Long-term effects of intravenous high dose methylprednisolone pulses on bone mineral density in patients with multiple sclerosis

To determine the effects of high dose methylprednisolone (HDMP) pulses on bone mineral density (BMD) in patients with multiple sclerosis (MS), we studied 25 MS patients who received regular pulses of HDMP as well as pulses of HDMP for relapses, 18 MS patients who received HDMP at the same dose schedule only for relapses, and 61 healthy controls. We measured BMDs at lumbar spine and femoral neck and we assessed biochemical markers of bone metabolism and turnover. The average lifetime dosage of MP was 75.4 (SD 11.9) g in the pulsed HDMP group and 28.6 (SD 18.3) g in the HDMP for relapses group (P < 0.0001). Two MS patients (4.7%) and four controls (6.6%) had osteoporosis (P = NS), whereas 25 patients with MS (58.1%) and 21 controls (34.4%) had osteopenia (P = 0.016). BMDs measured at lumbar spine and femoral neck and biochemical indices of bone metabolism did not differ in MS patients and controls. BMD measures were not associated with lifetime methylprednisolone dosage. In partial correlation analysis, controlling for age, gender and menopausal status there was a significant inverse correlation between BMD at femoral neck and Expanded Disability Status Scale (EDSS) score (r = -0.31, P = 0.05). In conclusion, treatment with repeated HDMP pulses was not associated with osteoporosis in patients with MS who participated in a trial of methylprednisolone. However, osteopenia was observed more frequently in MS patients than healthy controls. Our data are reassuring, as them suggest that repeated pulses of methylprednisolone do not result in substantially increased risk of osteoporosis in MS patients. Moreover, osteopenia was found only in patients treated for relapses, who had a significantly higher EDSS score than patients in the HDMP group, suggesting that decreased mobility may contribute to bone loss more than corticosteroid use. BMD should be monitored in patients with MS, regardless of the use of methylprednisolone.

Longitudinal single-cell cytokine responses reveal recurrent autoimmune myelin reactivity in relapsing--remitting multiple sclerosis patients

The relationship between multiple sclerosis (MS) disease activity and myelin protein-induced cytokine responses over time is not elucidated. We addressed this relationship by examining longitudinal cytokine responses to myelin proteins every three months for one year, in the context of gadolinium (gad)-enhancing brain lesions and of clinical relapses. The ELISPOT assay was used to determine the ex vivo cytokine production in response to nine amino acid long peptides spanning the entire proteolipid protein (PLP) and myelin basic protein (MBP) molecules in relapsing-remitting (RR) MS patients and matched healthy controls. We identified three longitudinal levels of myelin-induced cytokine secretion by adding up the positive responses for all PLP or MBP peptides obtained for five timepoints, at three-month intervals: low reactivity (< 200 cumulative cytokine-secreting cells), isolated peptide reactivity (201-450 cumulative cytokine-secreting cells) and recurrent protein-wide bursts of cytokine reactivity (> 451 cumulative cytokine-secreting cells). The majority of MS patients showed recurrent bursts to PLP and MBP. In contrast, controls showed a more even distribution between all levels of cytokine reactivity. The majority of patients with gad-enhancing lesions showed PLP/IFN gamma and MBP/IFN gamma recurrent burst responses. This is the first longitudinal study on MS patients in which nine amino acid long myelin peptides are used to reveal the broad range of PLP- and MBP-peptide cytokine reactivity across the whole molecule of these two major myelin proteins. This study also reveals the extremely dynamic nature of the immune reactivity to numerous regions of myelin, which can fluctuate dramatically over time. Such fluctuation could hamper the efficacy of antigen-based therapies for MS.

Association of fatigue and brain atrophy in multiple sclerosis

Functional imaging studies have demonstrated a relationship between fatigue and altered cerebral activation patterns in multiple sclerosis patients, but no relationship between fatigue and brain atrophy has been demonstrated. We hypothesized that the subjective complaint of fatigue would predict the severity of destructive brain pathology. We assessed the relationship between fatigue and brain atrophy longitudinally in a cohort of 134 patients previously enrolled in a 2-year clinical trial of interferon beta-1a and re-evaluated 8 years after randomization into the trial. Brain atrophy was measured using the brain parenchymal fraction (BPF), and disability was measured using the Multiple Sclerosis Functional Composite at baseline, year 2 and year 8. Fatigue was measured using the Sickness Impact Profile's Sleep and Rest Scale (SIPSR) at baseline, year 2 and year 8. Linear regression analyses were used to assess the relationship between changes in fatigue and atrophy progression. Worsening fatigue on the SIPSR during the initial 2 years was significantly associated with progressive brain atrophy over the subsequent 6 years. The relationships between fatigue and brain atrophy were independent of changes in disability, mood, or other MRI characteristics. This suggests that the subjective complaint of fatigue is linked to destructive pathologic processes in RRMS patients.

