Clinical trial NCT06796647: ESAT6/CFP10 Skin Testing for TB Infection in Rheumatologic Patients
Official title: The Use of a Novel ESAT6/CFP10 Skin Test in Diagnosis of Latent Tuberculosis Infection Among Rheumatologic Patients
Study type: OBSERVATIONAL
Overall status: NOT_YET_RECRUITING
Conditions: Tuberculosis (TB)
Keywords: tuberculosis
skin testing
ESAT6/CFP10
rheumatology patients
Lead sponsor: Chinese University of Hong Kong
Sponsor class: OTHER
First posted: 2025-01-28
Enrollment: 100
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_ONLY
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Rheumatology patients followed up at the Specialist Services of regional hospitals in New Territories East Cluster in Hong Kong (Prince of Wales Hospital, Alice Ho Miu Ling Nethersole Hospital and North District Hospital)

Brief summary: The aim of the study is to pilot the application of a novel ESAT6/CFP10 (C-TST) skin test in rheumatologic disease patients prior to initiation of treatment with biologic and/or targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARD). This is a prospective observational study involving the recruitment of patients with rheumatologic diseases who are planned for initiation of b/tsDMARD. Eligible patients would undergo skin testing by the Mantoux technique with purified protein derivative (PPD) RT23 on one forearm and C-TST on the other, alongside routine blood sampling for Interferon-Gamma Release Assay. The skin test results would be read within 48-72 hours afterwards. Treatment of TB infection would be provided in accordance with current clinical guidelines, followed by regular clinical monitoring for 2 years. Analyses involve performance evaluation of C-TST, and decision-analytical modelling incorporating multiple Markov process to evaluate the impact of management by LTBI testing methods on clinical outcomes and health care costs.

Detailed description: Objective. The aim of the study is to pilot the application of a novel ESAT6/CFP10 (C-TST) skin test in rheumatologic disease patients prior to initiation of treatment with biologic and/or targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARD), with the objectives of determining its performance and the cost-effectiveness of clinical management for latent tuberculosis infection (LTBI).

Design. A prospective observational study

Setting. Rheumatology Specialist clinic services in Hong Kong

Methods. This study involves the recruitment of patients with rheumatologic diseases who are planned for initiation of b/tsDMARD. Eligible patients would undergo skin testing by the Mantoux technique with intradermal injection of 2U purified protein derivative (PPD) RT23 on one forearm and 5U of C-TST on the other, alongside routine blood sampling for Interferon-Gamma Release Assay (IGRA) with QuantiFERON-TB Gold. The skin test results would be read within 48-72 hours afterwards. Treatment of LTBI would be provided in accordance with current clinical guidelines, followed by regular clinical monitoring for 2 years. Analyses involve performance evaluation of C-TST, and decision-analytical modelling incorporating multiple Markov process to evaluate the impact of management by LTBI testing methods on clinical outcomes and health care costs.

Main outcome measures. Concordance between different tests for LTBI by Kappa measure; sensitivity and specificity of C-TST test estimated with current standard; proportion of new TB cases averted, discounted QALYG and ICER.

Anticipated outcome. The study would provide preliminary evidence regarding the diagnostic performance of C-TST, and impact of its utilisation for treatment decision for rheumatologic diseases patients in the prevention of active tuberculosis diseases.

Eligibility criteria: Inclusion Criteria:

1. adult of age ≥ 18 and up to 65 years;
2. diagnosis of at least one classified rheumatologic disease; and
3. being planned to receive b/tsDMARDs therapy,
4. can communicate in Chinese and/or English.

Exclusion Criteria:

* diagnosis of active TB diseases,
* currently receiving TB or LTBI treatment;
* concurrent mental illnesses;
* prisoners.

Primary outcomes:
measure: C-TST reading
timeFrame: from enrolment to reading test result at 48-72 hours
measure: C-TST reading
timeFrame: from enrolment to reading test result at 2 weeks
Secondary outcomes:
measure: Proportion with TB disease
timeFrame: from enrolment to last followup at 2 years
Other outcomes:
Locations:
city: Shatin
country: Hong Kong
facility: S.H. Ho Research Centre for Infectious Diseases
Study officials:
affiliation: Chinese University of Hong Kong
name: David SC Hui, MD
role: STUDY_DIRECTOR
References: