Biomedical subjects

P Villoslada

Publications and source records attributed to P Villoslada.

10 recordsLinked to original sources

PubMed2006

Cognitive impairment in patients with multiple sclerosis using the Brief Repeatable Battery-Neuropsychology test.

AIMS: To assess the cognitive impairment of multiple sclerosis (MS) patients using the Brief Repeatable Battery-Neuropsychology (BRB-N) test. METHODS: The performance of 59 patients with MS in the BRB-N test was assessed and compared with 152 matched healthy controls (HC). RESULTS: In most tests, MS patients performed worse than controls. Age and educational level strongly influenced the performance of the subjects. The Symbol Digit Modality Test (SDMT) best correlated with the other individual tests and contributed most to the general BRB-N factor. Furthermore, a correlation between physical disability and performance in some BRB-N tests was observed. Indeed, patients with progressive MS and greater physical disability performed worse in some tests than less disabled patients with relapsing MS. By creating a global BRB-N Z score, we found that patients generally performed 0.7 standard deviation (SD) below the level of controls. We obtained cut-off values stratified by age and education to determinate cognitive impairment in MS patients. CONCLUSIONS: Our data show that cognitive impairment is prevalent amongst MS patients, and that a single cognitive measurement might be useful for monitoring patients during the progression of this illness.

Adolescent↗

PubMed2005

Multiple Sclerosis Severity Score: using disability and disease duration to rate disease severity.

BACKGROUND: There is no consensus method for determining progression of disability in patients with multiple sclerosis (MS) when each patient has had only a single assessment in the course of the disease. METHODS: Using data from two large longitudinal databases, the authors tested whether cross-sectional disability assessments are representative of disease severity as a whole. An algorithm, the Multiple Sclerosis Severity Score (MSSS), which relates scores on the Expanded Disability Status Scale (EDSS) to the distribution of disability in patients with comparable disease durations, was devised and then applied to a collection of 9,892 patients from 11 countries to create the Global MSSS. In order to compare different methods of detecting such effects the authors simulated the effects of a genetic factor on disability. RESULTS: Cross-sectional EDSS measurements made after the first year were representative of overall disease severity. The MSSS was more powerful than the other methods the authors tested for detecting different rates of disease progression. CONCLUSION: The Multiple Sclerosis Severity Score (MSSS) is a powerful method for comparing disease progression using single assessment data. The Global MSSS can be used as a reference table for future disability comparisons. While useful for comparing groups of patients, disease fluctuation precludes its use as a predictor of future disability in an individual.

Adult↗

PubMed2004

TNF-376A marks susceptibility to MS in the Spanish population: A replication study.

This study was designed as a reappraisal of the association between the TNF-376A promoter polymorphism and susceptibility to multiple sclerosis found in the Spanish population but not in other populations. With a new dataset of patients (n = 241) and control subjects (n = 288), the association was confirmed (p = 0.018). The authors' data suggest that this association is specific of the Spanish white (or related) population or, alternatively, that only studies in their population have the adequate statistical power because of the higher frequency of an extended, conserved haplotype carrying the TNF-376A allele.

Adult↗

PubMed2004

Mitochondrial haplogroups in Basque multiple sclerosis patients.

Previous studies have suggested that mitochondrial metabolism and/or mitochondrial DNA (mtDNA) could be, in conjunction with other genetic or environmental factors, a risk factor for the development of multiple sclerosis (MS). One of these studies establishes that mitochondrial haplogroup JT is a risk factor for developing the disease, in particular the visual manifestations [optic neuritis (ON)]. Nevertheless, as distribution of these haplogroups varies between populations, the observed association may be due to a slanted sample with no physiopathological value. This hypothesis was checked with MS patients, originals from Basque country (this population has peculiar genetic characteristics) and from other Spanish regions. We concluded that such an association does not exist. By contrast, a decrease could be seen in the frequency of the JT haplogroup in the ON group and in the MS-Basque group. That trend could be a protective effect, which needs to be verified in further investigations.

Adult↗

PubMed2003

The immune response against herpesvirus is more prominent in the early stages of MS.

OBJECTIVE: To assess antibody levels against human herpesvirus type 6 (HHV-6), Epstein-Barr virus (EBV), and Chlamydia pneumoniae (CP) in serum from individuals in the early and late phase of MS. RESULTS: A strong association was found between anti-HHV-6 immunoglobulin M antibodies and early MS (clinically isolated syndromes at high risk for MS, and short duration active relapsing-remitting MS) when compared with healthy controls and secondary progressive MS. Moreover, in this group of patients, titers for anti-EBV immunoglobulin G were also elevated. The authors found no association between the levels of serum antibodies against CP and MS, nor did they detect the presence of DNA for these pathogens in the serum of patients with MS. Finally, serum from two patients with other inflammatory neurologic diseases also had elevated immunoglobulin M antibodies to HHV-6, indicating that the presence of this antibody is not specific to MS. CONCLUSION: An immune response against herpesviruses such as HHV-6 and EBV is associated with early MS.

Adjuvants, Immunologic↗

PubMed2003

Pharmacogenomic analysis of interferon receptor polymorphisms in multiple sclerosis.

