Lagomorph Antibody Immunoassay for ALT1 Isoform Discrimination

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Solution Overview

Problem

Existing liver disease tests, particularly those for ALT enzyme levels, are limited by the need for instruments to maintain fixed temperatures and measure enzymatic products under kinetic conditions, and they fail to distinguish between ALT1 and ALT2 isoforms, leading to false diagnoses and are not diagnostic in severe disease cases.

Innovation Solution

Development of a point-of-care immunoassay using lagomorph antibodies that specifically recognize the ALT1 isoform, allowing for accurate detection of ALT1 mass concentration even in the presence of human plasma, enabling early detection of liver disease.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If enzymatic assay methods are used to detect ALT levels, then liver disease can be detected, but the test cannot distinguish between ALT1 and ALT2 isoforms leading to false diagnoses

Engineering Contradiction:
Improveisoform discrimination accuracyVSAvoiddiagnosis accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The invention segments the ALT detection by developing separate monoclonal antibodies (MAb 4A9 for ALT1, MAb M02A for ALT2) that specifically recognize each isoform. This allows the assay to distinguish between ALT1 (liver-specific) and ALT2 (muscle-specific) independently, eliminating false diagnoses caused by inability to differentiate isoforms.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention applies local quality by creating antibodies with specific binding properties tailored to each isoform's unique epitopes. MAb 4A9 is specifically designed to bind ALT1 epitopes while MAb M02A binds ALT2 epitopes, allowing localized detection of each isoform's contribution to total ALT activity.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If visual color reaction method is used in POC device, then instrument-free detection is achieved, but the dynamic range is limited to highly elevated ALT levels only

Engineering Contradiction:
Improveinstrument-free detectionVSAvoiddetection sensitivity range
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The invention changes the detection parameter from direct visual color reaction to a two-antibody immunological detection system with photometric measurement. This allows quantification across a broader dynamic range (2-300 IU/L) while maintaining POC applicability, as the method can be adapted to simple photometric devices.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If automated analytical instruments are used for ALT testing, then precise measurements under kinetic conditions are achieved, but device complexity and resource requirements increase

Engineering Contradiction:
Improveenzymatic activity measurement accuracyVSAvoidinstrument requirements
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention extracts the essential detection function from complex automated instruments by using a simplified two-antibody immunological assay. The method separates the critical detection step (antibody-antigen binding) from the complex kinetic measurement requirements, allowing implementation in simpler POC devices while maintaining diagnostic accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

4Quantity of substance

If rodent antibodies are used in the presence of human plasma, then ALT detection is possible, but plasma components interfere with antibody binding reducing assay performance

Engineering Contradiction:
Improveantibody availabilityVSAvoidbinding specificity
Core Design Contradiction:
Quantity of substanceVSMeasurement precision

Solution Approach 1:

The invention uses human IgG1 constant regions in the monoclonal antibody designs to reduce interference from human plasma components. This human-like structure allows the antibodies to function effectively in human plasma without the same degree of interference that would affect non-human antibodies, improving assay performance in clinical samples.

Inventive Principle:
Principle #26Copying

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The immunoassay provides accurate and quantitative assessment of liver disease by correlating ALT1 mass concentration with enzyme levels, suitable for resource-poor settings and capable of detecting severe liver disease.

Implementation Method 1

contacting the blood sample from a subject with a specific binding agent that recognizes an epitope of the liver enzyme (antigen), to form an antigen-binding agent complex

Methodology Applied
Scientific EffectAntigen-antibody binding:

Implementation Method 2

detecting the complex using a second binding agent linked to a detectable reporter

Methodology Applied
Scientific EffectAntigen-antibody binding:

Data Source

PatentEP3523655B1Point of care assays
Publication Date: 2025.10.08 BIOPOINT HONG KONG LTD
  • EP3523655B1 patent drawingFigure 1A~1B
  • EP3523655B1 patent drawingFigure 2A
  • EP3523655B1 patent drawingFigure 2A

AI summary

An immunoassay suitable for point of care to assess liver disease or function comprising contacting a blood sample from a subject with a specific binding agent that recognizes an epitope of ALT1, that is not recognized by rodent antibodies when the rodent antibodies are in the presence of human plasma, to form an antigen-binding agent complex and detecting the complex using a second or further binding agent linked to or comprising a detectable reporter; and detecting liver disease or liver function in the subject contingent upon the mass concentration of ALT1 in the sample. Kits or devices comprising lagomorph antibodies or binding agents comprising the antigen binding component thereof suitable for measuring the mass concentration of ALT1 in a blood sample from a subject to determine liver function.