MLAB 2401: Clinical Chemistry Keri Brophy-Martinez

Disorders of Iron, Porphyrins and Hemoglobin

MLAB 2401: Clinical ChemistryKeri Brophy-Martinez

Iron DeficiencyIron depletion

Diminished total body iron storesFunctional iron not effected

Advanced iron deficiency = ANEMIAIron Deficiency Anemia(IDA)

absolute iron deficiencyAnemia of Chronic Disease(ACD)

functional iron deficiency

Iron DeficiencyPopulations affected

ChildrenYoung women/Expectant womenElderly

Iron Deficiency AnemiaDecreased hemoglobin production due to

decreased total body iron contentCauses of IDA:

Increased demandpregnancy

Increased lossMenstruationGI bleed

Nutritional deficiencyMalabsorption

Crohn’s or celiac diseaseIntestinal parasites

3 Stages of IDA

Stage 1 : Iron DEPLETION Decrease in storage iron (ferritin decrease) No anemia RBC morphology normal

Stage 2: Iron-deficient Erythropoiesis Decrease in iron for erythropoiesis Decrease in ferritin, serum iron Increased TIBC No anemia: RBC slightly microcytic, no hypochromia

Stage 3 : Iron DEFICIENCY Decrease in hgb, ferritin, serum iron Decrease in peripheral tissue oxygen delivery Increased TIBC All lab tests abnormal Microcytic, hypochromic anemia

Iron Deficiency Anemia

Lab FeaturesMicrocytic,

hypochromic anemia

Anisocytosis, poikilocytosis

Total iron and ferritin decreased

TIBC increased

Anemia of Chronic DiseaseDecreased hemoglobin production due to

decreased amount of free ironAlso known as anemia of chronic

inflammationDecreased bone marrow erythropoiesis

Anemia of Chronic Disease

Lab featuresIron, TIBC decreasedFerritin increased

Iron Overload Syndromes

Hemochromatosis HemosiderosisHereditary disorders

of iron metabolismHemosiderin is

deposited within cells and interstitial fluid

Primarily effects liver, heart, endocrine glands

Irreversible

Secondary/acquired iron accumulation

Hemosiderin is deposited in cells only

No tissue damageReversible

HemochromatosisCharacterized by an

increased rate of absorption of iron

Excessive iron deposits in organs, tissues, and interstitial fluid

Patient develops bronze color in the tissues

Total iron, percent saturation increased

TIBC decreased

Iron Status in Disease StatesCondition Serum

IronTransferrin

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/decreased

Normal/increased

decreased

Acute liver disease

Increased Variable Increased Increased

Hemoglobin DisordersRefer to Hematology notes

HemoglobinopathiesThalassemia

Lab valuesIncreased ferritin

Porphyrin Disorders= Porphyrias

Enzyme deficiencies resulting in overproduction of heme precursors in bone marrow or liver

• Disorders of porphyrin metabolism = porphyrias• Inherited • Acquired - lead, alcohol and other toxins,

iron deficiency, renal or liver malfunctions.

PorphyriasClassification

Based onSpecific enzyme deficiencyHepatic vs erythropoieticCutaneous vs neurologicInherited or acquired

PorphyriasClinical symptoms

Port wine colored urineCutaneous photosensitivityItchy skin (photodermitidis)HyperpigmentationInflammatory reaction occurs on exposure to

ultraviolet lightNeurologic abnormalities

MyoglobinElevations

Acute myocardial infarctionRenal failureVigorous exerciseElectric shockIntramuscular injections

LEADClinical Features

ChildrenCNS symptoms: headache ,clumsiness, seizures,

behavioral changesGI symptoms: Abdominal pain, colic, constipation

AdultsPeripheral neuropathies, motor weakness, anemia

ReferencesArneson, W. (2007). Clinical Chemistry: A

Laboratory Perspective. Philadelphia, PA: F.A. Davis Company.

Bishop, M., Fody, E., & Schoeff, l. (2010). Clinical Chemistry: Techniques, principles, Correlations. Baltimore: Wolters Kluwer Lippincott Williams & Wilkins.

http://phosphorus15.glogster.com/Sunheimer, R., & Graves, L. (2010). Clinical

Laboratory Chemistry. Upper Saddle River: Pearson .

Wier, Dr. Edward. (2010, December). Principles and Pathology of Iron Metabolism [PowerPoint slides].