Anemia
also see Normal values, CBC, Anemia in the newborn, Anemia, physiologic

I. Microcytic, Hypochromic – due to impairment of synthesis of heme or globin

• Iron-deficiency anemia – low serum iron and ferritin, high TIBC

• acute & chronic inflammation – can be normocytic or microcytic; have low serum iron, low TIBC, high ferritin; iron is not released from storage sites in macrophages

• thalassemias

• sideroblastic – e.g., lead poisoning, pyridoxine deficiency (may be due to INH), pyridoxine dependency.

  • have metabolic block so can’t incorporate iron into hemoglobin

  • iron accumulates in mitochondria so get ringed sideroblasts when stained

  • basophilic stippled RBCs

II. Normochromic, Normocytic:

• low retic count:

  • disease states that cause pancytopenia; drugs or toxins

  • bacterial or viral suppression

  • pure RBC aplasia:

    • Diamond-Blackfan Anemia (often macrocytic, earlier onset, high hgb F, i antigen)

    • Transient Erythroblastopenia of Childhood

• normal or high retic count:

  • also see Anemia, Acute hemolytic

  • antibody-mediated hemolytic anemia:

    • iso-immune

    • auto-immune (infectious, drugs, lymphomas, disorders of immune regulation)

  • hemorrhagic disorder

  • microangiopathic hemolytic anemia (e.g. artificial heart valves, HUS, DIC, hemangiomas)

  • membrane defects

    • spherocytosis (defects in spectrin, less deformability): Causes of spherocytosis include: - Hereditary Spherocytosis, Immunohemolytic Anemia (isoimmune and autoimmune), and  membrane damage (Clostridial toxin, severe burns, Wilson disease)

    • elliptocytosis

    • stomatocytosis

    • paroxysmal nocturnal hemoglobinuria: complement-mediated lysis. Consider with pancytopenia, unexplained thrombosis (especially intra-abdominal) and an elevated reticulocyte count and LDH. A rare diagnosis.

  • hemoglobinopathies

  • enzyme defects:

    • G6PD deficiency

    • Pyruvate Kinase deficiency

from CHLA Board Review 2005