Progressive forms of MS: classification streamlined or consensus overturned?

Multi-Platform Characterization of Cerebrospinal Fluid and Serum Metabolome of Patients Affected by Relapsing-Remitting and Primary Progressive Multiple Sclerosis

Background: Multiple sclerosis (MS) is a chronic immunemediated disease of the central nervous system with a highly variable clinical presentation and disease progression. In this study, we investigate the metabolomics profile of patients affected by relapsing–remitting MS (RRMS)and primary progressive MS (PPMS), in order to find potential biomarkers to distinguish between the two forms. Methods: Cerebrospinal Fluid CSF and blood samples of 34 patients (RRMS n = 22, PPMS n = 12) were collected. Nuclear magnetic resonance (¹H-NMR) and mass spectrometry (coupled with a gas chromatography and liquid chromatography) were used as analytical techniques. Subsequently, a multivariate statistical analysis was performed; the resulting significant variables underwent U-Mann–Whitney test and correction for multiple comparisons. Receiver Operating Characteristic ROC curves were built and the pathways analysis was conducted. Results: The analysis of the serum and the CSF of the two classes, allowed the identification of several altered metabolites (lipids, biogenic amines, and amino acids). The pathways analysis indicated the following pathways were affected: Glutathione metabolism, nitrogen metabolism, glutamine–glutamate metabolism, arginine–ornithine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis etc. Conclusion: The analysis allowed the identification of a set of metabolites able to classify RRMS and PPMS patients, each of whom express different patterns of metabolites in the two biofluids.

The relation between menarche and the age of first symptoms in a multiple sclerosis cohort

BACKGROUND

Previously, multiple sclerosis (MS) has been thought to be associated with changes in hormone levels. This study investigates the association between the age of menarche and the age of onset of the first symptoms of MS.

METHODS

A complete list of patients diagnosed with MS in the province of Newfoundland and Labrador was constructed. The age of menarche for our entire relapsing remitting female MS (RRMS) population was requested by mailout survey. Age of symptom onset was ascertained by chart review.

RESULTS

A 74% rate of return on the survey results was obtained (150 RRMS patients). A linear regression model demonstrated that the age of first symptoms increased by 1.16 years as the age of menarche increased by one year (R2 = 0.69, P = 0.04). Another analysis showed that the average age of first symptoms for women with reported menarche from 10 to 12 years was 28.96 years compared with 31.83 years for a reported menarche from 13 to 15 years, a significant difference (P = 0.047, t-test).

CONCLUSIONS

This study suggests that menarche may be related to the pathogenesis of MS.

Natural history of multiple sclerosis: a unifying concept

Multiple sclerosis can follow very different patterns of evolution and variable rates of disability accumulation. This raises the issue whether it represents one or several distinct diseases. We assessed demographic and clinical characteristics in 1844 patients with multiple sclerosis that we categorized according to the classification of Lublin and Reingold (1996) into 1066 (58%) relapsing-remitting, 496 (27%) secondary progressive, 109 (6%) progressive relapsing and 173 (9%) primary progressive cases of multiple sclerosis. Relapsing-remitting and secondary progressive cases shared similar age at disease onset (median = 28.7 versus 29.5 years; P = 0.21), initial symptoms of the relapsing-remitting phase, degree of recovery from the first neurological episode, and time from the first to the second episode. By contrast, disease duration was twice as long in secondary progressive than in relapsing-remitting cases (mean +/- SD = 17.6 +/- 9.6 versus 8.7 +/- 8.6 years; P < 0.001). Progressive relapsing and primary progressive cases were essentially similar in their clinical characteristics. In patients experiencing a progressive course, median age at onset of progressive phase was similar in secondary progressive cases and in cases who were progressive from onset (39.1 versus 40.1 years; P = 0.47). The proportion of cases with superimposed relapses during progression was approximately 40% in both categories. Finally, the 1562 patients with an exacerbating-remitting initial course and the 282 patients with a progressive initial course of the disease were essentially similar with respect to the time course of disability accumulation from assignment to a given disability score, and the age at assignment of disability landmarks. These observational data suggest that the clinical phenotype and course of multiple sclerosis are age dependent. Relapsing-remitting disease can be regarded as multiple sclerosis in which insufficient time has elapsed for the conversion to secondary progression; secondary progressive forms as relapsing-remitting multiple sclerosis that has 'grown older'; and progressive from onset cases as multiple sclerosis 'amputated' from the usual preceding relapsing-remitting phase. Times to reach disability milestones, and ages at which these landmarks are reached, follow a predefined schedule not obviously influenced by relapses, whenever they may occur, or by the initial course of the disease, whatever its phenotype. This leads to a unifying concept of the disease in which primary and secondary progression might be regarded as essentially similar. From the clinical and statistical positions, multiple sclerosis might be considered as one disease with different clinical phenotypes rather than an entity encompassing several distinct diseases-the position of complexity rather than true heterogeneity.

