Neutropenia Fever, pharyngitis, oral ulceration, cellulitis, Congenital or drug-induced agranulocytosis, leukemia lymphadenopathy, bacteremia, gingivitis
Thrombocytopenia Petechiae, ecchymosis, gastrointestinal hemorrhage, ITP, leukemia epistaxis
Coagulopathy Bruising, hemarthrosis, mucosal bleeding von Willebrand disease, hemophilia, DIC
Thrombosis Pulmonary embolism, deep vein thrombosis Lupus anticoagulant; protein C, protein S, or antithrombin III deficiency; factor V Leiden, prothrombin 20210
DIC, Disseminated intravascular coagulation; ITP, idiopathic thrombocytopenic purpura.
Cord 16.8 13.7–20.1 55 45–65 5 18,000 9000–30,000 61 40–80 31 2 6 7 blood 2 wk 16.5 13–20 50 42–66 1 12,000 5000–21,000 40 3 mo 12.0 9.5–14.5 36 31–41 1 12,000 6000–18,000 30 6 mo–6 12.0 10.5–14 37 33–42 1 10,000 6000–15,000 45 7–12 yr 13.0 11–16 38 34–40 1 8000 4500–13,500 55
Female 14.0 12–16 42 37–47 1.6 7500 5000–10,000 55 35–70 35 3 7 0
Male 16.0 14–18 47 42–52
From Behrman RE, editor: Nelson Textbook of Pediatrics, ed 14, Philadelphia, 1992, WB Saunders. WBCs, White blood cells.
erythroid line and is made by the juxtaglomerular apparatus of the kidney in response to local tissue hypoxia. Thenormally high hemoglobin level of the fetus is a result of fetal erythropoietin production in the liver in response tolow Po2 in utero. Erythropoietin leads to production of theerythroid colony-forming unit. The earliest recognizableerythroid cell is the erythroblast, which forms eight or moredaughter cells. The RBC nucleus becomes gradually pyknotic and eventually is extruded. The cell is then releasedfrom the marrow as a reticulocyte that maintains residual mitochondrial and protein synthetic capacity. Thesehighly specialized RBC precursors are engaged primarily inthe production of globin chains, glycolytic enzymes, and heme. Iron is taken up via transferrin receptors and incorporated into the heme ring, which combines with globinchains synthesized within the immature RBC. When themessenger RNA and mitochondria are gone from the RBC,heme or protein synthesis is no longer possible; however,the RBC continues to function for its normal life span of about 120 days.