Magnetic resonance imaging in monitoring the treatment of multiple sclerosis: concerted action guidelines

Partial inhibition of AT-EAE by an antibody to ICAM-1: clinico-histological and MRI studies

The role of quantitative proton magnetic resonance imaging (MRI) for the evaluation of immunopathological lesions in the CNS was studied in adoptively transferred experimental allergic encephalomyelitis (AT-EAE). We utilized a recently established treatment model, inhibition of the cell adhesion molecule ICAM-1 by the monoclonal antibody 1A-29. The animals were scanned on days 3, 5 and 7 after injection of encephalitogenic T-cells, before and after bolus injection of Gd-DTPA by performing T1-measurements to assess the integrity of the blood-brain barrier (BBB). On day 7, immunohistochemistry was performed looking for T-cells, activated macrophages, and albumin staining. There was clinical evidence of partial inhibition of AT-EAE in rats treated with antibodies against ICAM-1. This finding was in line with a significantly reduced number of T-cells in the medulla. However, the number of activated macrophages and the distribution of albumin did not differ from untreated AT-EAE animals. The histological findings are in agreement with the MRI data before and after Gd-DTPA injection which were similar in treated and untreated AT-EAE rats on day 3 and 5. On day 7 after Gd-DTPA injection there was evidence of a delayed breakdown of the BBB in the treated rats. The observation of a dissociation of clinical and MRI findings, especially evidence of Gd-enhancement despite clinical improvement, may be important in the context of interpreting MRI studies in MS patients in treatment trials.

Correlation between brain MRI lesion volume and disability in patients with multiple sclerosis

In this study we evaluated the relationships between clinical variables and lesion volumes measured from magnetic resonance imaging (MRI) scans in a large cohort of multiple sclerosis (MS) patients. One hundred and thirty patients with MS entered the study: 36 patients had relapsing-remitting (RR), 39 benign (B), 42 secondary progressive (SP) and 13 primary progressive (PP) courses. There was a significant correlation (r = 0.3; p = 0.0006) between the total lesion load and the EDSS score when the whole cohort of patients was considered. This correlation increased (r = 0.5) when only patients with RRMS and SPMS were considered. Our data indicate that a correlation between disability and MRI lesion volume in MS exists, but its strength is moderate.

Treatment of relapsing-remittent multiple sclerosis with recombinant human interferon-alfa-2a: design of a randomised, placebo-controlled, double blind trial in Norway

A multicentre, randomised, double-blind, placebo controlled study to evaluate the efficacy and safety of 4.5 and 9.0 MIU recombinant human interferon alfa-2a (Roferon-A) given thrice weekly in patients with relapsing-remittent multiple sclerosis is described. The patients are treated for 6 months followed by a 6 months drug-free period. The primary objective is to determine new disease activity analysed by monthly MRI with gadodiamide (GdDTPA-BMA, Omniscan). The study is conducted at eight centers in Norway and is completed in January 1996.

Emerging treatments in multiple sclerosis: azathioprine and mofetil

Global immunosuppression instead of focused selective or specific immunomodulating strategies may still be relevant in diseases with chronic and broad immune dysregulation such as multiple sclerosis (MS). Among classical or new immunosuppressive drugs, two of them, both inhibiting purine synthesis, show an attractive profile for MS treatment. Azathioprine (AZA) is the most anciently and widely used global immunosuppressive drug in MS. Despite founded initial fears, it can be stated today that AZA is usually well tolerated and compatible with normal daily activities, that it requires minimal monitoring and does not significantly increase the risk of cancer induction after 5 years of continuous usage at the conventional 2.5 mg/kg daily dose. The only two presently available well conducted trials of AZA in ambulatory patients with relapsing-remitting MS show marginally significant beneficial results of AZA treatment on relapse frequency and disability. Some preliminary data on brain MRI are also promising. Mycophenolate mofetil (MMF) affects mainly the desired cell types, with a good safety profile, a rapidly reversible activity, and an absence of mutagenic effect and chromosome breakage. However, it remains to be shown that promising experimental results can be converted into significant clinical results in MS. It is presently demonstrated for AZA and it is presumable for MMF that neither drug is able to cure MS. However, it can be anticipated that either drug in combination with other strategies such as recombinant beta interferon could represent a significant adjunct for the therapeutic control of MS, at least in early ambulatory relapsing-remitting MS. Presently, the choice between the old, no longer 'sexy', but well-known drug as AZA and a young, appealing, but still to be better evaluated drug (notably for the long run) as MMF is a matter of personal, community, industrial and scientific inclination.

A phase II trial of anti-CD4 antibodies in the treatment of multiple sclerosis

In multiple sclerosis (MS) myelin damage is the result of a chronic inflammatory process mediated by CD4 positive T helper/effector cells. In experimental allergic encephalomyelitis (EAE), the animal model of MS, treatment with anti-CD4 antibodies can prevent the onset of disease. Natural history studies have demonstrated that gadolinium enhanced magnetic resonance imaging (MRI) of the brain is more sensitive and objective in assessing inflammatory disease activity in MS than clinical monitoring, so that less patients and shorter studies suffice to reach the same statistical power as compared to trials using clinical outcome parameters. In this paper we describe the design of an exploratory trial of chimeric monoclonal anti-CD4 antibodies in the treatment of MS. For this study we chose the number of active MS lesions on monthly gadolinium enhanced MRI scans as the primary outcome measure.

CAMPATH-IH in multiple sclerosis

In a pilot study, seven patients with multiple sclerosis were treated with CAMPATH-IH which targets the CD52 antigen present on lymphocytes and monocytes. There was a substantial reduction in disease activity as measured by gadoliunium-enhancing lesions on MRI. Encouraged by this result a further seven patients have been treated with CAMPATH-IH; four also received anti-CD4 antibody. Lymphopaenia developed rapidly and was sustained for at least one year. In 12 patients, the first infusion of antibody was characterised by significant exacerbation or re-awakening of pre-existing symptoms lasting several hours. These clinical effects of antibody treatment correlated with increased levels of circulating cytokines. Peak levels of tumour necrosis factor alpha (TNF alpha) and interferon gamma (IFN gamma) occurred at 2 h whereas the rise in interleukin-6 (IL-6) was significantly delayed and peaked at 4 h after starting antibody treatment. The neurological symptoms could not be attributed directly to pyrexia and were not provoked (in one patient) by an artificial rise in temperature. In the remaining two patients, a single pre-treatment with intravenous methylprednisolone (500 mg) prevented both the transient increase in neurological symptoms and the cytokine release. Our results suggest that soluble immune mediators contribute to symptom production in multiple sclerosis by directly or indirectly blocking conduction through partially demyelinated pathways.

