John N. Whitaker

Myelin antigen-specific CD8+ T cells are encephalitogenic and produce severe disease in C57BL/6 mice

Encephalitogenic T cells that mediate experimental autoimmune encephalomyelitis (EAE) are commonly assumed to be exclusively CD4+, but formal proof is still lacking. In this study, we report that synthetic peptides 35–55 from myelin oligodendrocyte glycoprotein (pMOG35–55) consistently activate a high proportion of CD8+ αβTCR+ T cells that are encephalitogenic in C57BL/6 (B6) mice. The encephalitogenic potential of CD8+ MOG-specific T cells was established by adoptive transfer of CD8-enriched MOG-specific T cells. These cells induced a much more severe and permanent disease than disease actively induced by immunization with pMOG35–55. CNS lesions in pMOG35–55 CD8+ T cell-induced EAE were progressive and more destructive. The CD8+ T cells were strongly pathogenic in syngeneic B6 and RAG-1−/− mice, but not in isogeneic β2-microglobulin-deficient mice. MOG-specific CD8+ T cells could be repeatedly reisolated for up to 287 days from recipient B6 or RAG-1−/− mice in which disease was induced adoptively with <1 × 106 T cells sensitized to pMOG35–55. It is postulated that MOG induces a relapsing and/or progressive pattern of EAE by eliciting a T cell response dominated by CD8+ autoreactive T cells. Such cells appear to have an enhanced tissue-damaging effect and persist in the animal for long periods.

Benefit of interferon β-1a on MSFC progression in secondary progressive MS

BackgroundInterferon &bgr;-1a (IFN&bgr;-1a, Avonex) is efficacious in relapsing forms of MS. Studies of other IFN&bgr; preparations in secondary progressive MS (SPMS) yielded conflicting results. This study was undertaken to determine whether IFN&bgr;-1a slowed disease progression in SP-MS. MethodsA total of 436 subjects with SPMS and Expanded Disability Status Scale (EDSS) score 3.5 to 6.5 were randomized to receive IFN&bgr;-1a (60 &mgr;g) or placebo by weekly intramuscular injection for 2 years. The primary outcome measure, used for the first time in a large-scale MS trial, was baseline to month 24 change in the MS Functional Composite (MSFC), comprising quantitative tests of ambulation (Timed 25-Foot Walk), arm function (Nine-Hole Peg Test [9HPT]), and cognition (Paced Auditory Serial Addition Test [PASAT]). ResultsMedian MSFC Z-score change was reduced 40.4% in IFN&bgr;-1a subjects (−0.096 vs −0.161 in placebo subjects, p = 0.033), an effect driven mainly by the 9HPT and PASAT. There was no discernible benefit on the EDSS, which in this range principally reflects walking ability. IFN&bgr;-1a subjects had 33% fewer relapses (p = 0.008). There was significant benefit on eight of 11 MS Quality of Life Inventory subscales. New or enlarging T2-hyperintense brain MRI lesions and gadolinium-enhancing lesions were reduced at months 12 and 24 (both p < 0.001). IFN&bgr;-1a was well tolerated by the majority of subjects. Neutralizing antibodies developed in 3.3% of IFN&bgr;-1a–treated subjects. ConclusionsIFN&bgr;-1a demonstrated benefit on MSFC progression, relapses, quality of life, and MRI activity in SPMS.

Myelin encephalitogenic protein fragments in cerebrospinal fluid of persons with multiple sclerosis

With a double-antibody radioimmunoassay performed on unconcentrated cerebrospinal fluid, eight of 14 patients in an acute phase of multiple sclerosis had levels of 3.4 to 15.4 ng per milliliter of the P1 fragment (residues 43–88) of myelin encephalitogenic protein. Encephalitogenic protein-P1 was found only in the acute phase and was present in six of seven persons in the first week of an exacerbation and absent in 29 multiple sclerosis patients who were stable or had a gradually progressive course. Six of 117 controls had detectable cerebrospinal fluid encephalitogenic protein-P1. Only in two of these, one with a recent cerebral infarction and one with diabetic nephropathy who was in coma, were the levels in the range encountered in patients in the acute phase of multiple sclerosis. Although not entirely specific for multiple sclerosis, the presence of material in the cerebrospinal fluid of multiple sclerosis patients cross-reacting with encephalitogenic protein-P1 appears to be a characteristic of acute exacerbations.

