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Iron Profile Ketonuria 1355

Iron Profile
VetBooks.ir Definition

renal disease)
Far smaller quantities are stored in muscles
Iron profiles can help characterize whether an as ferritin and hemosiderin within macrophages. chronic inflammatory conditions, liver or
animal has an iron-deficient or iron-overload (myoglobin), plasma proteins and enzymes,
state. and only 0.1% bound to transferrin in the Important Interspecies Differences
• Serum iron (Fe): circulating Fe bound to plasma. • Cats do not typically have visual stainable
transferrin iron in the bone marrow on aspiration or
• Total iron-binding capacity (TIBC): mea- Reference Interval core tissue biopsy.
surement of plasma’s capacity to carry Fe Dog: serum iron 125-225 mcg/dL; TIBC
in serum by estimating the concentration 225-325 mcg/dL; ferritin 525-1100 mcg/dL Drug Effects
of Fe carrying serum and plasma proteins Glucocorticoids increase serum iron levels in
in blood Causes of Abnormally High Levels dogs (unknown mechanism).
• Unbound iron-binding capacity (UIBC): • Serum Fe: Fe overload from excess intake
calculated value; TIBC minus serum Fe (diet or iatrogenic), increased glucocorticoid Lab Artifacts
• Stainable iron in macrophages of the bone (endogenous or exogenous) Hemolysis falsely increases serum iron
marrow, spleen, or liver: subjective visual • TIBC: Fe deficiency, Fe overload from excess concentrations.
assessment of bone marrow aspirates and/ intake (diet or iatrogenic),
or bone marrow core sections for free or • Stainable iron: inflammation, pathologic Specimen Collection and Handling
stainable iron hemolysis, Fe overload from excess intake Fast patient overnight. Collect in serum (red
• Serum ferritin: an intracellular iron-binding (diet or iatrogenic) top) tube; spin and separate cells from serum
protein that changes in proportion to body • Serum ferritin: inflammation, Fe overload within 2 hours; transfer serum to plastic tube.
stores from excess intake (diet or iatrogenic), Freeze and ship to lab on ice. Specimen must
• Serum transferrin: a circulating transport pathologic hemolysis, hepatic insufficiency, be free of hemolysis.
protein for iron. Transferrin concentration hepatocyte necrosis
(mg/dL) can be converted to TIBC (mcg/ • % transferrin saturation: increased serum Fe, Relative Cost: $$
dL) by multiplying by 1.389. decreased TIBC
• % Transferrin saturation: estimates the Pearls
percentage of Fe-binding sites occupied by Next Diagnostic Steps to Consider • Serum iron profiles are seldom used in small
Fe on apotransferrin (unsaturated transferrin if Levels Are High animal veterinary medicine.
molecule) by calculating serum Fe × 100 Rule out supplementation/intoxication, liver • Iron deficiency may cause anemia character-
divided by TIBC. disease; consider referral. ized by microcytosis and hypochromasia.
• Serum Fe concentrations are often an unreli-
Synonyms Causes of Abnormally Low Levels able measurement of total body iron status.
Iron profile, iron panel, iron testing, Fe profile • Serum Fe: Fe deficiency, inflammation, young • Assessment of an animal’s Fe status is
animal (kittens) enhanced when laboratory tests are grouped
Physiology • TIBC: hepatic insufficiency, inflammation, as a profile.
Iron is an essential mineral that is taken up protein-losing nephropathy, protein-losing • In young animals, intestinal parasitism is a Laboratory Tests Laboratory Tests
by small intestinal enterocytes and transferred enteropathy common cause of Fe-deficiency anemia.
to the bone marrow and other tissues by the • Stainable iron: Fe deficiency, young animals • In older animals, chronic gastrointestinal
acute-phase plasma protein transferrin. Iron • Serum ferritin: Fe deficiency, young animals, bleeding is a common cause of Fe-deficiency
3+
(Fe ) is stored in the cytoplasm of numerous hepatic insufficiency anemia.
cells (muscle, macrophages, enterocytes) by • % transferrin saturation: decreased serum • Animals with anemia of inflammatory disease
an intracytoplasmic protein (ferritin). Most Fe, increased TIBC typically have normal to low serum iron,
(75%) plasma iron is transferred to the bone TIBC, and normal to high serum ferritin.
marrow for erythropoiesis; the remainder is Next Diagnostic Steps to Consider
stored in various organs (mainly liver). The if Levels Are Low AUTHOR: Erin N. Burton, DVM, MS, DACVP
EDITOR: Lois Roth-Johnson, DVM, PhD, DACVP
majority of total body iron (≈65%) is found in • Investigate for underlying cause, depending
hemoglobin, with much of the remainder stored on signalment and clinical signs (e.g., anemia,

Ketonuria

Definition when the blood ketone concentration exceeds Reference Interval
The presence of ketones (beta-hydroxybutyrate, the renal threshold allowing ketones to enter the Negative in healthy patients; positive results are
acetoacetate, acetone) in the urine urine through glomerular filtration and tubular reported in semi-quantitative values.
secretion. Urine ketones can be measured via
Physiology urine dipstick or the Acetest®; however, beta- Causes of Abnormally High Levels
Ketogenesis is initiated during states of limited hydroxybutyrate is not detected by either of Diabetes mellitus, starvation/negative energy
carbohydrate availability. Ketonuria develops these methods. balance, persistent hypoglycemia. See p. 1248.

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