Host Response to Infection by Direct Analysis of Leukocyte Single Cell-type Gene Expression/transcript Abundance, Direct LS-TA. a Prospective Study Will Evaluate the Performance of Direct LS-TA in Triage Febrile Patients Into Major Categories of Infections: Viral, Bacterial or Active Tuberculosis.

NCT06846645 | Not Yet Recruiting

• 1 other identifier: Direct LS-TA prospective study
• Study Type: observational
• Target: 200
• Locations: 1 country
• Sites: 1

Brief Summary

Febrile illness is a common condition and it is crucial to have an early triage of patients according to various aetiologies to enable appropriate treatment. Currently, most screening/diagnostic tests target the detection of pathogens, while only a few assays aim to understand the host response, and they are mostly based on a measurement of serum proteins (e.g. CRP or procalcitonin). Recently, blood transcriptome has been explored to differentiate bacterial and viral infections. However, gene expression in blood represents a composite score of gene expression of all the component cell-types present in the sample. Here, we propose to develop a rapid test that can determine gene expressions of a specified single cell type in peripheral blood (e.g., monocytes or granulocytes) as a host response biomarker to differentiate three major categories of infections that are bacterial, viral, and tuberculosis The assay is called Direct Leukocyte Single cell-type transcript abundance (TA) assay (DIRECT LS-TA) as it can directly determine the gene expression of a specified single cell-type among various other leukocyte populations directly in a peripheral blood sample. Such results signify the nature of host response according to 3 or more axes (Type I or Type II interferon signaling response or pro-inflammatory cytokine signaling) And it can be used to indicate the type of underlying infection (viral, bacterial, or active tuberculosis).

Conditions

Single Cell Sequencing Technology; Gene Expression Profiling; Gene Expression; Infection; Viral Diseases; Bacterial Diseases; Active Tuberculosis; Host Defense Mechanisms; Host Microbial Interactions; Transcriptome

Keywords

host response; transcriptome; single cell-type gene expression; single cell RNA; triage; fever; febrile patient; Direct LS-TA

Outcome Measures

Primary Outcomes (6)

• Viral host response Direct LS-TA in monocytes (Type I interferon response)

  Direct LS-TA is a kind of RBB that can be readily quantified by qPCR or dPCR of a pair of genes, the RBB numerator gene and the RBB denominator gene. The biomarker is the ratio of the 2 genes. Single cell-type: Monocyte. RBB numerator gene: IFI27 or IFI44L. RBB denominator gene: PSAP, CTSS or CPVL. The various RBB (e.g. IFI27/PSAP and IFI44L/PSAP ratios) will be compared in terms of their sensitivity/specificity of diagnostic performance in the samples from infection groups. AUC of ROC analysis will be performed where appropriate.

  first collected sample within the first week after admission

• Viral host response Direct LS-TA in granulocytes (Type I interferon response)

  Direct LS-TA is a kind of RBB that can be readily quantified by qPCR or dPCR of a pair of genes, the RBB numerator gene and the RBB denominator gene. The biomarker is the ratio of the 2 genes. Single cell-type: Granulocyte. RBB numerator gene: RSAD2 or IFIT1. RBB denominator gene: SAT1 or SRGN. The various RBB will be compared in terms of their sensitivity/specificity of diagnostic performance in the infection groups. AUC of ROC analysis will be performed where appropriate.

  first collected sample within the first week after admission

• Bacterial infection host response Direct LS-TA in monocytes (pro-inflammatory response)

  Direct LS-TA is a kind of RBB that can be readily quantified by qPCR or digital PCR (dPCR) of a pair of genes, the RBB numerator gene and the RBB denominator gene. The biomarker is the ratio of the 2 genes. Single cell-type: Monocyte. RBB numerator gene: VNN1 or NLRC4. RBB denominator gene: PSAP, CTSS or CPVL. The various RBBs will be compared in terms of their sensitivity/specificity of diagnostic performance in the infection groups. AUC of ROC analysis will be performed where appropriate.

  first collected sample within the first week after admission

• Bacterial infection host response Direct LS-TA in granulocytes (pro-inflammatory response)

  Direct LS-TA is a kind of RBB that can be readily quantified by qPCR or dPCR of a pair of genes, the RBB numerator gene and the RBB denominator gene. The biomarker is the ratio of the 2 genes. Single cell-type: Granulocyte. RBB numerator gene: ALPL, ANXA3 or ARG1. RBB denominator gene: SAT1 or SRGN. The various RBB will be compared in terms of their sensitivity/specificity of diagnostic performance in the infection groups. AUC of ROC analysis will be performed where appropriate.

  first collected sample within the first week after admission

• Active TB host response Direct LS-TA in monocytes (Type II interferon response)

