Robert J. Fox

B-Cell Depletion with Rituximab in Relapsing–Remitting Multiple Sclerosis

BACKGROUND There is increasing evidence that B lymphocytes are involved in the pathogenesis of multiple sclerosis, and they may be a therapeutic target. Rituximab, a monoclonal antibody, selectively targets and depletes CD20+ B lymphocytes. METHODS In a phase 2, double-blind, 48-week trial involving 104 patients with relapsing-remitting multiple sclerosis, we assigned 69 patients to receive 1000 mg of intravenous rituximab and 35 patients to receive placebo on days 1 and 15. The primary end point was the total count of gadolinium-enhancing lesions detected on magnetic resonance imaging scans of the brain at weeks 12, 16, 20, and 24. Clinical outcomes included safety, the proportion of patients who had relapses, and the annualized rate of relapse. RESULTS As compared with patients who received placebo, patients who received rituximab had reduced counts of total gadolinium-enhancing lesions at weeks 12, 16, 20, and 24 (P<0.001) and of total new gadolinium-enhancing lesions over the same period (P<0.001); these results were sustained for 48 weeks (P<0.001). As compared with patients in the placebo group, the proportion of patients in the rituximab group with relapses was significantly reduced at week 24 (14.5% vs. 34.3%, P=0.02) and week 48 (20.3% vs. 40.0%, P=0.04). More patients in the rituximab group than in the placebo group had adverse events within 24 hours after the first infusion, most of which were mild-to-moderate events; after the second infusion, the numbers of events were similar in the two groups. CONCLUSIONS A single course of rituximab reduced inflammatory brain lesions and clinical relapses for 48 weeks. This trial was not designed to assess long-term safety or to detect uncommon adverse events. The data provide evidence of B-cell involvement in the pathophysiology of relapsing-remitting multiple sclerosis. (ClinicalTrials.gov number, NCT00097188 [ClinicalTrials.gov].).

Defining the clinical course of multiple sclerosis The 2013 revisions

Accurate clinical course descriptions (phenotypes) of multiple sclerosis (MS) are important for communication, prognostication, design and recruitment of clinical trials, and treatment decision-making. Standardized descriptions published in 1996 based on a survey of international MS experts provided purely clinical phenotypes based on data and consensus at that time, but imaging and biological correlates were lacking. Increased understanding of MS and its pathology, coupled with general concern that the original descriptors may not adequately reflect more recently identified clinical aspects of the disease, prompted a re-examination of MS disease phenotypes by the International Advisory Committee on Clinical Trials of MS. While imaging and biological markers that might provide objective criteria for separating clinical phenotypes are lacking, we propose refined descriptors that include consideration of disease activity (based on clinical relapse rate and imaging findings) and disease progression. Strategies for future research to better define phenotypes are also outlined.

Mitochondrial dysfunction as a cause of axonal degeneration in multiple sclerosis patients.

Degeneration of chronically demyelinated axons is a major cause of irreversible neurological disability in multiple sclerosis (MS) patients. Development of neuroprotective therapies will require elucidation of the molecular mechanisms by which neurons and axons degenerate.

Treatment of neuromyelitis optica with rituximab: Retrospective analysis of 25 patients

BACKGROUND Neuromyelitis optica (NMO) is an uncommon, life-threatening inflammatory demyelinating disorder. Recently, much has become known about its immunopathogenesis. However, optimal treatments, with expected outcomes, have not been established. OBJECTIVE To evaluate the use and efficacy of rituximab for treating NMO. DESIGN Retrospective multicenter case series of NMO patients treated with rituximab. SETTING Seven tertiary medical centers in the United States and England. PATIENTS Twenty-five patients (including 2 children), 23 of whom experienced relapses despite use of other drugs before rituximab. Extended follow-up of 7 previously reported patients is included. INTERVENTIONS Infusions of rituximab at median intervals of 8 months. MAIN OUTCOME MEASURES Annualized relapse rate and disability (expressed as Expanded Disability Status Scale score). RESULTS At a median follow-up of 19 months, the median annualized posttreatment relapse rate was lower than the pretreatment rate (0 [range 0-3.2] vs 1.7 [range, 0.5-5] relapses, P < .001). Disability improved or stabilized in 20 of 25 patients (80%, P = .02). Two patients died during the follow-up period, 1 owing to a brainstem relapse and 1 owing to suspected septicemia. Infections were reported in 20% of patients. CONCLUSIONS In NMO, treatment with rituximab appears to reduce the frequency of attacks, with subsequent stabilization or improvement in disability.

Rituximab in Relapsing-Remitting Multiple Sclerosis : A 72-Week, Open-Label, Phase I Trial

We evaluated the safety, tolerability, pharmacodynamics, and activity of B‐cell depletion with rituximab in patients with relapsing‐remitting multiple sclerosis, receiving two courses of rituximab 6 months apart, and followed for a total of 72 weeks. No serious adverse events were noted; events were limited to mild‐to‐moderate infusion‐associated events, which tended to decrease with subsequent infusions. Infections were also mild or moderate, and none led to withdrawal. Fewer new gadolinium‐enhancing or T2 lesions were seen starting from week 4 and through week 72. An apparent reduction in relapses was also observed over the 72 weeks compared with the year before therapy. Ann Neurol 2008

Effect of plasma exchange in accelerating natalizumab clearance and restoring leukocyte function

