Antivirus immune activity in multiple sclerosis correlates with MRI activity

OBJECTIVE

The objective of this study was to determine whether reactivation of Epstein-Barr (EBV) or activation of the anti-EBV immune response correlates with MS disease activity on MR imaging.

METHODS

Subjects with early, active relapsing-remitting MS were studied for 16 weeks with blood and saliva samples collected every 2 weeks and brain MRI performed every 4 weeks. We isolated peripheral blood mononuclear cells from each blood sample and tested the immune response to EBV, autologous EBV-infected lymphoblastoid cell lines (LCL), human herpesvirus 6 (HHV6), varicella zoster virus (VZV), tetanus, and mitogens. We measured the proliferative response and the number of interferon-γ secreting cells with ELISPOT. We measured the amounts of EBV, HHV6, and VZV DNA in blood and saliva with quantitative PCR. On MRI, we measured number and volume of contrast enhancing and T2 lesions. We tested for correlation between the immunologic assays and the MRI results, assessing different time intervals between the MRI and immunologic assays.

RESULTS

We studied 20 subjects. Ten had enhancing lesions on one or more MRI scans and one had new T2 lesions without enhancement. The most significant correlation was between proliferation to autologous LCL and the number of combined unique active lesions on MRI 4 weeks later. Both proliferation and number of cells secreting interferon-γ in response to LCL correlated with the number of enhancing lesions 8 weeks later.

CONCLUSIONS

We find evidence for correlation of antiviral immune responses in the blood with subsequent disease activity on MRI scans.

Variable results after rituximab in neuromyelitis optica

Our objective was to assess the efficacy of rituximab (RTX) in neuromyelitis optica (NMO). We conducted a retrospective review of cases personally treated by the authors. We identified nine subjects meeting criteria for either NMO or recurrent longitudinally extensive transverse myelitis (LETM) who were treated with RTX and documented their clinical course. Six of the nine subjects continued to have relapses after RTX treatment. RTX was the first immunosuppressive treatment used after diagnosis in five subjects, and four of these continued to have relapses. We conclude that outcomes after RTX treatment of NMO are inconsistent. The observed variability may reflect differences in disease activity between individuals, differences in disease activity over time, or differences in the underlying immunopathogenesis of NMO. More effective treatments are needed.

Epstein-Barr virus neutralizing and early antigen antibodies in multiple sclerosis

BACKGROUND

Our objective was to determine whether antibodies against the Epstein-Barr virus (EBV) nuclear antigen-1 (EBNA-1), early antigen (EA), and EBV neutralizing antibodies (NeutAb) are altered in multiple sclerosis (MS).

METHODS

We measured EBNA-1 IgG, EA IgG, and EA IgA using quantitative ELISA. We measured NeutAb using a quantitative competitive ELISA. We studied 80 patients with MS, 80 matched controls, and 19 patients with MS with samples collected both whilst stable and in relapse.

RESULTS

Epstein-Barr virus nuclear antigen-1 IgG and EA IgA were increased in MS compared to controls. The EBNA-1 index value was 23.3 ± 18.3 in the patients with MS (mean ± SD) and 16.3 ± 17.4 in the controls (P = 0.007, paired t-test). EA IgA had a median value of 1.964 in the patients with MS and 1.248 in the controls (P = 0.029, Wilcoxon signed rank test). EA IgG and NeutAb were not significantly different. None of the antibody levels were altered in relapse. The correlation between concentrations of different antibodies was minimal.

CONCLUSIONS

IgG antibodies to EBNA-1 are significantly increased in MS. IgA antibodies against EBV EA are also increased. The EBV neutralizing antibody response is similar in MS and controls.

