Metabolite Panel for Cystic Fibrosis Diagnostic Accuracy

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Solution Overview

Problem

Current methods for population-based cystic fibrosis screening, such as the two-tiered approach using elevated immunoreactive trypsinogen and DNA mutation panels, suffer from high false positives, false negatives, and ethical concerns related to asymptomatic carrier identification, particularly in diverse populations, leading to ambiguous diagnostic outcomes and increased healthcare costs.

Innovation Solution

A novel method utilizing specific CF-specific metabolites, including L-glutamine, L-threonine, nicotinamide, and others, measured in biological specimens via capillary electrophoresis-mass spectrometry (CE-MS) to diagnose cystic fibrosis by comparing metabolite levels to control levels, thereby reducing false positives and improving diagnostic accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a two-tiered screening approach using elevated immunoreactive trypsinogen and DNA mutation panels is used, then screening coverage is provided, but false positive rate increases to approximately 85-90%

Engineering Contradiction:

Improvediagnostic accuracyVSAvoidfalse positive rate

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent transitions from traditional screening parameters (immunoreactive trypsinogen levels and DNA mutation presence) to metabolite concentration profiles as the diagnostic parameter. This fundamental parameter change enables differentiation between affected individuals and carriers by detecting characteristic metabolic patterns rather than relying on single biomarkers that produce high false positives.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The diagnostic method employs a composite metabolite panel comprising multiple metabolites (amino acids, acylcarnitines, organic acids, etc.) analyzed simultaneously through mass spectrometry. This composite approach captures the systemic metabolic disruptions caused by CFTR dysfunction, providing a more reliable diagnostic signature than individual biomarkers and reducing false positive rates.

Inventive Principle:

Principle #40Composite materials

2Productivity

If IRT and DNA mutation screens are used for population-based screening, then screening capacity is increased, but the ability to provide definitive diagnosis is limited with only 10-15% of screen-positive infants having elevated sweat chloride

Engineering Contradiction:

Improvescreening capacityVSAvoiddefinitive diagnosis rate

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The metabolite profile analysis serves as an intermediary diagnostic step between initial screening (IRT/DNA) and the gold standard sweat chloride test. By measuring metabolic intermediates that reflect CFTR function in multiple tissues, this intermediary test provides more definitive diagnostic information earlier, reducing the gap between screening and confirmatory diagnosis.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical/physical sweat chloride measurement system with a biochemical analysis system using mass spectrometry. This substitution enables high-throughput analysis of metabolic profiles from dried blood spots, maintaining screening capacity while dramatically improving diagnostic reliability through detection of tissue-specific metabolic effects of CFTR dysfunction.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Loss of time

If population-based CF screening is conducted using traditional methods, then early detection is achieved, but ethical concerns arise related to asymptomatic carrier identification and increased healthcare costs

Engineering Contradiction:

Improvetime to diagnosisVSAvoidinformation about disease status

Core Design Contradiction:

Loss of timeVSLoss of information

Solution Approach 1:

The metabolite profile analysis detects localized metabolic disruptions in specific tissue contexts (pancreatic, intestinal, respiratory) that reflect actual CFTR functional impact. By identifying metabolites affected by tissue-specific CFTR dysfunction rather than general carrier status, the method provides locally-relevant diagnostic information that distinguishes affected individuals from asymptomatic carriers.

Inventive Principle:

Principle #3Local quality

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

This method enhances the specificity and sensitivity of cystic fibrosis diagnosis, reducing false positives and unnecessary testing, while providing a cost-effective means to differentiate affected individuals from carriers, thus addressing the limitations of existing screening strategies.

Implementation Method 1

capillary electrophoresis-mass spectrometry (CE-MS)

Methodology Applied

Scientific EffectCapillary electrophoresis: Capillary Electrophoresis

Implementation Method 2

capillary electrophoresis-mass spectrometry (CE-MS)

Methodology Applied

Scientific EffectMass spectrometry: Ionisation

Data Source

PatentUS10768183B2Metabolite panel for improved screening and diagnostic testing of cystic fibrosis

Publication Date: 2020.09.08 MCMASTER UNIV

AI summary

A method of diagnosing cystic fibrosis in a human subject is provided. The method includes the steps of: i) determining in a biological sample from the subject the level of one or more metabolic biomarkers; ii) comparing the level of the biomarker to a control level and determining the difference between the biomarker level and the control level; and iii) determining that the subject has cystic fibrosis or a related disorder when the difference in the level of the biomarker in the sample is statistically different from the control level.