Hemat Approach😍

Pancytopenia

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  • Pancytopenia → On bone marrow biopsy (Cellularity = 100 - Age)

Bone marrow failure syndromes

  1. Aplastic anemia
  1. Myelodysplastic syndrome (MDS)
  1. Pure Red Cell Aplasia (PRCA)
  1. Secondary myelofibrosis (Secondary to drugs & toxin)

Approach to Pancytopenia

  • Hypocellular marrow
      1. Aplastic anemia: Chronic course
      1. MDS (Hypocellular variants)
      1. Aleukemic leukemia
  • Hypercellular marrow
      1. AML/ALL
      1. MDS
      1. Megaloblastic anemia (Rare)
      1. PMF
      1. Hairy cell leukemia (Good prognosis)
      1. PNH
      1. Lymphoma with BM involvement
      1. TB, SLE, HIV, sarcoidosis

Reticulocyte Production Index (RPI)

  • Best parameter for assessing erythropoiesis
  • Measures % of young, immature RBCs (reticulocytes) in blood
  • Used when polychromatophilic macrocytes seen on smear
    • These are prematurely released reticulocytes / shift cells
  • Formula:
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      RPI = Corrected Retic Count / (Maturation Time in days)
      RPI = (Hg of Patient / Target Hg) × (Reticulocyte / 2)
  • Maturation Time:
    • Varies depending on severity of anemia
  • Interpretation:
    • RPI < 2.5:
      • Hypoproliferative anemia.
        • Serum Ferritin (Iron Store) → ↓↓
        • MCV < 100 fL
        • S. Fe → ↓↓ 
        • TIBC → ↑↑ 
        • PSAT → Decreased (<33%) 
          • (Serum Ferritin / TIBC) x 100).
      • Causes:
        • Iron deficiency anemia (initially hypoproliferative)
        • Anemia of chronic disease
        • Sideroblastic anemia
        • Thalassemia trait
    • RPI > 2.5:
      • Hyperproliferative anemia.
  • Corrected Reticulocyte Count
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    • For severe anemias
    • Formula:
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        Corrected Retic Count = Retic count (%) x (Patient's Hb / Desired Hb)
    • Average normal Hb used: 15 g.

Reticulocytes

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Bluish color inside granules
Bluish color inside granules
  • Normal count: 0.5 to 2%
  • Contain Reticulum of RNA
  • Requires Supra vital staining
    • Stains RNA in reticulocytes
    • To be viewed ≤ 2 hrs after staining.
      • New methylene blue >>
      • Brilliant Cresyl blue
  • Super Vital () avanel → Brilliantil () padikkanam → New (New meth) Life kittum

Significance in Different Anemias

Feature
Iron Deficiency
Thalassemia
AOCD
Sideroblastic Anemia
Macrocytosis (Megaloblastic)
Serum Iron
↑
Normal
↓
↑
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Ferritin
↓ or normal
Normal
↑
↑
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TIBC
↑
Normal
↓
N/A
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Transferrin Saturation
Very low
Normal
Low
N/A
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MCV
Low / Normal
Low / Normal
Normal / Low
Low / High
High
Retic Count
Low
Normal
Low / Normal
Low / Normal
Low

Approach to Polycythemia

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Male
Female
Hb
>16.5g/dL
>49%
PCV
>16g/dL
>48%

Classification of Polycythemia

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Absolute Polycythemia / Erythrocytosis

  • ↑ RBC mass
  • Primary Polycythemia
    • Polycythemia Rubra Vera (PCRV)
      • A/w ↑ WBC, RBC & platelets
    • Erythropoietin (EPO) Normal / ↓ 
      • Normal range: 4 to 10
  • Secondary Polycythemia
    • Causes with Hypoxia:
      • COPD
      • Smoker
      • Obstructive sleep apnea
      • CO poisoning
    • Erythropoietin (EPO) ↑
    • Causes with No Hypoxia 
      (Paraneoplastic polycythemia):
      • Renal cell carcinoma (RCC)
      • Hepatoma
      • Cerebellar hemangioblastoma
      • Uterine leiomyoma
      • Pheochromocytoma

Relative Erythrocytosis

  • Due to ↓ plasma volume
  • Examples:
    • Post dengue
    • Dehydration
  • Management:
    • Hydration

Approach to Hemolysis😍

DAT Positive → Immune Mediated

DAT Result
Mechanism
Category
Examples
Positive
Immune Mediated
Antibody related
• Warm Antibody
• Cold Antibody
• Paroxysmal Cold Hemoglobinuria (PCH)
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Others
• Drugs
• Blood Transfusion reactions,
• Hemolytic disease of Newborn (HDN)
Negative
Non-Immune
Congenital
• Sickle Cell Anemia
• Thalassemia
• Hereditary Spherocytosis
• G-6-PD Deficiency
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Acquired
• Paroxysmal Nocturnal Hemoglobinuria (PNH)
• Fragmentation Hemolysis/MAHA
• Drugs / Infection

Classification by Site of RBC Destruction

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Feature
Intravascular Hemolysis
Extravascular Hemolysis
Site
Within blood vessels
Spleen, Liver, Bone Marrow
Examples
• MAHA (eg. HUS)
• PNH 
• PCH 
• Infections
• Drugs (some)
• Snake bites
• Hereditary Spherocytosis
• Sickle Cell Anemia
• Thalassemia
• G-6-P D deficiency
• Warm AIHA
• Cold Agglutinin Disease
Common Presentation
Acute > Chronic
Insidious, Rapidly Progressive
LDH
+++ (high)
++ (moderate)
Serum Haptoglobulin
Decreased
(Hb bind with Haptoglobulin)
Decreased (↓↓) ????
Investigations
• ↑Hb in plasma & urine
• Hemoglobinuria
• Hemosiderinuria
• ↑↑S. bilirubin
• ↑↑↑↑S. bilirubin (↑ Protoporphyrin)
• Splenomegaly
• Urobilinogen positive
• Tissue iron ↑↑
• S. ferritin ↑↑
Urine Color
High coloured urine 
Normal
Both Intra- and Extravascular:
• G6PD Deficiency
• Cold AIHA
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PURE RED CELL APLASIA

  • Diamond Blackfan Syndrome
    • Congenital cause.
    • Associated with RP S19.
  • Thymoma/CLL
    • Acquired cause
  • Mnemonic:
    • For Pure () Diamond () Call (CLL) the mama (thymoma)
    • mRP → $19 (RP S19)
  • Transient Aplastic Crisis
    • Seen in hereditary spherocytosis and SCA
    • Caused by Parvovirus B19 infection.
    • Presents with sudden reticulocytopenia.
    • Smear shows giant Pronormoblasts.
    • Treatment: IVIG.
  • Post EPO administration
    • Due to anti-EPO antibodies.