Linomide in relapsing and secondary progressive MS: Part II: MRI results

Objective: To determine the safety and efficacy of roquinimex (linomide) in the management of relapsing-remitting and secondary progressive MS as monitored by MRI. Background: Preclinical studies and several short term randomized trials of linomide suggested clinical and MRI-measured benefits with acceptable risk for closely followed MS patients. Methods: The North American Linomide Trial formally screened 853 individuals for relapsing or secondary progressive, clinically definite MS; recent disease activity or progression; and an Expanded Disability Status Scale score at entry of 3.0 to 6.5 inclusive. MRI was obtained on 811 subjects at pre-enrollment, 718 cases at enrollment, and then at three monthly intervals until the trial was prematurely terminated for unacceptable toxicity. Results: Enhancement was found on 40.2% of 718 entry scans. Statistically robust correlations were found between clinical demographic data and several entry MRI measures including CSF volume, a reflection of brain atrophy. Assessment of the effect of treatment on MRI-measured disease was limited by early trial termination. However, active treatment for 3 months reduced the proportion of patients with one or more enhancements. An exploratory analysis suggested that 2.5 mg was the most active of three doses tested in limiting the total volume of enhanced tissue, the proportion of MRI-defined lesions designated as “black holes,” and by a novel MRI composite disease measure. Conclusions: The short term signature of the effect of linomide on MRI-measured aspects of the disease suggests that safer drugs of this class might be useful in the management of MS. The use of a composite index of the heterogeneous nature of the pathology of MS as captured by MRI may have merit as an outcome measure in clinical trials.

Immunocytochemical localization of the sodium, potassium activated ATPase in knifefish brain

SummaryResults presented in this paper demonstrate the feasibility of using immunocytochemical methods to localize the (Na+ + K+)-ATPase, and its subunits, in the C.N.S. We have shown that in the Black Ghost knifefish,Sternarchus albifrons, the enzyme is located on the plasma membrane of the somata and dendrites of neurons and on the somata and cellular processes of glia. In myelinated axons the enzyme is restricted in localization to those portions of the axolemma not covered by the myelin sheath. The capacity of cell plasma membranes to restrict mobility of functionally important proteins should be considered in models of membrane structure in which lateral mobility of membrane components is considered a major characteristic.

Practice parameter: The role of corticosteroids in the management of acute monosymptomatic optic neuritis Report of the Quality Standards Subcommittee of the American Academy of Neurology

Optic neuritis (ON) is an inflammatory disorder of the optic nerve. Most cases are idiopathic or associated with MS. ON can be associated with a variety of systemic or ocular disorders and is the most common acute optic neuropathy in adults younger than 46 years. Among high-risk populations for MS, the incidence of ON is about 3 per 100,000 population per year, whereas in other areas the incidence is about 1 per 100,000 population per year.1-13 Acute ON often presents as an isolated clinical event without contributory systemic abnormalities (monosymptomatic ON). Clinical features include periocular pain, abnormal visual acuity and fields, reduced color vision, a relative afferent pupillary defect, and abnormal visual evoked potentials. The fundus may appear normal or demonstrate edema of the optic nerve head (papillitis).12-18 MRI white matter abnormalities identical to those seen in MS are found in 50 to 70% of monosymptomatic ON cases.19-22 The visual deficit of ON may worsen over 1 to 2 weeks and usually begins improving over the next month. Lack of improvement in visual function by 30 days is unusual.23 However, most patients have some residual visual function deficit, even if visual acuity improves to 20/20.1-18 Differential diagnosis includes compressive, ischemic, hereditary, toxic, or other inflammatory optic neuropathies (e.g., sarcoid). These conditions usually do not exhibit the same clinical pattern (table 1) or rate of recovery as monosymptomatic ON.1-13 View this table: Table 1. Features of acute demyelinating monosymptomatic optic neuritis Treatment of monosymptomatic ON has included oral, retrobulbar, and IV steroids, immunoglobulin, and acupuncture.23-77 Monosymptomatic acute ON is not rare and because the usefulness of oral prednisone in this disorder has recently been questioned,23,78-82 this practice parameter was developed to provide …

Identification and Characterization of Gangliosides Reacting with IgM Paraproteins in Three Patients with Neuropathy Associated with Biclonal Gammopathy

Abstract: IgM monoclonal antibodies from three patients with polyneuropathy associated with biclonal gammopathy reacted with monosialoganglioside GM1 on thin‐layer chromatograms. An IgM paraprotein in one of the patients with a predominantly motor neuropathy also reacted strongly with the ganglioside GD1b and asialo‐GM1. All three of these antigenic lipids have a Gal(β1–3)GalNAc moiety in common which would appear to be the antigenic determinant. However, this IgM also cross‐reacted weakly with paragloboside which has an N‐acetyllactosaminyl [Gal(β1–4)GlcNAc] terminal structure. The specificity of the other paraprotein in this patient is not known. The IgM paraproteins reacting with GM1 in both of the other patients exhibited different specificity because they did not react with GD1 b and asialo‐GM1, but reacted strongly with GM2 ganglioside. The data suggest that the epitope for both of these IgMs is in the GalNAc(β31–4)(NeuAcα2–3)Gal(β1–4)Glc region of the gangliosides that is common to both GM2 and GM1. The second IgM paraproteins in both of these latter patients react with the myelin‐associated glycoprotein (MAG) and two 3‐sulfoglucuronyl glycolipids that share antigenic determinants with MAG.

