Reproducibility of Novel Immune-Inflammatory Biomarkers Over 4 Months: An Analysis with Repeated Measures Design

Abstract

Aim: Assessment of the feasibility and reliability of immune-inflammatory biomarker measurements. Methods: The following biomarkers were assessed in 207 predominantly healthy participants at baseline and after 4 months: MMF, TGF-β, suPAR and clusterin. Results: Intraclass correlation coefficients (95% CIs) ranged from good for TGF-β (0.75 [95% CI: 0.33–0.90]) to excellent for MMF (0.81 [95% CI: 0.64–0.90]), clusterin (0.83 [95% CI: 0.78–0.87]) and suPAR (0.91 [95% CI: 0.88–0.93]). Measurement of TGF-β was challenged by the large number of values below the detection limit. Conclusion: Single measurements of suPAR, clusterin and MMF could serve as feasible and reliable biomarkers of immune-inflammatory pathways in biomedical research.

Keywords:

• clusterin
• immune-inflammatory biomarkers
• MMF
• repeated measures design
• reproducibility
• suPAR
• TGF-β

Acknowledgements

We express special thanks to K Ritter (DIfE) for her valuable work on biomarker measurements. We thank the Human Study Centre (DIfE) for data collection and biological sample logistics. We express special thanks to M Bergmann for her contribution by leading the underlying processes of data generation, as well as to SN Fruth and H Piechot for their valuable assistance with biosample management. Particular thanks are given to the data managers, especially E Kohlsdorf. Finally, we express special thanks to all EPIC-Potsdam participants for their invaluable contribution to the study. This study is based on the master's thesis of the first author for the Master of Science Toxicology Program at the Charité University of Medicine, Berlin, Germany.

Financial & competing interests disclosure

The project was supported by institutional funding of the German Institute of Human Nutrition Potsdam-Rehbrücke. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

All participants provided written informed consent prior to recruitment and the study procedures were approved by the Ethics Committee of the Medical Association of the State of Brandenburg.

Additional information

Funding

The project was supported by institutional funding of the German Institute of Human Nutrition Potsdam-Rehbrücke. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.