ORIGINAL RESEARCH article

Front. Immunol.

Sec. Microbial Immunology

Volume 16 - 2025 | doi: 10.3389/fimmu.2025.1586789

This article is part of the Research TopicEffects of COVID-19 Infection or Vaccination on Interferon-gamma Release Assays in Latent TuberculosisView all articles

Previous COVID-19 infection significantly reduces elastase levels in newly diagnosed pulmonary tuberculosis patients

Provisionally accepted
Nancy Hilda JNancy Hilda J1*Alangudi Palaniappan NatarajanAlangudi Palaniappan Natarajan1Saravanan NatarajanSaravanan Natarajan1Chinnaiyan PonnurajaChinnaiyan Ponnuraja1Madeshwaran AMadeshwaran A1Gunaparvathy IGunaparvathy I2Hemalatha PHemalatha P2Rajeshwari SRajeshwari S3Lavanya JLavanya J4Mahilmaran AyyamperumalMahilmaran Ayyamperumal3Ramesh P MRamesh P M5Elizabeth Hanna LukeElizabeth Hanna Luke1
  • 1ICMR- National Institute for Research in Tuberculosis, Chennai, India
  • 2Government Hospital of Thoracic Medicine, Chennai, Tamil Nadu, India
  • 3Institute of Thoracic Medicine, Chennai, India
  • 4NTEP, Chennai, India
  • 5Government Thiruvatteeswarar Hospital of Thoracic Medicine, Chennai, India

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Tuberculosis (TB) is considered a risk factor for severe COVID-19 disease and the quality of life of patients co-infected with COVID-19 and TB is significantly impacted due to the nature of these diseases. It is still unknown how our immune system will respond to both these pathogens in sequel. As it has been discovered that Neutrophil extracellular traps (NETs) result in caseating granulomas in TB and pathology in COVID-19, we conducted this work to determine the amounts of NET molecules in the bloodstream and to comprehend their function during TB and subsequent SARS-CoV-2 infection. We recruited 43 healthy volunteers, 40 newly diagnosed pulmonary tuberculosis patients who were negative for SARS-CoV-2 IgG antibody and 18 newly diagnosed pulmonary tuberculosis patients who were positive for SARS-CoV-2 IgG. Although Citrullinated Histone H3 and myeloperoxidase, did not show any difference in their levels, the NET marker elastase had significantly reduced circulatory levels in the tuberculosis group with SARS-CoV IgG positivity compared to tuberculosis group without SARS-CoV-2 IgG positivity. The substantial decrease in elastase levels observed in the diabetic cohort of TB patients with SARS-CoV-2 IgG positivity is intriguing and needs large cohort studies in the future to understand the influence of diabetes in TB patients exposed to SARS-CoV-2.

Keywords: neutrophil extracellular traps, elastase, diabetes, pulmonary tuberculosis, x-ray

Received: 03 Mar 2025; Accepted: 10 Jul 2025.

Copyright: © 2025 J, Natarajan, Natarajan, Ponnuraja, A, I, P, S, J, Ayyamperumal, P M and Luke. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Nancy Hilda J, ICMR- National Institute for Research in Tuberculosis, Chennai, India

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