Background: Accelerating the clearance of therapeutic monoclonal antibodies (mAbs) from the body may be useful to address uncommon but serious complications from treatment, such as progressive multifocal leukoencephalopathy (PML). Treatment of PML requires immune reconstitution. Plasma exchange (PLEX) may accelerate mAb clearance, restoring the function of inhibited proteins and increasing the number or function of leukocytes entering the CNS. We evaluated the efficacy of PLEX in accelerating natalizumab (a therapy for multiple sclerosis [MS] and Crohn disease) clearance and α4-integrin desaturation. Restoration of leukocyte transmigratory capacity was evaluated using an in vitro blood–brain barrier (ivBBB). Methods: Twelve patients with MS receiving natalizumab underwent three 1.5-volume PLEX sessions over 5 or 8 days. Natalizumab concentrations and α4-integrin saturation were assessed daily throughout PLEX and three times over the subsequent 2 weeks, comparing results with the same patients the previous month. Peripheral blood mononuclear cell (PBMC) migration (induced by the chemokine CCL2) across an ivBBB was assessed in a subset of six patients with and without PLEX. Results: Serum natalizumab concentrations were reduced by a mean of 92% from baseline to 1 week after three PLEX sessions (p < 0.001). Although average α4-integrin saturation was not reduced after PLEX, it was reduced to less than 50% when natalizumab concentrations were below 1 μg/mL. PBMC transmigratory capacity increased 2.2-fold after PLEX (p < 0.006). Conclusions: Plasma exchange (PLEX) accelerated clearance of natalizumab, and at natalizumab concentrations below 1 μg/mL, desaturation of α4-integrin was observed. Also, CCL2-induced leukocyte transmigration across an in vitro blood–brain barrier was increased after PLEX. Therefore, PLEX may be effective in restoring immune effector function in natalizumab-treated patients.

MRI findings in Susac’s syndrome

Background: Susac syndrome (SS) is a self-limited syndrome, presumably autoimmune, consisting of a clinical triad of encephalopathy, branch retinal artery occlusions, and hearing loss. All three elements of the triad may not be present or recognized, and MR imaging is often necessary to establish the diagnosis. Objective: To determine the spectrum of abnormalities on MRI in SS. Methods: The authors reviewed the MR images of 27 previously unreported patients with the clinical SS triad, and 51 patients from published articles in which the MR images were depicted or reported. Results: All 27 patients had multifocal supratentorial white matter lesions including the corpus callosum. The deep gray nuclei (basal ganglia and thalamus) were involved in 19 (70%). Nineteen (70%) also had parenchymal enhancement and 9 (33%) had leptomeningeal enhancement. Of the 51 cases from the literature, at least 32 had callosal lesions. The authors could not determine the presence of callosal lesions in 18 of these patients, and only one was reported to have a normal MRI at the onset of encephalopathy. Conclusions: The MR scans in SS show a rather distinctive pattern of supratentorial white matter lesions that always involve the corpus callosum. There is often deep gray matter, posterior fossa involvement, and frequent parenchymal with occasional leptomeningeal enhancement. The central callosal lesions differ from those in demyelinating disease, and should support the diagnosis of SS in patients with at least two of the three features of the clinical triad.

Demyelination causes synaptic alterations in hippocampi from multiple sclerosis patients

Multiple Sclerosis (MS) is an inflammatory demyelinating disease of the human central nervous system. Although the clinical impact of gray matter pathology in MS brains is unknown, 30 to 40% of MS patients demonstrate memory impairment. The molecular basis of this memory dysfunction has not yet been investigated in MS patients.

Kinetics of myeloid and lymphocyte recovery and infectious complications after unrelated umbilical cord blood versus HLA-matched unrelated donor allogeneic transplantation in adults.

Sources for allogeneic stem cells for patients with haematological disorders lacking a histocompatible sibling donor include matched unrelated donor (MUD) and umbilical cord blood (UCB). A total of 51 patients with haematological disorders, treated with myeloablation and transplantation with either unrelated human leucocyte antigen (HLA) partially matched UCB (28 patients) or HLA‐matched MUD grafts (23 patients) during 1997–2003, were evaluated for life‐threatening infections, haematological reconstitution, graft versus host disease, relapse and event‐free survival (EFS). The median duration of neutropenia after transplantation was longer (29 d vs. 14 d) in the UCB group. The probability of donor‐derived neutrophil engraftment by day 42 was 0·86 [95% confidence interval (CI) 0·71–1·0] in UCB recipients versus 0·96 (95% CI 0·87–1·0) in MUD recipients surviving >28 d. Overall infection rates were higher in UCB recipients, particularly at the early time points (before day +50) after transplantation. Graft failure occurred in five UCB recipients and two MUD recipients and was associated with the occurrence of bacteraemia during neutropenia. The EFS at 3‐year follow‐up was 0·25 in UCB and 0·35 in MUD recipients. UCB transplantation in adults is associated with delayed neutrophil and lymphocyte recovery compared with MUD grafting, and higher rates of bacteraemia at early time points after transplantation.

Multiple Sclerosis Normal-Appearing White Matter: Pathology-Imaging Correlations

The study was undertaken to determine the pathologic basis of subtle abnormalities in magnetization transfer ratio (MTR) and diffusion tensor imaging (DTI) parameters observed in normal‐appearing white matter (NAWM) in multiple sclerosis brains.