Primary progressive multiple sclerosis: increasing clarity but many unanswered questions

Real-world challenges in the diagnosis of primary progressive multiple sclerosis

BACKGROUND AND PURPOSE

Despite the 2017 revisions to the McDonald criteria, diagnosing primary progressive multiple sclerosis (PPMS) remains challenging. To improve clinical practice, the aim was to identify frequent diagnostic challenges in a real-world setting and associate these with the performance of the 2010 and 2017 PPMS diagnostic McDonald criteria.

METHODS

Clinical, radiological and laboratory characteristics at the time of diagnosis were retrospectively recorded from designated PPMS patient files. Possible complicating factors were recorded such as confounding comorbidity, signs indicative of alternative diagnoses, possible earlier relapses and/or incomplete diagnostic work-up (no cerebrospinal fluid examination and/or magnetic resonance imaging brain and spinal cord). The percentages of patients fulfilling the 2010 and 2017 McDonald criteria were calculated after censoring patients with these complicating factors.

RESULTS

A total of 322 designated PPMS patients were included. Of all participants, it was found that n = 28/322 had confounding comorbidity and/or signs indicative of alternative diagnoses, n = 103/294 had possible initial relapsing and/or uncertainly progressive phenotypes and n = 73/191 received an incomplete diagnostic work-up. When applying the 2010 and 2017 diagnostic PPMS McDonald criteria on n = 118 cases with a full diagnostic work-up and a primary progressive disease course without a better alternative explanation, these were met by 104/118 (88.1%) and 98/118 remaining patients (83.1%), respectively (p = 0.15).

CONCLUSION

Accurate interpretation of the initial clinical course, consideration of alternative diagnoses and a full diagnostic work-up are the cornerstones of a PPMS diagnosis. When these conditions are met, the 2010 and 2017 McDonald criteria for PPMS perform similarly, emphasizing the importance of their appropriate application in clinical practice.

Clinical trials in multiple sclerosis: potential future trial designs

Clinical trials of new treatments in multiple sclerosis (MS) currently require large sample sizes and long durations in order to yield reliable results. The differential responses of an already heterogeneous population of MS patients to individual disease-modifying therapies (DMTs) will further complicate future trials. MS trials with smaller samples and faster outcomes are conceivable through the substitution of current clinical and MRI outcomes with objectively measureable genomic and proteomic biomarkers. Currently, biomarkers that could be utilized for diagnosis and monitoring of MS disease activity are in the early validation phase. The power of single biomarkers or multiple correlated biomarkers to predict prognosis and response to treatment could initially be compared with currently accepted methods. These prospectively validated disease biomarkers could then be used to subcategorize the spectrum of MS patients into a finite number of endophenotypes with demonstrable different molecular pathogeneses and DMT response profiles. Newly developed DMT could potentially be assessed within specific endophenotypes and compared with pharmacogenomically relevant active comparator DMT. This approach may increase the efficiency of MS trials through homogenization of patient population and minimization of nonresponders in study groups, providing the potential for the development of targeted therapies.

Progranulin gene variability increases the risk for primary progressive multiple sclerosis in males

Progranulin (GRN) gene variability has been analyzed in a sample of 354 patients with multiple sclerosis (MS) compared with 343 controls. No significant differences were observed, but by stratifying according to MS subtypes, a significant increased frequency of the rs2879096 TT genotype was found in primary progressive MS (PPMS) patients versus controls (16.0 vs 3.5%, P=0.023, odds ratio (OR) 5.2, 95% confidence interval (CI) 1.2-21.4). In addition, in PPMS, an association with the C allele of rs4792938 was observed (55.3 vs 33.5%, P=0.011, OR 2.4, 95% CI 1.2-4.7). An independent population was studied as replication, failing to confirm results previously obtained. Stratifying according to gender, an association with rs4792938 C allele was found in male PPMS patients compared with controls (40.7 vs 26.9%, P=0.002, OR 1.87, 95% CI 1.2-2.8). An association with the rs2879096T allele was observed (29.2 in patients compared with 18.9% in controls, P=0.012, OR 1.77, 95% CI 1.1-2.8). Haplotype analysis showed that TC haplotype frequency is increased in PPMS male patients compared with male controls (25.7 vs 16.6%; P=0.02, OR 1.69, 95% CI 1.1-2.7), whereas the respective GC haplotype seems to exert a protective effect, as its frequency is decreased in patients compared with controls (55.8% vs 70.9%; P=0.001, OR 0.52, 95% CI 0.4-0.8). Therefore, GRN haplotypes likely influence the risk of developing PPMS in males.

