Abstract
Objectives Serum biomarkers of neuronal damage might improve reliability, accuracy, and objectivity of assessments of disease activity in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) where differentiating patients in remission from those with active but stable disease on therapy is a challenge to the clinician and trial design. We explored associations between plasma neurofilament light chain (pNfL) and disease activity in CIDP patients and examined its usefulness in determining disease remission.
Methods We examined pNfL in untreated CIDP patients (n=10) before and after intravenous immunoglobulin (IVIg) induction treatment, differences in pNfL in patients on maintenance IVIg treatment (stable patients n=15, unstable patients n=9), and in clinically stable IVIg treated patients (n=10) in whom we stopped IVIg to determine their disease activity and need for maintenance IVIg.
Results Untreated patients with CIDP: pNfL was significantly higher in patients than an age-matched, healthy control group and comparable to control group values post IVIg induction.
Clinically stable and unstable patients with CIDP on IVIg treatment: pNfL was significantly greater in unstable patients than stable patients. A pNFL value above 16.6 pg/mL identified unstable treated CIDP from stable treated CIDP (sensitivity= 86.7%, specificity= 66.7%, area under ROC= 0.73).
Treatment withdrawal group: There was a strong and statistically significant correlation between pNfL concentration at time of IVIg withdrawal and the occurrence of relapse, suggesting an association of higher pNfL with active disease.
Conclusion pNfL concentrations may be a sensitive, clinically useful biomarker in assessing subclinical disease activity.