Continuous long-term immunomodulatory therapy in relapsing multiple sclerosis: results from the 15-year analysis of the US prospective open-label study of glatiramer acetate

The ongoing US Glatiramer Acetate (GA) Trial is the longest evaluation of continuous immunomodulatory therapy in relapsing-remitting multiple sclerosis (RRMS). The objective of this study was to evaluate up to 15 years of GA as a sole disease-modifying therapy. Two hundred and thirty-two patients received at least one GA dose since study initiation in 1991 (mITT cohort), and 100 (43%, Ongoing cohort) continued as of February 2008. Patients were evaluated every 6 months using the Expanded Disability Status Scale (EDSS). Mean GA exposures were 8.6 +/- 5.2, 4.81 +/- 3.69, and 13.6 +/- 1.3 years and mean disease durations were 17, 13, and 22 years for mITT, Withdrawn and Ongoing cohorts, respectively. For Ongoing patients, annual relapse rates (ARRs) maintained a decline from 1.12 +/- 0.82 at baseline to 0.25 +/- 0.34 per year; 57% had stable/improved EDSS scores (change < or = 0.5 points); 65% had not transitioned to secondary progressive multiple sclerosis (SPMS); 38%, 18%, and 3% reached EDSS 4, 6, and 8. For all patients on GA therapy (the mITT cohort), ARRs declined from 1.18 +/- 0.82 to 0.43 +/- 0.58 per year; 54% had stable/improved EDSS scores; 75% had not transitioned to SPMS; 39%, 23%, and 5% reached EDSS 4, 6, and 8. In conclusion, multiple sclerosis patients with mean disease duration of 22 years administering GA for up to 15 years had reduced relapse rates, and decreased disability progression and transition to SPMS. There were no long-term safety issues.

Quantitative PCR for Epstein–Barr virus DNA and RNA in multiple sclerosis

Background

Epstein–Barr virus (EBV) is associated with MS, but it is not clear whether EBV plays a role in the pathogenesis of MS.

Hypothesis

We hypothesized that the immune control of EBV might be defective in MS, and that reactivation of EBV might drive the immune response in MS.

Methods

We collected blood from controls and patients with MS, and measured the amounts of EBV DNA and RNA using quantitative PCR.

Results

We found that EBV DNA and RNA were frequently detectable in peripheral blood leukocytes from both patients with MS and normal controls. There was no significant difference between patients with MS or controls. Paired samples from a small number of subjects suggest that EBV DNA may increase before and during clinical relapse.

Conclusions

We conclude that the immune control of EBV infection is similar in MS and controls, and that reactivation of EBV may correlate with MS disease activity.

Epstein-Barr virus genotypes in multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is associated with Epstein-Barr virus (EBV) infection, but the relationship between the virus and the disease is not clear. As many different types of EBV exist, it is possible that MS is caused by one particular type of EBV. Objectives - The aim of this study was to determine whether MS is associated with a particular genotype of EBV.

MATERIALS AND METHODS

We collected blood from MS patients and controls, amplified and sequenced the latent membrane protein-1 (LMP-1) gene, and compared the groups.

RESULTS

We found a variety of LMP-1 sequences in both MS and controls, with no significant differences between the groups. Conclusion - We conclude that MS is not associated with a particular genotype of EBV.

Dexamethasone-induced Ras-related protein 1 is a potential regulatory protein in B lymphocytes

Dexamethasone-induced Ras-related protein 1 (RASD1) is a protein of the Ras family which probably has a regulatory function. We demonstrate that Rasd1 mRNA is expressed in mouse lymph node cells in response to inhibitory stimuli. Rasd1 mRNA is present at very low levels in freshly isolated cells, but it is rapidly up-regulated in culture and is expressed at elevated levels in cells whose proliferation is blocked by exposure to homogenized brain tissue. The cells expressing Rasd1 mRNA are positive for MHC class II and B220 and negative for Thy-1. Expression of Rasd1 mRNA is very low in B cell-deficient mice. We conclude that Rasd1 mRNA is expressed by B lymphocytes derived from lymph node cells in response to inactivating or inhibitory stimuli. It may play a role in regulating B lymphocyte activity and proliferation.

Ingested IFN-alpha: results of a pilot study in relapsing-remitting MS

OBJECTIVE

To investigate whether ingested human recombinant interferon-alpha2a (IFN-alpha2a) was safe and whether treatment reduces the number of gadolinium-enhanced lesions on serial MRI in patients with active relapsing-remitting MS (RRMS).

METHODS

Entry criteria included clinically definite RRMS and one or more gadolinium-enhanced lesions on a screening MRI.

RESULTS

Of 80 patients screened, 33 were eligible and 30 patients were enrolled for treatment. Patients were randomized (10 per group) to placebo, 10,000 or 30,000 IU IFN-alpha2a ingested on alternate days for 9 months. They were examined clinically and with monthly cerebral MRI. Sample size projections were based on the assumption of a parenteral IFN-like effect, a 90% reduction of enhancing lesions evident within 1 month of the initiation of treatment in the active treatment groups sustained during the 9-month study as the primary outcome variable.

