Reference limits for copper and iron in liver biopsies.

Area of Science:

• Clinical Chemistry
• Hepatology
• Trace Element Analysis

Background:

• Accurate reference intervals for trace elements in liver tissue are crucial for diagnosing metabolic disorders.
• Liver biopsies are a primary diagnostic tool for conditions like Wilson's disease and hemochromatosis.
• Simultaneous measurement of copper and iron in liver biopsies is often performed.

Purpose of the Study:

• To determine reference limits for copper and iron in liver biopsies using a rank-order approach.
• To evaluate the utility of concurrent copper and iron measurements in clinical practice.
• To identify potential indicators of sample contamination.

Main Methods:

• Analysis of 141 liver biopsy results (103 adults, 38 children).
• Application of a rank-order approach to establish reference limits.
• Measurement of copper and iron as standard practice in all liver biopsy specimens.

Main Results:

• Established reference limits: copper 55 µg/g dry weight, iron 1800 µg/g dry weight (adults), and iron index 1.0.
• Elevations in both copper and iron were infrequent (7/141).
• Significant concurrent elevations (copper >200 µg/g, iron index >2.0) suggested contamination.

Conclusions:

• The established reference intervals are comparable to those from autopsy studies.
• Concurrent measurement of copper and iron in liver biopsies can aid in diagnosis and identify potential contamination.
• Utilizing patient data provided insights into clinical distributions of elevated results despite increased uncertainty.