Expression of the inhibitor of apoptosis protein family in multiple sclerosis reveals a potential immunomodulatory role during autoimmune mediated demyelination

A failure of autoreactive T cells to undergo apoptosis may contribute to the pathogenesis of multiple sclerosis (MS). The role of the inhibitor of apoptosis (IAP) family of anti-apoptotic proteins such as X-linked IAP (XIAP), human inhibitor of apoptosis-1 (HIAP-1), human inhibitor of apoptosis-2 (HIAP-2), neuronal apoptosis inhibitory protein (NAIP) and Survivin in relapsing–remitting, secondary-progressive, primary-progressive or benign forms of MS is unclear. We report here that expression of the IAP family of genes in peripheral blood samples and brain tissues from MS cases support a role for differential regulation of these potent anti-apoptotic proteins in the pathology of MS. XIAP mRNA and protein levels were elevated in peripheral blood mononuclear cells from patients with active disease relative to normal subjects. In patients with active MS, HIAP-1 and HIAP-2 mRNA levels were elevated in resting T cells while NAIP mRNA was increased in whole blood. In post-mortem MS brain tissue, XIAP and HIAP-1 in myelin lesions were co-localized with microglia and T cells, respectively. Only in primary-progressive patients was Survivin expression elevated suggestive of a distinct pathological basis for this subtype of MS. Taken together, these results suggest that patterns of inhibitor of apoptosis expression in immune cells may have value in distinguishing between MS subtypes and offer insight into the mechanisms responsible for their distinct clinical courses.

Incidence of multiple sclerosis in the United Kingdom

Existing data on the incidence of multiple sclerosis (MS) in the UK have some limitations. Few studies have reported age- and sex-specific incidence rates of MS, and none of those is based on a large sample of the general population. Further, no published reports have provided age- and sex-specific incidence rates of MS by clinical course from onset. To estimate the age- and sex-specific incidence rate and lifetime risk of multiple sclerosis, we identified all new cases of MS during the period 1993-2000 in the General Practice Research Database, which includes health information on over three million Britons. Based on 642 incident cases, incidence rates of MS adjusted to the world population were 7.2 (95 % CI 6.5, 7.8) in women and 3.1 (95 % CI 2.6, 3.5) in men. The incidence of MS with relapsing-remitting onset was higher in women than in men (incidence rate ratio 2.5, 95% CI 2.1, 3.1), but there were no sex differences for primary-progressive MS (incidence rate ratio 1.1, 95% CI 0.7, 1.8). The estimated lifetime risk from birth of receiving an MS diagnosis was 5.3 per 1,000 in women and 2.3 per 1,000 in men. These results confirm the relatively high incidence of MS in the UK and show marked differences in the sex-specific pattern of MS incidence by clinical course from onset.

Multiple sclerosis with a progressive course from onset in Lorraine-Eastern France

To investigate the patient characteristics, disease progression, and associated risk factors in patients with multiple sclerosis (MS) with a progressive onset, we conducted a longitudinal population-based study of 359 patients (252 with primary progressive MS (PPMS) and 107 with progressive relapsing MS (PRMS)) in Lorraine, France. As outcome measures, we assessed the time from MS onset to reaching disability status scale (DSS) scores of 4, 6 and 7 and the time from assignment of DSS score of 6 to assignment of DSS score of 7. We studied the influence on these outcomes of sex, age of onset and symptoms of onset. We also studied the influence of the time from MS onset to assignment of DSS 6 on the time from MS onset to assignment of DSS 7. There were no significant differences in the demographic data (gender and age at onset of MS) and clinical data (median time to DSS scores of 4, 6 and 7) between the patients with PPMS and PRMS suggesting such a distinction may be unnecessary. The male/female ratio in all 359 patients with MS with a progressive onset was 1/1.36. The median age at onset was 42.7 years (25% Q1 = 34.7; 75% Q3 = 50.0), was lower for male (40.5 years) than for female patients (44.2 years; p = 0.002). The median time to DSS scores of 4, 6 and 7 were (in years) 3.0 (95% CI = 2.8 to 3.7), 9.9 (95% CI = 9.0 to 10.6), and 17.0 (95% CI = 14.9 to 19.0). A cane was required in 25% of patients 5 years after onset and in 75% 15 years after onset. We did not find any significant unfluence of sex, age at onset, or symptoms at onset on the time from MS onset to assignment of scores 6 or 7 or on the time from the assignment of a score of 6 to the assignment of a score of 7.

