The Association of TSH and Thyroid Hormones With Lymphopenia in Bacterial Sepsis and COVID-19.

Abstract

CONTEXT:

Lymphopenia is a key feature of immune dysfunction in patients with bacterial sepsis and coronavirus disease 2019 (COVID-19) and is associated with poor clinical outcomes, but the cause is largely unknown. Severely ill patients may present with thyroid function abnormalities, so-called nonthyroidal illness syndrome, and several studies have linked thyrotropin (thyroid stimulating hormone, TSH) and the thyroid hormones thyroxine (T4) and 3,5,3'-triiodothyronine (T3) to homeostatic regulation and function of lymphocyte populations.

OBJECTIVE:

This work aimed to test the hypothesis that abnormal thyroid function correlates with lymphopenia in patients with severe infections.

METHODS:

A retrospective analysis of absolute lymphocyte counts, circulating TSH, T4, free T4 (FT4), T3, albumin, and inflammatory biomarkers was performed in 2 independent hospitalized study populations: bacterial sepsis (n = 224) and COVID-19 patients (n = 161). A subgroup analysis was performed in patients with severe lymphopenia and normal lymphocyte counts.

RESULTS:

Only T3 significantly correlated (ρ = 0.252) with lymphocyte counts in patients with bacterial sepsis, and lower concentrations were found in severe lymphopenic compared to nonlymphopenic patients (n = 56 per group). Severe lymphopenic COVID-19 patients (n = 17) showed significantly lower plasma concentrations of TSH, T4, FT4, and T3 compared to patients without lymphopenia (n = 18), and demonstrated significantly increased values of the inflammatory markers interleukin-6, C-reactive protein, and ferritin. Remarkably, after 1 week of follow-up, the majority (12 of 15) of COVID-19 patients showed quantitative recovery of their lymphocyte numbers, whereas TSH and thyroid hormones remained mainly disturbed.

CONCLUSION:

Abnormal thyroid function correlates with lymphopenia in patients with severe infections, like bacterial sepsis and COVID-19, but future studies need to establish whether a causal relationship is involved.

• Authors: Inge Grondman, Aline H de Nooijer, Nikolaos Antonakos, Nico A F Janssen, Maria Mouktaroudi, Konstantinos Leventogiannis, Marco Medici, Jan W A Smit, Antonius E van Herwaarden, Leo A B Joosten, Frank L van de Veerdonk, Peter Pickkers, Matthijs Kox, Martin Jaeger, Mihai G Netea, Evangelos J Giamarellos-Bourboulis, Romana T Netea-Maier
• Journal: The Journal of clinical endocrinology and metabolism (J Clin Endocrinol Metab) Vol. 106 Issue 7 Pg. 1994-2009 (06 16 2021) ISSN: 1945-7197 [Electronic] United States
• PMID: 33713408 (Publication Type: Journal Article, Multicenter Study, Observational Study, Research Support, Non-U.S. Gov't)
• Copyright: © The Author(s) 2021. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: [email protected].

Chemical References

• Thyroid Hormones
• Thyrotropin

Topics

• Aged
• Aged, 80 and over
• COVID-19 (blood, complications, immunology)
• Euthyroid Sick Syndromes (blood, diagnosis, immunology)
• Female
• Greece
• Humans
• Lymphocyte Count
• Lymphopenia (blood, diagnosis, immunology)
• Male
• Netherlands
• Retrospective Studies
• SARS-CoV-2 (immunology)
• Sepsis (blood, complications, immunology)
• Thyroid Hormones (blood, immunology)
• Thyrotropin (blood, immunology)