Language
English
Publication Date
12-1-2025
Journal
Journal of Clinical Laboratory Medicine
DOI
10.1002/jcla.70122
PMID
41047907
PMCID
PMC12699199
PubMedCentral® Posted Date
10-6-2025
PubMedCentral® Full Text Version
Post-print
Abstract
Background: The soluble C5b-9 (sC5b-9) is a soluble form of the Terminal Complement Complex (TCC) that is released into the circulation with elevated levels, associated with increased morbidity and mortality in patients with complement-mediated inflammatory conditions. With the advent of eculizumab and ravulizumab, proper testing for diagnoses and therapeutic monitoring is warranted.
Methods: We evaluated both the analytical and clinical performance of the Quidel Microvue sC5b-9 Plus enzyme immunoassay. Analytical performance was evaluated with precision, linearity, interference studies, and correlation with a reference laboratory. Reference intervals were established using control donor samples [n = 26; median age 18.5 years (range 2-59)]. Clinical performance of the assay was assessed using plasma samples of patients who (i) developed transplant-associated thrombotic microangiopathy [n = 10; median age 14 years (range 3-19)], (ii) had reduced ADAMTS13 activity [n = 6; median age 16 years (range 9-18)], and (iii) developed acquired Von-Willebrand disease [n = 10; median age 18.5 years (range 0.5-18)].
Results: The assay showed acceptable intra and inter-precision at both low and high levels. Linearity ranged from 12.6 to 160.66 ng/mL, while accuracy and method correlation studies with a reference laboratory yielded a correlation coefficient (R) of 0.96. The reference range in control donors was established at ≤ 268.0 ng/mL. Clinical performance of the assay in patients' plasma revealed elevated sC5b-9 levels suggesting complement activation in these patient cohorts compared with control levels.
Conclusion: The Quidel Microvue sC5b-9 plus EIA assay demonstrated acceptable analytical performance and clinical utility for monitoring complement activation in patients. Further studies are needed to correlate sC5b-9 levels with existing markers of complement activation.
Keywords
Humans, Complement Membrane Attack Complex, Child, Adolescent, Child, Preschool, Young Adult, Middle Aged, Male, Adult, Female, Reproducibility of Results, Immunoenzyme Techniques, Reference Values, Thrombotic Microangiopathies, analytical precision, complement activation, eculizumab, ravulizumab, transplant‐associated thrombotic microangiopathy, Von‐willebrand disease
Published Open-Access
yes
Recommended Citation
Ibrahim, Ridwan B; Almamoun, Radwa; Sartain, Sarah E; et al., "Soluble C5b-9 (sC5b-9) in Pediatrics-A Clinical Assessment" (2025). Faculty and Staff Publications. 5574.
https://digitalcommons.library.tmc.edu/baylor_docs/5574
Included in
Allergy and Immunology Commons, Biological Phenomena, Cell Phenomena, and Immunity Commons, Pathology Commons