Déficit oligodendrocytaire et insuffisance de la remyélinisation au cours de la SEP : étude anatomoclinique et expérimentale comparative

INTRODUCTION

The mechanisms responsible for the failure of remyelination during MS are poorly understood. We have analyzed in which way oligodendrocytes (OL) could be involved.

METHODS

The number of remyelinated fiber per OL has been determined in 18 chronic MS lesions and compared to normal appearing white matter (NAWM), as well as in the center of lysophosphatidyl choline (LPC)-induced lesions in adult rats in which remyelination was accelerated by microinjection of neurotrophin-3 (NT-3).

RESULTS

In chronic MS lesions and in LPC-induced lesions the number of myelinated fibers per OL was strongly decreased compared to NAWM and to animals treated with NT-3 respectively.

CONCLUSION

Our results suggest that the capacity of OL to remyelinate axons could be impaired, due to successive relapses, during MS.

Glatiramer acetate in primary progressive multiple sclerosis: results of a multinational, multicenter, double-blind, placebo-controlled trial

OBJECTIVE

To determine whether glatiramer acetate (GA) slows accumulation of disability in primary progressive multiple sclerosis.

METHODS

A total of 943 patients with primary progressive multiple sclerosis were randomized to GA or placebo (PBO) in this 3-year, double-blind trial. The primary end point was an intention-to-treat analysis of time to 1- (entry expanded disability status scale, 3.0-5.0) or 0.5-point expanded disability status scale change (entry expanded disability status scale, 5.5-6.5) sustained for 3 months. The trial was stopped after an interim analysis by an independent data safety monitoring board indicated no discernible treatment effect on the primary outcome. Intention-to-treat analyses of disability and magnetic resonance imaging end points were performed.

RESULTS

There was a nonsignificant delay in time to sustained accumulated disability in GA- versus PBO-treated patients (hazard ratio, 0.87 [95% confidence interval, 0.71-1.07]; p = 0.1753), with significant decreases in enhancing lesions in year 1 and smaller increases in T2 lesion volumes in years 2 and 3 versus PBO. Post hoc analysis showed that survival curves for GA-treated male patients diverged early from PBO-treated male subjects (hazard ratio, 0.71 [95% confidence interval, 0.53-0.95]; p = 0.0193).

INTERPRETATION

The trial failed to demonstrate a treatment effect of GA on primary progressive multiple sclerosis. Both the unanticipated low event rate and premature discontinuation of study medication decreased the power to detect a treatment effect. Post hoc analysis suggests GA may have slowed clinical progression in male patients who showed more rapid progression when untreated.

Balance performance in three forms of multiple sclerosis

OBJECTIVES

To compare and document balance performance between patients with multiple sclerosis (MS) and healthy control subjects and balance performance among patients with different MS forms using a set of clinical balance tests.

MATERIAL AND METHODS

Twenty eight primary progressive (PPMS), 34 secondary progressive (SPMS), and 62 relapsing remitting (RRMS), totalling 124 MS patients were included in the present study. Results from patients were compared with those of 31 healthy control subjects matching in age, gender, weight and height. Ashworth scale, mini-mental state examination and motricity index were used consecutively to evaluate spasticity, cognitive impairment and lower extremity muscle strength. Vision, sensation, proprioception, cerebellar and vestibular tests were also performed on the patients. The balance performance was evaluated using a set of clinical tests including steady stance tests (eyes in opened and closed positions, feet apart, feet together, stride stance, tandem stance and single stance), self-generated perturbations (functional reach, arm raise and step test), external perturbations, Tinetti-gait and 10 m gait time tests.