Combinations of drugs

As a result of recent therapeutic trials, recombinant Interferon beta (rIFN beta)-Ib and -Ia as well as Copolymer I (COP I) and to some extent unspecific immunosuppressants have been accepted as partially efficient treatments of relapsing-remitting MS. In view of partially effective single treatments, the question arises if combination of two or even more-agents could improve efficacy without increasing side effects. The theoretical background of possible combinations is discussed. The selection of combination partners should be based on their proven efficacy as single treatment, on their mode of action and their distinct target in the pathogenetic cascade of events and on their specific side effect profile. Combination regimens selected in this way should undergo evaluation in short term early phase II studies and if the results are positive enter phase III studies. The use of surrogate markers (especially MRI-findings) may help to accelerate this process. Combinations that could enter phase II and III studies in the near future are rIFN beta with unspecific immunosuppressants, e.g. Azathioprine or Methotrexate and rIFN beta with COP I. Combinations including agents just entering phase I and II studies as a single treatment may be more promising for the future.

Patterns of disease activity in multiple sclerosis patients: a study with quantitative gadolinium-enhanced brain MRI and cytokine measurement in different clinical subgroups

In this study we assessed the subclinical disease activity in 45 patients with primary progressive, secondary progressive or relapsing-remitting multiple sclerosis (MS). The patients had gadolinium-enhanced brain MRI scans, which were analysed using a semiquantitative method both for lesion load and for degree of enhancement. At the same time cerebrospinal fluid (CSF) and serum samples were collected and, from these, cytokine levels were measured in most cases by enzyme-linked immunoassay using commercially available kits. Enhancing lesions on MRI were found in 73% of the patients. The sensitivity of this test was greatly increased by our method of analysis as far as the primary progressive patients are concerned (70% vs 40% for conventional evaluation). CSF interleukin-1 beta (IL-1 beta) levels were above the normal range in 22% and IL-6 levels in 13% of patients, while tumour necrosis factor alpha (TNF-alpha) was undetectable or below the upper normal limits in all the samples tested. Serum IL-1 beta was above the normal limits in 40%, IL-6 in 42% and TNF-alpha in 7% of patients. No significant differences in cytokine profiles were found between the clinical subgroups. This study confirms the high sensitivity of gadolinium-enhanced MRI in detecting MS activity, which was further increased by our method of analysis. Longitudinal studies performed with more sensitive immunological techniques are needed to define better the relationship between cytokine, clinical and MRI data in MS patients.

Multiple sclerosis: prospective analysis of TNF-alpha and 55 kDa TNF receptor in CSF and serum in correlation with clinical and MRI activity

The possibility of antagonizing tumor necrosis factor-alpha (TNF-alpha) in vivo with antibodies or soluble TNF receptor has focused much interest on the role of this cytokine in the natural course of MS. We studied nine patients prospectively and serially for one year (14 time points, 131 observations). TNF-alpha and the 55 kDa soluble TNF receptor were measured every 4 weeks in the serum and at defined time points in the CSF. Each value was correlated to clinical symptoms and to MRI measurements obtained on the same day. All patients with relapsing-remitting disease showed periodic increases of TNF concentrations. Overall, the association between serum TNF-alpha levels and bursts of Gd-DTPA enhancement on cranial MRI was not sufficiently tight to reach statistical significance. However, serum TNF levels > 50 pg/ml and measurable CSF levels were always associated with Gd-DTPA enhancing MRI lesions. Isolated high serum TNF peaks were noted during episodes of infection, hay fever or psychic stress. After treatment with glucocorticoids, TNF levels were suppressed for several months, whereas new Gd-DTPA enhancing lesions continued to appear. The concentrations of the soluble 55 kDa TNF receptor did not show marked fluctuations. These results are consistent with an active role of TNF-alpha in MS during periods of disease activity and provide further support for the clinical evaluation of anti-TNF therapies.

High-dose contrast-enhanced MRI in multiple sclerosis

Contrast-enhanced MRI is effective for assessing disease activity in multiple sclerosis (MS) and may provide an outcome measure for testing the efficacy of treatment in clinical trials. To compare the sensitivity of high-dose gadolinium-HP-DO3A with that of a standard dose of gadolinium-DTPA, we studied 16 patients with relapsing-remitting MS in the acute phase of the disease. Each underwent two MRI examinations within at most 48 h. The initial MRI study was with a standard dose of gadolinium-DTPA (0.1 mmol/kg), and the second one an experimental dose of gadolinium-HP-DO3A (0.3 mmol/kg). No adverse effects were attributed to the contrast media. The high-dose study revealed more enhancing lesions than the standard-dose study (56 vs 38). This difference was found to be more relevant for infratentorial and small lesions. Furthermore, with the higher dose, there was a marked qualitative improvement in the visibility and delineation of the lesions.

Triple dose of gadolinium-DTPA and delayed MRI in patients with benign multiple sclerosis

OBJECTIVES

To evaluate whether a triple dose of gadolinium-DTPA (Gd-DTPA) or delayed MRI increase the number, size, and conspicuousness of enhancing lesions in patients with benign multiple sclerosis.

METHODS

T1 weighted brain MRI was carried out on 20 patients with benign multiple sclerosis (expanded disability status scale < 3 with a disease duration > 10 years) in two sessions. In the first session, one scan was obtained before and two scans five to seven minutes and 20-30 minutes after the injection of 0.1 mmol/kg Gd-DTPA (standard dose). In the second session, six to 24 hours later, the same procedure was repeated with 0.3 mmol/kg Gd-DTPA (triple dose).

