Varicella zoster-associated acute retinal necrosis and central nervous system complications in natalizumab treated MS patients.

There is not much awareness of varicella zoster virus (VZV) associated central nervous system (CNS) infections under treatment with natalizumab. Here we describe two natalizumab treated MS patients who developed acute retinal necrosis combined with CNS vasculitis caused by VZV. In natalizumab treated patients, visual symptoms atypical of optic neuritis should be promptly evaluated by an ophthalmologist. Currently, a total of 12 cases of natalizumab-associated VZV CNS or retinal infections are reported in literature. Our two cases and overview of currently available data provide information on prognosis and treatment decisions of this rare but devastating complication.

Infusion-related events during natalizumab: No need for post-infusion monitoring.

This retrospective cohort study assessed the timing of infusion-related adverse events (IAEs) during natalizumab (NTZ) administration in well-documented relapsing-remitting multiple sclerosis (RRMS) patients who had received NTZ infusions in our centre between 2006 and 2018. In 225 RRMS patients (14,174 NTZ infusions), 276 IAEs (1.95%) occurred in 60 patients. All documented severe IAE occurred during infusion. Of the 19 moderate adverse events, 17 were during infusion. None of the reactions that occurred after the infusion required intervention. These results suggest that post-infusion monitoring is not necessary in patients who do not have an adverse event during infusion.

Abnormalities and erythroblasts in peripheral blood of multiple sclerosis patients treated with natalizumab.

BACKGROUND: In natalizumab treated patients several hematopoietic abnormalities including erythroblasts, myeloblasts and neutrophilic precursors in peripheral blood have been described. So far, long term effects of the hematopoietic changes have not been reported. OBJECTIVE: To describe hematopoietic abnormalities in longitudinally monitored MS patients treated with natalizumab. Patients treated with dimethyl fumarate, teriflunomide and fingolimod served as controls. Secondly, the relation between natalizumab serum levels and the occurrence of hematopoietic abnormalities was explored. METHODS: 212 natalizumab treated patients were included, 91 patients with available baseline samples (998 follow-up samples) were compared with patients with dimethyl fumarate (n = 166, 1154 samples), teriflunomide (n = 38, 228 samples) and fingolimod (n = 114, 853 samples). One hundred twenty one patients without baseline samples (1952 follow-up samples) were included in the follow-up group. RESULTS: More than half of all natalizumab treated patients developed hematopoietic abnormalities, almost a quarter had erythroblasts. Natalizumab use was associated with an increased risk of developing abnormalities in comparison to oral treatment, with a corrected hazard ratio of 2.3, 10.0 and 8.1 in comparison to fingolimod, dimethyl fumarate and teriflunomide respectively. No difference in developing abnormalities was observed in relation to natalizumab serum concentrations. None of the patients developed a hematologic malignancy during follow up. CONCLUSION: Hematopoietic abnormalities are common during natalizumab treatment. Given the lack of consequences of this finding during long-term follow-up, it is generally justifiable to refrain from further diagnostic procedures when observing hematopoietic abnormalities in patients using natalizumab.

Longitudinal JCV serology in multiple sclerosis patients preceding natalizumab-associated progressive multifocal leukoencephalopathy.

The presence of anti-John Cunningham Virus (JCV) antibodies is a risk factor for the development of progressive multifocal leukoencephalopathy (PML) in MS patients treated with natalizumab. It has been suggested that an increase in serum anti-JCV antibody index precedes the development of PML. We here describe extensive longitudinal serum anti-JCV antibody indexes of four MS patients who developed PML. Anti-JCV antibodies were measured using the STRATIFY JCV™DxSelect™ test. All four patients had rather stable high anti-JCV antibody indexes in all samples obtained before developing PML. Possibly caused by reaching the saturation level of the assay, no increase in anti-JCV antibody indexes was seen just before the diagnosis of PML. This study confirms that high serum anti-JCV antibody indexes precede natalizumab-associated PML.

Safety, anxiety and natalizumab continuation in JC virus-seropositive MS patients.

The use of natalizumab in multiple sclerosis has been restricted by the risk of progressive multifocal leukoencephalopathy (PML). JC virus carriership, duration of natalizumab treatment and past immunosuppression are known risk factors. This has allowed for calculated risk assessment for individual patients to be implemented. Not much data are available about the effect of JCV carriership on patient willingness to continue natalizumab. Here, we evaluated the impact of JCV seropositivity on safety feelings, anxiety and treatment continuation for patients treated with natalizumab, using a visual analog scale, the Hospital Anxiety and Depression Scale and a decisional conflict scale. Seropositivity led to an elevated anxiety level for PML (p = 0.004). However, so far only 3% of patients have discontinued natalizumab because of JCV positivity in our cohort.