Clinical characteristics of progressive relapsing multiple sclerosis

OBJECTIVE

Patients with progressive relapsing (PR) multiple sclerosis (MS) may accrue disability by incomplete recovery from acute exacerbations and by ongoing deterioration. In primary progressive (PP) MS, disability accumulates solely by continuous decline. Because it is the least common form of MS, there is scant information regarding the clinical characteristics of PRMS, but relapses are reportedly uncommon. The purpose of this study is to describe the clinical features of a cohort of patients with PRMS.

METHODS

A retrospective chart review of 16 patients diagnosed with PRMS at two academic MS centres over a four-year period.

RESULTS

Nine men and seven women had PRMS. The mean age at onset was 35.1+/-11.2 years. The most common presenting symptom was a progressive myelopathy. The mean disease duration was 10.1+/-8.5 years and the average time to first exacerbation was 4.1+/-3.7years. Patients had an average of 2.8+/-2.3 relapses with an annualized relapse rate of 0.6+/-0.8. Time to Expanded Disability Status Scale (EDSS) 6.0 was strongly associated with time to first exacerbation. Although there was no correlation between the number of relapses and time to EDSS 6.0, there was a modest inverse relation between time to EDSS 6.0 and annualized relapse rate.

CONCLUSIONS

Relapses in PRMS may occur more often than previously described and disability may accumulate more rapidly in PRMS than in PPMS. We suggest differentiating between these two forms of MS.

Primary and secondary progressive multiple sclerosis

The progressive phase of multiple sclerosis (MS) is the one most often associated with irreversible accumulation of disability. An important question remains about the place of primary progressive MS (PP-MS): does it form an integral part of the disease spectrum, or is it maybe a distinct entity? This question could apparently be very theoretical, but it is not, as patients with PP-MS remain orphans when regarding disease-modifying treatments. Thus, they are usually excluded from therapeutic trials. A clue to this question could be the comparison between the different MS subtypes with a progressive phase. We discuss here the clinical similarities and differences between secondary and primary progressive MS.