Primary progressive multiple sclerosis as a phenotype of a PLP1 gene mutation

We report a 49-year-old woman with a history of progressive gait disturbance, white matter disease, and cerebrospinal fluid immunoglobulin abnormalities who met criteria for primary progressive multiple sclerosis and whose son died at age 10 years of an unknown congenital neurodevelopmental disorder. Sequencing of the proteolipid protein 1 gene showed a novel mutation, Leu30Arg (c.89TG), in the mother and son. Pelizaeus-Merzbacher disease is the cause of death in the son and explains the mother's adult-onset neurological disorder. This case goes against dogma that mothers of severely affected sons are asymptomatic as adults and expands the differential diagnosis of primary progressive multiple sclerosis to include proteolipid protein 1 gene mutations.

Impact of Disease-Modifying Therapies on Brain and Spinal Cord Atrophy in Multiple Sclerosis

Brain and spinal cord atrophy occur early in the course of multiple sclerosis (MS) and continue throughout this lifelong illness, resulting in substantial parenchymal tissue loss at later disease stages. Treatments that slow or prevent atrophy may reduce disability progression in the long term. Disease-modifying agents (DMAs) such as interferon beta-1b (IFNbeta-1b), IFNbeta-1a, and glatiramer acetate inhibit inflammatory events believed to initiate and perpetuate the disease process. DMAs have been shown to inhibit aspects of MS related to brain inflammation such as relapses and gadolinium-enhanced lesions. Because brain inflammation has been linked to irreversible brain tissue injury, DMAs should be effective in reducing the rate of brain atrophy progression. Weekly IFNbeta-1a (Avonex or Rebif) has been shown to slow the rate of brain atrophy; a large study of a frequent injection regimen with IFNbeta-1a (Rebif) showed continued atrophy progression despite IFNbeta-1a at a rate similar to placebo-treated patients. It is not clear why weekly treatment regimens with lower total doses of IFNbeta-1a would show beneficial effects on brain atrophy compared with frequent injections with larger weekly doses. This article reviews results of clinical trials that have examined the effects of DMAs on brain and spinal cord atrophy in patients with MS. Some of these agents have demonstrated positive effects in well-controlled studies, suggesting that anti-inflammatory therapy can delay or prevent the emergence of irreversible central nervous system pathology.

Defining interferon ? response status in multiple sclerosis patients

IFN-beta is effective in reducing relapses and magnetic resonance imaging (MRI) lesions in multiple sclerosis (MS). It is assumed that individual therapeutic responses vary, but methods to identify IFN-beta responsiveness have not been validated. Our objective was to evaluate methods to classify IFN-beta responder status using relapses and MRI lesions. Data was analyzed from 172 patients who were followed up in a placebo-controlled clinical trial of IFN-beta1a for 2 years. Patients were classified as responders or nonresponders using (1) the number of relapses during the 2-year trial; (2) the number of new T2 lesions after 2 years; and (3) the number of gadolinium-enhancing lesions at year 1 and year 2 on study. Outcomes included 2-year change in the Expanded Disability Status Scale, Multiple Sclerosis Functional Composite, and brain parenchymal fraction. We found that subgroups with high on-study relapse numbers had more disease progression, differences between responder subgroups were similar in the IFN-beta1a and placebo arms. In contrast, subgroups with high numbers of new MRI lesions had significantly more disease progression only in the IFN-beta1a arm. Baseline characteristics failed to account for differential outcome. New MRI lesion activity during IFN-beta1a treatment correlates with poor response to IFN-beta1a. MRI classification may facilitate rational therapeutic decisions, better clinical trial designs, and studies correlating biomarkers with therapeutic response.

Atrophy Is Detectable Within a 3-Month Period in Untreated Patients With Active Relapsing Remitting Multiple Sclerosis

BACKGROUND

Atrophy is recognized as a measure of destructive changes in multiple sclerosis (MS). The time course and pathologic mechanisms of atrophy development are not well understood. Significant atrophy was reported to occur within 9 to 12 months in relapsing remitting MS.

OBJECTIVES

To test whether atrophy can be detected over short time intervals, and to evaluate its relationship to inflammation.

