Approach to Hemolytic Anemia
CLASSIFICATION OF HEMOLYTIC ANEMIAS
Intra Corpuscular Defects | Extra Corpuscular Factors | |
---|---|---|
Hereditary | • Hemoglobinopathies • Enzymopathies • Membrane-cytoskeletal defects | • Familial hemolytic uremic syndrome |
Acquired | • Paroxysmal nocturnal hemoglobinuria | • Mechanical destruction (microangiopathic) • Toxic agents • Drugs • Infectious • Autoimmune |
classification of haemolytic disorders
Inherited hemolytic disorders
-
Defects in the structure of the red cell membrane:
- Hereditary spherocytosis
- Hereditary elliptocytosis
- Hereditary stomatocytosis
-
Defects of erythrocyte metabolism:
- G6PD deficiency
- Pyruvate kinase deficiency
- Other enzyme disorders
-
Qualitative haemoglobin disorders:
- Stable variants, such as sickle cell disease
- Unstable variants
-
Quantitative haemoglobin disorders:
- Impaired globin chain synthesis
- Thalassaemias
Hemolytic Anemia Diagnosis
Two main principles:
- Confirm hemolysis
- Determine the etiology
The Key To The Etiology Of Hemolytic Anemia
- The history
- The peripheral blood film
How to diagnose hemolytic anemia
- New onset pallor or anemia
- Jaundice
- Splenomegaly
- Gall stones - Calciumbilirubinate stones
- Dark colored urine (hemoglobinuria)
- Leg ulcers (poor circulation and microinfarcts, healing is delayed and infection becomes established).
Patient History
- Acute or chronic
- Medication/Drug precipitants
- G6PD
- AIHA
- Family history
- Concomitant medical illnesses
- Clinical presentation
GENERAL FEATURES OF HEMOLYTIC DISORDERS
- General Examination: Jaundice, Pallor, Bossing Of Skull
- Physical Findings: Enlarged Spleen
- Hemoglobin: From Normal To Severely Reduced
- MCV: Usually Increased
- Reticulocytes: Increased
- Bilirubin: Increased [mostly Unconjugated]
- LDH: Increased
- Haptoglobulin: Reduced To Absent
Laboratory Diagnosis of Hemolytic Anemia:
Evidence for Red cell Destruction
- i) PERIPHERAL BLOOD SMEAR → - Burr Cell - Tear drop cell (Intravascular Hemolysis) - Fragmented cell ⇒ Spherocytes - Spherocytes → H. spherocytosis - Malaria → Malaria parasite - Sickle cells → Sickle cell anemia
- ii) Plasma haptoglobin & Plasma hemopexin → ↓
- iii) Plasma Hb ↑
- iv) Serum LDH & Serum Carboxy Hb → ↑
- v) Indirect bilirubin & urobilinogin → ↑
- vi) Red cell survival → ↓ Using Chromium 52
Evidence of Red cell Generation:
- Peripheral blood smear
- Polychromasia
- Nucleated red cells
- Reticulocyte count → ↑
Laboratory Evaluation of Hemolysis
Laboratory Evaluation of Hemolysis | Extravascular | Intravascular |
---|---|---|
HEMATOLOGIC | ||
Routine blood film | Polychromatophilia | Polychromatophilia |
Reticulocyte count | ↑ | ↑ |
Bone marrow examination | Erythroid hyperplasia | Erythroid hyperplasia |
PLASMA OR SERUM | ||
Bilirubin | Unconjugated ↑ | Unconjugated |
Haptoglobin | ↓, Absent | Absent |
Plasma hemoglobin | N/↑ | ↑↑ |
Lactate dehydrogenase | ↑ (Variable) | ↑↑ (Variable) |
URINE | ||
Bilirubin | + | + |
Hemosiderin | 0 | + |
Hemoglobin | 0 | + → severe cases |