Multiple sclerosis (MS) is a common inflammatory disease of the central nervous system characterized by progressive neurological dysfunction. No curative therapy is currently available, and approximately 80-90% of afflicted individuals are ultimately disabled. Interferon beta (IFNbeta) has been shown to decrease clinical relapses, reduce brain disease activity, and possibly slow progression of disability. However, the overall effect of treatment is partial and a substantial number of patients are considered poor or nonresponders. For this report, we tested the pharmacogenomic effects of eight polymorphisms in the interferon receptor genes (IFNAR1 and IFNAR2) in a group of 147 patients undergoing open-label IFNbeta therapy. Overall, no significant differences in the distribution of responders and nonresponders, classified based on prospectively acquired primary and secondary clinical end points, were observed when stratified by any of the studied IFNAR gene polymorphisms. A trend detected with a single nucleotide polymorphism SNP 16469 (A/T) located at the third intron of the IFNAR1 gene, suggesting modest association with relapse-free status, will require confirmation in an independent data set. In addition, no significant association was observed of any of the IFNAR gene polymorphisms with susceptibility to MS, as studied by a family-based association analysis.

Adolescent↗

PubMed2001

Frequency, heterogeneity and encephalitogenicity of T cells specific for myelin oligodendrocyte glycoprotein in naive outbred primates.

Auto-reactive T cells present in healthy subjects remain in a state of unresponsiveness, but may trigger autoimmunity under various situations. Although myelin oligodendrocyte glycoprotein (MOG) is a potential target antigen in multiple sclerosis (MS), MOG-reactive T cell responses are present in the blood of both healthy subjects and MS-affected individuals. To investigate the disease-inducing potential and regulation of these autoreactive T cells in healthy outbred populations, we have characterized MOG-reactive T cell clones obtained by limiting dilution from peripheral blood of unimmunized C. jacchus marmosets. We report an extraordinarily high prevalence of circulating MOG-reactive T cells in these naive animals (2.6 +/- 1.4 / 10(5) PBMC), and a broadly diverse repertoire of epitope recognition encompassing at least three regions within the extracellular domain of MOG. Adoptive transfer of a MOG21-40-specific T cell clone resulted in mild clinical experimental allergic encephalomyelitis, characterized pathologically by rare foci of inflammation and minimal demyelination. We conclude that MOG-reactive T cells are present in healthy primates at a highly prevalent frequency, and are potentially capable of triggering central nervous system autoimmunity. Expansion of these autoreactive T cells must be tightly controlled to maintain immune homeostasis in healthy individuals.

Animals↗

PubMed2001

Immune responses against the myelin/oligodendrocyte glycoprotein in experimental autoimmune demyelination.

Myelin/oligodendrocyte glycoprotein (MOG) is a surface-exposed antigen of myelin and an important target for autoimmune responses which mediate inflammatory demyelination in the central nervous system. Experimentally, MOG induces strong pathogenic T cell responses in many strains of laboratory animals. Immunological studies in humans also identify MOG as a surprisingly prevalent antigenic molecule among the myelin proteins. In addition, the encephalitogenic properties of MOG are linked to the induction of antibody responses which have been demonstrated to directly promote central nervous system demyelination, a hallmark neuropathological feature in disorders such as human multiple sclerosis. Factors responsible for autoimmunity to MOG likely include genetic influences as well as other mechanisms, which are the subject of intense investigation. This article reviews experimental data currently available on specificity and pathogenic roles of T cell and antibody responses against MOG, which have implications relevant to multiple sclerosis and related disorders.

Amino Acid Sequence↗

PubMed2001

Frequency of multiple sclerosis in Menorca, Balearic islands, Spain.

OBJECTIVE: To establish prevalence and incidence of multiple sclerosis (MS) in Menorca (Balearic Islands, Spain; population: 67,009). METHODS: An extensive epidemiological study was undertaken using all available information sources. Patients were classified according to Poser's criteria. RESULTS: The prevalence rate of definite and probable MS was 68.6/100,000 (95% confidence interval 50.3-91.6). The incidence rate was 3.4/100,000/year (95% CI 2.2-5.3). The time lag between the first symptom and diagnosis was 10.2 years for patients with disease onset before 1987 and 2.1 years for patients with onset between 1987 and 1996. CONCLUSION: Menorca's population has a moderately high MS risk, with a prevalence rate the highest reported for a Spanish region.

Adult↗

PubMed2000

Human nerve growth factor protects common marmosets against autoimmune encephalomyelitis by switching the balance of T helper cell type 1 and 2 cytokines within the central nervous system.

Multiple sclerosis is a demyelinating disorder of the central nervous system (CNS), in which an immune attack directed against myelin constituents causes myelin destruction and death of oligodendrocytes, the myelin-producing cells. Here, the efficacy of nerve growth factor (NGF), a growth factor for neurons and oligodendrocytes, in promoting myelin repair was evaluated using the demyelinating model of experimental allergic encephalomyelitis (EAE) in the common marmoset. Surprisingly, we found that NGF delayed the onset of clinical EAE and, pathologically, prevented the full development of EAE lesions. We demonstrate by immunocytochemistry that NGF exerts its antiinflammatory effect by downregulating the production of interferon gamma by T cells infiltrating the CNS, and upregulating the production of interleukin 10 by glial cells in both inflammatory lesions of EAE and normal-appearing CNS white matter. Thus, NGF, currently under investigation in human clinical trials as a neuronal trophic factor, may be an attractive candidate for therapy of autoimmune demyelinating disorders.

Animals↗