Precipitation method for separating and quantifying bone and liver alkaline phosphatase isoenzymes

Area of Science:

• Biochemistry
• Clinical Chemistry

Background:

• Alkaline phosphatase (ALP) exists in multiple isoenzyme forms.
• Accurate quantification of bone ALP is crucial for diagnosing bone diseases and detecting metastases.

Purpose of the Study:

• To evaluate a novel wheat-germ lectin precipitation method for quantifying bone isoenzyme of alkaline phosphatase (ALP).
• To assess the method's analytical performance, clinical applicability, and suitability for routine use.

Main Methods:

• Wheat-germ lectin was used to precipitate the bone isoenzyme of ALP.
• Assay precision, linearity, and correlation with an affinity electrophoretic method were assessed.
• Reference ranges were established in healthy adults, children, and adolescents.
• Clinical applicability was evaluated in various patient groups, including those with hepatobiliary diseases and metastases.

Main Results:

• The method demonstrated good precision (CVs 3.2-11.5%) and linearity up to 1100 U/L.
• A high coefficient of correlation (r = 0.886) was observed when compared to an affinity electrophoretic method.
• The assay was easily adapted for automated kinetic measurement.
• The method proved suitable for routine bone ALP determination and screening for bone metastases.

Conclusions:

• The wheat-germ lectin precipitation method is a technically simple and analytically sound approach for quantifying bone ALP.
• This method offers a viable alternative to heat-inactivation procedures for routine clinical use.
• It is effective for both general bone ALP measurement and the specific screening of bone metastases.