RESULTS

Nine enhancing lesions were found in seven patients (35%) using the standard dose of Gd-DTPA. The numbers of enhancing lesions increased to 13 (P = 0.03) and the number of patients with such lesions to eight (40%) on the delayed standard dose scans. On the early triple dose scans, we found 19 enhancing lesions in 10 patients (50%). The number of enhancing lesions was significantly higher (P = 0.01) than that obtained with the early standard dose. The number of enhancing lesions was 18 and the number of "active" patients 11 (55%) on the delayed triple dose scans. The enhancing areas increased progressively from the early standard dose scans to the delayed triple dose scans. The contrast ratios of the lesions detected in early standard dose scans was lower than those of lesions present in the early (P = 0.01) and delayed (P = 0.04) triple dose scans.

CONCLUSIONS

More enhancing lesions were detected in patients with benign multiple sclerosis with both delay of MRI and the use of triple dose of Gd-DTPA suggesting that the amount of inflammation in the lesions of such patients is mild and heterogeneous.

A preliminary study into the sensitivity of disease activity detection by serial weekly magnetic resonance imaging in multiple sclerosis

Long TR and gadolinium enhanced spin echo brain MRI was performed weekly for three months in three patients with relapsing-remitting or secondary progressive multiple sclerosis. During the study, 38 new enhancing lesions were seen; 11 showed enhancement for less than four weeks, and two enhanced on only one scan. All 16 new lesions seen on long TR scans showed initial enhancement. When only every fourth (monthly) scan was analysed, a total of 33 new enhancing lesions were seen. Subject to confirmation in a larger cohort, the results suggest: (a) that blood brain barrier leakage is an invariable event in new lesion development in relapsing-remitting and secondary progressive multiple sclerosis; (b) the small increase in sensitivity of weekly scanning does not justify its use in preference to monthly scanning when monitoring treatments.

The treatment of chronic progressive multiple sclerosis with cladribine

A 2-year, placebo-controlled, double-blind, crossover study was started in 1992 to evaluate cladribine, an immunosuppressive drug, in the treatment of chronic progressive multiple sclerosis. In the first year patients were given cladribine 0.10 mg/kg per day for 7 days as four monthly courses for a total of 2.8 mg/kg or placebo. During the second year patients treated with placebo during the first year were given i.v. infusions of 0.10 mg, 0.05 mg, and 0.05 mg of cladribine per kg of body weight per day for 7 consecutive days in three successive monthly courses, for a total dose of 1.4 mg/kg. Patients who had been treated previously with cladribine were crossed over to placebo. Analysis of the results revealed a favorable influence on the neurological performance scores, both in the Kurtze extended disability status and the Scripps neurological rating scale, and on MRI findings in patients treated with cladribine. In the first year the most striking finding was that while clinical deterioration continued in the placebo-treated patients, the condition of patients who received cladribine stabilized or even improved slightly. Toxicity and therapeutic response were dose-related.

Different antiganglioside antibody pattern between relapsing-remitting and progressive multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is an autoimmune disorder, but an unique antigen has not been found. Antiganglioside antibodies (AGA) have been reported in MS, nevertheless, a clinical significance of AGA in MS has not been established. The aims of this study were to study AGA in sera of MS patients and to investigate relationships between AGA and clinical course of MS.

MATERIAL AND METHODS

42 patients with MS who fulfilled the criteria of clinically definite disease (59% RRMS, 21% SPMS, 20% PPMS), 89 patients with systemic lupus erythematosus and 36 healthy controls were studied. A modification of previously described ELISA techniques was used to estimate serum IgG and IgM anti-GM1, asialoGM1 and anti-GD1a antibodies.

RESULTS

47.6% of the patients showed AGA reactivity. Anti-GM1 was found in 38% of MS patients, anti-asialoGM1 in 23.8% and anti-GD1a in 33.3%. IgG was the isotype more commonly found. A correlation between presence of AGA and progressive disease and between anti-GD1a and PPMS was found.

CONCLUSIONS

The presence of AGA in MS patients is elevated. In contrast with the results of others authors, a strong correlation between AGA and progressive disease is showed in our study.

A study of oligoclonal band negative multiple sclerosis

OBJECTIVES

To determine whether oligoclonal band (OCB) negative multiple sclerosis is a reliable diagnosis and, if so, whether it has a distinctive prognosis.

METHODS

Retrospective and matched prospective comparison of the clinical and laboratory features of patients with clinical definite multiple sclerosis with and without intrathecal synthesis of oligoclonal IgG.

RESULTS

Thirty four patients were identified with apparent OCB negative clinically definite multiple sclerosis. The results of oligoclonal banding proved to have been equivocal in 14 of 34; the clinical diagnosis of multiple sclerosis was questionable in 8 of 34. The remaining 12 patients with "true" OCB negative multiple sclerosis were significantly less disabled than matched OCB positive controls. Re-examination of CSF-serum pairs from six OCB negative patients showed that three remained OCB negative while three showed evidence of intrathecal synthesis of OCBs.

CONCLUSIONS

OCB negative clinically definite multiple sclerosis is rare and should be diagnosed with caution; in unequivocal cases it seems to have a relatively benign prognosis.

Quantification of MRI lesion load in multiple sclerosis: a comparison of three computer-assisted techniques

Several computer-assisted techniques for measuring multiple sclerosis lesion load on MR images have been developed to provide a quantitative and sensitive means for monitoring disease activity, particularly in the context of treatment trials. We have evaluated three techniques: manual outlining (similar to that of the North American interferon beta-1b trial), semiautomated lesion contouring (local lesion based threshold), and intensity-based thresholding for the whole brain. Contiguous, 5 mm-thick, axial, T2-weighted images of the brain were obtained on a 1.5T MR imager in eight patients with clinically definite multiple sclerosis. Analyses of the scans were performed twice, independently by three operators, using the three different techniques. The coefficient of variation of the measurement techniques was: (a) intrarater precision, 9.0 +/- 5.2 (mean +/- SD) (range 0.4-18.5) for the manual outlining, 2.5 +/- 2.1 (0.1-7.7) for the contour technique, and 7.5 +/- 6.9 (0.2-22.0) for the global threshold technique; (b) interrater precision, 11.0 +/- 5.8 (4.9-21.7) for the manual outlining, 4.5 +/- 1.6 (1.8-6.6) for the contour technique, and 11.4 +/- 4.9 (2.8-19.2) for the global threshold technique (0.0 = perfect precision). The absolute lesion loads measured were very similar using the manual outlining and the contour techniques but were significantly smaller using the global threshold technique. We conclude that the contour technique is a promising tool for use in treatment trials. Further studies are needed to assess sensitivity to changes in lesion load over time.

