ELISPOT Assay for Aspergillus-Specific T Cell Detection

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Solution Overview

Problem

Current diagnostic methods for invasive aspergillosis are invasive, slow, non-sensitive, lack standardization, and have variable kinetics, limiting their effectiveness in clinical settings, particularly in patients with malignant hemopathies undergoing chemotherapy.

Innovation Solution

An in vitro immunoenzymatic ELISPOT assay is used to detect Aspergillus-specific T cells by placing patient-derived biological fluid in contact with an antigen extract from Aspergillus fumigatus, specifically identifying and counting IFN-γ and IL-10 producer T cells to determine the infection risk, with threshold values for diagnosis set between 15-25 SFCs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If current diagnostic methods (histological exam, culture exam, HRCT, serologic exams, PCR) are used, then diagnostic confirmation can be obtained, but the methods are invasive, slow, have low sensitivity, lack standardization, and have variable kinetics

Engineering Contradiction:
Improvediagnostic accuracyVSAvoidmethod complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical and procedural diagnostic systems (histological exams, culture exams, HRCT, serologic exams, PCR) with an immunoenzymatic ELISPOT assay that detects T-cell responses. This substitution simplifies the diagnostic workflow while maintaining or improving reliability through objective quantification of immune responses to Aspergillus antigens.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the diagnostic parameter from direct detection of fungal presence (culture, histology) or fungal markers (galactomannan, beta-glucan, PCR) to detection of host immune response parameters (T-cell frequency, IFN-γ production, IL-10 production). This parameter change enables standardized, sensitive detection without the limitations of previous methods.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If invasive diagnostic procedures are performed to confirm IA, then absolute diagnosis can be obtained, but patient burden and diagnostic speed are reduced

Engineering Contradiction:
Improvediagnostic confirmationVSAvoiddiagnostic time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The ELISPOT assay performs preliminary detection of T-cell responses to Aspergillus antigens before invasive procedures are needed. By detecting specific immune responses in peripheral blood, the assay provides early diagnostic information that can guide whether invasive confirmation is necessary, reducing overall diagnostic time and patient burden.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses the patient's own T cells as an intermediary marker to indirectly detect Aspergillus infection. Instead of directly observing the fungus or its effects on tissue, the assay measures the immune system's response to fungal antigens, providing a non-invasive window into the infection status.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If standard diagnostic methods are used, then diagnostic procedures can be performed, but sensitivity and early detection capability are limited

Engineering Contradiction:
Improvedetection sensitivityVSAvoiddiagnostic throughput
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The ELISPOT assay creates a detectable copy of the immune response through spot formation on the membrane. Each spot represents a T cell that has secreted cytokine in response to Aspergillus antigen, providing an amplified, visible copy of the immune response that is highly sensitive and suitable for automated counting and analysis.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The assay uses colorimetric detection where cytokine-secreting cells produce visible spots through enzymatic reaction with substrate. This color change provides a sensitive, quantifiable signal that can be detected by eye or automated systems, enabling both high sensitivity and efficient throughput.

Inventive Principle:
Principle #32Color changes

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 method provides a sensitive and specific early diagnosis of invasive aspergillosis, improving diagnostic accuracy and overcoming limitations of existing methods by quantifying the ratio of IFN-γ and IL-10 producer T cells, thereby enhancing clinical detection and management of the infection.

Implementation Method 1

carrying out an in vitro immunoenzymatic ELISPOT assay wherein the biological fluid drawn from the patient is placed in contact with an antigen of Aspergillus fumigatus

Methodology Applied
Scientific EffectImmunoenzymatic reaction: Enzyme

Data Source

PatentEP2094295B1Method for the diagnosis and/or monitoring of invasive aspergillosis
Publication Date: 2011.06.22 UNIV DEGLI STUDI DI MODENA E REGGIO EMILIA
  • EP2094295B1 patent drawingFigure 1A~1E

AI summary

The present invention refers to a method for the diagnosis and/or monitoring of the active or previous infection from Aspergillus fiimigatus which comprises carrying out an in vitro immunoenzymatic assay (ELISPOT) wherein the sample, from biological fluids drawn from the patient, is placed in contact with an antigen of Aspergillus fiimigatus.