Becky J. Parks

Changes in B- and T-Lymphocyte and Chemokine Levels With Rituximab Treatment in Multiple Sclerosis

BACKGROUND B cells are implicated in the pathogenesis of multiple sclerosis. A beneficial effect of B-cell depletion using rituximab has been shown, but the complete mechanism of action for this drug is unclear. OBJECTIVE To determine the relationship between T and B cells and changes in cerebrospinal fluid (CSF) chemokine levels with rituximab, a monoclonal antibody that targets CD20. DESIGN Phase 2 trial of rituximab as an add-on therapy. SETTING The John L. Trotter Multiple Sclerosis Center, Washington University. Participants and Intervention Thirty subjects who had relapsing-remitting multiple sclerosis with clinical and magnetic resonance imaging activity despite treatment with an immunomodulatory drug received 4 weekly doses of rituximab (375 mg/m(2)). MAIN OUTCOME MEASURES Lumbar puncture was performed before and after rituximab infusions in 26 subjects. Levels of B and T lymphocytes in the CSF were enumerated by flow cytometry, and chemoattractant levels were measured by enzyme-linked immunosorbent assay. RESULTS After rituximab administration, CSF B-cell levels were decreased or undetectable in all subjects, and CSF T-cell levels were reduced in 21 subjects (81%). The mean reduction in CSF cellularity was 95% for B cells and 50% for T cells. After rituximab infusion, CSF CXCL13 and CCL19 levels decreased (P = .002 and P = .03, respectively). The proportional decline in CSF T-cell levels correlated with the proportional decrease in CXCL13 levels (r = 0.45; P = .03), suggesting a possible relationship. The CSF IgG index, IgG concentration, and oligoclonal band number were unchanged following treatment. CONCLUSIONS In subjects with multiple sclerosis, B cells are critical for T-cell trafficking into the central nervous system and may alter the process by influencing chemokine production within the central nervous system.

Rituximab add-on therapy for breakthrough relapsing multiple sclerosis: A 52-week phase II trial

Objective: B cells and the humoral immune system have been implicated in the pathogenesis of multiple sclerosis (MS). This study sought to evaluate the efficacy, safety, and tolerability of add-on therapy with rituximab, a monoclonal antibody that depletes circulating B cells, in subjects with relapsing MS with breakthrough disease defined by clinical and MRI activity (Class III evidence). Methods: Thirty subjects with a relapse within the past 18 months despite use of an injectable disease-modifying agent, and with at least 1 gadolinium-enhancing (GdE) lesion on any of 3 pretreatment MRIs, received rituximab administered at 375 mg/m2 weekly × 4 doses. Three monthly posttreatment brain MRI scans were obtained beginning 12 weeks after the first infusion. Multiple Sclerosis Functional Composite (MSFC) and Expanded Disability Status Scale (EDSS) were obtained at baseline and throughout the posttreatment follow-up. Results: GdE lesions were reduced after treatment with rituximab, with 74% of posttreatment MRI scans being free of GdE activity compared with 26% free of GdE activity at baseline (p < 0.0001). Median GdE lesions were reduced from 1.0 to 0, and mean number was reduced from 2.81 per month to 0.33 after treatment (88% reduction). MSFC improved as well (p = 0.02). EDSS remained stable. Conclusion: Rituximab add-on therapy was effective based upon blinded radiologic endpoints in this phase II study. In combination with standard injectable therapies, rituximab was well-tolerated with no serious adverse events. B-cell–modulating therapy remains a potential option for treatment of patients with relapsing MS with an inadequate response to standard injectable therapies. Classification of evidence: This study provides Class III evidence that add-on rituximab reduces gadolinium-enhancing brain lesions in multiple sclerosis.

