Quantification of blood glial fibrillary acidic protein using a second-generation microfluidic assay. Validation and comparative analysis with two established assays.
Clin Chem Lab Med
; 62(8): 1591-1601, 2024 Jul 26.
Article
in En
| MEDLINE
| ID: mdl-38353147
ABSTRACT
OBJECTIVES:
Increased levels of glial fibrillary acidic protein (GFAP) in blood have been identified as a valuable biomarker for some neurological disorders, such as Alzheimer's disease and multiple sclerosis. However, most blood GFAP quantifications so far were performed using the same bead-based assay, and to date a routine clinical application is lacking.METHODS:
In this study, we validated a novel second-generation (2nd gen) Ella assay to quantify serum GFAP. Furthermore, we compared its performance with a bead-based single molecule array (Simoa) and a homemade GFAP assay in a clinical cohort of neurological diseases, including 210 patients.RESULTS:
Validation experiments resulted in an intra-assay variation of 10â¯%, an inter-assay of 12â¯%, a limit of detection of 0.9â¯pg/mL, a lower limit of quantification of 2.8â¯pg/mL, and less than 20â¯% variation in serum samples exposed to up to five freeze-thaw cycles, 120â¯h at 4⯰C and room temperature. Measurement of the clinical cohort using all assays revealed the same pattern of GFAP distribution in the different diagnostic groups. Moreover, we observed a strong correlation between the 2nd gen Ella and Simoa (r=0.91 (95â¯% CI 0.88-0.93), p<0.0001) and the homemade immunoassay (r=0.77 (95â¯% CI 0.70-0.82), p<0.0001).CONCLUSIONS:
Our results demonstrate a high reliability, precision and reproducibility of the 2nd gen Ella assay. Although a higher assay sensitivity for Simoa was observed, the new microfluidic assay might have the potential to be used for GFAP analysis in daily clinical workups due to its robustness and ease of use.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Glial Fibrillary Acidic Protein
Limits:
Aged
/
Female
/
Humans
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Male
/
Middle aged
Language:
En
Journal:
Clin Chem Lab Med
Year:
2024
Document type:
Article