1 / 41

Bleeding disorders

Bleeding disorders. Dr. Edmond S. K. Ma Division of Haematology Department of Pathology The University of Hong Kong. Components of normal haemostasis. Blood vessels Endothelial cells Sub-endothelial surface Platelets: primary haemostasis Platelet membrane Platelet granules

rosa
Download Presentation

Bleeding disorders

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Bleeding disorders Dr. Edmond S. K. Ma Division of Haematology Department of Pathology The University of Hong Kong Bachelor of Chinese Medicine, The University of Hong Kong

  2. Components of normal haemostasis • Blood vessels • Endothelial cells • Sub-endothelial surface • Platelets: primary haemostasis • Platelet membrane • Platelet granules • Coagulation factors • Fibrinolytic pathway • Naturally occurring inhibitors of coagulation Bachelor of Chinese Medicine, The University of Hong Kong

  3. The endothelial cell Bachelor of Chinese Medicine, The University of Hong Kong

  4. Haemostatic response to vessel injury Bachelor of Chinese Medicine, The University of Hong Kong

  5. Conventional model of coagulation Bachelor of Chinese Medicine, The University of Hong Kong

  6. New model of coagulation Bachelor of Chinese Medicine, The University of Hong Kong

  7. The fibrinolytic pathway Bachelor of Chinese Medicine, The University of Hong Kong

  8. Naturally occurring inhibitors: e.g. Protein C pathway Bachelor of Chinese Medicine, The University of Hong Kong

  9. Coagulation tests • Prothrombin time • Activate partial thromboplastin time • Thrombin time • Fibrinogen level • Tests for platelet disorders • Platelet count • Platelet aggregation test • Skin bleeding time Bachelor of Chinese Medicine, The University of Hong Kong

  10. Conventional model of coagulation Bachelor of Chinese Medicine, The University of Hong Kong

  11. Prothrombin time • Tests the extrinsic and final common pathways • Prolongation in: • Liver disease • vitamin K antagonism (i.e. warfarin) and deficiency • Disseminated intravascular coagulation • Factor VII, X, V, II and fibrinogen defect Bachelor of Chinese Medicine, The University of Hong Kong

  12. Activated partial thromboplastin time • Tests the intrinsic and common pathways • Prolongation in: • Liver disease • Disseminated intravascular coagulation • Heparin therapy • Vitamin K antagonism or deficiency • Factor XII, XI, IX, VIII, X, V, II, and fibrinogen defect Bachelor of Chinese Medicine, The University of Hong Kong

  13. Thrombin time • Evaluate fibrinogen and for inhibition of thrombin action • Prolongation in: • Hypofibrinogenaemia • Dysfibrinogenaemia (http://www.fmshk.com.hk/hkabth) • Heparin therapy • Disseminated intravascular coagulation Bachelor of Chinese Medicine, The University of Hong Kong

  14. Platelet aggregometry: testing for platelet dysfunction Bachelor of Chinese Medicine, The University of Hong Kong

  15. Clinical features of bleeding disorders • History • Personal (age of onset) • Family • Pattern of bleeding • Platelet / vessel type • Coagulation type • Drugs • Associated systemic illnesses Bachelor of Chinese Medicine, The University of Hong Kong

  16. Platelet Bachelor of Chinese Medicine, The University of Hong Kong

  17. Bachelor of Chinese Medicine, The University of Hong Kong

  18. Platelet disorders • Bleeding due to low platelet count • Bleeding due to platelet dysfunction Bachelor of Chinese Medicine, The University of Hong Kong

  19. Bruises Bachelor of Chinese Medicine, The University of Hong Kong

  20. Petechiae Bachelor of Chinese Medicine, The University of Hong Kong

  21. Causes of Thrombocytopenia (N.B. analogous to anaemia) • Production failure • Isolated thrombocytopenia • Pancytopenia • Increased peripheral destruction • immune • non-immune • Splenic pooling (sequestration) • Hypersplenism • Dilutional • Massive blood transfusion Bachelor of Chinese Medicine, The University of Hong Kong

