Complete Blood Count (CBC): Difference between revisions

Latest revision as of 17:32, 18 February 2025


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

$M C H = \frac{H G B}{R B C}$

$M C V = \frac{H C T * 1000}{R B C}$

$M C H C = \frac{H G B}{H C T}$

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)

@@ Line 107: / Line 107: @@
 |
 |}
-[[File:CBC Equations.jpg|thumb]]
-*
+=== Calculated Parameters ===
+<math>MCH=\frac{HGB}{RBC}</math>
+<math>MCV=\frac{HCT\ast 1000}{RBC}</math>
+<math>MCHC=\frac{HGB}{HCT}</math>
+=== 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 [Fe<sup>3+</sup>] 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 [Fe<sup>2+</sup>] state)
+** ~10% myoglobin (ferrous [Fe<sup>2+</sup>] state)
+** ~3% within enzymes
+* Stored Iron
+** ~20% in storage forms, mostly within liver
+** Ferritin (ferric [Fe<sup>3+</sup>] 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)