RESULTS

There was no significant effect on enhancing lesions. However, post hoc analysis suggested a possible treatment effect in the 10,000 IU group. By direct monthly comparison of placebo and 10,000 IU group in treatment month 5, there were 73% (p < 0.05) fewer enhancements in the 10,000 IU group than in the placebo group. There was a decrease of tumor necrosis factor-alpha protein secretion at months 4 and 5. Relapses and adverse events were not different among the treatment groups. Ingested IFN-alpha2a did not induce systemic anti-IFN-alpha antibodies.

CONCLUSIONS

This trial showed no benefit based on the primary outcome measure. Because changes were detected in immune response and post hoc analysis suggested that a smaller dose could have an effect, IFN-alpha may deserve further study.

Immune regulatory effects of central nervous system antigens in culture

Evidence from several different experimental systems suggests that regulatory cells specific for self-antigens exist in the normal immune repertoire, and that these cells are necessary for maintenance of self-tolerance and prevention of autoimmune disease. We attempted to demonstrate the existence of regulatory cells specific for central nervous system (CNS) antigens in normal mice. We tested the effects of myelin basic protein (MBP), glial fibrillary acidic protein (GFAP) and a mixture of soluble brain proteins (SBP) on cultured splenocytes. MBP at 50 microg/ml inhibited antigen-driven proliferation and this suppressive effect could be partially blocked by neutralizing antibodies to transforming growth factor (TGF)-beta. MBP decreased expression of mRNA for the cytokines IL-2 and IFN-gamma, and slightly increased mRNA expression for TGF-beta. These effects did not appear to be mediated by regulatory cells specific for MBP, since MBP also suppressed proliferation in MBP-deficient shiverer mice and the suppressive effect could not be reproduced with selected MBP peptides. SBP at 250 microg/ml also inhibited antigen-driven proliferation, but this effect could not be blocked by neutralizing antibodies against IL-4, IL-10 or TGF-beta. SBP reduced expression of mRNA for IL-2, IL-10 and TGF-beta. These results are more consistent with the presence of a soluble inhibitory factor than with the action of SBP-specific regulatory cells. GFAP had no significant effect on proliferation. These results do not support the existence of regulatory cells specific for CNS antigens. Further investigation into non-antigen-specific mechanisms will be important in defining how autoimmune damage in the CNS is prevented.

An alkali-soluble factor present in normal brain tissue inhibits antigen-specific lymphocyte proliferation

The brain has long been recognized as an immune privileged site and probably contains multiple immune regulatory factors. We have investigated the immune regulatory properties of brain tissue on cultured lymphocytes. Homogenized brain tissue inhibits proliferation to antigen, but stimulates proliferation in response to most mitogens. The inhibitory activity is destroyed by treatment with proteases or neuraminadase. The activity is in the insoluble fraction of the homogenate, but becomes soluble in 0.04 M NaOH. After gel filtration chromatography of the alkali soluble material, the suppressive activity is in the high molecular weight fraction which contains protein and carbohydrate. The brain homogenate blocks the effects of IL-2. The activity is not affected by neutralizing antibodies against regulatory cytokines, does not depend on Fas or FasL, and is not due to the presence of gangliosides. These data suggest that a brain glycoprotein or proteoglycan which is either membrane-bound or part of the extracellular matrix has immune regulatory effects in culture. The relevance of these findings to immune regulation in the intact animal deserves further investigation.

Combination therapy with glatiramer acetate (copolymer-1) and a type I interferon (IFN-alpha) does not improve experimental autoimmune encephalomyelitis

We sought to determine whether combinations of glatiramer acetate and parenteral or ingested type I interferon were synergistic in experimental autoimmune encephalomyelitis. Glatiramer acetate, subcutaneous murine interferon-alpha, or ingested murine interferon-alpha individually improved clinical scores. In contrast, glatiramer acetate in conjunction with either subcutaneous or ingested interferon-alpha did not improve clinical scores compared with control. These data suggest that clinical trials designed to test a possible synergistic effect of glatiramer acetate and type I interferon in humans should be designed to detect possible adverse effects of this combination of immunomodulatory agents.