RESULTS

There were no differences in age, sex, weight, height, sense impairment and lower extremity strength in patients with the three MS forms (p>0.05). No difference was found among patients with the three MS forms and the control subjects in the test of eyes closed with feet apart (p>0.05). The PPMS patients in all the balance tests except tests of eyes closed with feet apart and eyes opened with feet together, SPMS patients in all the balance tests except that of eyes closed with feet apart and RRMS patients in tandem stance, single leg stance, self-generated perturbations, external perturbations, Tinetti-gait and 10 m gait time tests had weaker balance than the control subjects (p<0.001). There were some differences between patients in the PPMS and SPMS groups in the eyes closed and feet apart test, between patients in the PPMS and RRMS groups in all the balance tests except eyes closed and feet apart and eyes opened and feet together tests and between patients in SPMS and RRMS group in all the balance tests except right and left arm raised tests (p<0.001).

CONCLUSION

Balance in MS patients is impaired. The results of the present study show that there is more impairment in progressive MS forms than in RRMS. Meanwhile, patients with progressive MS are more likely to fall.

Region with persistent high frequency of multiple sclerosis in Croatia and Slovenia

OBJECTIVE

The aim of this study was to evaluate the prevalence of multiple sclerosis (MS), and to determine the clinical characteristics and the occurrence of familial MS in the Gorski kotar-Kocevje region, which was previously considered to be a region of high prevalence of MS.

METHODS

All clinically and laboratory supported definite cases of MS according to Poser's criteria, living residents of the chosen area on June 1, 1999 were included in the study. The patients were ascertained through national case registers for MS at the University Medical Centers (Rijeka and Ljubljana), registries of the national associations of MS patients, as well as from the medical records of regional outpatient clinics.

RESULTS

The crude annual prevalence per 100,000 population was 151.9 (95% CI 123.2-187.4). 28.7% of patients had a history of MS among first-, second-, or third-degree relatives. The frequency of primary progressive course of disease was 23.5%. The sex ratio (F/M) was 1.41.

CONCLUSION

A stable high prevalence of MS as well as a high number of familial MS cases was identified in the neighbouring regions of Slovenia and Croatia.

Clinical Course of Progressive Multiple Sclerosis in Brazilian Patients

OBJECTIVE

To describe the clinical course and outcome of multiple sclerosis with progressive onset in Brazilian patients. A total of 238 medical records were reviewed, 26 cases (10.9%) fulfilled Thompson criteria (2000), and 5.80% classified as primary progressive and 5.04% relapsing progressive according to Lublin and Reingold.

STUDY POPULATION

19 Caucasians and 7 non-Caucasians; male:female ratio 1.2:1, mean age at onset was 34 +/- 7.9 years.

RESULTS

Non-Caucasian patients had earlier onset of disease. The most common manifestations at onset were pyramidal and cerebellar (89% and 34.6%). After 11.3 +/- 6.35 years of disease more than 50% of the patients had involvement of most of their functional systems. No statistically significant differences were observed between the subgroups.

CONCLUSION

The clinical course and outcome of progressive multiple sclerosis in Brazil, a tropical country with low prevalence, were very similar to those in the multiple sclerosis high prevalence areas.

Interaction of loci within the HLA region influences multiple sclerosis course in the Sardinian population

We examined the influence of alleles at the HLA loci, previously found to be associated with multiple sclerosis (MS) in Sardinia, on the clinical course of the disease in 835 relapsing (R) and 100 primary progressive (PP) patients. Multivariate analysis was carried out on predisposing 0301 or non-associated DPB1 alleles, susceptible or non-associated DRB1-DQB1 haplotypes, both predisposing and non-predisposing, and negatively and non-negatively associated D6S1683 alleles, taking interaction between them into account. Intra-patient analysis showed that the presence of the susceptible or protective D6S1683 allele interacting with predisposing DP 0301 modulated risk of PP disease. These findings suggest that a locus telomeric to HLA class I exerts an effect on alleles at the DPB1 locus in modulating disease course.

Gene expression and genotyping studies implicate the interleukin 7 receptor in the pathogenesis of primary progressive multiple sclerosis

