The Effect of Preanalytical Conditions on Blood-Based Inflammation Biomarkers

Blood-based inflammation biomarkers have potential for diagnostic, prognostic, and predictive testing, but preanalytical processing conditions can affect biomarker levels. We investigated how needle-to-freezer time, centrifugation timing, and tube types influence inflammation biomarkers. Twenty subjects donated 21 different blood samples in collection tubes, including plasma and serum types. Ninety-two biomarkers from each sample were analyzed using the Olink Target 96 Inflammation panel. We compared biomarker concentrations across different preanalytical variables to a reference standard tube. Intraclass, Pearson, and Spearman's correlation coefficients were calculated. We also assessed the impact of these conditions on age-related associations with biomarkers. Across the preprocessing protocol/blood matrix combinations, 38%-83%, 50%-87%, and 47%-79% of proteins showed good to excellent correlations in intraclass, Pearson, and Spearman analyses, respectively. Eighteen proteins differed by >0.5 NPX units between test and reference protocols. Among 30 comparisons of age-related biomarker associations showing p ≤ 0.05 at baseline, 12 (40%) maintained a p ≤ 0.05 across all needle-to-freezer times. Many proteins in the Olink Target 96 Inflammation panel exhibited robust stability across various preanalytical conditions, indicating that blood-based inflammation biomarkers are suitable for testing across different blood specimen types. Further studies are needed to evaluate the impact of long-term storage.