Tissue distribution, metabolism, and clearance of the convulsant trimethylolpropane phosphate in rats

The distribution, metabolism, and clearance of trimethylolpropane phosphate (TMPP), a potent, bicyclophosphate, gamma-aminobutyric acid-ergic convulsant, were studied in male Fischer-344 rats. Intraperitoneal administration of TMPP was compared with oral gavage with respect to rates of absorption, distribution, and clearance. Distribution of TMPP to major body tissues was evaluated for the first 24 hr after administration or, in the case of regional brain distribution, immediately after the first TMPP-induced clinical seizure. Samples purified from the urine, feces, and bile of rats exposed to TMPP, as well as from rat liver microsomes incubated with TMPP in vitro, were analyzed for possible phase I and phase II metabolism, using HPLC. The disposition and clearance of TMPP in the blood and major body tissues were measured. TMPP was found to be well distributed to highly vascularized tissue compartments, with little retention >24 hr after administration. TMPP was eliminated through the urine and feces as the parent compound, with no evidence of phase I or phase II metabolism. TMPP was rapidly cleared from the blood during the first 30 min after exposure, with slower clearance of >87% of the drug during the following 8-hr period and >99.5% clearance by 100 hr after injection. Repeated daily exposure to TMPP for up to 5 successive days resulted in no measurable accumulation in the brain or other major tissue compartments. Possible mechanisms for TMPP-induced, short- and long-term, neurobehavioral modulation are discussed.

Acute effects of a bicyclophosphate neuroconvulsant on monoamine neurotransmitter and metabolite levels in the rat brain

Naive male Sprague-Dawley rats were injected intraperitoneally (i.p.) with the bicyclophosphate convulsant trimethylolpropane phosphate (TMPP) at dose levels from 0.2 to 0.6 mg/kg. Rats were observed for convulsive activity, and were sacrificed 15 min posttreatment. Levels of the monoamine neurotransmitters norepinephrine (NE), epinephrine (EPI), dopamine (DA), and serotonin (5-HT) and the major metabolites 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) were assayed in forebrain, midbrain, hindbrain, cerebellum and brainstem regions. Neurotransmitter and metabolite levels were compared between control rats and rats that did and did not experience seizures. TMPP administration induced significant decreases in levels of measured neurotransmitters that varied as a function of brain region, dose, and expression of the seizure activity. These results show that tonic or tonic-clonic seizures induced by TMPP administration (0.6 mg/kg) are reliably associated with regional decreases in serotonin, dopamine, and norepinephrine. Convulsive activity resulting from lower dose administrations (0.2-0.4 mg/kg) of TMPP result only in decreased regional levels of serotonin.

Use of reinduced experimental autoimmune encephalomyelitis to evaluate the importance of epitope spread

Several investigators have reported experimental evidence of epitope spreading in experimental autoimmune encephalomyelitis (EAE). The role of epitope spreading in the pathogenesis of relapsing or chronic autoimmune disease is not established and the in vivo function of the T cells specific for new epitopes which appear during an autoimmune response is unclear. We recently demonstrated that mice which have recovered from an episode of EAE suffer a relapse shortly after reinjection with the original encephalitogen. The reinduced disease occurs in a reproducible fashion with an accelerated onset. This may be due to persistence of an expanded population of previously activated encephalitogenic cells which are rapidly reactivated when re-exposed to antigen. We reasoned that if epitope spread produces a significant number of encephalitogenic cells specific for a new epitope, then reinjection with that epitope should also cause the rapid onset of an episode of EAE. We tested this hypothesis using the known encephalitogenic epitopes in SJL mice. After recovery from EAE induced with the proteolipid protein peptide PLP139-151, five of 16 mice had an accelerated relapse of EAE when reinjected with a second encephalitogenic peptide, PLP178-191. All of the 10 mice reinjected with the original PLP139-151 peptide relapsed. We conclude that epitope spread may produce encephalitogenic cells specific for new epitopes, but that the response to new epitopes is minor compared to the response to the initial epitope.

