Neuropathology in multiple sclerosis: new concepts

The natural history of multiple sclerosis: a geographically based study. 7. Progressive-relapsing and relapsing-progressive multiple sclerosis: a re-evaluation

Classifications of multiple sclerosis subtypes have been largely based on clinical phenomenology. Nevertheless, definitions of relapse, remission and progression have been imprecise. Recently an international consensus group, as part of a reclassification of disease subtypes, recommended dropping the term 'relapsing-progressive' (RP) and retaining the term 'progressive-relapsing' (PR) multiple sclerosis. The term 'RP' multiple sclerosis had been applied when the early course combined both relapses and progression and was believed to identify some patients with a worse than average outcome. The PR group consisted of patients with primary progressive disease who later in their course developed relapses. Since the terminology has been largely arbitrary, we have evaluated the validity of the terms 'RP' and 'PR' multiple sclerosis in the context of long-term outcome within a large population-based cohort of progressive multiple sclerosis patients seen at the London Multiple Sclerosis Clinic (Canada) between 1972 and 1984. Mean follow-up of the entire cohort was 25 years. Designation of RP multiple sclerosis did identify a more rapidly progressive subgroup. To realign these natural history data with consensus recommendations, these patients were reassigned to secondary progressive (SP) or to primary progressive (PP) multiple sclerosis, with progression defined as at least 1 year of progressive deterioration. PP multiple sclerosis patients with relapses after a year were designated as having PR multiple sclerosis. Relapses in primary progressive multiple sclerosis occurred in 27.8% of patients at some point even two to three decades after onset. In general these relapses were mild and remitting, but served to blur the distinction between progressive and relapsing-remitting disease. The long-term outcomes of time to Kurtzke disability scores (DSS) of 3, 6, 8 and 10 were compared among the progressive subtypes. Times to these disability end-points and to death were not different between PR and PP multiple sclerosis. Survival curves for progressive patients have been amended to incorporate the reassignment of PR multiple sclerosis patients into the PP group and the RP multiple sclerosis patients into the PP and SP subgroups. The time to reach DDS 3, 6, 8 and 10 for a population-based cohort of primary and secondary progressive patients resulting from the elimination of the categories of RP multiple sclerosis and PR multiple sclerosis has been established. These results provide justification for retaining only PP and SP multiple sclerosis as the subgroups of progressive disease.

Primary structure of the antigen-binding domains of a human oligodendrocyte-reactive IgM monoclonal antibody derived from a patient with multiple sclerosis

Several murine IgM monoclonal antibodies (mAbs) promoting remyelination in mice were shown to be germline gene-encoded natural autoantibodies that react with oligodendrocytes and intracellular antigens. Here, we show that human oligodendrocyte-reactive IgM mAb DS1F8 derived from a patient with multiple sclerosis targets microtubule-like structures similar to the murine mAbs. Sequencing of the cDNAs of the variable regions revealed that the antigen-binding domains are also encoded by germline genes. These similarities of mAb DS1F8 to the murine mAbs promoting remyelination suggest that this human mAb is a natural autoantibody. This may imply that the engineering of human autoantibodies for therapy of demyelinating diseases is feasible.

Biological markers in body fluids for activity and progression in multiple sclerosis

Reliable biological markers in body fluids for disease activity and progression are important for our understanding of the pathophysiology and therapeutic decisions in various subtypes of multiple sclerosis. Sampling from body fluids such as cerebrospinal fluid, blood, and urine constitutes the problem that the local immuno-inflammatory process takes place in the central nervous system whereas the disease activity is only to some extent reflected in the systemic immune compartment. Promising results have been obtained in studies of adhesion molecules, pro-inflammatory cytokines, co-stimulatory molecules and neopterin as markers of disease activity in relapsing-remitting multiple sclerosis. However, these results apply to groups of patients but not necessarily to individual patients. Currently no single body fluid marker is sufficiently correlated to disease activity to be used in the individual patient in monitoring disease activity, progression, or therapeutic effects.

The pathology of multiple sclerosis: a historical perspective

In the century and a half since multiple sclerosis (MS) was first recognized, the pathology of the condition has been defined with increasing detail. From the recognition and definition of MS as a clinical phenomenon, studies of the diseased brain tissue have progressed in a manner dependent on the science of the time. Through multiple generations, the increasingly detailed analysis of the MS lesion itself has lead to an increasingly sophisticated understanding of a complex, apparently diverse, immunopathological process. During this evolution, many hypotheses concerning the pathogenesis of MS have been overturned, and the interpretation of some clearly delineated gross and histological findings have been reversed. This review plots the progress and highlights current theories and emerging concepts regarding one of the most enigmatic of neurological diseases.