Multiple sclerosis (MS) is an enigmatic disease of the central nervous system resulting in sclerotic plaques with the pathological hallmarks of demyelination and axonal damage, which can be directly or indirectly orchestrated by cells from the peripheral circulation. The majority of patients with MS follow a relapsing-remitting course in the early stages of the disease (RRMS) but most ultimately enter a secondary progressive phase (SPMS). About 10% of patients follow a primary progressive course from the onset (PPMS). We measured gene expression in whole blood of people with and without chronic progressive MS (CPMS), PPMS and SPMS, to discover genes which may be differentially expressed in peripheral blood in active disease, and so identify pathologically significant genes and pathways; and we investigated genetic differences in the promoters of dysregulated genes encoded in genomic regions associated with MS. If SPMS and PPMS were independently compared to the controls, there was little overlap in the set of most dysregulated genes. Ribosomal protein genes, whose expression is usually associated with cell proliferation and activation, were dramatically over-represented in the set of most down-regulated genes in PPMS compared to SPMS (P < 10(-4), chi(2)). The T cell proliferation gene IL7R (CD127) was also underexpressed in PPMS, but was up-regulated in SPMS compared to the controls. One interleukin 7 receptor (IL7R) promoter single nucleotide polymorphism (SNP), -504 C, was undertransmitted in PPMS trios (P = 0.05, TDT), and carriers of this allele were under-represented in PPMS cases from two independent patient cohorts (combined P = 0.006, FE). The four known IL7R promoter haplotypes were shown to have similar expression levels in healthy controls, but not in CPMS (P < 0.01, t test). These data support the hypothesis that PPMS has significant pathogenetic differences from SPMS, and that IL7R may be a useful therapeutic target in PPMS.

Clinical and laboratory features of in-patients with multiple sclerosis in a University Hospital in Tokyo from 1988-2002

OBJECTIVE

The aim of this study was to analyze the clinical and laboratory features of each subtype of multiple sclerosis (MS) (relapsing-remitting, primary progressive, and secondary progressive) in the Tokyo metropolitan area.

METHODS AND PATIENTS

We retrospectively analyzed the medical records of 104 consecutive patients with a diagnosis of MS, who had been admitted to our university hospital from 1988 to 2002. They all met criteria for definite MS, by clinical or laboratory standards.

RESULTS

Eighty-four (80.8%) patients were classified as having relapsing-remitting MS, while 8 patients (7.7%) and 12 patients (11.5%) were classified as having primary progressive MS and secondary progressive MS, respectively. A significant female predominance existed in the relapse-remitting MS (female : male=2.4 : 1) cohort, but this ratio was 1 : 1 in both primary progressive and secondary progressive MS. The age at onset was older in the primary progressive MS (36.6+/-17.1 years of old) population than in either the relapsing-remitting MS (27.9+/-11.1) or the secondary progressive MS (27.8+/-11.5) subjects. Although the duration of illness was similar among the three types of MS, the number of exacerbations in the secondary progressive (5.9+/-4.6) cohort was significantly higher than that in the relapsing-remitting MS subjects (3.2+/-2.6). Patients with primary progressive MS showed a significantly higher rate of gait disturbance (87.5%) as the initial symptom than those with relapsing-remitting MS (23.8%), and this was thought to be due to the higher incidence of brainstem and spinal cord lesions. Visual disturbance as the initial symptom was frequently noted in those with secondary progressive MS (50.0%), while it was noted only in 29.8% and 12.5% in the relapsing-remitting and primary progressive patients, respectively. Primary progressive MS subjects had a higher propensity to be wheelchair-bound (75.0%) than those suffering from relapsing-remitting MS (1.2%). Increased total protein in the cerebrospinal fluid (CSF) of the secondary progressive cohort was statistically significant compared to the relapsing-remitting cohort. The frequency of oligoclonal IgG bands was rather low in each type of MS (17.1-33.3%). Gadolinium enhancement of plaques on MRI was more frequently present in secondary progressive MS (66.7%) than in either relapsing-remitting MS (32.1%) or primary progressive MS (50.0%). Of note, the opticospinal form was found in only 16.3% of the total MS patients, a proportion less than that in previous reports from southern Japan.

CONCLUSION

The present study confirms that while the clinical and laboratory features of the MS patients in the Tokyo metropolitan area are similar to those in Western countries in most regards, features such as proportionally fewer primary and secondary progressive MS patients as well as less oligoclonal IgG bands on CSF analysis are different from those in Western countries.

The presence of glutamic acid at positions 71 or 74 in pocket 4 of the HLA-DRbeta1 chain is associated with the clinical course of multiple sclerosis

BACKGROUND

Primary progressive multiple sclerosis (PP-MS) differs from relapsing-remitting or secondary progressive MS (RR/SP-MS) in ways suggesting differences in the pathogenic pathways. Susceptibility to both PP-MS and RR/SP-MS is linked to carriage of the HLA molecule DRB1*1501. Several serologically defined HLA-DR groups (DR1, DR4, DR6, and DR9) occur less often in RR/SP-MS than in controls. Some or all of the HLA-DR molecules encoded by alleles in these serologically defined groups have a negatively charged glutamic acid at residue 71 or 74 of the beta1 chain (beta1(71)/beta1(74)). Residues at these positions are important in the formation of pocket 4 in the antigen binding site of the HLA-DR molecule.

