2020-11-30
Kapica-Topczewska, K; Collin, F; Tarasiuk, J; Czarnowska, A; Chorąży, M; Mirończuk, A; Kochanowicz, J; Kułakowska, A
European Neurology, 83:487–492
My contribution: data curation and analysis, formal analysis, methodology, software.
Introduction
Presence of anti-JC-virus antibodies (JCVAb) is associated with increased risk of natalizumab-related progressive multifocal leukoencephalopathy (PML). Less it is known about seroconversion rate and time to seroconversion in relapsing-remitting multiple sclerosis (RRMS) patients treated with natalizumab (NAT) in Poland. The aim of the study was to assess the true risk of PML, seroconversion rate and time to seroconversion in all JCVAb negative RRMS patients treated with NAT in Poland.
Methods
Demographic and clinical data of all Polish RRMS patients treated with NAT reimbursed by National Health Fund (NFZ) were prospectively collected in electronic files using the Therapeutic Program Monitoring System (SMPT) provided by NFZ. The assessment of JCVAb presence (without collection of JCVAb index value) in serum (Unilabs, STRATIFY JCV: anti-JCV antibody ELISA) was done at the beginning of therapy and then repeated every 6 months. The maximum follow-up time was 4 years. In Poland, since 2013, according to the NFZ drug programme guidance only patients with negative JCVAb test have started treatment with NAT.
Results
In all Polish MS centres 210 negative JCVAb RRMS patients with at least 9 (±3) months of observation (146 females, 64 males; the median age at baseline: 33 years) were included in the study. During follow-up period JCVAb status changed from negative to positive in 34 patients (16.2%). For half of the patients the seroconversion was diagnosed 1 year after starting NAT treatment. In 4 patients (1.9%) during follow-up JCVAb status changed again from positive to negative. In Poland, before establishment of NFZ drug programme, 4 cases of PML in patients treated with NAT in clinical trials were diagnosed. In the NFZ drug programme, since 2013 no patient treated with NAT has been diagnosed with PML.
Conclusions
Natalizumab therapy in JCV seronegative RRMS patients is safe and results in absence of PML cases. In Poland, JCV seroconversion rate is similar to observed in other European countries.
Image by Gerd Altmann from Pixabay
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