ELISpot Assay LTBI Detection Using Co-Stimulatory Antibodies
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Accurate detection of latent tuberculosis infection (LTBI) remains challenging, particularly in differentiating dormant forms from cleared infections, and existing tests like tuberculin skin tests and interferon-gamma release assays often produce discordant results.
Innovation Solution
The use of ELISpot assays that include stimulating cells with anti-CD28 and anti-CD49d antibodies, along with ESAT-6 and CFP-10 polypeptides, to differentiate LTBI from healthy controls and identify false negatives in commercial assays such as QuantiFERON TB Gold In-Tube.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional TST or IGRA tests are used to detect LTBI, then the testing process is simple and quick, but the accuracy is insufficient and cannot differentiate dormant forms from cleared infections
Solution Approach 1:
The patent segments the detection process into multiple distinct steps: initial TST screening, followed by IGRA testing for positive cases, and finally ELISpot assays for discordant or positive IGRA results. Each step uses different reagents and protocols, allowing progressive refinement of detection accuracy while maintaining manageable complexity at each stage.
Solution Approach 2:
The patent introduces ELISpot assays as an intermediary testing step between conventional TST/IGRA tests and definitive diagnosis. This intermediate assay uses co-stimulatory antibodies (anti-CD28 and anti-CD49d) to enhance T-cell activation and interferon-gamma release, providing more accurate differentiation of latent from cleared infections without requiring direct jumps to complex molecular diagnostics.
2Measurement precision
If ELISpot assays with co-stimulatory antibodies are used to improve LTBI detection accuracy, then detection precision improves, but the assay complexity and time required increase
Solution Approach 1:
The patent applies preliminary action by using TST and IGRA tests first to screen and identify candidates who need further evaluation. Only those with positive or discordant results proceed to the more time-consuming ELISpot assays with co-stimulatory antibodies. This staged approach minimizes overall time loss by reserving complex procedures for necessary cases only.
Solution Approach 2:
The patent employs periodic action through the sequential, stepwise progression of tests: TST first, then IGRA for positives, and finally ELISpot for discordant or positive IGRA cases. This periodic testing strategy allows adequate time for each assay type while maintaining a structured workflow that prevents unnecessary delays in the overall diagnostic process.
3Ease of operation
If standard IGRA tests are used, then the procedure is straightforward, but false negatives occur in highly likely LTBI cases
Solution Approach 1:
The patent changes key parameters of the IGRA test by incorporating co-stimulatory antibodies (anti-CD28 and anti-CD49d) into the ELISpot assay protocol. These parameter changes enhance T-cell activation and interferon-gamma release, improving reliability and reducing false negatives while maintaining procedural simplicity through standardized reagent addition and incubation steps.
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 approach allows for accurate identification of LTBI, improving the ability to target TB prevention strategies and ensuring timely treatment by differentiating between latent and active infections with high sensitivity and specificity.
Implementation Method 1
performing an interferon-γ release assay using cells obtained from the mammal, wherein the assay comprises contacting the cells with an anti-CD28 antibody and an anti-CD49d antibody
Implementation Method 2
The interferon-γ release assay can be an ELISpot assay
Data Source
AI summary
This document provides methods and materials related to identifying mammals having a LTBI. For example, methods and materials for using ELISpot assays to identify mammals (e.g., humans) having a LTBI are provided.