Trimethylolpropane phosphate (TMPP) perfusion into the nucleus accumbens of the rat: electroencephalographic, behavioral and neurochemical correlates

The infusion (0.13 mumol/infusion) of the convulsant trimethylolpropane phosphate (TMPP) into the nucleus accumbens (NA) of adults Sprague-Dawley rats reliably induced subclinical seizures, hyperlocomotor activity, and integrated stereotypies. Observation of these behaviors was temporally correlated with the appearance of EEG paroxysms, as well as with significant decreases in extracellular concentrations of both dopamine (DA) and norepinephrine (NE) in the NA. Repeated perfusion of TMPP revealed significant increases in stereotypic behavior during subsequent pre-drug baseline testing.

T cell-T cell activation in multiple sclerosis

Activated T cells are able to stimulate proliferation in resting T cells through an antigen non-specific mechanism. The in vivo usefulness of this T cell-T cell activation is unclear, but it may serve to amplify immune responses. T cell-T cell activation could be involved in the well-documented occurrence of multiple sclerosis (MS) exacerbations following viral infections. Excessive activation via this pathway could also be a factor in the etiology of MS. We tested the hypothesis that excessive T cell-T cell activation occurs in MS patients using in vitro proliferation assays comparing T cells from MS patients to T cells from controls. When tested as responder cells, T cells from MS patients proliferated slightly less after stimulation with previously activated cells than T cells from controls. When tested as stimulator cells, activated cells from MS patients stimulated slightly more non-specific proliferation than activated cells from controls. Neither of these differences were statistically significant. We conclude that T cell proliferation in response to activated T cells is similar in MS and controls.

Relationship of the antispasticity effect of tizanidine to plasma concentration in patients with multiple sclerosis

BACKGROUND

Spasticity is a serious problem in multiple sclerosis (MS) and many patients do not achieve a satisfactory response to currently available oral antispasticity drugs. Tizanidine hydrochloride, an alpha 2-noradrenergic agonist, has been shown to have an antispasticity effect in single center trials of patients with MS.

OBJECTIVE

To compare plasma concentrations of tizanidine with objective measures of muscle tone in patients with MS with moderate to severe spasticity.

SETTING

Ten centers, all tertiary referral centers for the specialized treatment of patients with MS, in the United States and Canada.

DESIGN

A randomized, double-blind, placebo-controlled, dose-response study of tizanidine hydrochloride (8 or 16 mg).

PATIENTS

One hundred forty-two patients with spastic MS who were not taking any interfering medication, such as an antispasticity drug or other alpha-noradrenergic agonist, entered the trial.

RESULTS

Tizanidine treatment reduced muscle tone significantly, as shown by improved Ashworth scores and increased knee swing amplitude recorded by the pendulum test, both of which correlated significantly with plasma concentration. Placebo had no significant effect on muscle tone. Dizziness, drowsiness, dry mouth, and fatigue were reported most often in the group treated with tizanidine at peak plasma concentration.

CONCLUSIONS

Tizanidine reduces spasticity in MS, and both therapeutic effects and side effects are related to the plasma drug levels.

Multiple sclerosis: clinical presentation, diagnosis and treatment

Multiple sclerosis is a chronic inflammatory disease of the central nervous system and is associated with periods of disability (relapse) alternating with periods of recovery (remission) and often results in progressive neurologic disability. Scientists believe that multiple sclerosis may be a T cell-mediated autoimmune disease. Treatment with high-dose pulses of intravenous methyl-prednisolone is usually associated with a good outcome in the short term. A recent study suggests that interferon beta-1b may decrease the number of relapses in relapsing-remitting multiple sclerosis by 30 percent and also may decrease the development of new central nervous system lesions. Recently, another clinical trial of interferon beta-1a showed a 31 percent reduction in relapse rate and a significant reduction in the average number of active lesions. A third trial showed that 20 mg of copolymer-1, a random polymer of glutamic acid, lysine, alanine and tyrosine, reduced relapses by 21 percent without significant side effects. Further investigation is needed, but these new treatments show great promise in alleviating this difficult clinical problem.