NMO-IgG DETECTED IN CSF IN SERONEGATIVE NEUROMYELITIS OPTICA

Neuromyelitis optica (NMO) is an inflammatory and demyelinating disease characterized by recurrent attacks of optic neuritis (ON) and longitudinally extensive transverse myelitis (LETM).1 NMO is associated with antibodies against the aquaporin-4 (AQP4) water channel.2 NMO–immunoglobulin G (IgG) predicts a relapsing course and is a supportive criterion for NMO.3–5 The high risk of relapse, sometimes with devastating effects, makes early diagnosis important. Early identification permits counseling and consideration for immunosuppressive therapy. The serum NMO-IgG assay, using indirect immunofluorescence, is 73% sensitive and 91% specific for clinically defined NMO.6 While helpful when positive, the sensitivity is insufficient to exclude the diagnosis. We describe 3 of 26 patients with NMO at our institution with NMO-IgG positivity restricted to CSF. ### Case reports. #### Case 1. A 25-year-old African American woman presented with leg numbness and mild tetraparesis that resolved over 1 month. Two months later, she developed a midthoracic sensory level, again with recovery. The next month, bilateral leg weakness impaired her ability to ambulate. MRI (figure, A–C) demonstrated T2 hyperintensities (T2H) and patchy enhancement spanning the medulla through C7 and T2–T11. Brain MRI revealed a single nonspecific T2H. Visual evoked potentials (VEPs) were normal. Serum NMO-IgG was negative but CSF NMO-IgG was positive. IgG index was elevated to 0.79, CSF leukocytes were 24/μL, but albumin index, IgG synthesis, and oligoclonal bands (OCBs) were normal. Serum antinuclear antibodies (ANA) were negative. Treatment included IV glucocorticoids and rituximab with no further exacerbations. After 8 months of disease, Expanded Disability Status Scale (EDSS) was 6.0. Figure Neuroimaging of CSF antibody-positive neuromyelitis optica Case 1: Sagittal T2-weighted STIR …

Decreased circulating miRNA levels in patients with primary progressive multiple sclerosis

Emerging evidence underlines the importance of micro(mi)RNAs in the pathogenesis of multiple sclerosis (MS). Free-circulating miRNAs were investigated in serum from MS patients compared to controls. Statistically significant decreased levels of miR-15b, miR-23a and miR-223 were observed in MS patients (p < 0.05). Results were validated and replicated in two further independent MS populations. A direct correlation between miRNA levels and the EDSS score was determined in PPMS (p < 0.007). The generalized trend toward miRNA down-regulation could result in over-expression of target genes involved in disease pathogenesis. Circulating miRNA profiling could thus represent a new avenue to identify easily detectable disease biomarkers.

The contemporary spectrum of multiple sclerosis misdiagnosis: A multicenter study

Objective: To characterize patients misdiagnosed with multiple sclerosis (MS). Methods: Neurologists at 4 academic MS centers submitted data on patients determined to have been misdiagnosed with MS. Results: Of 110 misdiagnosed patients, 51 (46%) were classified as “definite” and 59 (54%) “probable” misdiagnoses according to study definitions. Alternate diagnoses included migraine alone or in combination with other diagnoses 24 (22%), fibromyalgia 16 (15%), nonspecific or nonlocalizing neurologic symptoms with abnormal MRI 13 (12%), conversion or psychogenic disorders 12 (11%), and neuromyelitis optica spectrum disorder 7 (6%). Duration of misdiagnosis was 10 years or longer in 36 (33%) and an earlier opportunity to make a correct diagnosis was identified for 79 patients (72%). Seventy-seven (70%) received disease-modifying therapy and 34 (31%) experienced unnecessary morbidity because of misdiagnosis. Four (4%) participated in a research study of an MS therapy. Leading factors contributing to misdiagnosis were consideration of symptoms atypical for demyelinating disease, lack of corroborative objective evidence of a CNS lesion as satisfying criteria for MS attacks, and overreliance on MRI abnormalities in patients with nonspecific neurologic symptoms. Conclusions: Misdiagnosis of MS leads to unnecessary and potentially harmful risks to patients. Misinterpretation and misapplication of MS clinical and radiographic diagnostic criteria are important contemporary contributors to misdiagnosis.

CXCL13 is a biomarker of inflammation in multiple sclerosis, neuromyelitis optica, and other neurological conditions.

CXCL13, a B-cell chemokine, has been proposed as a biomarker in a variety of conditions, some of which can mimic multiple sclerosis and can have very high levels. In this case-control study, cerebrospinal fluid (CSF) CXCL13 was elevated in multiple sclerosis, neuromyelitis optica and other inflammatory neurological controls compared with noninflammatory controls. Levels did not differentiate disease groups. For all subjects taken together, CSF CXCL13 correlated with CSF WBC, oligoclonal band numbers, CSF protein, EDSS, and neurofilament levels. In subgroup analyses, CSF CXCL13 correlated with CSF WBC in neuromyelitis optica and IgG index in multiple sclerosis. Additionally, serum CXCL13 was elevated in neuromyelitis optica.