DESIGN AND METHODS

Prior to randomization to a treatment trial, 138 untreated patients with relapsing remitting MS had 3 magnetic resonance imaging scans within a mean +/- SD follow-up of 76 +/- 20.2 days. Brain parenchymal fraction (BPF), a normalized measure of whole brain volume, the proportion of active (gadolinium-enhancing) scans, and the volume of T1-weighted gadolinium-enhancing and T2-weighted hyperintense lesions were determined at all time points. An annualized atrophy rate was estimated by calculating a regression slope.

RESULTS

The median Expanded Disability Status Scale score was 3.5, the mean disease duration was 7.6, and the mean age was 38.5 years. The BPF decreased significantly by -0.229% from scan 1 to scan 3, while the proportion of active scans remained high (65%, 63%, and 67%). The BPF change was only weakly correlated to the volume of T1-weighted gadolinium-enhancing lesions in scan 1 (r = -0.185). The estimated annualized atrophy rate was -1.06% (95% confidence interval, -1.50% to -0.62%).

CONCLUSIONS

The annualized atrophy rate found in this study is comparable with rates reported previously. Measurements of BPF allow detection of atrophy over short time intervals in active disease. The short-term relationship of inflammation to atrophy development was weak. Brain parenchymal fraction might be a promising measure in future phase 2 studies of agents, with an expected effect on tissue-destructive pathologic mechanisms of MS.

Biologic impact of interferon antibodies, and complexities in assessing their clinical significance

The relevance of neutralizing antibodies (NAb) to interferon-beta (IFNbeta) for patients with MS treated with IFNbeta injections has been controversial. Published data from several double-blind, randomized clinical trials demonstrate that disease activity in IFNbeta-treated patients with MS is similar to placebo-treated patients within the same study. This observation is easily understood by other studies that demonstrate attenuation of the biologic response to IFNbeta injections in patients who are NAb positive. Because of the period over which antibodies develop, however, studies will demonstrate an impact of IFNbeta NAb only after the initial 18 months of therapy. Further, because the effects of IFNbeta on MS disease activity and progression are partial, large sample sizes are required to demonstrate clinical correlates of NAb. Therapeutic decisions related to disease management for patients with MS must consider IFNbeta NAb.

Interferon gamma responses to myelin peptides in multiple sclerosis correlate with a new clinical measure of disease progression

The relationship between autoreactivity to myelin antigens and disease progression in multiple sclerosis (MS) is not fully understood. We addressed this relationship by cross-sectionally comparing an objective measure of MS disability with immune cytokine responses to myelin proteins. The ELISPOT assay was used to determine the ex vivo interferon gamma (IFNgamma) and interleukin-10 (IL-10) production by peripheral blood mononuclear cells (PBMCs) in response to peptides spanning the entire proteolipid protein (PLP) and myelin basic protein (MBP) molecules in 20 patients with relapsing-remitting (RR) MS and 27 age- and sex-matched healthy controls. MS patients showed significantly higher MBP-induced IFNgamma responses and PLP-induced IL-10 responses compared with healthy controls. Using the Multiple Sclerosis Functional Composite (MSFC), a new multifactorial measure of disability, MS patients showed a significant correlation between the IFNgamma response to PLP peptides and MBP peptides, and disability. In contrast, in MS patients, there was no correlation between the MSFC and the response to unrelated control antigens or mitogens. These data show that myelin-specific T lymphocytes secreting the inflammatory cytokine IFNgamma correlate with functional impairment in MS, supporting an antigen-specific link between the immune response to myelin and disability in MS.

Interferon-beta 1a does not reduce expression of CCR5 and CXCR3 on circulating T cells

The expression of CCR5 and CXCR3, two chemokine receptors involved with homing of T cells to inflamed tissue, was examined longitudinally on CD4+ and CD8+ T cells in patients with a first demyelinating event of the central nervous system (CNS) randomized to receive i.m. injections of interferon-beta1a (IFN-beta1a) or placebo. Blood for analysis was collected before and 48 h after injection at baseline and after 3 and 12 months of treatment. The results showed that treatment with IFN-beta1a did not affect numbers of T cells expressing CCR5 and CXCR3 during the first 12 months of treatment, either at the peak of biological response or at the trough of interferon effect, at steady-state.

