Q-fever Diagnosis via Cellular Immune Assay
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Solution Overview
Problem
Current methods for diagnosing Q-fever are challenging due to difficulties in culturing Coxiella burnetii, variability in antibody responses, and the need for a more sensitive and specific method that assesses cellular immunity, particularly in acute and chronic infections, and for vaccination screening.
Innovation Solution
A method involving contacting a subject's sample with Coxiella burnetii antigens and determining the expression level of pro-inflammatory cytokines like IFN-γ, which is indicative of acute or chronic Q-fever infection, using techniques such as PCR or ELISA to quantify cytokine levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If serology and skin test are used for Q-fever diagnosis, then vaccination screening can be performed, but the methods are laborious, have unknown sensitivity and specificity, and do not assess cellular immunity
Solution Approach 1:
The patent replaces the mechanical skin test procedure with an in vitro cellular immunological assay. PBMCs are isolated from patient blood samples and cultured with C. burnetii antigens in the laboratory, allowing measurement of IFN-γ production without requiring skin puncture, patient presence, or subjective interpretation of skin reactions. This substitution improves both reliability through objective quantification and ease of operation by eliminating complex skin test procedures.
Solution Approach 2:
The patent introduces PBMCs as an intermediary between the patient's immune system and the diagnostic test. Instead of directly testing serum antibodies or skin reactions, the assay uses isolated immune cells as mediators that can be cultured and stimulated with antigens in a controlled environment. This intermediary approach allows for standardized, reproducible measurement of cellular immunity while improving diagnostic reliability.
2Measurement precision
If phase dependent antibodies are used for diagnosis, then acute and chronic infection can be differentiated, but the antibody response varies and serology standardization is difficult
Solution Approach 1:
The patent changes the measured parameter from antibody levels (humoral immunity) to cytokine production (cellular immunity). By measuring IFN-γ production in response to C. burnetii antigens, the assay provides a stable and consistent readout of cellular immune activation. This parameter change eliminates the variability and standardization problems associated with phase-dependent antibody responses while maintaining the ability to differentiate infection stages through cytokine kinetics and magnitude.
3Measurement precision
If Coxiella burnetii culturing is attempted, then direct bacterial detection is possible, but the bacterium is difficult to culture in the laboratory
Solution Approach 1:
The patent extracts the diagnostic function from direct bacterial culturing to isolated immune cell responses. Instead of attempting to culture the difficult-to-grow C. burnetii bacterium, the assay extracts and cultures only the patient's PBMCs with added bacterial antigens. This extraction approach allows detection of immune responses to the pathogen without requiring cultivation of the pathogen itself, eliminating the culturing difficulty while maintaining diagnostic precision.
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 provides a rapid, sensitive, and specific diagnosis of Q-fever infections, including acute and chronic cases, and differentiates between infected and uninfected individuals, offering improved accuracy over existing serology methods and non-invasive, cost-effective testing.
Implementation Method 1
determining the expression level of a pro-inflammatory cytokine in said sample at the end of step (b)
Implementation Method 2
using techniques such as PCR or ELISA to quantify cytokine levels
Data Source
Figure 1~2
AI summary
The present invention relates to a method for diagnosing Q-fever in a subject, the method comprising the steps of: (a) obtaining a sample from said subject, (b) contacting said sample with a source of a Coxiella burnetii antigen and (c) determining the expression level of a pro-inflammatory cytokine such as IFN-? in said sample at the end of step (b).