Quartz 5

Hematology (5%)

2 min read

Autoimmune Disorders

Coagulation Disorders

  • Hemophilia A

    • X-linked recessive → most common in males

    • Classically presents with hemarthrosis

    • ↓ Factor VIII

  • Hemophilia B

    • “Christmas disease” → Factor IX deficiency

    • Clinically indistinguishable from Hemophilia A

Clotting Factor Disorders

Thrombocytopenias

Cytopenias

  • Anemia

  • Leukopenia

    • ANC <1500 (oncology: <1000)

  • Lymphopenia

Cytoses

Polycythemia

  • Primary (JAK2 mutation)

  • Secondary (e.g., smokers, hypoxia)

  • No splenomegaly

Polycythemia Vera (PCV)

  • JAK2 mutation

  • Aquagenic pruritus

  • Erythromelalgia (red hands)

  • Ruddy cyanosis

  • ↑ LDH

  • Treatment: phlebotomy, low-dose aspirin

Thrombocytosis

  • Usually reactive

  • Essential thrombocythemia → JAK2 mutation

  • ↑ risk of PE/DVT

  • Risk of AML transformation

Hereditary Disorders

Hereditary Spherocytosis

  • Most common in Northern Europeans

  • Pigmented gallstones

  • Hyperchromic anemia, ↑ RDW, ↑ MCHC

  • Diagnosis: osmotic fragility test

G6PD Deficiency

  • Most common in males (African, Mediterranean)

  • ↑ sensitivity to oxidative stress:

    • Fava beans

    • Infections

    • Medications (sulfa, nitrofurantoin, phenazopyridine)

Hemochromatosis

  • Total body iron overload

  • Bronzed skin, arthralgias

  • Genetic testing (HFE gene)

Sickle Cell Disease

  • Functional asplenia → ↑ risk of encapsulated organisms

  • Prophylaxis: antibiotics

Complications

  • Osteomyelitis: Salmonella

  • Aplastic crisis: Parvovirus B19

  • Microthrombosis

    • Avascular necrosis (long bone heads)

    • H-shaped vertebrae

    • Priapism

Management

  • Hydroxyurea

  • Folate supplementation

Acute Chest Syndrome

  • New lung infiltrate + fever, cough, chest pain, tachypnea

  • Leading cause of death

  • Treatment:

    • Oxygen

    • IV fluids

    • Analgesia

    • ± Exchange transfusion

Thalassemia

Immunologic Disorders

Neoplasms, Premalignancies, and Malignancies

  • Acute lymphocytic leukemia (ALL)

  • Chronic lymphocytic leukemia (CLL)

  • Acute myelogenous leukemia (AML)

  • Chronic myelogenous leukemia (CML)

  • Lymphoma

  • Multiple myeloma

  • Myelodysplasia

Transfusion Reactions

  • TACO (Transfusion-associated circulatory overload)

  • TRALI (Transfusion-related acute lung injury)

Thrombotic Microangiopathies

Thrombotic Thrombocytopenic Purpura (TTP)

  • Pentad:

    • MAHA

    • Thrombocytopenia

    • Neurologic symptoms

    • Renal dysfunction

    • Fever

Hemolytic Uremic Syndrome (HUS)

  • MAHA

  • Thrombocytopenia

  • Renal insufficiency

  • Classically in children after diarrheal illness

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