Caeruloplasmin

Specimen:

5 mL blood in lithium heparin or plain tube.

Method:

Immunoassay.

Reference Interval:

0-30 days: 0.05-0.30 g/L

1-12 months: 0.15-0.45 g/L

1-16 yrs: 0.22-0.50 g/L

Adults: 0.24-0.60 g/L

Application:

Suspected Wilson's disease, Menkes disease. Urinary and hepatic copper are more reliable tests for Wilson's disease.

Interpretation:

Low levels are found in Wilson's disease but a normal level does not exclude this diagnosis. The molar copper/caeruloplasmin ratio is increased in Wilson's disease due to increased albumin-bound copper.

Decreased caeruloplasmin levels occur in liver failure and in Menkes disease (where the copper/cearuloplasmin ratio is decreased).

Idiopathic hypocaeruloplasminaemia occurs as a non-pathogenic genetic variant but acaeruloplasminemia causes massive iron overload.

Increased levels may occur in pregnancy and in patients on oestrogen therapy. Levels are increased by oestrogens, in an acute phase response and in liver disease and this may mask a deficiency state.

See also Copper and Copper urine.

Reference:

Ferenci P et al. Liver Int 2003; 23: 139-142.