Evaluating the long-term biological stability of cytokine biomarkers in ocular fluid samples

• Published in: BMJ open ophthalmology 2023-12, Vol.8 (1), p.e001346
• Main Authors: Felfeli, Tina, Park, Jeff, Nestor, Bret, Altomare, Filiberto, Rai, Amandeep S, Mandelcorn, Efrem D, Chow, David R, Wong, David T
• Format: Article
• Language: English
• Subjects: Aqueous humour; Biomarkers; Cataracts; Cytokines; Eye surgery; Granulocytes; Inflammation; Original Research; Patients; Retinal detachment; Tears; Tumor necrosis factor-TNF; Variance analysis; Vitreous
• ISSN: 2397-3269; 2397-3269
• DOI: 10.1136/bmjophth-2023-001346

PurposeThe quality of biological fluid samples is vital for optimal preanalytical procedures and a requirement for effective translational biomarker research. This study aims to determine the effects of storage duration and freeze-thawing on the levels of various cytokines in the human aqueous humour and vitreous samples.Methods and analysisHuman ocular aqueous humour and vitreous samples were obtained from 25 eyes and stored at −80°C for analysis. All samples were assayed for 27 cytokine biomarker concentrations (pg/mL) using a multiplex assay. Four sample storage durations following sample collection were evaluated (1 week, 3 months, 9 months and 15 months). Additionally, samples underwent up to three freeze-thaw cycles within the study period.ResultsAmong the 27 cytokine biomarkers, concentrations of four cytokines (Interleukin (IL)−2, IL-10, IL-12 and platelet-derived growth factor-BB) were significantly decreased by storage duration at all time points, as early as 3 months following sample collection (range of 9%–37% decline between 1 week and 15 months, p