Page 301 - Concise Pathology for Exam Preparation ( PDFDrive )

286 SECTION II Diseases of Organ Systems

TABLE 12.1. Normal haematological values—cont’d

RBC life span 120 6 30 days
12
RBC count Adult male: 5.5 6 1 3 10 /L
Adult female: 4.8 6 1 3 10 /L
12
9
WBC or TLC 7.5 6 3.5 3 10 /L
Differential leukocyte count (DLC) Adults:
Neutrophils 2–7.5 3 10 /L (40–75%)
9
Lymphocytes 1.5–4 3 10/L (20–45%)
9
Monocytes 0.2–0.8 3 10 /L (2–10%)
9
Eosinophils 0.04–0.4 3 10 /L (1–6%)
9
Basophils 0.02–0.1 3 10 /L (1%)
Children:
9
Neutrophils 2–6 3 10 /L
9
Lymphocytes 5.5–8.5 3 10 /L
9
Monocytes 0.7–1.5 3 10 /L
9
Eosinophils 0.3–0.8 3 10 /L
Basophils 0.02–0.1 3 10 /L
9
9
Platelet count 150–400 3 10 /L
Reticulocyte count Adults: 0.5–2.5%
Infants: 2–6%
Erythrocyte sedimentation rate (ESR) Westergren (1 h at 20 6 3°C)
Adult male: 10 mm
Adult female: 15 mm
Children: 10 mm
Bleeding time (BT) Ivy’s method: 2–7 min
Template method: 2.5–9.5 min
Prothrombin time (PT) 11–16 s
Partial thromboplastin time with kaolin (PTTK) 30–40 s
Plasma fibrinogen 1.5–4 g/L

Q. Write briefly on haematopoietic growth factors.

Ans. Haematopoiesis is regulated by several growth factors.
• Interleukins (ILs)-1, -3, -6 exert their primary effects early in stem cell differentiation
(therefore, important for the differentiation of multiple blood lineages). IL-1 and -2 are
B- and T-cell regulators; IL-3 stimulates granulocyte, macrophage, eosinophil and
megakaryocyte colonies.
• Granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage
colony-stimulating factor (GM-CSF) and thrombopoietin (TPO) exert their effects
later in the differentiation cascade, and their effects are more lineage specific.
• Erythropoietin (EPO) is a heat-stable glycoprotein having a molecular weight of 36 kD.
About 90% EPO is produced in the kidney and the remaining in extrarenal sites like the
liver. EPO gene is present on human chromosome 7q21. It is the prime regulator of
erythropoiesis. Hypoxia induces the release of EPO from juxtaglomerular cells of the
kidney. EPO then binds to receptors on erythroid cells in the bone marrow inducing their
proliferation and differentiation.
• G-CSF promotes the differentiation of granulocytes and GM-CSF causes an increase in
neutrophils, eosinophils, macrophages and sometimes lymphocyte counts.
• TPO is the most potent cytokine-promoting proliferation and maturation of
megakaryocytes.

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