Myeloid-derived suppressor cells in pleural effusion as a diagnostic marker for early discrimination of pulmonary tuberculosis from pneumonia

Front Immunol. 2024 Apr 29:15:1390327. doi: 10.3389/fimmu.2024.1390327. eCollection 2024.

Abstract

Introduction: Tuberculous pleural effusion (TPE) stands as one of the primary forms of extrapulmonary tuberculosis (TB) and frequently manifests in regions with a high prevalence of TB, consequently being a notable cause of pleural effusion in such areas. However, the differentiation between TPE and parapneumonic pleural effusion (PPE) presents diagnostic complexities. This study aimed to evaluate the potential of myeloid-derived suppressor cells (MDSCs) in the pleural fluid as a potential diagnostic marker for distinguishing between TPE and PPE.

Methods: Adult patients, aged 18 years or older, who presented to the emergency room of a tertiary referral hospital and received a first-time diagnosis of pleural effusion, were prospectively enrolled in the study. Various immune cell populations, including T cells, B cells, natural killer (NK) cells, and MDSCs, were analyzed in both pleural fluid and peripheral blood samples.

Results: In pleural fluid, the frequency of lymphocytes, including T, B, and NK cells, was notably higher in TPE compared to PPE. Conversely, the frequency of polymorphonuclear (PMN)-MDSCs was significantly higher in PPE. Notably, compared to traditional markers such as the neutrophil-to-lymphocyte ratio and adenosine deaminase level, the frequency of PMN-MDSCs emerged as a more effective discriminator between PPE and TPE. PMN-MDSCs demonstrated superior positive and negative predictive values and exhibited a higher area under the curve in the receiver operating characteristic curve analysis. PMN-MDSCs in pleural effusion increased the levels of reactive oxygen species and suppressed the production of interferon-gamma from T cells following nonspecific stimulation. These findings suggest that MDSC-mediated immune suppression may contribute to the pathology of both TPE and PPE.

Discussion: The frequency of PMN-MDSCs in pleural fluid is a clinically useful indicator for distinguishing between TPE and PPE.

Keywords: myeloid-derived suppressor cells; parapneumonic effusion; pleural effusion; pneumonia; tuberculosis; tuberculous pleural effusion.

MeSH terms

  • Adult
  • Aged
  • Biomarkers*
  • Diagnosis, Differential
  • Female
  • Humans
  • Male
  • Middle Aged
  • Myeloid-Derived Suppressor Cells* / immunology
  • Myeloid-Derived Suppressor Cells* / metabolism
  • Pleural Effusion* / diagnosis
  • Pleural Effusion* / immunology
  • Pneumonia / diagnosis
  • Pneumonia / immunology
  • Prospective Studies
  • Tuberculosis, Pleural / diagnosis
  • Tuberculosis, Pleural / immunology
  • Tuberculosis, Pulmonary* / diagnosis
  • Tuberculosis, Pulmonary* / immunology

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by a grant from the Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University Bundang Hospital, and by the Basic Science Research Program through the National Research Foundation (NRF) of the Republic of Korea [2015R1C1A1A01054596, 2018R1D1A1A02085326]. The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.