Thrombocytopenia: Quantitative Bleeding Disorders

• Bleeding disorders are categorized into quantitative and qualitative disorders

Quantitative Disorders

• Thromocytopenia is defined by a platelet count of less than 100,000/uL
• Thrombocytopenia is a common cause of clinically important bleeding
• Thrombocytopenia presents clinically as petechiae, purpura, and ecchymoses
• Thrombocytopenia is caused by decreased production, increased destruction, or increased sequestration of platelets in the spleen, or dilution of platelets
• Impaired or decreased platelet production may be congenital or acquired, associated with conditions like megakaryocyte hypoplasia, aplastic anemia, or infiltration of the bone marrow by malignant cells
• Immune thrombocytopenic purpura (ITP) is differentiated into acute and chronic forms based on age of onset, sex predilection, prior infection, and duration, among other characteristics
• Immunologic drug-induced thrombocytopenia is caused by drug-dependent antibodies, drug-induced auto-antibodies, hapten-induced antibodies, or immune complex-induced thrombocytopenia, typically occurring 1-2 weeks after exposure to a new drug
• Post-transfusion purpura is a rare disorder typically developing a week after transfusion of platelet-containing blood products and involves (+) anti-HPA-1a (platelet antibodies) from recipient
• Isoimmune neonatal thrombocytopenia develops because the mother lacks a platelet-specific antigen, leading to IgG Ab from mothers attaching the fetal platelet antigen.
• Thrombotic thrombocytopenic purpura is a rare disorder related to accumulation of ultra large vWF multimers in plasma due to deficient ADAMTS-13
• Disseminated Intravascular Coagulation (DIC) is a rare but serious condition with abnormal blood clotting throughout the body
• Hemolytic Uremic Syndrome (HUS) damages blood vessels in the kidneys and causes acute kidney failure
• Thrombocytosis is characterized by an increase in circulating platelets, specifically > 450,000/uL
• Reactive thrombocytosis involves elevation in the platelet count secondary to inflammation, trauma, or other underlying conditions, where platelet counts can be between 450,000-800,000/uL

Qualitative Disorders

• Clinical presentation includes excessive bruising and superficial bleeding
• Qualitative disorders are categorized based on adhesion disorders, aggregation defects, storage pool diseases, and procoagulant activity defects
• Glanzmann Thrombasthenia involves a bleeding disorder, abnormal in vitro clot retraction test and normal platelet count
• Bernard-Soulier Syndrome manifests during infancy/childhood
• Bernard-Soulier Syndrome involves ecchymoses, epistaxis, and gingival bleeding.
• Storage-Pool Defects occur when giant platelets are present

Vascular Disorders

• An alpha granules deficiency is described by autosomal recessive absence of alpha granules and large Platelets
• A Quebec platelet disorder is an autosomal dominant
• Defect in multimerin
• Hereditary vascular disorders include Hereditary Hemorrhagic Telangiectasia, Hemangioma Thrombocytopenia Syndrome, and Ehler-Danlos Syndrome
• Acquired vascular disorders include Allergic Purpura, Senile Purpura, Purpura Simplex, and Psychogenic Purpura

Coagulation Disorders

• Coagulation disorders include hereditary disorders and acquired disorders
• Hereditary disorders have wither qualitative or quantitative defects in single coagulation factor
• Acquired disorders have a defiecency in multiple coagulation factors
• Common presentations of coagulation disorders includelarge ecchymosis and hematomas, bleeding from the nose, gums, GIT, joints, and excessive bleeding post-dental, surgical or trauma
• Hemophilia A is a "Royal Disease"
• Incidence is found in 1 in 10,000 live births
• Severity is linked to factor VIII:C activity, occurring in joints, urinary tract, intracranial, and deep muscle injuries
• Hemophilia B is clinically indistinguishable from Hemophilia A
• Von Willebrand disease is the qualitative or quantitative absence of VWF
• Von Willebrand type 1 is the most common, is autosomal dominant and has prolonged bleeding time with a normal platelet count
• Von Willebrand type 2 has qualitative alterations in VWF structure and function
• Von Willebrand type 3 is the least common and most severe

Acquired coagulation disorders

• Disseminated intravascular coagulation (DIC) is also known as defibrination syndrome, consumptive coagulopathy
• DIC occurs as a secondary complication of other diseases.
• Laboratoy results show increased D-dimer and antithrombin III
• Acquired Von Willebrand Disease is related to Lymphoproliferative disease, tumors and autoimmune diseases

Overview of quantitative bleeding disorders with a focus on thrombocytopenia. Includes causes such as decreased platelet production, increased destruction, or splenic sequestration. Specific conditions like immune thrombocytopenic purpura (ITP) and drug-induced thrombocytopenia are also discussed.