Dynamics of cytokines, immune cell counts and disease severity in patients with community-acquired pneumonia - Unravelling potential causal relationships.

Abstract

BACKGROUND:

Community acquired pneumonia (CAP) is a severe and often rapidly deteriorating disease. To better understand its dynamics and potential causal relationships, we analyzed time series data of cytokines, blood and clinical parameters in hospitalized CAP patients.

METHODS:

Time series data of 10 circulating cytokines, blood counts and clinical parameters were related to baseline characteristics of 403 CAP patients using univariate mixed models. Bivariate mixed models were applied to analyze correlations between the time series. To identify potential causal relationships, we inferred cross-lagged relationships between pairs of parameters using latent curve models with structured residuals.

RESULTS:

IL-6 levels decreased faster over time in younger patients (Padj = 0.06). IL-8, VCAM-1, and IL-6 correlated strongly with disease severity as assessed by the sequential organ failure assessment (SOFA) score (r = 0.49, 0.48, 0.46, respectively; all Padj < 0.001). IL-6 and bilirubin correlated with respect to their mean levels and slopes over time (r = 0.36 and r = 0.46, respectively; Padj < 0.001). A number of potential causal relationships were identified, e.g., a negative effect of ICAM-1 on MCP-1, or a positive effect of the level of creatinine on the subsequent VCAM-1 concentration (P < 0.001).

CONCLUSIONS:

These results suggest that IL-6 trajectories of CAP patients are associated with age and run parallel to bilirubin levels. The time series analysis also unraveled directed, potentially causal relationships between cytokines, blood parameters and clinical outcomes. This will facilitate the development of mechanistic models of CAP, and with it, improvements in treatment or surveillance strategies for this disease.

TRIAL REGISTRATION:

clinicaltrials.gov NCT02782013, May 25, 2016, retrospectively registered.

• Authors: Maciej Rosolowski, Volker Oberle, Peter Ahnert, Petra Creutz, Martin Witzenrath, Michael Kiehntopf, Markus Loeffler, Norbert Suttorp, Markus Scholz
• Journal: Cytokine (Cytokine) Vol. 136 Pg. 155263 (12 2020) ISSN: 1096-0023 [Electronic] England
• PMID: 32896803 (Publication Type: Clinical Trial, Journal Article, Multicenter Study, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2020 Elsevier Ltd. All rights reserved.

Chemical References

• CXCL8 protein, human
• ICAM1 protein, human
• IL6 protein, human
• Interleukin-6
• Interleukin-8
• Vascular Cell Adhesion Molecule-1
• Intercellular Adhesion Molecule-1

Topics

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Community-Acquired Infections (blood)
• Female
• Humans
• Intercellular Adhesion Molecule-1 (blood)
• Interleukin-6 (blood)
• Interleukin-8 (blood)
• Leukocyte Count
• Male
• Middle Aged
• Pneumonia (blood)
• Prospective Studies
• Severity of Illness Index
• Vascular Cell Adhesion Molecule-1 (blood)