Characteristics of initial and reinduced experimental autoimmune encephalomyelitis

The factors which influence expression of autoimmune disease in the central nervous system are still poorly understood. We determined the characteristics of experimental autoimmune encephalomyelitis (EAE) in twelve different inbred strains of mice using either mouse spinal cord homogenate or synthetic peptides as the encephalitogen. We also determined whether these strains were susceptible to reinduction of EAE at six weeks after the initial injection. The incidence, time of onset, severity, duration, and number of spontaneous relapses varied widely among the different strains. Duration of initial EAE correlated significantly with incidence of spontaneous relapses, and was greatest in C57L mice and in mice with a C57BL/10 background. Most strains of mice recovered from initial EAE, but recovery was unusual in A.SW and PERA mice. Incidence of reinduced EAE differed from incidence of initial EAE in some strains and did not correlate with incidence of spontaneous relapse. We conclude that the same factors control disease duration and incidence of spontaneous relapse, and that these factors are independent of the factors which control initial incidence. The factors controlling incidence of reinduced EAE are distinct from those controlling spontaneous relapse, and may also differ from those controlling initial incidence. Further investigation of the mechanisms effecting recovery from EAE and the genetic background underlying those mechanisms may help us understand human diseases such as multiple sclerosis.

Reinduction of experimental autoimmune encephalomyelitis in mice

Experimental autoimmune encephalomyelitis (EAE) in Lewis rats and some strains of mice is typically a monophasic disease, and recovered animals are resistant to reinduction of disease. We demonstrate that SJL mice remain susceptible to disease after recovery, and suffer a second episode of disease when reinjected with spinal cord homogenate in complete Freund's adjuvant. Reinduced disease occurs earlier after injection than the initial disease (mean onset 7.3 days compared with 14.5 days), and has comparable severity and incidence. The susceptibility to reinduced disease is present for at least 20 weeks after the initial injection. If the initial episode of EAE is elicited using a synthetic peptide of proteolipid protein, then reinjection of the same peptide causes reinduced disease. PL/J mice and PL/J x SJL F1 mice are also susceptible to reinduced disease which occurs with an accelerated onset and higher incidence than the initial disease. We conclude that SJL and PL/J mice have a defect in immunoregulation which causes them to be susceptible to recurrent episodes of autoimmune disease.

Repeated treatment with chimeric anti-CD4 antibody in multiple sclerosis

We treated 21 multiple sclerosis patients with two to four doses of cM-T412, a chimeric monoclonal antibody against the CD4 antigen found on helper/inducer T lymphocytes. The mean number (+/- standard error) of circulating CD4 lymphocytes decreased from 888 (+/- 81) cells/mm3 at baseline to 246 (+/- 18) after treatment. At 1 year after the last treatment, the CD4 count had recovered to only 335 (+/- 32). The antibody had no effect on CD8 lymphocytes, B lymphocytes, or other leukocytes. Side effects were minimal. Despite the prolonged depletion of CD4 lymphocytes, no opportunistic infections occurred. Only 1 patient had a possible allergic reaction. Most patients were clinically stable, but a few progressed. We conclude that repeated treatment with cM-T412 is effective in reducing the number of circulating CD4 lymphocytes and has no limiting side effects.

Phase 1 clinical trial of chimeric monoclonal anti-CD4 antibody in multiple sclerosis

We conducted an open trial of cM-T412, a chimeric monoclonal anti-CD4 antibody, in 29 patients with MS. This antibody caused a prompt and long-lasting depletion of circulating CD4 (helper/inducer) lymphocytes. The mean (+/- SE) CD4 count for the group decreased from 870 (+/- 66) cells/mm3 at baseline to 76 (+/- 11) 3 hours after treatment, and then increased to 425 (+/- 38) at 1 month after treatment and 475 (+/- 39) at 6 months after treatment. Numbers of CD8 (cytotoxic/suppressor) lymphocytes, B lymphocytes, granulocytes, and monocytes changed transiently but showed no significant long-term effects. The most common side effects were headache, nausea, myalgia, fever, and tachycardia occurring in the first few hours after treatment. No serious or unexpected infections or other significant adverse effects occurred. Kurtzke EDSS scores remained stable, and MRI scans showed less contrast enhancement 1 week after treatment. We conclude that treatment of MS patients with cM-T412 chimeric anti-CD4 antibody is well tolerated at the doses tested and produces a long-lasting, selective depletion of CD4 lymphocytes.