Expression of CCR2, CCR5, and CXCR3 by CD4+ T cells is stable during a 2-year longitudinal study but varies widely between individuals

Blockade of chemokine receptors (CKRs) has recently emerged as a possible pathway for therapeutic intervention in disease. In the present report, the expression of CCR2, CCR5, and CXCR3, associated with migration of mononuclear cells to inflamed tissue, was determined on CD4+ T cells in a 2-year longitudinal study of healthy volunteers using flow cytometry. Large interindividual variations in the expression of these receptors on CD4+ T cells were observed, whereas levels remained remarkably stable over time within subjects. The expression of CCR2, CCR5, and CXCR3 on CD4+ T cells was directly proportional to percentages of CD45RO(hi)/CD4+ T cells. In addition, highly significant associations between levels of CCR2, CCR5, and CXCR3 on CD4+ T cells were demonstrated in individual subjects, implying a common mechanism for regulating the expression of these CKRs on circulating T cells. These associations were not due to coexpression of CKRs on individual CD45RA-/CD4+ T cells. The results provide insight into the regulation of CKR expression on CD4+ T cells in vivo, and suggest that major fluctuations of CKR expression in individuals are uncommon.

Flow cytometric analysis of chemokine receptor expression on cerebrospinal fluid leukocytes

Collection of cerebrospinal fluid (CSF) from the lumbar subarachnoid space is a routine procedure in clinical neurology, providing an opportunity to obtain hematogenous cells from the central nervous system environment in vivo. The ability to study individual cells in samples with low cell numbers has made flow cytometry an attractive method for studies of chemokine receptor expression on such cells. Several methodological variables such as staining temperature and cell isolation techniques may, however, influence the final outcome of the staining. In addition, low numbers of cells in the normal lumbar CSF, together with a tendency of CSF cells to decay rapidly after sampling, require meticulous handling of the samples. Here, we describe the methodology used in our laboratory to study chemokine receptor expression on cells in paired samples from peripheral blood and CSF using flow cytometry.

Factors that predict health-related quality of life in patients with relapsing-remitting multiple sclerosis

Health-Related Quality of Life (HRQoL) research is gaining acceptance in the field of multiple sclerosis (MS). Little is known about what precipitates quality of life change. It was hypothesized that physical aspects of quality of life decline with worsening objective disease measures and psychosocial aspects remain relatively stable regardless of change in objective measures. These assumptions are tested using data from a Phase 3 study of relapsing-remitting MS patients treated with interferon beta-1a and reassessed approximately eight years after study initiation. The Sickness Impact Profile (SIP) questionnaire is the generic quality of life measure used in this study. Three summary scores of the SIP (Physical, Psychosocial, and Total scores), Expanded Disability Status Scores, Multiple Sclerosis Functional Composite, and Brain Parenchymal Fraction were determined at baseline, year 2, and after an average of 8.1 years from study entry. SIP data collected during a clinic visit were available from 137 of the original 172 participants. All objective indicators worsened by follow-up. SIP Physical and Total scores significantly worsened from baseline to follow-up. SIP Psychosocial showed nonsignificant worsening. Regression analysis indicated that final measures of SIP Physical and Total scores were most strongly associated with change in objective measures and follow-up SIP Psychosocial was most strongly related to earlier scores on the same measure.

Eight-year follow-up study of brain atrophy in patients with MS

OBJECTIVE

To characterize whole-brain atrophy in relapsing-remitting MS (RRMS) patients over an 8-year period. The specific goals of this study were to determine if brain atrophy is related to subsequent disability status and to identify MRI correlates of atrophy progression.

METHODS

A follow-up study was conducted to reassess patients from a phase III trial of interferon beta-1a (IFNbeta-1a) 8 years after randomization. Clinical and MRI data from 172 patients followed over 2 years in the original trial were used as baseline data. Follow-up data were obtained on 160 patients, including 134 patients with follow-up MRI examinations. Brain atrophy was estimated by automated calculation of brain parenchymal fraction. The relation between atrophy during the original trial and disability status at follow-up was determined. Correlations were also determined between lesion measurements from the original trial and the brain parenchymal fraction at follow-up.

RESULTS

Brain atrophy was correlated with subsequent disability status. Atrophy rate during the original trial was the most significant MRI predictor of disability status at follow-up. Brain atrophy at follow-up was related to lesion volumes measured during the original trial.

CONCLUSIONS

The relation between atrophy progression and subsequent neurologic disability status suggests that atrophy progression during RRMS is clinically relevant. Therefore, atrophy progression may be a useful marker for disease progression in clinical trials. The relation between lesions and subsequent atrophy indicates that brain atrophy may be related to focal tissue damage at earlier points in time, but important predisposing or other factors contributing to atrophy remain undefined.