OBJECTIVES

To investigate whether the presence of alleles encoding HLA-DR molecules containing glutamic acid at beta1(71)/beta1(74) correlates with the course of MS.

METHODS

HLA-DR and HLA-DQ alleles and genotypes were analysed in 121 MS patients (50 with PP-MS) and 109 controls by molecular typing.

RESULTS

Alleles encoding HLA-DR molecules containing a glutamic acid at beta1(71)/beta1(74) occurred less often in patients with RR/SP-MS than in those with PP-MS or controls. In subjects not carrying the DRB1*1501 allele, a much higher proportion of PP-MS patients carried alleles encoding HLA-DR molecules containing a glutamic acid at beta1(71)/beta1(74) than did RR/SP-MS patients or controls.

CONCLUSIONS

The amino acid residues involved in determining the shape and charge of pocket 4 of the HLA-DR beta1 chain could influence the clinical course of MS by determining protection against RR/SP-MS or susceptibility to the development of PP-MS.

Overview of primary progressive multiple sclerosis (PPMS): similarities and differences from other forms of MS, diagnostic criteria, pros and cons of progressive diagnosis

Patients with the primary progressive form of multiple sclerosis (PPMS) have a unique clinical course and demonstrate additional demographic and imaging features, which separate them from the relapsing/remitting form of the condition. Whether these features indicate a fundamental difference in the underlying pathogenesis of the condition or simply reflect opposite ends of a clinical spectrum is unclear. What is clear, however, is that this form of MS provides a valuable model of progression, which has the potential to explain this most disabling component of the disease process. The lack of the hallmark relapses and remissions in PPMS poses diagnostic difficulties, some of which have been addressed by recently published diagnostic criteria. Following diagnosis, the need for information, specific to this form of MS, must be recognized and addressed.

Recombinant adeno-associated viral (rAAV) vectors as therapeutic tools for Duchenne muscular dystrophy (DMD)

Duchenne muscular dystrophy (DMD) is a lethal genetic muscle disorder caused by recessive mutations in the dystrophin gene. The size of the gene (2.4 Mb) and mRNA (14 kb) in addition to immunogenicity problems and inefficient transduction of mature myofibres by currently available vector systems are formidable obstacles to the development of efficient gene therapy approaches. Adeno-associated viral (AAV) vectors overcome many of the problems associated with other vector systems (nonpathogenicity and minimal immunogenicity, extensive cell and tissue tropism) but accommodate limited transgene capacity (<5 kb). As a result of these observations, a number of laboratories worldwide have engineered a series of microdystrophin cDNAs based on genotype-phenotype relationship in Duchenne (DMD) and Becker (BMD) dystrophic patients, and transgenic studies in mdx mice. Recent progress in characterization of AAV serotypes from various species has demonstrated that alternative AAV serotypes are far more efficient in transducing muscle than the traditionally used AAV2. This article summarizes the current progress in the field of recombinant adeno-associated viral (rAAV) delivery for DMD, including optimization of recombinant AAV-microdystrophin vector systems/cassettes targeting the skeletal and cardiac musculature.

Primary progressive multiple sclerosis: clinical and paraclinical characteristics with application of the new diagnostic criteria

The aim of our study was to analyse clinical and paraclinical characteristics of patients with multiple sclerosis (MS) with previous diagnosis of primary-progressive (PP) MS according to the Poser's criteria and further investigate if they fulfil the McDonald's diagnostic criteria for this disorder. A total of 561 MS patients were registered in the database at the Institute of Neurology, Belgrade, from 1 January 1997 to 31 December 2000 and 63 of them (11.2%) with previous diagnosis of PPMS were analysed retrospectively. Male/female ratio was 1.3:1 and mean age at onset 33.2 years. Most frequent at onset were pyramidal (in 73% of patients) and sensory symptoms (in 41% of patients); 74.6% of patients had greater than or equal to nine brain magnetic resonance imaging (MRI) lesions. Intrathecal oligoclonal immunoglobulin G (IgG) was detected in 96.7% and prolonged visual evoked potentials (VEP) P100 latency in 82.4% of patients. Of the total study group of 561 patients, 10.2% fulfilled the recently recommended McDonald's diagnostic criteria for the diagnosis of PPMS. Our findings further support the significance of the brain/spinal cord MRI, cerebrospinal fluid and VEP findings for precise diagnostic assessment in patients with suspected PP form of MS.