Competitive PCR quantification of CD4, CD8, ICAM-1, VCAM-1, and MHC class II mRNA in the central nervous system during development and resolution of experimental allergic encephalomyelitis

We used competitive polymerase chain reaction to quantify messenger RNA for the lymphocyte antigens CD4 and CD8, the adhesion molecules ICAM-1 and VCAM-1, and the MHC class II I-A molecule in the spinal cords of SJL/J mice at multiple times during the development and resolution of experimental allergic encephalomyelitis (EAE). CD4 and CD8 were not quantifiable at baseline, became detectable at 5 days after immunization, and increased steadily to a peak during clinical disease. I-A increased after CD4 and CD8, but before onset of disease. ICAM-1 and VCAM-1 did not increase until after onset of clinical disease. CD4, CD8, and I-A remained elevated long after recovery from disease. These results suggest that infiltration of CD4 and CD8 cells into the spinal cord and subsequent upregulation of I-A mRNA play an important role in the development of EAE, but reversal of these processes is not necessary for recovery. Upregulation of ICAM-1 and VCAM-1 mRNA does not appear to be important for development of disease.

Usage of T cell receptor beta-chain variable gene is highly restricted at the site of inflammation in murine autoimmune uveitis

Improved molecular methods allow identification of the specific autoaggressive T cells involved in autoimmune inflammations. In this study of interphotoreceptor retinoid-binding protein-induced uveitis, TCR V beta usage was studied using RNA-polymerase chain reaction amplification of transcripts derived directly from ocular tissues and from T cell lines obtained from the spleen. Specific V beta 5' primers from the major murine TCR V beta families were coupled with a common 3' primer from the V beta C region. Amplification of rearranged TCR V beta-D beta-J beta-C beta sequences was confirmed by Southern blot analysis. In ocular tissue from sensitized mice, TCR V beta expression was limited mainly to one to three V beta families, with predominant expression of V beta 2, V beta 12, and V beta 15. In most animals there was similar, albeit limited, TCR gene usage in both the recognition of autoantigen in uveitogenic T cell lines and at the site of inflammation in the eye. Identification of a limited TCR V beta repertoire in Ag-reactive T cell lines correlated with TCR usage at the target site of autoimmune expression. The gene products of the restricted TCR V beta rearrangements found in lesions and in the cell lines may serve as the target for selective immunotherapy.

Usage of T cell receptor beta-chain variable gene is highly restricted at the site of inflammation in murine autoimmune uveitis

Improved molecular methods allow identification of the specific autoaggressive T cells involved in autoimmune inflammations. In this study of interphotoreceptor retinoid-binding protein-induced uveitis, TCR V beta usage was studied using RNA-polymerase chain reaction amplification of transcripts derived directly from ocular tissues and from T cell lines obtained from the spleen. Specific V beta 5' primers from the major murine TCR V beta families were coupled with a common 3' primer from the V beta C region. Amplification of rearranged TCR V beta-D beta-J beta-C beta sequences was confirmed by Southern blot analysis. In ocular tissue from sensitized mice, TCR V beta expression was limited mainly to one to three V beta families, with predominant expression of V beta 2, V beta 12, and V beta 15. In most animals there was similar, albeit limited, TCR gene usage in both the recognition of autoantigen in uveitogenic T cell lines and at the site of inflammation in the eye. Identification of a limited TCR V beta repertoire in Ag-reactive T cell lines correlated with TCR usage at the target site of autoimmune expression. The gene products of the restricted TCR V beta rearrangements found in lesions and in the cell lines may serve as the target for selective immunotherapy.

Diverse T cell receptor V beta gene usage in the central nervous system in experimental allergic encephalomyelitis

The repertoire of TCR V beta genes transcribed and expressed within the central nervous system was determined in mice with experimental allergic encephalomyelitis. Disease was induced in (PL/J x SJL/)F1 mice by immunizing with myelin basic protein-acetylated peptide 1-11, and mice were sacrificed at intervals from day 3 postimmunization to 3 wk after recovery from disease. Transcription of V beta genes was determined by reverse transcriptase polymerase chain reaction on RNA extracted from spinal cord, and expression of the V beta gene products was detected by immunohistochemistry with mAb specific for various V beta proteins. Multiple V beta genes were found to be transcribed and expressed in the central nervous system starting 7 days after immunization, and continuing up to 3 wk after clinical recovery. Preferential utilization of a single TCR V beta gene was not detected in the central nervous system at any time in the course of disease.

