Ferritin

Physiology:

Ferritin is a large protein shell that covers an iron core and acts primarily as the soluble storage form of iron in tissue. It may serve other functions as well, although these are controversial. It is found in most cells of the body, especially in macrophages, hepatocytes and erythrocytes. The function of serum ferritin is not known, but the concentration correlates well with the amount of stored iron in normal subjects. Serum ferritin concentrations are quite stable from day-day in contrast to serum iron.

Indications:

Ferritin assay may be indicated in cases of suspected iron deficiency in which a bone marrow aspirate is not planned (iron status is reported as part of the bone marrow evaluation based on visible stained iron).

Samples should be obtained before transfusion, iron supplementation or glucorticoid therapy.

Notes:

Low Serum Ferritin

A decrease in the amount of stored iron is the only known cause for a low serum ferritin. However, in dogs, serum ferritin values do not appear to correlate with bone marrow iron stores and normal serum ferritin values may be seen in dogs with documented iron deficiency. In cats, ferritin appears to be a better indicator of iron stores.

High Serum Ferritin

Increased stored iron is associated with raised serum ferritin levels. Ferritin is an acute phase reactant protein, and as such, high serum ferritin levels are seen in liver disease, infection, inflammation or malignancy. The presence of these conditions in an iron deficient subject may raise serum ferritin concentration to a level that is not clearly indicative of iron deficiency.

Protocol:

Canine and feline specific assays are available directly through:

Kansas State University
Vet. Clin. Sci. Building
1800 Denison Avenue
Manhatten, KS USA 66506

Telephone: 00-1-785-532-4424

Requires 1 ml serum sent, frozen and packed on ice. Do not put in a glass tube or transfer with a glass pipette. The cost is $15 (US) plus shipment, when sent directly to Kansas State University. The assays are run every two weeks.

Stability:

Serum ferritin is not stable at ambient temperatures, so samples must be shipped directly from the practice to the US laboratory by means of a rapid Courier.

Samples submitted to IDEXX Laboratories in Wetherby will be unsuitable for analysis.

Suggested courier services include DHL International, TNT, AirExpress Northern Ltd. or FedEX®.