Preparation of a monoclonal antibody to citrullinated epitopes: Its characterization and some applications to immunohistochemistry in human brain

Using hybridoma technology, an IgM monoclonal antibody (mAb), designated as F95, was developed against a deca‐citrullinated peptide (DCP) consisting of 10 citrulline residues and a carboxyl Gly‐Gly‐Cys through which DCP was covalently linked to an activated carrier protein, keyhole limpet hemocyanin (KLH). Clones were selected on the basis of not reacting with human unmodified and noncitrullinated myelin basic protein (MBP), MBP‐C1, but reacting well with human citrullinated MBP (MBP‐C8). When tested by ELISA, this mAb demonstrated minimal reactivity with human MBP‐C1, varying reactivity with the C2–C5 isomers of human MBP, moderate binding with guinea pig MBP‐C8, and strong reactivity with human MBP‐C8. By ELISA, mAb F95 was directed predominantly against citrulline, not MBP, as revealed by its binding to DCP linked with activated KLH, bovine serum albumin (BSA), or ovalbumin (OA), but not with KLH, BSA, or OA alone. Immunohistochemistry of normal human brain demonstrated that F95 stained central nervous system myelin and a subset of astrocytes. Given the citrulline‐directed features of mAb F95, this immunohistochemical pattern suggests that certain astroglial filaments expressing glial fibrillary acidic protein also contain citrulline‐bearing components. These potentially implicate citrullinated proteins, notably in astroglial filaments, in a variety of normal and pathological neurobiological processes. GLIA 37:328–336, 2002.

Cerebrospinal fluid in acute optic neuritis Experience of the optic neuritis treatment trial

The Optic Neuritis Treatment Trial (ONTT) is a prospective study of corticosteroid treatment of acute optic neuritis (ON), with subsequent longitudinal follow-up to determine development of clinically definite multiple sclerosis (CDMS). We analyzed the CSF of 83 patients with clinically isolated ON who underwent lumbar puncture within 24 hours of enrollment into the ONTT to determine the value of CSF changes in ON, especially regarding diagnostic utility, immunologic changes, MRI correlations, and progression to CDMS All patients had baseline MRI scans graded for changes typical of MS CSF measurements included immunoglobulin G (IgG) synthesis, IgG ratio, myelin basic protein, IgG kappa light chains, and oligoclonal banding. No patients had their diagnosis or management altered as a result of CSF findings. Except for oligoclonal bands, few patients showed any abnormalities on CSF tests, and no tests correlated with the 2-year development of CDMS. Oligoclonal banding, present at baseline in 11 of 13 patients who developed CDMS, did predict progression to CDMS, but this was not independent of MRI abnormalities. Two patients with oligoclonal bands and a normal MRI did progress to CDMS. We conclude that CSF analysis may not be necessary in the routine evaluation of patients presenting with a typical clinical profile of acute ON, and that most CSF tests add little additional information to MRI results for predicting the 2-year development of CDMS. However, the precise role of oligoclonal banding in the analysis of such patients awaits longer follow-up of this cohort. NEUROLOGY 1996,46 368-372

Clinical and laboratory features of primary progressive and secondary progressive MS.

Objective: To compare the clinical and laboratory features of primary progressive (PP) and secondary progressive (SP) MS, to evaluate the role of CSF and urine myelin basic protein-like material (MBPLM) in differentiating PP from SP MS, and to assess the utility of urine MBPLM as a surrogate marker of disease activity in progressive MS. Background: The current categorization of subtypes of MS is based solely on clinical and temporal characteristics of the disease. Laboratory markers are needed that can differentiate reliably the subtypes of MS and serve as surrogate markers of disease progression. Methods: Clinical and paraclinical data of 51 PPMS and 140 SPMS patients were reviewed retrospectively. CSF and urine MBPLM were measured using a double-antibody radioimmunoassay. Results: PPMS was more likely to present with progressive myelopathy (p ≤ 0.001) after the age of 40 years (p = ≤0.001), and it affected men relatively more often than SPMS (male-to-female ratio, 1:1.7 versus 1:3.2 respectively). Ambulatory assistance was required by PP patients more often and earlier than in those with SPMS. The incidence of abnormal CSF, evoked potential, and cranial MRI studies was similar in the two groups. Spinal cord MRI abnormalities were noted significantly more often in SP disease. There was an insignificant trend of higher CSF MBPLM in SPMS compared with PPMS. Urine MBPLM and MBPLM/creatinine were significantly higher in SPMS than in PPMS. However, the values of urine MBPLM and MBPLM/creatinine at the initial visits of patients with PPMS and SPMS were not significantly different. Urine MBPLM/creatinine was significantly higher in both PPMS and SPMS compared with normal control subjects. No correlation was found between urine MBPLM and disease duration or between urine MBPLM and clinical disability. There was no correlation between urine MBPLM/creatinine and either disease duration or clinical disability. Conclusions: These findings provide additional evidence of the differences in PPMS and SPMS, notably in the associated changes in MBPLM in urine, and also suggest a possible role for urine MBPLM in identifying patient cohorts. The high urine MBPLM levels in progressive MS patients indicate a potential role of this marker for assessing responsiveness to therapeutic interventions.