Anemia Types and Causes

Anemia of Chronic Disease

• Occurs in the setting of chronic infection, cancer, inflammation, or trauma
• Release of inflammatory cytokines suppresses erythropoiesis
• Laboratory findings: low serum iron, low TIBC, and low serum transferrin levels; serum ferritin levels are increased
• Anemia is usually normocytic and normochromic, but may be microcytic and hypochromic as well
• No specific treatment is necessary other than treating the underlying process; do not give iron

Aplastic Anemia

• Bone marrow failure leading to pancytopenia (anemia, neutropenia, thrombocytopenia)
• Causes: idiopathic, radiation exposure, medications, viral infection, chemicals
• Clinical features: symptoms of anemia, signs and symptoms of thrombocytopenia, increased incidence of infections
• Diagnosis: normocytic, normochromic anemia; bone marrow biopsy reveals hypocellular marrow and absence of progenitors of all three hematopoietic cell lines
• Treatment: bone marrow transplantation, transfusion of PRBCs and platelets, treating underlying causes

Vitamin B12 Deficiency

• Vitamin B12 is involved in the conversion of homocysteine to methionine and methylmalonyl CoA to succinyl CoA
• Vitamin B12 stores in the liver can sustain an individual for 3 or more years
• Main dietary sources of vitamin B12 are meat and fish
• Causes: pernicious anemia, gastrectomy, poor diet, Crohn's disease, ileal resection, and certain organisms competing for vitamin B12
• Clinical features: anemia, sore tongue, neuropathy
• Diagnosis: peripheral blood smear shows megaloblastic anemia and hypersegmented neutrophils; serum vitamin B12 level is low