HEMOGLOBIN Flashcards
One of the tests used to diagnose and follow the treatments of anemia.
Hemoglobin (HgB)
hemoglobin also known as
Respiratory Pigment
Main component of the RBC percent
95%
Carry oxygen to and carbon from tissues.
Hemoglobin
has iron (in ferrous state: binds 02)
heme
portion
globin
portion
globin
Each Hgb has 4 subunits
4 heme & 4 globin
Hemoglobin A
(2 alpha chains/2 beta chains)
> 95%
Hemoglobin A2
(2 alpha chains/2 delta chains)
< 3.5%
Hemoglobin F
(2 alpha chains and 2 gamma chains)
1-2%
Alpha chain is coded by
Chromosome 16
Gamma, delta and beta by
Chromosome 11
Types of Hemoglobin (Abnormal)
● Hemoglobin S
● Hemoglobin C
● Hemoglobin E
● Hemoglobin D
● Hemoglobin G
● Hemoglobin Lepore
the predominant form of hemoglobin in healthy adults, comprising about 95–98% of the total
hemoglobin.
Hemoglobin A
• Its primary function is oxygen transport, and it binds oxygen in the lungs and releases it in peripheral
tissues.
Hemoglobin A
• a minor adult hemoglobin variant, accounting for about 2–3.5% of the total hemoglobin.
• significance of ____ lies in its use as a marker in diagnosing certain hemoglobinopathies, such as β-
thalassemia, where its levels are often elevated.
Hemoglobin A2
is the primary hemoglobin present during fetal development
Hemoglobin F
has a higher affinity for oxygen compared to HbA, which facilitates oxygen transfer from the mother’s bloodstream to the fetus. HbF levels decrease significantly after birth and are usually replaced by HbA. In adults, HbF typically constitutes less than 1% of total hemoglobin, though elevated levels can be observed in conditions like hereditary persistence of fetal hemoglobin (HPFH) and some hemoglobinopathies.
Hemoglobin F
• Hemoglobin whose structures has been modified due to drugs or environmental chemicals. They are dysfunctional hemoglobin that are unable to transport oxygen.
Hemoglobin Variants / Abnormal Hemoglobin Pigmentation/ Dyshemoglobin
Can cause Increased O2 affinity thus decreasing the efficiency of Oxygen to be
delivered to the tissues.
Methemoglobin
Caused by: oxidants (Nitrite, Primaquine, dapsone, Benzocane) or Methemoglobin Reductase deficiency
Methemoglobin
Reversible (Treated by administration of Ascorbic Acid and Methylene Blue)
Methemoglobin
Addition of Hydrogen sulfide to the hemoglobin (greenish pigment)
Sulfhemoglobin
Irreversible
Sulfhemoglobin
caused by sulfonamides, phenacetin, nitrites, phenylhydrazine
Sulfhemoglobin
combination of heme and carbon monoxide
Carboxyhemoglobin
CO has an affinity to hemoglobin of 240x than that of oxygen.
Carboxyhemoglobin
reversible (Treated by Oxygen Saturation or Hyperbaric oxygen therapy)
Carboxyhemoglobin
Hemoglobin Determination: Reference Method
Cyanmethemoglobin (Hemiglobincyanide)
Uses Drabkin’s Reagent
• Contains
PotassiumCyanide,PotassiumFerricyanide,potassiumdihydrogenphosphateor
sodium bicarbonate, and a non ionic compound (improves cell lysis)
Potassium ferricyanide:
hemoglobin - methemoglobin
Potassiumcyanide:
methemoglobin-cyanmethemoglobin
All hemoglobin types and variants are measures except
sulfhemoglobin
reagent and blood measurement
5 ml or 5000 ul of regent, 20 ul or 0.02 ml of whole blood.
read
540nm
Reference Range (Rodak)
• Male- 14-18 g/dL
• Female- 12-15 g/dL
• Newborn- 16.5 -21.5 g/dL
Sources of Error for Hemoglobin
Technical
Pipetting errors
• Dirty and scratch cuvettes • Deteriorated reagent
Biologic
Lipemic Sample
• Leukocytosis
•HgbSandHgbC
• Waldenstorm Macroglobulinemia and Multiple Myeloma
is the volume of packed RBC that occupies a given volume of blood.
Hematocrit (HCT) or packed cell volume
reported as
% or L/L
hematocrit anticoagulant
edta or heparin
seal clay at least
4mm long
Centrifuge for
5 mins between speed of 10,000 x g – 15,000 x g
two methods
• Macrohematocrit (uses wintrobe tube)
• Microhematocrit (uses capillary tube)
Hematocrit (HCT)
• Male 40-54% (0.40-0.54 L/L)
Female 35-49% (0.35-0.49 L/L)
Newborn 53-65% (0.53-0.65 L/L)
Child 30-43% (0.30-0.43 L/L)
Hematocrit (HCT): Sources of Error
Falsely Decrease
• Incomplete sealing of tubes.
• Hemolysis
• Overanticoagulated Blood
Falsely Increased
• Reading including the buffy coat
• Inadequate centrifugation
• Abnormal RBC Morphology: Macrocytic Anemia, Spherocytosis, Thalassemia, Hypochromic Anemia, Sickle Cell Anemia