The multiple sclerosis functional composite: a new clinical outcome measure for multiple sderosis trials

With the advent and widespread use of partially effective disease modifying drug therapies for multiple sderosis (MS), future dinical trials will undoubtedly test experimental interventions against standard therapy, or will test combinations of drugs against standard therapy. In either case, incremental progress in slowing disability progression in future MS dinical trials will require much larger sample sizes, more sensitive outcome measures, or a combination of the two. Because improved dinical outcome methods would likely accelerate progress in MS therapeutics, the National Multiple Sclerosis Society (NMSS) convened an international task force in 1994 to recommend improved clinical outcome measures. As the result of a two-year process of discussion and data analysis, the task force recommended the Multiple Sderosis Functional Composite (MSFC) as a new clinical outcome measure for future MS trials. MSFC consists of timed tests of walking, arm function, and cognitive function, expressed as a single score along a continuous scale. The task force recommended that MSFC be induded in future MS trials, and recommended a series of validation studies. Subsequent studies have provided evidence that MSFC correlates moderately with Expanded Disability Status Scale (EDSS), and that correlation is driven by strong correlations with the ambulatory function component; arm function and cognitive function correlate at lower levels with EDSS. The MSFC correlates better than EDSS with magnetic resonance imaging (MRI) variables, including brain atrophy, and shows significant correlation with patient-reported disease-related quality of life (QOL). MSFC and short-term change in MSFC correlate with future clinical and MRI status, and the strength of the correlations compares favorably with well-known cardiovascular risk factors. The studies in aggregate indicate that MSFC and MSFC change are clinically meaningful, and that MSFC has substantial advantages over alternative clinical outcome measures for MS clinical trials.

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

BACKGROUND

Interferon beta-1a (IFNbeta-1a, Avonex) is efficacious in relapsing forms of MS. Studies of other IFNbeta preparations in secondary progressive MS (SPMS) yielded conflicting results. This study was undertaken to determine whether IFNbeta-1a slowed disease progression in SP-MS.

METHODS

A total of 436 subjects with SPMS and Expanded Disability Status Scale (EDSS) score 3.5 to 6.5 were randomized to receive IFNbeta-1a (60 micro g) or placebo by weekly intramuscular injection for 2 years. The primary outcome measure, used for the first time in a large-scale MS trial, was baseline to month 24 change in the MS Functional Composite (MSFC), comprising quantitative tests of ambulation (Timed 25-Foot Walk), arm function (Nine-Hole Peg Test [9HPT]), and cognition (Paced Auditory Serial Addition Test [PASAT]).

RESULTS

Median MSFC Z-score change was reduced 40.4% in IFNbeta-1a subjects (-0.096 vs -0.161 in placebo subjects, p = 0.033), an effect driven mainly by the 9HPT and PASAT. There was no discernible benefit on the EDSS, which in this range principally reflects walking ability. IFNbeta-1a subjects had 33% fewer relapses (p = 0.008). There was significant benefit on eight of 11 MS Quality of Life Inventory subscales. New or enlarging T2-hyperintense brain MRI lesions and gadolinium-enhancing lesions were reduced at months 12 and 24 (both p < 0.001). IFNbeta-1a was well tolerated by the majority of subjects. Neutralizing antibodies developed in 3.3% of IFNbeta-1a-treated subjects.

CONCLUSIONS

IFNbeta-1a demonstrated benefit on MSFC progression, relapses, quality of life, and MRI activity in SPMS.

Sex differences in cytokine responses to myelin peptides in multiple sclerosis

Many autoimmune diseases preferentially affect women; however, the underlying mechanisms for the sex differences are poorly understood. We examined sex-dependent differences in the immunologic response to myelin proteins in 22 multiple sclerosis (MS) patients and 22 healthy controls. Using ELISA spot assay (ELISPOT) methodology, interferon (IFN) gamma and IL-5 secretions were examined at the single cell level in response to overlapping proteolipid protein (PLP) peptides. As previously reported, we observed an overall disease effect in the IFNgamma response, such that MS patients were significantly higher than controls. With respect to PLP-induced IFNgamma secretion, both MS and control females responded higher than their corresponding males. Female MS patients demonstrated the highest responses compared to MS males or healthy controls of either sex. Although MS females had high IFNgamma responses to PLP, they had no IL-5 responses at all, suggesting strong Th1 skewing. In contrast, MS males had more IL-5 than control males, who lacked IL-5 responses. These IL-5 responses suggested that disease and gender are not independent, but rather interact to influence the cytokine response to myelin. The data suggest a gender bias towards Th1 responses in MS, which may contribute to the female predominance in this disease.

