Cp

Ceruloplasmin

Liver Function

What is Ceruloplasmin?

Ceruloplasmin is a copper-carrying glycoprotein synthesized primarily by the liver. It is the major copper transport protein in the blood, carrying approximately 65–90% of circulating copper. Each ceruloplasmin molecule binds six copper atoms and functions as a ferroxidase, catalyzing the oxidation of ferrous iron (Fe²⁺) to ferric iron (Fe³⁺), which is necessary for iron binding to transferrin and proper iron metabolism. Ceruloplasmin also has antioxidant properties, scavenging free radicals and protecting tissues from oxidative damage.

The most important clinical application of ceruloplasmin measurement is in the diagnosis of Wilson disease, a rare autosomal recessive disorder of copper metabolism caused by mutations in the ATP7B gene. In Wilson disease, impaired biliary copper excretion leads to toxic copper accumulation in the liver, brain, cornea, and other organs. Ceruloplasmin is characteristically low in Wilson disease because the ATP7B protein is required for incorporating copper into apoceruloplasmin in the liver. Without copper loading, apoceruloplasmin is unstable and rapidly degraded, resulting in low serum ceruloplasmin.

Why It Matters

Ceruloplasmin measurement is essential for diagnosing Wilson disease, a treatable but potentially fatal condition if missed. Untreated Wilson disease leads to progressive liver failure, irreversible neurological damage, and psychiatric illness. Low ceruloplasmin in a young patient with liver disease, neuropsychiatric symptoms, or Kayser-Fleischer rings on eye exam should trigger a comprehensive Wilson disease workup. Additionally, ceruloplasmin is an acute-phase reactant that rises in inflammation, pregnancy, and estrogen use, which can mask the low levels expected in Wilson disease.

Normal Reference Ranges

GroupRangeUnit
Adults20–60mg/dL
Neonates5–18mg/dL
Children (1–12 years)20–45mg/dL

Reference ranges may vary by laboratory. Always compare results to the ranges provided by your testing facility.

What High Cp Levels Mean

Common Causes

  • Acute or chronic inflammation (acute-phase reactant)
  • Pregnancy
  • Estrogen therapy or oral contraceptives
  • Infection
  • Malignancy (especially lymphoma)
  • Smoking
  • Rheumatoid arthritis

Possible Symptoms

  • No specific symptoms from high ceruloplasmin itself
  • Symptoms relate to the underlying inflammatory or hormonal condition
  • Fatigue (from associated inflammation)
  • Joint pain or swelling (in rheumatoid arthritis)

What to do: Elevated ceruloplasmin is typically a reactive phenomenon and does not require specific treatment. Identify and treat the underlying cause (infection, inflammation, malignancy). If ceruloplasmin is elevated in a patient being evaluated for Wilson disease, be aware that concurrent inflammation may mask the characteristically low levels—check 24-hour urine copper and serum free copper to complete the evaluation.

What Low Cp Levels Mean

Common Causes

  • Wilson disease
  • Menkes disease (X-linked copper deficiency)
  • Severe liver disease (decreased synthetic capacity)
  • Nephrotic syndrome (urinary protein loss)
  • Severe malnutrition or malabsorption
  • Aceruloplasminemia (rare genetic condition)
  • Copper deficiency

Possible Symptoms

  • Liver disease (hepatitis, cirrhosis, acute liver failure)
  • Neurological symptoms (tremor, dystonia, dysarthria, gait changes)
  • Psychiatric symptoms (depression, personality changes, psychosis)
  • Kayser-Fleischer rings (golden-brown corneal deposits)
  • Hemolytic anemia (in acute Wilson disease presentation)
  • Fatigue and weakness

What to do: Ceruloplasmin below 20 mg/dL should prompt evaluation for Wilson disease, especially in patients under 40 with unexplained liver disease or neuropsychiatric symptoms. Complete workup includes 24-hour urine copper (elevated in Wilson disease, >40 µg/day, often >100 µg/day), serum free copper (non-ceruloplasmin-bound copper, elevated in Wilson disease), slit-lamp examination for Kayser-Fleischer rings, and if needed, liver biopsy for hepatic copper content. Genetic testing for ATP7B mutations can confirm the diagnosis. Treatment involves copper chelation (D-penicillamine or trientine) and zinc to block intestinal copper absorption.

When Is Cp Testing Recommended?

  • When Wilson disease is suspected in a young person with liver disease
  • When unexplained neurological or psychiatric symptoms occur under age 40
  • When Kayser-Fleischer rings are detected on eye exam
  • When evaluating unexplained hemolytic anemia with liver disease
  • When a family member has been diagnosed with Wilson disease

Frequently Asked Questions

Wilson disease is an autosomal recessive disorder caused by mutations in the ATP7B gene, which encodes a copper-transporting ATPase in the liver. This protein is responsible for two critical functions: incorporating copper into ceruloplasmin and excreting excess copper into bile. When ATP7B is defective, copper cannot be excreted, leading to progressive accumulation in the liver (causing hepatitis, cirrhosis, and acute liver failure), brain (causing tremor, dystonia, parkinsonism, and psychiatric symptoms), cornea (Kayser-Fleischer rings), and kidneys. The incidence is approximately 1 in 30,000 births. Wilson disease is treatable with lifelong copper chelation therapy and zinc supplementation, and early treatment can prevent irreversible organ damage. Liver transplantation cures the metabolic defect in patients with acute liver failure or decompensated cirrhosis.
Yes. Approximately 5–15% of patients with Wilson disease have ceruloplasmin in the low-normal range (20–25 mg/dL), particularly because ceruloplasmin is an acute-phase reactant—concurrent inflammation, infection, pregnancy, or estrogen use can raise levels into the normal range despite underlying Wilson disease. Conversely, about 10–20% of carriers (heterozygotes) have mildly low ceruloplasmin without disease. This is why ceruloplasmin alone is insufficient for diagnosis. The Leipzig scoring system integrates ceruloplasmin, 24-hour urine copper, liver copper content, Kayser-Fleischer rings, and genetic testing into a composite score for reliable diagnosis.
Ceruloplasmin plays an important role in iron metabolism through its ferroxidase activity. It oxidizes ferrous iron (Fe²⁺) to ferric iron (Fe³⁺), which is required for iron to bind to transferrin for transport in the blood. Without functional ceruloplasmin (as in aceruloplasminemia or severe Wilson disease), iron accumulates in tissues, particularly the liver, pancreas, and brain. Aceruloplasminemia—a rare genetic condition with absent ceruloplasmin—causes diabetes (pancreatic iron deposition), retinal degeneration, and progressive neurodegeneration from brain iron accumulation. This condition demonstrates the critical link between copper and iron metabolism.

Related Biomarkers

ALTAlanine AminotransferaseASTAspartate AminotransferaseTBILBilirubinALBAlbumin

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Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Reference ranges may vary between laboratories. Always consult your healthcare provider for interpretation of your specific test results.

Disclaimer: SymptomGPT is not a medical diagnosis tool and does not provide medical advice. Always consult a qualified healthcare professional. If you are experiencing a medical emergency, call 911 immediately.