Title:
Diagnostic Performance of ELISA Based IGRA in Detecting Latent Tuberculosis Among Rheumatoid Arthritis Patients

Authors:
Fatima Alzahraa hussien abed ali, Ahmad Salman Al-Amary, Rusul Sabah Azeez, Mohammed Hamza Abdul Zahra, Baraa Jawad Kadhim, Iraq

Abstract:

Background: Rheumatoid arthritis (RA) is a chronic autoimmune disorder marked by persistent inflammation and progressive joint damage. Patients with RA are at elevated risk of latent tuberculosis infection (LTBI), particularly when receiving immunosuppressive or biologic therapies. Accurate LTBI screening is therefore critical before initiating such treatments.

Objective: This study aimed to evaluate the diagnostic performance of an ELISA-based interferon-gamma release assay (IGRA) in detecting latent tuberculosis infection among RA patients and to examine its association with demographic factors.

Methods: A total of 230 whole-blood samples were collected from RA patients at Mergan Teaching Hospital between January 2025 and July 2026. The Wantai TB-IGRA ELISA was employed to quantify interferon-γ release following stimulation with Mycobacterium tuberculosis–specific antigens. Statistical analyses, including Chi-square tests, assessed the relationship between IGRA results and demographic variables such as age, gender, and treatment type, with significance set at p ≤ 0.05.

Results: Most patients were female, aged 36–55 years, aligning with the typical RA onset range. The ELISA-based IGRA demonstrated high sensitivity (80–90%) for detecting latent TB. Patients undergoing immunosuppressive therapy had a higher proportion of indeterminate results, consistent with prior studies.

Conclusion: ELISA-based IGRA is a reliable and sensitive diagnostic tool for identifying latent TB infection in RA patients, supporting timely screening prior to immunosuppressive therapy and improving patient management.

DOI: http://dx.doi.org/10.51505/ijmshr.2025.9615