1Professor Hayder K.Hassoun, 2Professor Akram Al-Mahdawi, 1 Huda Khadi
1Faculty of Medicine, Baghdad University, baghdad, Iraq; 2Faculty of Medicine, Kufa University, Annajaf, Iraq
Currently MS disease activity, neurodegeneration and treatment response are assessed mainly through clinical evaluation and magnetic resonance imaging. These measures lack sensitivity and accuracy, so new biomarkers are necessary.
Several markers have been studied and to date among the most promising is the neurofilament light chain (NfL).Many studies have shown elevated CSF Nf levels in a wide variety of neurological disorders in which axonal degeneration occurs including MS.The release of NfL into the peripheral blood represents a significant opportunity for monitoring disease activity and progression without the need for the more invasive CSF sampling.this study is conducted to assess the relationship between serum neurofilament (NfL & NfH chain) levels and the disease type, duration, disease activity, severity, and other variables among Iraqi multiple sclerosis patients.
Material(s) and Method(s):
Patients and Methods: A case-control study was conducted in the Middle-Euphrates-Neuroscience Centre, Al-Najaf, over a period of 4 months from June to October, 2019. Fifty-six Adult patients who fulfilled the revised McDonalds
criteria (2017) for the diagnosis of MS and forty four healthy controls were enrolled. Serum samples for NfL and NfH were collected and processed using ELISA method, the results were compared for MS patients and controls ; the serum
results of MS patients were also correlated to type of MS,disease duration,,EDSS, MSSS,and disease activity (as detected by MRI Gadolinium enhancement and clinical relapses) .The NFL and NfH levels were also compared between treated and untreated patients and the treatment group was subdivided and compared to each other according to the type of treatment.
Fifty-six cases were enrolled in the study. Mean age (SD) was 34.3 (9.1) years with a median disease duration of 3 (0 – 14) years. Forty-four subjects were included as controls with a mean age of 33.7 (SD = 7.2). The male: female ratio was 1:3 for the cases and 1:2 for controls. Forty-nine patients (83%) had RRMS, six patients (10%) had SPMS and one patient (1.7%) with PPMS. Forty-eight patients (81%) had no gadolinium-enhanced lesions on MRI. Forty-four patients (74.6%) were on remission at the time of data collection, and twelve patients (24.4%) were in clinical relapse. The mean serum NfL level
for cases was 133.3 (SD = 62.6) pg/ml which is significantly higher than that for controls (Mean = 80 pg/ml; SD = 22.5; p value <0.001). The mean serum NfH level was 3654.5 (SD = 567.8) pg/ml for cases which is also significantly higher
than the levels obtained from healthy subjects (408.8 pg/ml; SD = 343.5; p value < 0.001). The mean serum NfL and NfH levels were not significantly different between patients with negative and positive gadolinium-enhancedlesions. There were no significant correlations between serum NfL and NfH levels, and EDSS, MSSS, age, type and duration of the disease, or treatment status. Regression analysis using NfL and NfH as dependent variables, and age, duration, type of MS, EDSS, MSSS, treatment status,and MRI- enhanced gadolinium lesions as the independent variables didn’t demonstrate any significant relationships.
Measuring serum NfL and NfH may represent a potentially significant biomarker for prognostication and making treatment decisions in MS with avoiding the more invasive and inconvenient CSF sampling. In this study Serum NfL and NfH levels are elevated in patients with MS when compared to controls but they don’t correlate with the presence or number of gadolinium enhanced MRI lesions, disability, or disease severity. however, for the future studies in this field using a more sensitive methods for assessment of NFs in serum with longitudinal sampling may yield a more accurate and reproducible results.