MLAB 2401: Clinical Chemistry Keri Brophy-Martinez Chapter 5: Hemoglobin Production Disorders.
-
Upload
jocelin-parsons -
Category
Documents
-
view
226 -
download
2
Transcript of MLAB 2401: Clinical Chemistry Keri Brophy-Martinez Chapter 5: Hemoglobin Production Disorders.
MLAB 2401: Clinical ChemistryKeri 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 StatesCondition Serum Iron Transferrin Ferritin % SaturationIDA 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/decreased
Normal/increased
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