  Direct LS-TA is a kind of RBB that can be readily quantified by qPCR or dPCR of a pair of genes, the RBB numerator gene and the RBB denominator gene. The biomarker is the ratio of the 2 genes. Single cell-type: Monocyte. RBB numerator gene: WARS1, ATF3 or CALHM6. RBB denominator gene: PSAP, CTSS or CPVL. The various RBB will be compared in terms of their sensitivity/specificity of diagnostic performance in infection groups. AUC of ROC analysis will be performed where appropriate.

  first collected sample within the first week after admission

• Active TB host response Direct LS-TA in granulocytes (Type II interferon response)

  Direct LS-TA is a kind of RBB that can be readily quantified by qPCR or dPCR of a pair of genes, the RBB numerator gene and the RBB denominator gene. The biomarker is the ratio of the 2 genes. Single cell-type: granulocyte. RBB numerator gene: ANKRD22, BATF2, CD274, FCGR1A or ETV7. RBB denominator gene: SAT1 or SRGN. The various RBB will be compared in terms of their sensitivity/specificity of diagnostic performance in infection groups. AUC of ROC analysis will be performed where appropriate.

  first collected sample within the first week after admission

Secondary Outcomes (2)

• DIRECT LS-TA results distribution and median of these DIRECT LS-TA RBB in infection groups

  first collected sample within the first week after admission

• Method evaluation to compare the performance of quantitative PCR and digital PCR

  first collected sample within the first week after admission

Study Arms (3)

Bacterial infection group

A prospective sample of adult patients who later confirmed to have fever due to bacterial infection by positive culture results.

Other: No intervention

Viral infection group

A prospective sample of adult patients who later confirmed to have fever due to viral infection by positive pathogen diagnostic results.

Other: No intervention

Active tuberculosis group

A prospective sample of adult patients who later confirmed to have fever due to active tuberculosis by clinical diagnosis and/or positive pathogen results.

Other: No intervention

Interventions

No intervention OTHER

Patients will receive clinical treatment with no special intervention in this observational study. There is no difference in term of treatment of patients. It only involves one additional blood sampling early after admission.

Active tuberculosis group; Bacterial infection group; Viral infection group

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patients with fever due to infections which are later clinically diagnosed as viral infection, bacterial infection or active tuberculosis.

You may qualify if:

• Adult patients with fever of acute onset which is defined by a raised body temperature.
• Patient should understand Chinese word to give informed consent.

You may not qualify if:

• Patients with a history of any immunodeficiency or immunocompromised condition. Patients received steriod or other immunotherapy.

Sponsors & Collaborators

• Chinese University of Hong Kong: lead

Study Sites (1)

Dept of Chemical Pathology, Chinese University of Hong Kong

Hong Kong, Hong Kong

Location

Related Publications (2)

• Huang D, Liu AYN, Leung KS, Tang NLS. Direct Measurement of B Lymphocyte Gene Expression Biomarkers in Peripheral Blood Transcriptomics Enables Early Prediction of Vaccine Seroconversion. Genes (Basel). 2021 Jun 25;12(7):971. doi: 10.3390/genes12070971.

  PMID: 34202032 BACKGROUND

• Huang B, Huang J, Chiang NH, Chen Z, Lui G, Ling L, Kwan MYW, Wong JSC, Mak PQ, Ling JWH, Lam ICS, Ng RWY, Wang X, Gao R, Hui DS, Ma SL, Chan PKS, Tang NLS. Interferon response and profiling of interferon response genes in peripheral blood of vaccine-naive COVID-19 patients. Front Immunol. 2024 Jan 10;14:1315602. doi: 10.3389/fimmu.2023.1315602. eCollection 2023.

  PMID: 38268924 BACKGROUND

Related Links

• Determination of gene expression levels of a cell type
• Method for measuring gene expression of single cell subpopulation, related kit, and application

Biospecimen

Retention: SAMPLES WITH DNA

Blood is collected into EDTA or citrate tubes. An aliquot of whole blood (WB) will be processed for RNA fixation by addition of Trizol solution and stored in -70C before total RNA extraction. Another aliquot of WB are separated into granulocytes and PBMC by the Ficoll gradient method. Granulocytes and a portion of PBMC will be fixed by Trizol.

MeSH Terms

Conditions

Infections; Virus Diseases; Bacterial Infections; Latent Tuberculosis; Fever

Condition Hierarchy (Ancestors)

Bacterial Infections and Mycoses; Tuberculosis; Mycobacterium Infections; Actinomycetales Infections; Gram-Positive Bacterial Infections; Latent Infection; Body Temperature Changes; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Central Study Contacts

Tang

CONTACT

852 35053330; nelsontang@cuhk.edu.hk

Study Design

• Study Type: observational
• Observational Model: CASE ONLY
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: February 18, 2025
• First Posted: February 26, 2025
• Study Start: February 1, 2025
• Primary Completion (Estimated): September 1, 2028
• Study Completion (Estimated): December 1, 2028
• Last Updated: March 3, 2025

Record last verified: 2025-02

Locations

HK (1)