Dimethyl fumarate-associated lymphopenia: Risk factors and clinical significance

Background Dimethyl fumarate (DMF), a disease-modifying therapy for multiple sclerosis (MS), causes lymphopenia in a fraction of patients. The clinical significance of this is unknown. Several cases of progressive multifocal leukoencephalopathy in lymphopenic fumarate-treated patients have raised concerns about drug safety. Since lymphocytes contribute to MS pathology, lymphopenia may also be a biomarker for response to the drug. Objective The objective of this manuscript is to evaluate risk factors for DMF-induced lymphopenia and drug failure in a real-world population of MS patients. Methods We conducted a retrospective cohort study of 221 patients prescribed DMF at a single academic medical center between March 2013 and February 2015. Results Grade 2–3 lymphopenia developed in 17% of the total cohort and did not resolve during DMF treatment. Older age (>55), lower baseline absolute lymphocyte count and recent natalizumab exposure increased the risk of developing moderate to severe lymphopenia while on DMF. Lymphopenia was not predictive of good clinical response or of breakthrough MS activity on DMF. Conclusions Lymphopenia develops in a significant minority of DMF-treated patients, and if grade 2 or worse, is unlikely to resolve while on the drug. Increased vigilance in lymphocyte monitoring and infection awareness is particularly warranted in older patients and those switching from natalizumab.

Clinical and laboratory assessment of distal peripheral nerves in Gulf War veterans and spouses.

Background: The prevalence of symptoms suggesting distal symmetric polyneuropathy (DSP) was reported to be higher among deployed veterans (DV) to the Persian Gulf in 1990–1991 than to control non-deployed veterans (NDV). The authors therefore compared the prevalence of DSP by direct examination of DV and their spouses to control NDV and spouses. Methods: The authors performed standardized neurologic examinations on 1,061 DV and 1,128 NDV selected from a cohort of veterans who previously participated in a national mail and telephone survey. Presence of DSP was evaluated by history, physical examination, and standardized electrophysiologic assessment of motor and sensory nerves. Similar examinations were performed without electrophysiologic tests in 484 DV spouses and 533 NDV spouses. Statistical analyses were performed with appropriate adjustments for the stratified sampling scheme. Results: No differences between adjusted population prevalence of DSP in DV and NDV were found by electrophysiology (3.7% vs 6.3%, p = 0.07), by neurologic examination (3.1% vs 2.6%, p = 0.60), or by the methods combined (6.3% vs 7.3%, p = 0.47). Excluding veterans with non-military service related diseases that may cause DSP did not alter outcomes. DV potentially exposed to neurotoxins from the Khamisiyah ammunition depot explosion did not significantly differ in DSP prevalence compared to non-exposed DV. The prevalence of DSP in DV spouses did not differ from NDV spouses (2.7% vs 3.2%, p = 0.64). Conclusions: Neither veterans deployed during the Gulf War era nor their spouses had a higher prevalence of DSP compared to NDV and spouses.

Cerebrospinal fluid progranulin levels in patients with different multiple sclerosis subtypes

Progranulin has recently attracted attention due to the discovery of mutations in its encoding gene (GRN) in several cases of frontotemporal lobar degeneration, but also for a possible role in inflammatory processes. In adult central nervous system, GRN mRNA is expressed in forebrain, olfactory bulbs and spinal cord. Progranulin cerebrospinal fluid (CSF) levels were evaluated in 55 patients with multiple sclerosis (MS) as well as in 35 subjects with non-inflammatory neurological diseases (NIND), 7 individuals with other inflammatory neurological disease (OIND) and 8 controls (CON), matched for ethnic background, gender and age. No statistically significant differences were found in patients compared with either NIND, OIND or CON (P>0.05), even stratifying according to disease subtype or gender. A positive correlation between progranulin CSF levels and age was observed in patients (rho=0.29, P=0.03). According to these data, progranulin does not likely play a major role in the pathogenesis of MS.

A role for functional classification in the early identification of prognostic factors in ALS

The aim of this study was to determine if the interval between onset of symptoms to initial electrodiagnostic studies indicates disease progression in amyotrophic lateral sclerosis (ALS). Fifty consecutive patients referred to our neurophysiology laboratory with clinical evidence of ALS were divided into two groups by outcome scores on the ALS Functional Rating Scale (ALSFRS) using 26 as a cut‐off. Our results, which showed a median of four months (range 2–24 months) duration to initial electrodiagnostics for Group I (ALSFRS scores below 26) versus 10 months (range 1–24 months) for Group II (p = 0.02), suggest this measure is a marker of disease progression in ALS.