Related Experiment Video
Updated: Feb 26, 2026
06:03
Author Spotlight: Advancing Immune Monitoring in Critical Care Patients Using Whole Blood Assays
Published on: September 20, 2024
1.9K
John Cunningham virus conversion in relation to natalizumab concentration in multiple sclerosis patients
Z L E van Kempen1, C E Leurs1, A de Vries2
1Department of Neurology, Amsterdam Neuroscience, VUmc MS Center Amsterdam, VU University Medical Center, Amsterdam, The Netherlands.
European Journal of Neurology
|July 15, 2017
Summary
Higher natalizumab levels do not increase the risk of John Cunningham virus (JCV) seroconversion in multiple sclerosis patients. This finding does not explain the higher JCV infection rate observed in patients undergoing natalizumab treatment.
Area of Science:
- Neuroimmunology
- Viral Infections
- Pharmacology
Background:
- Progressive multifocal leukoencephalopathy (PML) is a serious risk for multiple sclerosis (MS) patients treated with natalizumab.
- John Cunningham virus (JCV) infection is a prerequisite for PML development.
- The rate of JCV seroconversion appears elevated in natalizumab-treated MS patients compared to the general population, but the reason remains unclear.
Purpose of the Study:
- To investigate the relationship between natalizumab concentration and JCV antibody status, including seroconversion, in a large cohort of MS patients.
- To determine if higher natalizumab concentrations correlate with an increased risk of JCV infection or seroconversion.
Main Methods:
- A cohort of 135 multiple sclerosis patients treated with natalizumab was analyzed.
- Natalizumab drug concentrations were measured and correlated with JCV antibody status and seroconversion rates.
- JCV index was also assessed in relation to natalizumab levels.
Main Results:
- No statistically significant correlation was identified between natalizumab concentration and JCV antibody status.
- Natalizumab levels did not correlate with JCV seroconversion rates in the studied cohort.
- There was no observed association between natalizumab concentration and the JCV index.
Conclusions:
- Elevated natalizumab concentrations do not appear to be the driving factor behind the increased JCV seroconversion rate observed in natalizumab-treated MS patients.
- The underlying cause for the higher JCV seroconversion rate in this patient group requires further investigation.
- These findings suggest that factors other than drug concentration may influence JCV susceptibility or reactivation during natalizumab therapy.