Diverse T cell receptor V beta gene usage in the central nervous system in experimental allergic encephalomyelitis

The repertoire of TCR V beta genes transcribed and expressed within the central nervous system was determined in mice with experimental allergic encephalomyelitis. Disease was induced in (PL/J x SJL/)F1 mice by immunizing with myelin basic protein-acetylated peptide 1-11, and mice were sacrificed at intervals from day 3 postimmunization to 3 wk after recovery from disease. Transcription of V beta genes was determined by reverse transcriptase polymerase chain reaction on RNA extracted from spinal cord, and expression of the V beta gene products was detected by immunohistochemistry with mAb specific for various V beta proteins. Multiple V beta genes were found to be transcribed and expressed in the central nervous system starting 7 days after immunization, and continuing up to 3 wk after clinical recovery. Preferential utilization of a single TCR V beta gene was not detected in the central nervous system at any time in the course of disease.

Recurrent transverse myelitis, myasthenia gravis, and autoantibodies

A 45-year-old man with a longstanding diagnosis of myasthenia gravis presented with four episodes of transverse myelitis in 5 years. Each episode improved after treatment with steroids. Laboratory studies revealed no evidence of multiple sclerosis or a structural spinal lesion. He had antinuclear and anti-DNA antibodies and the HLA-A1, B8, DR3 haplotype known to be associated with certain autoimmune diseases. We propose an autoimmune cause for the recurrent episodes of myelitis.

Role of monkey midbrain near-response neurons in phoria adaptation

1. One striking characteristic of the way in which accommodation and convergence of the eyes are organized is that although the two responses are usually tightly coupled, a brief period of binocular viewing through prisms that require extra convergence brings about a persistent, adaptive alteration in the relationship between the two responses: the vergence during monocular viewing of a target at a given distance is biased in a convergent direction. We sought to discover the role of the near-response neurons we have previously described in the monkey midbrain in such phoria adaptation. 2. Phoria adaptation was produced in two monkeys by having them view binocularly stereoscopic targets under conditions that mimicked prism viewing, i.e., the mirrors of the stereoscope were set so as to require more convergence than that associated with a real target at the same distance as the images seen in the stereoscope. The activity of 57 near-response neurons located dorsally and dorsolaterally to the oculomotor nucleus was recorded before and after adaptation while the monkeys monocularly viewed targets at a range of distances. 3. Comparison of a neuron's response in normal binocular viewing with the response when the accommodation and vergence stimuli were in conflict allowed us to distinguish 24 neurons that behaved as though they were related exclusively to the vergence response. 5 neurons that behaved as though they were exclusively related to the accommodation response, and 12 neurons whose firing was not so simply related to either response. We were unable to classify the remaining 16 near-response cells by this method. 4. In accommodation-related neurons, the relationship between firing rate and accommodation did not alter, or only altered slightly, when the animal's phoria was adapted. 5. The relationship between firing rate and vergence was unaltered by phoria adaptation in only a small proportion of vergence-related neurons, showing that most neurons do not carry the entire signal responsible for phoria adaptation. On the other hand, in the majority of vergence-related neurons the relationship between firing rate and accommodation was altered by phoria adaptation, showing that most neurons do carry part of the phoria adaptation signal. 6. The implication is that the increase in vergence observed after adaptation is mediated at more than one site. A proportion of the phoria adaptation signal is present at the level of the midbrain vergence-related neurons, with the remainder of the signal being added later, presumably at the motoneurons.

47-year-old woman with six-week history of lower extremity weakness and eosinophilia

This discussion was selected from the Department of Medicine Morbidity and Mortality Conference held at the Stanford University Medical Center, Stanford, California, on January 9, 1991. The editor of the conference is Philip C. Lee, MD, Chief Resident, Department of Medicine.

Controlled trial of isoniazid therapy for severe postural cerebellar tremor in multiple sclerosis

Six patients with severe postural cerebellar tremor were studied in a double-blind, placebo-controlled, crossover trial with isoniazid. Each phase of the study lasted 4 weeks, and in the isoniazid phase patients received an increasing dose up to 1200 mg/d. Patients were studied with self-rating scales, quantitative tremor recording, and blinded ratings of videotapes. All patients improved by at least one method, three improved by all methods, and four improved sufficiently to want to continue with the drug after the trial was finished. There is a definite, but limited, therapeutic role for isoniazid.