F. Kakar^1,2, A. Fontes⁵, D. McDonald¹, JDE.Parratt⁵, MW. Lin*^1,2,3,4 and D.A. Brown*^1,2,3,4, 

 

¹ Department of Immunopathology, ICPMR, NSW Health Pathology, Westmead Hospital, Sydney

²Faculty of Medicine and Health Sciences, University of Sydney 

³ Department of Clinical Immunology, Westmead Hospital, Westmead, Sydney

⁴ Centre of Immunology and Allergy Research, Westmead Institute of Medical Research, Westmead, Sydney

⁵Neurology Department, Royal North Shore Hospital, Sydney, NSW

 

Aim: Validation of serum neurofilament light chain (sNFL) by Single Molecular Array (SiMOA) technology.  

 

Introduction: sNFL is an ultrasensitive diagnostic, monitoring and prognostication biomarker of neuronal damage in neurodegenerative disorders, allowing measurement of sNfL values in picograms/ml.

 

Method: NfL levels from 89 healthy males and females ages 20-89 years were measured to establish age partitioned reference range based on existing literature ^[1]. These were compared to 20 multiple sclerosis (MS) patients with high and 20 with low disease activity scores. Further studies included precision testing, batch to batch variation, fridge stability and freeze thaw cycle effects on serum samples. Inter-laboratory quality control testing was also performed.

 

Results: Age partitioned normal reference levels were established. Comparison of diseased samples with age matched controls revealed a significant relationship between sNfL levels and disease activity (p-value of <0.0001). Precision testing showed a maximum intra-laboratory CV of 15%. Stability studies indicated serum samples remain stable for up to 2 weeks in the fridge and 2 freeze thaw cycles. Batch to batch variation, intra and inter-laboratory comparisons were satisfactory.  

 

Conclusion: SiMOA technology reliably measures sNfL levels, meeting NATA accreditation standards at ICPMR, NSW Health Pathology. 

 

 

1.       Hviid, C.V.B., Knudsen, C.S. and Parkner, T. (2020). Reference interval and preanalytical properties of serum neurofilament light chain in Scandinavian adults. Scandinavian Journal of Clinical and Laboratory Investigation, 80(4), pp.291–295.