T-cells in the cerebrospinal fluid express a similar repertoire of inflammatory chemokine receptors in the absence or presence of CNS inflammation: implications for CNS trafficking

It is believed that chemokines and their receptors are involved in trafficking of T-cells to the central nervous system (CNS). The aim of the current study was to define the expression on cerebrospinal fluid (CSF) T-cells of six chemokine receptors associated with trafficking to sites of inflammation. Flow cytometry was used to detect chemokine receptor expression. We observed that CD3+T-cells in the CSF express a restricted array of inflammatory chemokine receptors, specifically CXCR3, CCR5 and CCR6, but little CCR1-3. This repertoire was independent of the presence of CNS inflammation, since comparable findings were obtained in patients with multiple sclerosis (MS) and individuals with non-inflammatory neurological diseases. The enrichment of CCR5+T-cells in the CSF could largely be explained by higher frequency of CD4+/CD45RO+T-cells in this compartment. In contrast, CD4+/CD45RO+T-cells expressing CXCR3 were significantly enriched in CSF as compared with blood. Similar levels of CCR6+/CD3+T-cells were observed in blood and CSF, while levels of CCR2+/CD3+T-cells were lower in CSF than in blood. The CSF was virtually devoid of CCR5+/CXCR3- T-cells, suggesting that the expression of CCR5 alone is not sufficient for the trafficking of CD3+T-cells to the CSF. We hypothesize that CXCR3 is the principal inflammatory chemokine receptor involved in intrathecal accumulation of T-cells in MS. Through interactions with its ligands, CXCR3 is proposed to mediate retention of T-cells in the inflamed CNS.

Evolving concepts in the pathogenesis of multiple sclerosis and their therapeutic implications

Recent evidence suggests that multiple sclerosis (MS) is a continuously active neuropathologic process, even during the subclinical relapsing/remitting phase of the disease. Patients commonly feel well and function without disability for many years, experiencing only occasional relapses and nondisabling symptoms. In time, many evolve into a pattern of continuously progressive neurologic disability termed secondary progressive MS (SP-MS). SP-MS is hypothesized to occur once disease severity has exceeded a threshold. Above that threshold, compensatory mechanisms are inadequate to maintain normal function, and further disease progression is accompanied by progressively worsening disability. Inflammation dominates the early stage of disease. Progressive axonal pathology may underlie clinical disease progression in later stages. These concepts have important implications related to the diagnosis, methods for patient follow-up, type and timing of disease therapy, and the testing of neuroprotective drugs in MS.

Contemporary immunomodulatory therapy for multiple sclerosis

Multiple sclerosis (MS) is no longer considered an unmanageable disease. Five drugs have obtained regulatory approval to safely and effectively modify the course of MS. Three preparations of interferon beta-Avonex (interferon beta-1a), Betaseron (interferon beta-1b), and Rebif (interferon beta 1a)-have shown efficacy in relapsing-remitting MS and show promise in slowing the course of secondary progressive MS. Glatiramir acetate (Copaxone) has demonstrated efficacy in relapsing-remitting MS, and is being tested for the management of primary progressive disease. Mitoxantrone (Novantrone) has been approved for secondary progressive and progressive relapsing MS. There is a tendency toward early diagnosis and treatment based on the hypothesis that treatment effectiveness declines with advancing disease.

Axonal loss in normal-appearing white matter in a patient with acute MS

BACKGROUND

Brain imaging studies detect abnormalities in normal-appearing white matter in patients with MS.

OBJECTIVE

To investigate the histopathologic basis for these changes in autopsy tissue from a patient with MS with 9 months' disease duration and a terminal brain stem lesion.

METHODS

The brain stem and spinal cord were analyzed ultrastructurally and immunocytochemically for axons, myelin, and activated microglia/macrophages.

RESULTS

Pathologic findings were consistent with a terminal inflammatory demyelinated lesion at the cervicomedullary junction. The ventral spinal cord column, containing descending tracts, exhibited 22% axonal loss at segment C7, but grossly normal immunostaining for myelin. Confocal and electron microscopy revealed myelin sheaths without axonal content and initial stages of myelin degradation by activated microglia/macrophages among intact myelinated axons. Axonal number and appearance was normal in ascending sensory tracts.

CONCLUSIONS

These studies confirm axonal degeneration in the absence of myelin loss as one histopathologic correlate to abnormal MR findings in patients with MS.