Understanding Platelet Disorders

Platelet disorders encompass a range of conditions that affect the function or production of platelets, crucial components of blood responsible for clotting. These disorders can manifest in various ways, leading to abnormal bleeding or clotting tendencies, posing significant health risks. Understanding the underlying causes, recognizing symptoms, and exploring treatment options are vital for effectively managing these conditions and minimizing their impact on individuals' health and well-being. This introduction aims to provide insight into the complexities of platelet disorders, offering a foundation for further exploration and understanding.

1. Immune Thrombocytopenic Purpura
   • It is a platelet disorder in which there is isolated thrombocytopenia and the platelets are less than 1,00,000 per microliter.
   • Acute Immune Thrombocytopenic Purpura:
   • Immune Thrombocytopenic Purpura causes
     • Primary causes - EBV, CMV, and Rubella.
     • Secondary causes- Myelodysplastic syndrome, SLE, and HIV.
   • Clinical features of Immune Thrombocytopenic Purpura (ITP)
     • The patient will present with Recurrent nose bleeding.
     • Menorrhagia in females
     • Petechiae in ankles.
     • Purpura will occur that is non-palpable.
     • Spleen will remain normal but may appear palpable in rare cases of ITP.
     • Sometimes mucocutaneous bleeding can occur. Eg.- epistaxis, hematuria, and gastrointestinal bleeding.
   • Diagnosis and Workup of ITP
     • The platelet counts will be low and mostly these are less than 1,00,000 per microliter.
     • In peripheral smear, the platelet count is less and the size is relatively larger.
     • On bone marrow aspiration, normal or large-size megakaryocytes will be seen. The number of megakaryocytes will be high.
   • Treatment of Acute Immune Thrombocytopenic Purpura 
     • Intravenous steroids like Methylprednisolone are an important line of management.
     • It is very important to clarify the blood group of the patient because RH-positive and RH-negative patients are treated differently.
     • In Rh+ patients- RhoGAM immunoglobulin can also be given. The mechanism of action is saturation of Fc receptors. This causes inhibition of the Fc receptors function.
     • In Rh-ve patients- intravenous immunoglobulins are given that help in the clearance of harmful antibodies.
     • No platelet transfusion is recommended because it will worsen the situation.
     • In the case of chronic immune thrombocytopenic purpura patients treatment is different.
     • Elective splenectomy is recommended. This can make the patient susceptible to infections, therefore vaccines against encapsulated bacteria like pneumococcus, meningococcus, and hemophilus influenza should be administered to the patient after splenectomy.
2. Hemophilia A
   • Hemophilia A is caused by factor VIII deficiency.
   • It is an X-linked recessive disease and the girls act as carriers whereas the disease is present in boys.
   • Clinical Features of Hemophilia A
     • There will be a family history of disease present.
     • The patient will present with easy disability. Bruises and marks at different places of the body mainly knees and elbows will be seen.
     • The most common feature is bilateral hemarthrosis which is bleeding in joints. It might be asymmetrical.
     • The patient is at great risk of developing intracranial hemorrhage.
     • The patient will be having a history of excessive bleeding on circumcision.
   • Investigations of Hemophilia A
     • A screening test is done in the form of a coagulogram.
       • Bleeding time is normal. (Normal range- 2 to 9 minutes).
       • Prothrombin time is normal. (Normal range- 11-16 sec)
       • Partial thromboplastin time is elevated. (Normal range- 30-40 sec)
       • The confirmatory test is to detect the level of factor 8. It will be extremely low.
   • Treatment of Hemophilia A
     • Factor VIII concentrate is given to the patient.
     • For mucosal bleeding desmopressin is a drug that can be administered.
     • For life-threatening bleeding ffp or cryoprecipitate is given.
     • Cryoprecipitate is used in developing countries only in case of life-threatening bleeding causes.
3. Bernard Soulier Syndrome
   • It is an autosomal recessive disease in which the adhesion part of the hemostasis does not take place due to genetic defects.
   • Receptor Ib/IX/V binds to the von Willebrand factor and causes adhesion.
   • The patient might have a history of consanguineous marriage.
   • Clinical features of Bernard Soulier Syndrome
     • Recurrent epistaxis
     • Menorrhagia
     • Post-operative excessive bleeding
   • Investigations of Bernard Soulier Syndrome
     • Platelet counts will be normal but there will be defects in the quality of the platelets.
     • Peripheral smear will show giant platelets.
     • Gram will show high bleeding time whereas other factors will be normal.
     • Platelet function analyzer is another technique that can be used to diagnose it.
     • The very important test to diagnose this disease is the Ristocein aggregation test:
     • Failure to agglutinate with Ristocetin.
     • Treatment is Platelet Transfusion.
4. Wiskott Aldrich syndrome
   • It is a genetic disorder that can be memorized using a mnemonic.
   • WAITER
     • Wiskott
     • Aldrich
     • Immunodeficiency (Low IgM levels)
     • Thrombocytopenia
     • Eczema
     • Recurrent pyogenic infection
5. Glanzmann Thrombocytopenia
   • It is a genetic disorder in which the platelet aggregation step of hemostasis is abnormal.
   • The defect in chromosome 17 is found.
   • It is an autosomal recessive condition.
   • Qualitative and quantitative deficiency of the IIb/B3 receptor.
   • There will be a history of consanguineous marriage.
   • Clinical features of Glanzmann Thrombocytopenia
     • Menorrhagia
     • Gingival bleeding
     • Postoperative bleeding
     • Recurrent epistaxis
     • GIT bleeding
   • Investigations of Glanzmann Thrombocytopenia
     • Platelet count will be normal.
     • This size of the platelets own smear will also be normal.
     • On coagulogram, bleeding time is increased.
     • A platelet function analyzer can be used.
     • Ristocein aggregation test is normal
   • Treatment of Glanzmann Thrombocytopenia
     • Platelet transfusion
     • Desmopressin for bleeding.
6. Von Willebrand disease
   • It has two types:
     • Type 1
       • It is most common and VWF function is altered.
       • The role of VWF is platelet adhesion and it also binds to factor 8.
       • The quality and quantity of the factor will be deficient.
     • Type 2
       • Von Willebrand factor multimers are destroyed by ADAM TS13.
       • VWF factor is dysfunctional.
       • Only quality is deficient.
   • Treatment of Von Willebrand disease
     • Infusion of VWF and Factor 8.

Also Read: Primary Biliary Cholangitis : Pathophysiology, Clinical Features

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