Color Atlas of Hematology - Practical Microscopic and Clinical ...

132Erythrocyte and Thrombocyte AbnormalitiesTable 23Normal ranges for physiological iron and its transport proteinsOld unitsSI unitsSerum ironNewborns 150–200µg/dl 27–36µmol/lAdultsFemale 60–140µg/dl 11–25µmol/lMale 80–150µg/dl 14–27µmol/lTIBC 300–350µg/dl 54–63µmol/lTransferrin 250–450µg/dl 2.5–4.5 g/lSerum ferritinTIBC = Total iron binding capacity.30–300µg/l(15–160µg/l premenopausal)This usually renders determination of transferrin and total iron bindingcapacity (TIBC) unnecessary. If samples are being sent away to a laboratory,it is preferable to send serum produced by low-speed centrifugation,since the erythrocytes in whole blood can become mechanically damagedduring shipment and may then release iron. Table 23 shows the variationof serum iron values according to gender and age.It is important to note that acute blood loss causes normochromic anemia.Only chronic bleeding or earlier serious acute blood loss leads to irondeficiency manifested as hypochromic anemia.Iron Deficiency and Blood Cell Analysis Focusing on the erythrocyte morphologyis the quickest and most efficient way to investigate hypochromicanemia when the serum iron has dropped below normal values. In hypochromicanemia with iron and hemoglobin deficiency (whether due to insufficientiron intake or an increased physiological iron requirement),erythrocyte size and shape does not usually vary much (see Fig. 45). Only inadvanced anemias (from approx. 11 g/dl, equivalent to 6.27 mmol/l Hb)are relatively small erythrocytes (microcytes) with reduced MCV andMCH and grayish stained basophilic erythrocytes (polychromatic erythrocytes)seen, indicating inadequate hemoglobin content. Cells with theappearance of relatively large polychromatic erythrocytes are reticulocytes.The details of their morphology can be seen after supravital staining(p. 141). A few target cells (p. 139) will be seen in conditions of severe irondeficiency.In severe hemoglobin deficiency ( 8 g/dl, equivalent to 4.96 mmol/l)the residual hemoglobin is found mostly at the peripheral edge of theerythrocyte, giving the appearance of a ring-shaped erythrocyte.