Background: The introduction of second-generation QuantiFERON-TB (QFT) enables the diagnosis of Mycobacterium tuberculosis (TB) infection with high specificity and sensitivity. This in vitro diagnostic test uses 2 TB-specific proteins (ESAT-6 and CFP-10) to stimulate cells in heparinized whole blood and detects interferon-gamma (IFN-gamma) produced from blood cells. When QFT is done in laboratories outside of the hospital, several hours may be required to transport blood samples. We studied the relationship between QFT results and the time taken from collection of blood to incubation (preincubation time).
Methods: Heparinized whole blood drawn from TB suspects was immediately transported to a laboratory. We started to incubate 4 aliquots of blood with ESAT-6, CFP-10, mitogen (phytohemagglutinin), and nil control, at 1, 3, 6, 9, and 12 h after blood was drawn. After incubation, the concentration of IFN-gamma in each plasma sample was determined by ELISA, and values E and C were expressed as the concentration of IFN-gamma with ESAT-6 or CFP-10, minus the concentration of IFN-gamma in the nil control. Value E or C > or =0.35IU/mL was considered positive, > or =0.10 and<0.35IU/mL as equivocal (gray zone), and<0.10IU/mL as negative. We analyzed 8 patients with value E or C > or =0.10IU/mL at a preincubation time of 1 h.
Results: Value E and C decreased especially for preincubation time >6 h. As a result, the interpretation of value E changed from "positive" to "equivocal" in 2 cases and from "equivocal" to "negative" in 2 cases. Interpretation of value C also changed from "positive" to "equivocal" or "negative" in 2 cases and from "equivocal "to "negative" in 1 case. Even if the higher of value E or C were used for analysis, QFT results changed in half of patients when preincubation time was>6 h.
Conclusion: Since QFT results in half of patients changed when preincubation time was>6 h, incubation of whole blood should start < or =6 h after blood drawing.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.11150/kansenshogakuzasshi1970.81.421 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Comparative Performance of Ante-Mortem Diagnostic Assays for the Identification of -Infected Domestic Dogs ().
Pathogens
January 2025
The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian EH25 9RG, UK.
The domestic dog () is a competent host for () infection but no ante mortem diagnostic tests have been fully validated for this species. The aim of this study was to compare the performance of ante mortem diagnostic tests across samples collected from dogs considered to be at a high or low risk of sub-clinical infection. We previously tested a total of 164 dogs at a high risk of infection and here test 42 dogs at a low risk of infection and 77 presumed uninfected dogs with a combination of cell-based and/or serological diagnostic assays previously described for use in non-canid species.
View Article and Find Full Text PDFCytokine and Chemokine Responses of Peripheral Blood Mononuclear Cells from Dogs Infected with .
Pathogens
December 2024
Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian EH25 9RG, UK.
Mycobacterial infections are an important emerging zoonosis in companion animals for which diagnostic options remain imperfect, and the canine immunological response to these infections has been poorly investigated. We sought to further define the cellular response of peripheral blood mononuclear cells (PBMCs) from dogs infected with , as determined using a commercial interferon-gamma response assay (IGRA). To this end, PBMCs from healthy or infected dogs were collected.
View Article and Find Full Text PDFFunctional Analysis of Promoters, mRNA Cleavage, and mRNA Secondary Structure on in .
Pathogens
November 2024
Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA 01609, USA.
The ESX-1 secretion system is critical for the virulence of as well as for conjugation in the saprophytic model . EsxB (CFP-10) and EsxA (ESAT-6) are secreted effectors required for the function of ESX-1 systems. While some transcription factors regulating the expression of and have been identified, little work has addressed their promoter structures or other determinants of their expression.
View Article and Find Full Text PDFPerformance of the PhoP (Rv0757/Mb0780) protein as diagnostic antigen for bovine tuberculosis.
Res Vet Sci
March 2025
Instituto Nacional de Tecnología Agropecuaria, Instituto de Agrobiotecnología y Biología Molecular (IB-IABiMo), UEDD INTA-CONICET, Hurlingham, Buenos Aires, Argentina; CONICET, Argentina. Electronic address:
Bovine tuberculosis (bTB), a global zoonotic disease, causes negative effects on human and animal health. PhoP protein is a key regulator of pathogenic phenotypes in members of the Mycobacterium tuberculosis complex, which includes the causative agent of bTB. Despite extensive research on this protein focused in deciphering its regulatory role, little was explored about it as a diagnostic antigen.
View Article and Find Full Text PDFMycobacterium tuberculosis: The Mechanism of Pathogenicity, Immune Responses, and Diagnostic Challenges.
J Clin Lab Anal
December 2024
Molecular Medicine Research Center, Khomein University of Medical Sciences, Khomein, Iran.
Background: The infection caused by Mycobacterium tuberculosis arises from a complex interplay between the host immune system and the bacteria. Early and effective treatment of this disease is of great importance in order to prevent the emergence of drug-resistant strains. This necessitates the availability of fast and reliable diagnostic methods for managing affected cases.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!