Soluble E-selectin in multiple sclerosis: raised concentrations in patients with primary progressive disease

OBJECTIVE

To determine whether concentrations of soluble E-selectin (sE-selectin), an immunological marker of endothelial activation, were correlated with gadolinium-DPTA enhancement on MRI in patients with multiple sclerosis.

METHODS

Serial sE-selectin concentrations were measured in 28 patients with multiple sclerosis undergoing monthly gadolinium (Gd) enhanced MRI of the brain and spinal cord, and in 10 control subjects. C reactive protein (CRP), von Willebrand factor (vWF), and tumour necrosis factor-alpha (TNF alpha) were also determined.

RESULTS

Primary progressive patients had significantly increased sE-selectin concentrations compared with the relapsing remitting and secondary progressive patients who had normal sE-selectin concentrations (22.2 (SD1 6.1) ng/ml v 9.8 (SD2.1) ng/ml and 7.7 (SD2.7) ng/ml, respectively, P = 0.03). This difference was attributable to five of the 10 primary progressive patients who had persistently raised sE-selectin concentrations, with relatively inactive MRI studies. No correlation could be found between sE-selectin concentrations and Gd enhancement on MRI, but a close correlation existed between mean concentrations of sE-selectin and TNF alpha (r = 0.71, P < 0.001). Despite raised sE-selectin and TNF alpha concentrations, primary progressive patients had normal CRP concentrations (1.03 (SD1.14) mg/l), which were significantly lower than the relapsing remitting (3.16 (SD2.54) mg/l) and secondary progressive patients (2.28 (SD2.1) mg/l, P = 0.03). Raised CRP concentrations did correlate with infectious episodes, clinical relapse, and Gd enhancement, and were significantly raised when no MRI activity was found. Concentrations of vWF were normal in all patient groups.

CONCLUSIONS

The results further high-light the differences between patients with primary progressive and those with relapsing remitting/secondary progressive multiple sclerosis.

The neuroimmunology of multiple sclerosis

The aim of this clinical review is to highlight recent advances in immunology, as well as new information from selected other areas, which have led to a better appreciation of the neuroimmunologic mechanisms involved in Multiple sclerosis (MS). New data on immunopathology, the cytokine network, and the role of oligodendrocytes, lymphocytes, and endothelial cells in this disease, have produced novel therapeutic approaches. New information on clinical course and neuroimaging disease features, as well as the role of genetic factors and infectious agents, have also improved our understanding of the immune basis for MS.

Guidelines for the use of magnetic resonance techniques in monitoring the treatment of multiple sclerosis. US National MS Society Task Force

Because of the major difficulties in measuring clinical end points in multiple sclerosis (MS) treatment trials, there has been much enthusiasm for using magnetic resonance imaging (MRI) findings as an alternative outcome. To provide international consensus guidelines for the use of MRI in MS clinical trials, a task force of the US National MS Society was convened. The recommendations of the task force are presented in this review. Given the high sensitivity for detecting pathological activity in relapsing-remitting and secondary progressive MS, monthly T2-weighted and gadolinium-enhanced brain MRI is an excellent tool for short-term exploratory trials of new agents where it serves as the primary end point; in particular, failure to demonstrate a reduction in lesion activity avoids the time, cost, and risks of a larger clinical end point study. However, conventional MRI findings have a limited correlation with disability in established MS. The primary end point of a definitive trial should therefore be clinical, although serial MRI at 6- to 12-month intervals is a useful secondary end point in providing an index of pathological progression. In trials of patients presenting with clinically isolated syndromes suggestive of MS, MRI findings can be used in the entry criteria, and as a secondary outcome measure, but conversion to clinically definite MS should be the primary outcome. The pathological substrates of irreversible disability are demyelination and axonal loss. Putative magnetic resonance markers for these processes include decreased N-acetylaspartate on proton magnetic resonance spectroscopy, decreased magnetization transfer ratios, hypointensity on T1-weighted images, and loss of short T2 water fractions, some of which relate more closely to disability than conventional MRI findings. Further technical developments should lead to more accurate quantitation, greater pathological specificity, and stronger clinical correlations.

Comparison of triple dose versus standard dose gadolinium-DTPA for detection of MRI enhancing lesions in patients with primary progressive multiple sclerosis

This study was performed to evaluate whether a triple dose of gadolinium-DTPA (Gd-DTPA) increases the sensitivity of brain MRI for detecting enhancing lesions in patients with primary progressive multiple sclerosis (PPMS). T1 weighted brain MRI was obtained for 10 patients with PPMS in two sessions. In the first session, one scan was obtained five to seven minutes after the injection of 0.1 mmol/kg Gd-DTPA (standard dose). In the second session, six to 24 hours later, one scan before and two scans five to seven minutes and one hour after the injection of 0.3 mmol/kg Gd-DTPA (triple dose) were obtained. Four enhancing lesions were detected in two patients when the standard dose of Gd-DTPA was used. The numbers of enhancing lesions increased to 13 and the numbers of patients with such lesions to five when the triple dose of Gd-DTPA was used and to 14 and six in the one hour delayed scans. The mean contrast ratio for enhancing lesions detected with the triple dose of Gd-DTPA was higher than those for lesions present in both the standard dose (P < 0.0009) and the one hour delayed scans (P = 0.04). These data indicate that with a triple dose of Gd-DTPA many more enhancing lesions can be detected in patients with PPMS. This is important both for planning clinical trials and for detecting the presence of inflammation in vivo in the lesions of such patients.

Magnetisation transfer ratios and transverse magnetisation decay curves in optic neuritis: correlation with clinical findings and electrophysiology

Conventional MRI sequences do not permit the distinction between the different pathological characteristics (oedema, demyelination, gliosis, axonal loss) of the multiple sclerosis plaque. Magnetisation transfer imaging and transverse magnetisation decay curve (tMDC) analysis may be more specific. These techniques have been applied to the optic nerves in 20 patients with optic neuritis and the results correlated with clinical and visual evoked potential (VEP) findings. tMDC analysis failed to identify separate intracellular and extracellular water compartments within the optic nerve but gave a measure of transverse relaxation time (T2) without the confounding effects of CSF in the nerve sheath. Both T2 and magnetisation transfer ratio (MTR) were abnormal after an episode of optic neuritis. T2 did not correlate with visual function or with VEP latency or amplitude. There was a significant correlation between MTR reduction and prolongation of VEP latency: this increased latency may reflect an effect of myelin loss on MTR. Longer lesions were associated with worse visual outcome, implying that the overall extent of pathological involvement is likely to influence the degree of functional deficit.

