hemolytic anemia

Hemolytic anemia is a form of anemia where red blood cells are destroyed faster than they can be replaced. This may happen either intravascularly or extravascularly.

Clinical presentation

The patient presents with anemia and jaundice. Diagnosis is based on several laboratory parameters:

• reticulocytosis
  • suggested by a raised mean cell volume (MCV)
  • a blood film can confirm
• increased unconjugated bilirubin
• increased lactate dehydrogenase
• decreased haptoglobin

Pathology

With the excessive red cell destruction, there is compensatory erythroid hyperplasia in the bone marrow, resulting in increased production of erythroid precursors (reticulocytosis).

Causes

Hereditary

Hemolytic anemia can be due to defects in:

• metabolism 
  • glucose-6-phosphate dehydrogenase deficiency
  • pyruvate kinase deficiency
• red blood cell membrane production
  • hereditary spherocytosis 
  • hereditary elliptocytosis
• hemoglobin production
  • thalassemia
  • sickle-cell disease
  • congenital dyserythropoietic anemia

Acquired

• autoimmune diseases
  • systemic lupus erythematosus
  • rheumatoid arthritis
  • infection
    • viral
    • mycoplasma
  • lymphoproliferative disorder
• portal hypertension (resulting in hypersplenism)
• paroxysmal nocturnal hemoglobinuria (PNH)
• drug-induced
  • phenacetin
  • quinidine
  • alpha-methyldopa
• lead poisoning
• secondary to malignancy
• prosthetic heart valves: primarily due to mechanical trauma of the RBCs

Radiographic features

Chronic hemolytic anemia may present on imaging as marrow reconversion and/or splenomegaly. Some underlying causes of hemolytic anemia (e.g. sickle cell disease) have more specific imaging findings: see the relevant articles for more details.

Siehe auch:

• haemolytic anaemia with secondary gout
• secondary gout