Complete Blood Count (CBC)

Parameter		Summary	RI Male	RI Female
RBC count			4.2-6.0×1012/L	3.8-5.2×1012/L
HGB			135-180 g/L	120-150 g/L
HCT			0.40-0.54 L/L	0.35-0.49 L/L
MCH		HGB/RBC	26-34 pg
MCV		HCT*1000/RBC	80-100 fL
MCHC		HGB/HCT >360 g/L hereditary spherocytosis (~50% of patients) >380 g/L specimen integrity issue (Icterus, Lipemia, high WBC or cold agglutinins)	320-360 g/L
RDW			11.5-14.5%
PLT count			150-450×109 /L
MPV
WBC count			3.6-10.6×109 /L
Relative WBC differential	Neutrophils
	Lymphocytes
	Monocytes
	Eosinophils
	Basophils
Absolute WBC differential	Neutrophils
	Lymphocytes
	Monocytes
	Eosinophils
	Basophils

Calculated Parameters

$MCH=\frac{HGB}{RBC}$

$MCV=\frac{HCT\ast 1000}{RBC}$

$MCHC=\frac{HGB}{HCT}$

Hemoglobin

• Binds O2 in the lungs (↑ pH)
  • High O2 affinity required to keep O2 bound
• Released O2 in tissues (↓ pH, ↑ pCO2)
  • Low O2 affinity required to release O2

O2 Saturation Curve

• 50% O2 saturation occurs at ~ 27 mmHg
• Right shift = decreased affinity of hemoglobin = more O2 released to tissues
  • ↑ temperature
  • ↑ 2,3-BPG
  • ↓ pH (acidosis)
  • Abnormal hemoglobin variants with low O2 affinity
  • "Acid, drugs (2,3-BPG), and heat - all up oxygen to tissue"
• Left shift = increased affinity of hemoglobin = less O2 released to tissues
  • ↓ temperature
  • ↓ 2,3-BPG
  • ↑ pH (alkalosis)
  • Abnormal hemoglobin variants with high O2 affinity

Abnormal Hemoglobins

• Variant hemoglobin structures
• Dyshemoglobins
  • Methemoglobin - oxidized ferric [Fe³⁺] iron
    • O2 can't bind properly, ↑ O2 affinity (left shift prevents O2 release)
    • Acquired (drugs, meds) or congenital (abnormal globin chains or ability to reduce iron)
    • Bluish-brown blood colour
  • Sulfhemoglobin
    • Sulfur attached to hemoglobin
    • Permanent inability to bind O2
    • Acquired (drug-induced)
    • Greenish blood colour
  • Carboxyhemoglobin
    • Out-competes O2 (binds ~200x more tightly)
    • Releases 10 000x slower

Iron

• Functional iron
  • ~70% hemoglobin (ferrous [Fe²⁺] state)
  • ~10% myoglobin (ferrous [Fe²⁺] state)
  • ~3% within enzymes
• Stored Iron
  • ~20% in storage forms, mostly within liver
  • Ferritin (ferric [Fe³⁺] state) in liver
    • Iron-Apoferritin complex keeps iron bound
  • Hemosiderin
    • Intracellular storage form in liver, spleen, and bone marrow
    • Formed from breakdown of ferritin aggregates
• Transported iron
  • ~1% in plasma
  • Transferrin
    • Transport protein in plasma to move iron between compartments
    • Transport of iron absorbed from duodenum (small intestine) to bone marrow
    • Produced by hepatocytes when ↓ iron
      • Regulated by hepcidin (binds ferroportin to block uptake)