Cobalt-55 positron emission tomography in relapsing-progressive multiple sclerosis

Multiple sclerosis (MS) is an immune-mediated disease of the white matter in the brain that can have a progressive course. However, the progression of relapsing-remitting (RR) MS into relapsing-progressive (RP) MS might represent a more fundamental change in disease activity, i.e. decay of vulnerable neurons and oligodendrocytes. In RP-MS, this may imply that the major loss of brain tissue structure is caused by a combination of demyelination and cellular loss, both of which are likely to cause disability in MS. We used the PET isotope cobalt-55 (Co) as a calcium (Ca) tracer to visualize brain tissue damage, based on the fact that Ca influx is essential in both cell death and T-lymphocyte activation in MS. The aim of this study was to determine whether Co-PET detects any RP-MS lesions and, if so, to assess any correlation with the progression rate (PR) of the disease and with MS lesions as detected by MRI. Seven RP-MS patients (Poser) with EDSS > 4.0 (Kurtzke) and 7 healthy controls underwent MRI (Miller, Barkhof) and Co-PET. Comparison of both image modalities was made by merging. Co-PET lesion frequency was assessed and correlated with the PR of the disease. Co-PET demonstrated significantly more lesions in the MS brain than in the healthy brain, both periventricular and cortical. Every single MRI lesion could be retrieved as a Co-PET lesion. The Co-PET lesion frequency correlated significantly with PR. Our pilot study possibly suggests Co-PET as a tool in estimating disease activity in RP-MS.(ABSTRACT TRUNCATED AT 250 WORDS)

Transitional progressive multiple sclerosis: MRI and MTI findings

Transitional progressive multiple sclerosis (MS) is quite an unusual form of presentation and course of the disease. A case with this progressive form is presented and brain MRI and MTI findings are discussed in relation to the possible insight they may provide for understanding the mechanisms that determine progressive disability in MS.

Circulating adhesion molecules and tumor necrosis factor receptor in multiple sclerosis: correlation with magnetic resonance imaging

Adhesion molecules are important in T-cell trafficking to sites of inflammation. We determined levels of circulating vascular cell adhesion molecule-1 (VCAM-1), L-selectin, and E-selectin in the serum of 147 patients with definite multiple sclerosis of the remitting-relapsing or secondary progressive type. Soluble VCAM-1 and L-selectin concentrations were increased compared to levels in a large group of control subjects. Levels were highest in patients with gadolinium-enhancing lesions on magnetic resonance imaging (VCAM-1: 1,011 +/- 276 vs 626 +/- 87 ng/ml; L-selectin: 1,130 +/- 272 vs 793 +/- 207 ng/ml [mean +/- standard deviation]; p < 0.0001 vs patients without enhancing lesions). Serum levels of soluble tumor necrosis factor receptor (60 kd) were also raised (2.64 +/- 1.23 vs 2.17 +/- 0.69 ng/ml in subjects with other neurological diseases and 2.1 +/- 0.77 ng/ml in healthy control subjects; p < 0.05). Soluble VCAM-1 and L-selectin levels were correlated to concentrations of soluble tumor necrosis factor receptor. In 13 patients with viral encephalitis, similar observations were made. Raised levels of soluble VCAM-1 and L-selectin probably reflect cytokine-induced endothelial cell and T-lymphocyte/monocyte activation occurring in the process of T-cell migration into the central nervous system. Tumor necrosis factor-alpha may be critically involved.

Proton MRS of gadolinium-enhancing MS plaques and metabolic changes in normal-appearing white matter

Localized short echo time (TE = 20 ms), stimulated echo acquisition mode, and double spin echo (TE = 135 ms) proton spectroscopy were performed in clearly defined, acute Gadolinium (Gd)-enhancing multiple sclerosis (MS) plaques of 22 patients with clinically definite MS. The resonances of N-acetylated metabolites (NA), creatine/phosphocreatine (Cr), choline-containing compounds (Cho), glycine/myo-inositol (Ino), and lactate were evaluated. The ratios of NA/Cr and NA/Cho were significantly decreased, Cho/Cr increased, and Ino/Cr remained unchanged. No marker peaks or elevated lactate levels were found. The measured metabolic changes were practically independent of the relative plaque size within the volume of interest (8 ml). Thus, the spectral changes measured with 1H MRS in acute Gd-enhancing MS plaques originate not only from the lesion as depicted by MRI, but also from the surrounding normal-appearing white matter.

Outcomes assessment in multiple sclerosis clinical trials: a critical analysis

The feasibility and precision of clinical trials for the treatment of MS must be improved. Subsequent to the approval by the Food and Drug Administration of the United States of interferon beta-Ib as a safe and effective, though not curative, treatment for relapsing-remitting MS, the testing of other agents in this disease has been undertaken or is anticipated. This report summarises the discussions and recommendations of an international workshop held to review critically the elements of current MS therapeutic trials and to identify the most important aspects of clinical evaluation, study design and data analysis that would allow agents for MS to be tested as accurately, rapidly and economically as possible. While acknowledging the many uncertainties about the pathophysiology and natural history of MS, the workshop participants made recommendations about the preferred components to be used in the design of trials which may be different depending on the treatment goal and agent studied. It was concluded that the formulation of a useful clinical trial design must be based on specific guidelines for clinical scales and imaging for which task forces were recommended and subsequently appointed.

Serial gadolinium-enhanced magnetic resonance imaging in patients with multiple sclerosis treated with mitoxantrone

Serial gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) was used to monitor the effect of mitoxantrone in ten patients with rapidly deteriorating multiple sclerosis (MS). MRI was performed as a baseline and thereafter at 1, 3, 6, 9, 12 and 24 months. The total number of Gd-enhancing lesions diminished from 169 at baseline to 10 after 1 year and to 5 after 2 years. This reduction and the percentage of follow-up MRI studies showing no Gd enhancement were more pronounced than in other MRI studies of the natural course of MS. Measured with quantitative neurological scales, only one patient showed deterioration after 2 years; nevertheless, the changes in MRI were much more marked than those observed clinically. Serial Gd-MRI therefore, seems necessary for documenting efficacy in future therapeutic trials.

