Anemias

Anemia is the presence of reduced hemoglobin in the blood. Formally, the World Health Organization (WHO) defines anemia by the hemoglobin concentration in the blood according to age and sex :

• adult men: <130 g/L
• adult women: <120 g/L

Values for pregnant women and children are different.

Pathology

Etiology

The etiology of anemia is traditionally categorized by the volume of the red cell, i.e. the mean cell volume (MCV), into microcytic (MCV <82 fL), normocytic (MCV = 82-98 fL) and macrocytic (MCV >98 fL) anemias.

Microcytic (MCV <82 fL)

• iron deficiency anemia (IDA): commonest cause of anemia
• thalassemia
• anemia of chronic disease: e.g. rheumatoid arthritis, Hodgkin lymphoma, malignancy, chronic infection
• sideroblastic anemia: very rare

Normocytic (MCV = 82-98 fL) 

• dietary anemia: mixed iron, vitamin B12, and/or folate deficiencies
• renal failure
• hemolytic anemia
• erythrocyte disease
  • intrinsic: membranopathy, enzymopathy, hemoglobinopathy
  • extrinsic: immune-mediated, microangiopathic, associated with infection, chemical agent (spider venoms), metabolic
• anemia of chronic disease
• bone marrow disease:
  • aplasia
    • idiopathic
    • paroxysmal nocturnal hemoglobinuria (PNH)
    • Fanconi syndrome
  • red cell aplasia
    • congenital
    • acquired
    • Diamond-Blackfan syndrome
  • myelodysplastic syndrome
• secondary bone marrow disease
  • infiltrative disease: metastases, lymphoma
  • drugs
  • toxins e.g. selenium
  • irradiation
  • infective: viral
  • immunological

Macrocytic (MCV >98 fL)

• dietary deficiency: vitamin B12, folate
• medication toxicity: hydroxyurea, AZT, methotrexate
• dyserythropoiesis, myelodysplastic syndrome, clonal hematologic disorder
• hereditary hematologic disorders

Siehe auch:

• Cameron-Läsionen

und weiter:

• Achor-Smith-Syndrom