  22. Peripheral destruction: immune thrombocytopenia • Autoimmue • ITP • acute • chronic • Alloimmune • Neonatal alloimmune thrombocytopenia • Post-transfusion purpura Bachelor of Chinese Medicine, The University of Hong Kong

  23. Peripheral destruction: microangiopathic syndromes Bachelor of Chinese Medicine, The University of Hong Kong

  24. Inherited platelet disorders • Glycoprotein defect • GP IIb/IIIa: Glanzmann’s thrombasthenia • GP Ib/IX/V complex: Bernard-Soulier syndrome • Granule defect • Storage pool disease • Grey platelet syndrome • Hereditary thrombocytopenia • Bernard-Soulier syndrome • Wiskott-Aldrich syndrome (small platelets, eczema, immunodeficiency) • May-Hegglin anomaly Bachelor of Chinese Medicine, The University of Hong Kong

  25. Bernard-Soulier Syndrome Bachelor of Chinese Medicine, The University of Hong Kong

  26. May-Hegglin Anomaly Bachelor of Chinese Medicine, The University of Hong Kong

  27. Low platelet count Bone marrow examination Platelet antibodies Screening tests for DIC Normal platelet count Bleeding time Platelet aggregation study Special platelet function tests (e.g. nucleotide pool assay) von Willebrand disease study Approach to platelet disorders Bachelor of Chinese Medicine, The University of Hong Kong

  28. Haemophilia • Insufficient activity of the tenase complex Factor VIII deficiency Haemophilia A Factor IX deficiency Haemophilia B Bachelor of Chinese Medicine, The University of Hong Kong

  29. Haemophilia A Factor VIII deficiency Haemophilia B Factor IX deficiency Clinical presentation: haemarthrosis Coagulation screening test: isolated prolongation of APTT Diagnostic test: Factor assay Haemophilia Bachelor of Chinese Medicine, The University of Hong Kong

  30. Haemophilia: clinical problems • Recurrent joint bleeds  Progressive joint deformity • Factor inhibitors • Viral agents transmitted by blood products • Diagnosis of carrier status in females • family history • phenotype • mutation detection Bachelor of Chinese Medicine, The University of Hong Kong

  31. Haemarthrosis Bachelor of Chinese Medicine, The University of Hong Kong

  32. Haemophilia A showing severe disability Bachelor of Chinese Medicine, The University of Hong Kong

  33. Genomic organization of the human FVIII gene Bachelor of Chinese Medicine, The University of Hong Kong

  34. Intron 22 inversion of the FVIII gene Bachelor of Chinese Medicine, The University of Hong Kong

  35. Intron 22 inversion of FVIII • Seen in 40 - 50% of severe haemophilia A • Error of DNA replication during spermatogenesis • In males, absence of a second X favours intrachromosomal alignment • Maternal grandfather • Distal inversion more common Bachelor of Chinese Medicine, The University of Hong Kong

  36. Platelet adhesion Bachelor of Chinese Medicine, The University of Hong Kong

  37. Von Willebrand Disease • Defect of Von Willebrand Factor • quantitative • qualitative • Autosomal dominant • Normal function of VWF • Mediate platelet adhesion • Stabilize factor VIII in circulation • Localize factor VIII to site of vessel injury Bachelor of Chinese Medicine, The University of Hong Kong

  38. Von Willebrand Disease • Pattern of bleeding • Usually platelet type • Coagulation type if severe • Diagnostic tests • Factor VIII activity • VWF antigen assay • VWF function, e.g. ristocetin cofactor assay Bachelor of Chinese Medicine, The University of Hong Kong

  39. Multimer analysis in vWD Bachelor of Chinese Medicine, The University of Hong Kong

  40. Comparison between haemophilia and vWD Bachelor of Chinese Medicine, The University of Hong Kong

  41. Reference • Chapters 18 - 20, Essential Haematology by AV Hoffbrand, JE Pettit and PAH Moss, 4th Edition 2001, Blackwell Science Bachelor of Chinese Medicine, The University of Hong Kong

More Related