Multiple sclerosis therapy. A practical guide

A growing amount of evidence suggests that a disturbance of immunological function is of importance in the pathogenesis of multiple sclerosis. This is reflected in the drugs used to slow progression and to treat relapses. Immunosuppressive drugs such as azathioprine, cyclophosphamide and cyclosporin might have some potential to slow down progression of multiple sclerosis, but their use is limited by potentially serious adverse effects. Recently, it was shown that interferon-beta-1b can diminish the exacerbation rate in multiple sclerosis without leading to unacceptable adverse effects. Nevertheless, symptomatic treatment remains of crucial importance in the management of multiple sclerosis patients. Spasticity, depression, fatigue and urinary, paroxysmal and sensory symptoms can all be alleviated to some extent with pharmacological interventions, although rehabilitation procedures and psychosocial consultations are no less important. Further therapeutic approaches to multiple sclerosis will be directed at either the specificity of the immune response or the grade of activation of the immune response. Magnetic resonance imaging techniques will play an important role in the evaluation of efficacy of new therapeutic agents.

A controlled trial of mitoxantrone in multiple sclerosis: serial MRI evaluation at one year

We present the results of a randomized double-blinded placebo controlled, multicenter trial, of low-dose mitoxantrone (MX), after one year, in 25 patients with relapsing-remitting multiple sclerosis, who had serial enhanced magnetic resonance imaging (MRI). Treatment groups were balanced for age, gender, duration of illness and neurological disability. Five of the 13 MX patients and 10 of the 12 placebo patients had exacerbations during treatment (p < 0.02). The mean change in the extended disability status scale was not significantly different between the MX and placebo treatment groups. Serial Gadolinium-DTPA enhanced MRI detected no significant difference between the MX treated and placebo groups in the mean total number of new, enlarging, or Gadolinium-DTPA enhancing lesions; there was a trend toward a reduction of new, enlarging and Gadolinium-DTPA enhancing lesions in MX patients. Despite this ameliorating effect, the results indicate that serial Gadolinium-DTPA enhanced MRI, performed over one year in a limited number of patients, could not provide conclusive evidence for a role of MX therapy in relapsing-remitting multiple sclerosis.

Preliminary evidence from magnetic resonance imaging for reduction in disease activity after lymphocyte depletion in multiple sclerosis

The central nervous system lesions of multiple sclerosis (MS) can be detected by magnetic resonance imaging (MRI) and the initial perivascular inflammatory component is distinguished by the presence of gadolinium enhancement. To assess the effect of systemic lymphocyte depletion on disease activity, seven patients with MS received a 10-day intravenous course of the humanised monoclonal antibody CAMPATH-1H (anti-CDw52). With some variations in the protocol, enhanced cerebral MR images were obtained monthly for 3-4 months before and at least 6 months after treatment. 28 enhancing areas were detected on the first series of 7 scans; 51 additional active lesions were identified on 18 scans before treatment; 15 were detected on 20 scans done over the next 3 months, but only 2 active lesions were seen on 23 scans during follow-up beyond 3 months. The difference in lesion incidence rate before and after treatment varied and the rate ratio was significantly reduced in only three patients. Collectively, in a "meta-analysis", the rate ratios were 0.15 [corrected] (95% CI 0.09-0.24) for all seven patients and 0.24 (0.14-0.42; p < 0.001) with exclusion of the patient whose scanning schedule differed. The effect of CAMPATH-1H on disease activity provides direct, but preliminary, evidence that disease activity in MS depends on the availability of circulating lymphocytes and can be prevented by lymphocyte depletion. It is too early to say anything about the clinical results of treatment with this agent.

A comparison between fast and conventional spin-echo in the detection of multiple sclerosis lesions

Long repetition time (TR) spin-echo (SE) with T2- or proton density weighting is the sequence of choice to detect the brain lesions of multiple sclerosis (MS). Fast spin-echo (FSE) permits the generation of T2-weighted images with similar contrast to SE but in a fraction of the time. We compared the sensitivity of FSE and SE in the detection of the brain lesions of MS. Six patients with clinically definite MS underwent brain imaging with both dual echo (long TR, long and short echo time (TE) SE and dual echo FSE. The SE and FSE images were first reviewed independently and then compared. A total of 404 lesions was detected on SE and 398 on FSE. Slightly more periventricular lesions were detected using SE than FSE (145 vs 127), whereas more posterior cranial fossa lesions were detected by FSE (77 vs 57). With both SE and FSE the short TE images revealed more lesions than the long echo. These results suggest that FSE could replace SE as the long TR sequence of choice in the investigation of MS.

Correlation of magnetization transfer ratio with clinical disability in multiple sclerosis

We performed spin echo magnetic resonance imaging with and without application of an off-resonance saturation pulse in 43 patients with multiple sclerosis (MS), 10 age-matched controls, and 4 elderly asymptomatic patients with the radiological diagnosis of small-vessel disease. Magnetization transfer (MT) ratio images were obtained from these. All MS subgroups (primary progressive, secondary progressive, benign, early relapsing-remitting) showed significantly lower average lesion MT ratios than small-vessel disease patients. Secondary progressive MS patients showed significantly lower lesion MT ratios than those with benign disease, and there was an inverse correlation of disability with average lesion MT ratio. The degree of reduction of MT ratios is an indicator of the extent of tissue destruction. Thus, reduced MT ratios in MS may provide an indication of the degree of demyelination and axonal loss, both of which are likely to cause functional deficits in MS. We conclude that MT measurement is (1) a robust quantitative method that may increase the pathological specificity of magnetic resonance imaging, (2) has the potential to differentiate demyelination in MS from less destructive pathological changes, and (3) may be useful in monitoring modifications in tissue structure brought about by treatment.