Differentiation of multiple sclerosis subtypes: implications for treatment

There has been tremendous progress in the immunomodulatory treatment of multiple sclerosis (MS) during recent years. With the introduction of interferon-beta, glatiramer acetate and mitoxantrone (recently registered for MS in the US), there are at least three therapeutic strategies that have proven effective in large phase III studies. However, not all patients with MS respond well to treatment with these drugs. This may largely be a consequence of disease heterogeneity. From a clinical perspective, patients with different disease courses show different treatment responses. Patients with relapsing-remitting MS are more likely to respond to immunomodulatory therapy than those with a progressive disease course. Studies of patients with secondary progressive MS have yielded inconsistent results and, so far, there has been no positive phase III study of immunomodulatory therapy in patients with primary progressive MS. Pathological evidence indicates that subtyping based on clinical findings alone does not reflect actual disease heterogeneity. In a large series of biopsy and autopsy specimens, at least four subtypes could be identified with respect to oligodendrocyte/myelin pathology and immunopathology. As long as the only method of identifying subtypes of disease is histopathology, differential therapy will remain a future goal. Thus, there is an urgent need for in vivo markers of immunopathogenesis in an individual patient that would allow treatment to be specifically directed towards a given pathological focus. However, at least from a theoretical point of view, some therapeutic approaches appear very attractive. Plasmapheresis and/or intravenous immunoglobulins could most plausibly be the best approach for the immunopathological subtype of MS, which is characterised by antibody and complement deposition next to demyelinated axons, in order to remove antibodies. The subtype of MS that is associated with heavy macrophage activation, T cell infiltration and expression of inflammatory mediator molecules, including tumour necrosis factor-alpha, may be most likely to respond to immunomodulation with interferon-beta or glatiramer acetate. There are other subtypes of MS in which viral infection or oligodendrocyte degeneration, rather than autoimmunity, appear to play a role. It is possible that these could benefit from antiviral therapy, oligodendrocyte protection or oligodendrocyte transplantation, although therapies based on these latter approaches have yet to be developed.

Primary progressive multiple sclerosis: increasing clarity but many unanswered questions

Heterogeneity in the clinical course of multiple sclerosis (MS) is well recognised and patients following a primary progressive course, 10-15% of the MS population, have a distinct clinical and paraclinical phenotype. This review examines recent advances in our understanding of this subgroup of patients and examines the new criteria to be applied in diagnosis. It also highlights developments in genetic, immunological, magnetic resonance and pathological aspects of the disease, whilst also outlining the results of recent therapeutic trials.

Observations on recent studies showing increased co-occurrence of autoimmune diseases

The co-occurrence of autoimmune diseases has been epidemiologically studied and has aided in our understanding of autoimmunity. However, as new perspectives develop on the pathogenesis and natural history of autoimmune diseases, a refinement in the methodology for the study of the co-occurrence of disease is warranted in order to maximize the information that one may realize from such studies. This paper presents some recent results of co-occurrence studies and then proposes several refinements in the design of epidemiological studies in light of current understanding of the natural history of autoimmune diseases. It also suggests an historical perspective on the results of past studies as to the type of information that can be inferred from them.

Intracellular cytokine profile in T-cell subsets of multiple sclerosis patients: different features in primary progressive disease

OBJECTIVE

To evaluate the expression of cytokines in both CD4+ and CD8+ T cells derived from peripheral blood of untreated multiple sclerosis (MS) patients with either relapsing-remitting (RR), secondary progressive (SP) or primary progressive (PP) MS and healthy controls (HC).

BACKGROUND

MS is an immune-mediated disease and cytokines hove been hypothesized to contribute significantly to disease progression. Compared to the relapse-onset (RR, SP) form of the disease, PPMS patients have different clinical, immunological and pathological features. Surprisingly, the ability of their circulating T cells to produce immunoregulatory cytokines has not been extensively studied so far.

METHODS

Seventy-two MS patients (24 RR, 26 SP, 22 PP) and 34 HC were studied. Stimulated peripheral blood derived CD4+ and CD8+ T MS patients express significantly more CD4+ and CD8+ T cells were analyzed for IFN-gamma, IL-2, TNF-alpha, IL-4, IL-10 and IL-13 production.

RESULTS

cells producing IFN-gamma compared to HC. Compared to the other forms of the disease, PPMS patients display a significant decrease in CD4+ T cells producing IL-2, IL-13 and TNF-alpha and a significant increase in CD8+ T cells producing IL-4 and IL-10.

CONCLUSIONS

The data presented here demonstrate that patients with PPMS express less pro- and more anti-inflammatory cytokine producing T cells compared to the relapse-onset form of the disease, confirming the view on PPMS as a distinct disease entity.