Specific assays for human alkaline phosphatase isozymes

Area of Science:

• Biochemistry
• Immunology

Background:

• Alkaline phosphatases (ALP) are enzymes with multiple isozymes.
• Accurate measurement of ALP isozymes is crucial for diagnosing various conditions.

Purpose of the Study:

• To develop specific and convenient assays for human intestinal and liver alkaline phosphatases.
• To quantify ALP isozyme levels in sera and tissues.

Main Methods:

• Development of specific assays using monoclonal antibodies against ALP isozymes.
• Immobilization of antibodies onto paper discs for assay development.
• Quantification of ALP isozyme activities in serum and tissue samples.

Main Results:

• Established fast, specific, and convenient assays for intestinal and liver alkaline phosphatases.
• In healthy individuals, tissue-unspecific alkaline phosphatase (32 +/- 12 IU/l) was significantly higher than intestinal (3.5 +/- 6.3 IU/l) and placental (0.3 +/- 0.2 IU/l) ALP.
• Normal tissues like intestinal mucosa express multiple ALP isozymes.
• Seminomas showed increased levels of intestinal and liver-bone-kidney alkaline phosphatases compared to normal testes.

Conclusions:

• The developed assays enable accurate quantification of ALP isozymes.
• Isozyme distribution in normal tissues and specific cancers provides diagnostic insights.
• These assays can aid in the differential diagnosis of diseases involving ALP dysregulation.