Limited duration of the effect of methylprednisolone on changes on MRI in multiple sclerosis

Treatment with methylprednisolone reduces the duration and severity of clinical relapses in multiple sclerosis (MS), while reducing the number of gadolinium-enhancing lesions on T1-weighted MRI. We performed serial MRI imaging after methylprednisolone treatment to see whether suppression of enhancement persists and whether related abnormalities on T2-weighted images disappear at follow-up. Thirteen patients with definite MS received a total of 31 courses of methylprednisolone over an average period of 50 weeks. Gadolinium-enhanced MRI was obtained before and after treatment, then at monthly intervals, using a standardised repositioning and imaging protocol. Two experienced readers in conference defined the number of active (gadolinium-enhancing and new or enlarging nonenhancing) lesions. We detected 609 active lesions on 195 examinations. Directly after treatment the reduction in the number of enhancing lesions was 78%, indicating restoration of the BBB and suppression of inflammation. It was uncommon for a lesion which stopped enhancing to show enhancement on a subsequent examination. No beneficial effect was observed on the rate of disappearance of related abnormalities on T2-weighted images, indicating persistent change such as oedema, cellular infiltration or demyelination. Moreover, in 89% of cases, an increase in the number of active lesions was observed before new clinical activity, if any, was observed (on average 52% earlier). MRI enabled us to demonstrate that the duration of the effect of methylprednisolone treatment is temporary (on average 9.7 weeks).

Computer-assisted identification and quantification of multiple sclerosis lesions in MR imaging volumes in the brain

Magnetic resonance (MR) imaging is the principal imaging technique for the diagnosis of multiple sclerosis (MS). However, quantifying the number and extent of lesions on MR images manually is arduous. The authors have developed a computerized three-dimensional (3D) quantitative system to assist in the identification and analysis of MS lesions in proton-density (PD)- and T2-weighted volumes of the head. The system provides intuitive, interactive operations that allow flexible extraction of information from the data. Use of the system to analyze MR examinations of a phantom containing regular "lesions" showed that accurate (average error, < 0.21 cm3) and precise (10% or better for lesions > 1 cm3) measurements of objects less than 7 cm3 is possible, and that an estimate of the quantization error predicted the uncertainty in the volume. Analysis of four MR examinations of a chronic-progressive MS patient conducted over an 18-month period was performed. A two-dimensional histogram showing the frequency of voxels with particular PD- and T2-weighted intensities revealed a distinct cluster only in histograms of sections that contained lesions. Measurements and 3D volume rendering of lesions clearly showed changes in lesion shape, position, and size.

Magnetic resonance imaging in monitoring the treatment of multiple sclerosis patients: statistical power of parallel-groups and crossover designs

Serial brain magnetic resonance (MR) imaging detects active lesions 5-10 times more frequently than the occurrence of clinical changes in patients with early relapsing-remitting and secondary progressive multiple sclerosis (MS). Based on monthly unenhanced and gadolinium enhanced MR findings in 23 unselected and untreated patients, the power of an MS treatment trial was calculated, using MR imaging activity as the primary measure of outcome. It was shown that a 80% reduction in the number of active lesions (i.e. an efficacy of 80%) should be detected using a placebo-controlled parallel-groups design with a power of 80%, if either 2 x 20 patients are scanned monthly for 4 months, or 2 x 30 patients monthly for 2 months. Short to medium term studies of new experimental treatments in MS, using MR imaging as the primary outcome measure, provide considerable statistical power in small patient populations studied over a short period of time.

A placebo-controlled trial of isoprinosine in patients with multiple sclerosis

Isoprinosine was used under double-blind, randomised, and placebo-controlled conditions in 52 patients with relapsing/remitting or progressive multiple sclerosis. All patients received pulsed treatment with methylprednisolone. There was no significant effect of treatment on clinical disability or the accumulation of MRI abnormalities, after correction of results for multiple comparisons. It is concluded that isoprinosine is not effective therapy for multiple sclerosis.

Total lymphoid irradiation in multiple sclerosis

Following a report of the efficacy of total lymphoid irradiation (TLI) in the treatment of chronic progressive multiple sclerosis a further randomised double-blind placebo-controlled study was undertaken with the intention of entering 56 patients. In the event it was possible to recruit only 27 patients in a 2.5 year period. Three patients received active treatment openly and 24 were randomised to either active (14) or sham (10) treatment. Treatment was 1980 cGy to the lymphoid system and spleen or sham treatment after full simulation. The primary outcome measure was a comparison of the mean rates of change between treatment groups on the expanded Kurtzke disability scale (EDSS) over the two year follow up period. Patients were also assessed on other clinical outcome measures, psychometry, and serial MRI of the brain. Active treatment resulted in a profound and prolonged fall in T lymphocytes especially those with the CD4 marker and a reversal in CD4:CD8 ratio. No significant benefit was demonstrated on the rate of clinical disease progression (EDSS). A small but significant benefit was found on a score of bladder function. No significant benefit was demonstrated on other clinical or psychometric indices or on subjective visual analogue scales. There was a small but significant difference in the rate of accumulation of lesions on brain MRI favouring the treatment group. The treated group had a higher incidence of clinically relevant side effects, notably amenorrhoea and infections: three deaths (one in the TLI group, two in the sham treated group) occurred. A post hoc calculation indicates that the study had a possible 35% risk of a false negative result using the principal outcome measure. The study fails to confirm the previously reported clinical benefit of TLI although there may be a minor benefit on disease progression as indicated by MRI lesion counts. It is concluded that TLI cannot be recommended for the routine treatment of chronic progressive multiple sclerosis but the beneficial effect on MRI lesions, though modest, suggests that further research into immune modulation of this condition may be worthwhile.

Magnetic resonance in monitoring the treatment of multiple sclerosis

Magnetic resonance imaging (MRI) is increasingly being used as a measure of pathological disease activity in monitoring the efficacy of potential new treatments for multiple sclerosis. A major advantage of MRI over clinical monitoring is that it detects a large amount of subclinical disease activity. The two main approaches to MRI are detecting active lesions and measuring total lesion load. In relapsing-remitting and secondary-progressive multiple sclerosis, gadolinium enhancement increases the number of detectable active lesions and also probably correlates with pathological activity. Total brain-lesion load can be measured from computerized images, either by manual outlining of lesions or by more fully automated lesion-segmentation strategies. An important limitation of MRI monitoring is that conventional brain MRI abnormalities often show little or no relationship with clinical disability. One explanation for this may be pathological heterogeneity of lesions that all look the same on a conventional image. Other MR techniques are needed that specifically identify the pathological features most likely to result in disability, namely demyelination and axonal loss. Magnetization transfer imaging and proton MR spectroscopy are two techniques that show promise in this regard.