Intrathecal production of Chlamydia pneumoniae-specific high-affinity antibodies is significantly associated to a subset of multiple sclerosis patients with progressive forms

The purpose of this study was to provide further insight into the effective relevance of the association between Chlamydia pneumoniae and MS. We evaluated by ELISA technique cerebrospinal fluid (CSF) and serum levels of anti-C. pneumoniae IgG in 46 relapsing-remitting (RR), 14 secondary progressive (SP) and 11 primary progressive (PP) MS patients grouped according to clinical and Magnetic Resonance Imaging (MRI) evidence of disease activity. Fifty-one patients with other inflammatory neurological disorders (OIND) and 52 with non-inflammatory neurological disorders (NIND) were used as controls. A C. pneumoniae-specific intrathecal IgG synthesis as detected by the relative specific index was present in a small proportion of MS (17%), OIND (22%) and NIND (2%) patients and was significantly more frequent in MS and in OIND than in NIND (p<0.001) and in SP and PP MS than in RR MS patients (p<0.02). Among the patients with C. pneumoniae-specific intratecally produced antibodies, CSF high-affinity anti-C. pneumoniae IgG were found in the majority of SP or PP MS, occasionally in OIND, but not in RR MS and NIND patients. These findings confirm that the presence of a humoral immune response to C. pneumoniae within the central nervous system (CNS) is not selectively restricted to MS, but is shared by several inflammatory neurological conditions. In addition, our results suggest that an intrathecal production of C. pneumoniae-specific high-affinity IgG can occur in a subset of patients with MS progressive forms in which a C. pneumoniae brain chronic persistent infection may play an important pathogenetic role.

Theiler's virus infection: a model for multiple sclerosis

Both genetic background and environmental factors, very probably viruses, appear to play a role in the etiology of multiple sclerosis (MS). Lessons from viral experimental models suggest that many different viruses may trigger inflammatory demyelinating diseases resembling MS. Theiler's virus, a picornavirus, induces in susceptible strains of mice early acute disease resembling encephalomyelitis followed by late chronic demyelinating disease, which is one of the best, if not the best, animal model for MS. During early acute disease the virus replicates in gray matter of the central nervous system but is eliminated to very low titers 2 weeks postinfection. Late chronic demyelinating disease becomes clinically apparent approximately 2 weeks later and is characterized by extensive demyelinating lesions and mononuclear cell infiltrates, progressive spinal cord atrophy, and axonal loss. Myelin damage is immunologically mediated, but it is not clear whether it is due to molecular mimicry or epitope spreading. Cytokines, nitric oxide/reactive nitrogen species, and costimulatory molecules are involved in the pathogenesis of both diseases. Close similarities between Theiler's virus-induced demyelinating disease in mice and MS in humans, include the following: major histocompatibility complex-dependent susceptibility; substantial similarities in neuropathology, including axonal damage and remyelination; and paucity of T-cell apoptosis in demyelinating disease. Both diseases are immunologically mediated. These common features emphasize the close similarities of Theiler's virus-induced demyelinating disease in mice and MS in humans.

Disease-modifying therapies in multiple sclerosis: an update on recent and ongoing trials and future strategies

Multiple sclerosis (MS) is the prototype inflammatory autoimmune disorder of the central nervous system and the most common cause of neurological disability in young adults exhibiting considerable clinical, radiological and pathological heterogeneity. Novel insights in the immunopathological processes, advances in biotechnology, development of powerful magnetic resonance imaging technologies together with improvements in clinical trial design led to a variety of evaluable therapeutic approaches. Therapy has changed dramatically over the past decade, yielding significant progress for the treatment of relapsing-remitting and secondary progressive MS. A substantial number of pivotal and preliminary reports continue to demonstrate encouraging new evidence that advances are being made in the care of MS patients. This review summarises recent progress with currently available disease-modifying therapies and - on the basis of present immunopathogenetic concepts - outlines ongoing studies as well as future treatment strategies.