - - -l manifestations and evaluation of thromb

- -ocytopenia in children

Thank you