Serial contrast-enhanced magnetic resonance imaging in patients with early relapsing-remitting multiple sclerosis: implications for treatment trials

Serial monthly contrast-enhanced MRIs were performed in 10 early relapsing-remitting patients with multiple sclerosis and 2 patients with chronic progressive disease for a period of 12 to 55 months. MRI was performed at 1.5 T using contiguous 5-mm slices with pre- and postgadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) T1-weighted and T2-weighted images. New and total number of Gd-DTPA-enhancing lesions were numbered and counted and lesion areas were correlated to an increase of > or = 0.5 in Expanded Disability Status Scale (EDSS) scores. The frequency of enhancing lesions varied from patient to patient; however, there was a correlation between a burst of enhancing lesion number and area above the individual's mean lesion frequency to an increase in EDSS score. A bootstrap analysis of the lesion count was performed to develop a statistical basis for determining population sizes for treatment trials. These results provide a basis for the potential use of contrast-enhanced MRI as a primary outcome measure in phase II treatment trials involving patients with relapsing-remitting MS.

Magnetic resonance imaging investigation of blood-brain barrier damage in adoptive transfer experimental autoimmune encephalomyelitis

Recent advances in fast magnetic resonance imaging (MRI) techniques have allowed quantification of parameters such as T1 relaxation time, which can be modified by changes in the water content of a tissue. We have used this new method to study the evolution of blood-brain barrier (BBB) changes after adoptive transfer of MBP-specific (AT-EAE) and ovalbumin-specific T cell lines in Lewis rats. Measurable changes in T1 relaxation time suggesting widespread increase in BBB permeability were found, starting on day 3 post inoculation (p.i.), in the midbrain and brainstem of AT-EAE rats. In addition, we noted a significant decrease in T1 relaxation time before injection of a paramagnetic agent, in the cisternal cerebrospinal fluid (CSF) of diseased animals, starting on day 5 p.i. In vitro measurement of T1 in CSF containing various concentrations of albumin, IgM and glucose showed that, at physiological concentrations, a T1 decrease is mainly associated with an increase in albumin concentration. A moderate increase in BBB and blood-CSF barrier permeability was found as early as 4-8 h p.i., in rats injected with MBP-specific as in animals injected with ovalbumin-specific T cell lines, suggesting a non-specific mechanism. Experimental MRI may become a powerful tool to sequentially analyse changes in barrier dynamics, for example following pharmacological intervention.

4-Aminopyridine induces functional improvement in multiple sclerosis patients: a neurophysiological study

This study reports on the neurophysiological measurements that were performed in the context of a randomized, double-blind, placebo-controlled, cross-over study with intravenously administered 4-aminopyridine (4-AP) in 70 patients with definite multiple sclerosis (MS). A beneficial effect of 4-AP was found for both visual evoked response and eye movement registration parameters. This study extends the experimental data obtained on animal nerve fibers, showing that 4-AP can improve impulse conduction in demyelinated nerve, to clinical data which indicate that 4-AP induces an objective improvement in the central nervous system function in MS-patients. It thereby also provides a theoretical basis for clinical efficacy of 4-AP in MS.

Clinical worsening in multiple sclerosis is associated with increased frequency and area of gadopentetate dimeglumine-enhancing magnetic resonance imaging lesions

It is now well established that clinically stable patients with relapsing-remitting multiple sclerosis have ongoing disease activity when evaluated by serial gadolinium-enhanced (Gd-DTPA) magnetic resonance imaging (MRI) scans. Despite this, the relationship between clinical disease and MRI lesions, though suspected, has not been extensively documented. The relationship between Gd-DTPA MRI lesions and clinical disease was examined in this study of 9 patients with mild relapsing-remitting multiple sclerosis (Expanded Disability Status Scale [EDSS] < 3.5) who had 24 to 37 monthly Gd-DTPA MRI scans, neurological examinations, and EDSS score assignments. The area and frequency of Gd-DTPA lesions were examined during months with and without clinical worsening as measured by EDSS. Forty-one episodes of clinical worsening were noted during the study. A significant association was observed between these periods of clinical worsening and MRI parameters, including increases in total number, number of new lesions, and the total area of enhancement. Logistic regression analysis showed a significant effect of the number and area of Gd-DTPA MRI lesions on both the onset and continuation of clinical worsening, confirming an important relationship between clinical disease and an increase in cerebral Gd-DTPA MRI activity. A relationship with long-term disability was suggested, but cannot be confirmed without longer follow-up of these patients.

The current therapy of multiple sclerosis

The mainstay of treatment for multiple sclerosis in the U.K., and worldwide, remains corticosteroid therapy. High-dose pulses of intravenous methylprednisolone is currently the most favoured agent for acute exacerbations or a sudden acceleration in clinical course. Many patients who follow a more insidious decline rely on symptomatic treatments designed to ameliorate the chronic symptoms associated with their condition. Attempts to influence disease progression using a wide range of immune-modulating agents have not to date been of sufficient clinical benefit to justify their routine usage. With increasing understanding of the underlying disease mechanisms future treatments are being more specifically directed toward disease prevention.

Database for serial magnetic resonance imaging in multiple sclerosis

The unique sensitivity of magnetic resonance imaging (MRI) in detecting disease activity in multiple sclerosis (MS) and the objective nature of the information obtained suggest that MRI will be a useful and reliable way of monitoring treatment trials. There is a need to develop an appropriate database which would provide a standardised means of assessment, not only of MRI, but also of essential clinical information. As part of the program of Concerted Action in Multiple Sclerosis, funded by the Commission of the European Community (CEC), we have developed a database for recording serial brain MRI results. The database consists of core, entry and follow-up sections. Both entry and follow-up parts are subdivided into clinical, MR system and MRI data. We expect that the use of this database will maximise efficiency of MRI monitoring in MS treatment trials, particularly in multicentre studies.

The dynamics of multiple sclerosis. The Charcot Lecture

The history of our understanding of the pathogenesis and pathophysiology of multiple sclerosis are reviewed in the context of Charcot's contribution. The implications for treatment of the new knowledge gained from studies during life of pathology and pathogenesis (by MRI) and pathophysiology (by evoked potentials) are reviewed.