MLAB 2401: Clinical Chemistry
Keri Brophy-Martinez
Chapter 5: Hemoglobin Production
Disorders
Iron Deficiency
• Lab Features
– Microcytic, hypochromic anemia
– Anisocytosis, poikilocytosis
– Total iron and Percent saturation decreased
– TIBC increased
Hemosiderosis
• Excessive levels of iron in storage
Hemochromatosis
• Characterized by an increased rate of
absorption and less ferritin production
• Excessive iron deposits in organs
• Patient develops bronze color in the tissues
• Total iron, percent saturation increased
• TIBC decreased
Iron Status in Disease States
Condition
Serum Iron
Transferrin
Ferritin
% Saturation
IDA
Decreased
Increased
Decreased
Decreased
Iron Overdose
Increased
Decreased
Increased
Increased
Hematochromatosis
Increased
Slight Decrease
Increased
Increased
Malnutrition
Decreased
Decreased
Decreased
Variable
Chronic anemia
Decreased
Normal/decrease
d
Normal/increase
d
decreased
Acute liver disease
Increased
Variable
Increased
Increased
Case Scenario #1
• A 40-year-old female is scheduled to have an
elective surgery. Her physician ordered a
routine CBC pre-op. The following test results
were obtained:
Test
Result
Reference Range
Hgb (g/dL)
10
12-16.0
Hct (%)
29.9
42-52
MCV (fL)
75
80-100
MCHC (g/dL)
30
32-36
WBC (x 103/L)
6.0
4.5-11
Plts (x 109/L)
200
150-450
Case Scenario #1
• On review of her blood smear, the technician
noted target cells.
• What other types of morphology would we
expect to see on this patient?
• The physician then ordered a serum iron,
ferritin and TIBC level.
Case Scenario #1
• Below are the results on the additional tests:
• What is her diagnosis?
Test
Result
Reference Range
Serum iron ( µg/dL) 20
65-165
Ferritin ( µg/dL)
5
20-200
TIBC ( µg/dL)
550
260-440
Hemoglobin Disorders
• Refer to Hematology notes
– Chapter 10: Hemoglobinopathies
– Chapter 11: Thalassemia
Porphyrin Disorders= Porphyrias
• Inherited or Acquired
• Enzyme deficiencies resulting in
overproduction of heme precursors in bone
marrow or liver
Porphrias
• Classification
– Based on
• Specific enzyme deficiency
• Hepatic vs erythropoietic
• Cutaneous vs neurologic
Porphyrias
• Clinical symptoms
– Cutaneous photosensitivity
– Itchy skin
– Hyperpigmentation
– Inflammatory reaction occurs on exposure to
ultraviolet light
– Neurologic abnormalities due to increased ALA
and PBG
Porphyrin Conditions
• Secondary Conditions
– Porphyrinuria
• Increase in coproporphyrin production
• Causes
– Lead intoxication
– Liver damage
– Infection
– Accelerated erythropoiesis
– Porphyrinemia
• Increase in erythrocytic protoporphyrin concentration
• Causes
– Lead intoxication
– Iron deficiency
– Impaired Iron absorption
– Chronic infection
Myoglobin
• Elevations
– Acute myocardial
– Renal failure
– Vigorous exercise
– Electric shock
– Intramuscular injections
LEAD
• Clinical Features
– Children
• CNS symptoms: headache ,clumsiness, seizures,
behavioral changes
• GI symptoms: Abdominal pain, colic, constipation
– Adults
• Peripheral neuropathies, motor weakness, anemia
Case Scenario #2
• A mother brings her active 2-year-old son to
the pediatrician for a routine visit. The
physician orders a CBC. Below are the results:
Test
Result
Reference Range
Hgb (g/dL)
10.2
14-17.4
Hct (%)
30.6
36-46
Case Scenario #2
• The mother reports that her son has had
some constipation and abdominal pain. The
child does eat well, and the mother gives the
child a vitamin supplement, which includes
iron
• The mother did mention that they live in an
older home that is in need of repainting.
• The physician orders further testing…
Case Scenario #2
• Results of testing
Test
Result
Reference Range
Serum iron
120
65-165
Ferritin
150
20-200
Whole blood lead
(µg/dL)
60
< 10
Erythrocyte
protoporphyrin
(µg/dL)
150
17-77
What is the diagnosis?
• Lead Poisoning
• How does this occur?
• Lead inhibits certain
enzymes in the heme
synthesis pathway
Case Scenario #2
• IDA was ruled out based on the serum iron
and ferritin levels