Biomedical subjects

S Fredrikson

Publications and source records attributed to S Fredrikson.

At least 19 recordsLinked to original sources

PubMed2001

The T cell regulator gene SH2D2A contributes to the genetic susceptibility of multiple sclerosis.

The T cell specific adapter protein (TSAd) encoded by the SH2D2A gene is involved in the control of T cell activation. The gene is located in the 1q21 region, which has been implicated in susceptibility to experimental allergic encephalomyelitis in the mouse. We therefore evaluated whether a polymorphic GA repeat (GA(13)-GA(33)) within the promoter region of the SH2D2A gene shows association to multiple sclerosis (MS). The frequency of the short alleles GA(13-16) was increased among 313 Norwegian MS patients compared to 277 healthy controls (0.332 vs 0.249, OR 1.5, Pc = 0.03). Transmission disequilibrium analysis in 146 Scandinavian families with at least two affected sibs showed increased transmission of GA(16) to MS patients. No linkage or association of MS to four genetic markers flanking the SH2D2A gene was observed. After activation of naive CD4(+) T cells, T cells homozygous for MS associated short alleles displayed lower level of TSAd ex vivo than T cells carrying at least one long allele, which were not associated to MS. Since the SH2D2A protein modulates T cell activation, this may be a mechanism for how short SH2D2A alleles confer susceptibility to develop MS.

Adaptor Proteins, Signal Transducing↗

PubMed2001

Linkage analysis suggests a region of importance for multiple sclerosis in 3p14-13.

Four genomic screens for linkage in multiple sclerosis (MS) have been reported. They confirmed the established role of the human leucocyte antigen (HLA) complex genes in MS and, in addition, suggested the importance of a few other chromosomal segments. Here we report evidence for the importance of 3p14-13 region identified by suggestive linkage in genomic screens from Canada and the United Kingdom. When studying 146 Nordic MS multiplex families, mostly affected sib-pairs, with eight microsatellite markers, spanning a 36-cM region, we observed a two-point non-parametric linkage (NPL) score of 2.39 (P = 0.007) by the GENEHUNTER package for marker D3S1285 and a multipoint NPL score of 1.20 in the same region. Association studies in Swedish MS patients revealed modest allelic associations of uncertain significance not supported by transmission analysis. Analysis of the trinucleotide repeat sequence of the SCA7 gene in Swedish index cases did not reveal expansions. We conclude that support was obtained for the location of a gene or genes with importance for MS susceptibility in 3p14-13 region.

Alleles↗

PubMed2001

Altered phenotype and function of blood dendritic cells in multiple sclerosis are modulated by IFN-beta and IL-10.

Multiple sclerosis (MS) is assumed to result from autoaggressive T cell-mediated immune responses, in which T helper type 1 (Th1) cells producing cytokines, e.g. IFN-gamma and lymphotoxin promote damage of oligodendrocyte-myelin units. Dendritic cells (DCs) as potent antigen presenting cells initiate and orchestrate immune responses. Whether phenotype and function of DCs with respect to Th1 cell promotion are altered in MS, are not known. This study revealed that blood-derived DCs from MS patients expressed low levels of the costimulatory molecule CD86. In addition, production of IFN-gamma by blood mononuclear cells (MNCs) was strongly enhanced by DCs derived from MS patients. IFN-beta and IL-10 inhibited the costimulatory capacity of DCs in mixed lymphocyte reaction (MLR) and showed additive effects on suppression of IL-12 production by DCs. Correspondingly, DCs pretreated with IFN-beta and IL-10 significantly suppressed IFN-gamma production by MNCs. IFN-beta in vitro also upregulated CD80 and, in particular, CD86 expression on DCs. In vitro, anti-CD80 antibody remarkably increased, while anti-CD86 antibody inhibited DC-induced IL-4 production in MLR. We conclude that DC phenotype and function are altered in MS, implying Th1-biased responses with enhanced capacity to induce Th1 cytokine production. In vitro modification of MS patients' DCs by IFN-beta and IL-10 could represent a novel way of immunomodulation and of possible usefulness for future immunotherapy of MS.

Adult↗

PubMed2001

Costs, quality of life and disease severity in multiple sclerosis: a cross-sectional study in Sweden.

This study assessed the cost to society of multiple sclerosis (MS) in Sweden in 1998. The cost-of-illness method, based on the human capital theory, was used as the theoretical framework. The study used a cross-sectional approach, in which resource utilization data and quality-of-life data (utilities) were collected at a single time point. The total cost of MS was estimated at 4868 MSEK, or 586 MEUR, giving an annual cost of 442 500 SEK, or 53 250 EUR, per patient (1USD = 9.73 SEK, 1 EUR = 8.31 SEK, as of 21 September 2000). Direct costs accounted for about 67% of total cost, and they were dominated by the cost of personal assistants and drugs. Indirect costs (loss of production) accounted for about 33% of total costs. To these economic costs, intangible costs of 2702 MSEK (325 MEUR) should be added as well. Direct, indirect and informal care costs all rose significantly with increased disability and were higher during a relapse. Quality of life declined substantially with increased disability and was lower during a relapse. Multiple sclerosis was found to be associated with much higher costs to society than has been ascertained by former studies. The study also revealed a strong correlation between severity of the disease and quality of life. These results are crucial for further studies on the cost-effectiveness of new treatments aimed at preventing relapses and reducing progression of the disease.

Ambulatory Care↗

PubMed2000

Multiple sclerosis: pro- and anti-inflammatory cytokines and metalloproteinases are affected differentially by treatment with IFN-beta.

Interferon-beta (IFN-beta) has a beneficial influence on the course of multiple sclerosis (MS) and has become standard treatment of this disease, though its mechanisms of action are incompletely understood. This study examines the effect of IFN-beta treatment on the cytokines IL-6, TNF-alpha, IFN-gamma and IL-10; the metalloproteinases MMP-3, -7 and -9 and the tissue inhibitor of metalloproteinase-1 (TIMP-1). IFN-beta treatment resulted in decreased numbers of mononuclear cells (MNC) secreting IL-6 and TNF-alpha and expressing mRNA of MMP-3 and MMP-9 compared to pretreatment levels. On the contrary, numbers of IL-10 secreting MNC and TIMP-1 mRNA expressing were augmented during IFN-beta therapy. Whether the down-regulatory effects on pro-inflammatory and upregulatory effects on anti-inflammatory molecules are a direct result of IFN-beta on the immune system or secondary to clinical stabilization of MS pathology induced by IFN-beta remains to be evaluated.

Cells, Cultured↗

PubMed2000

Cost-utility analysis of interferon beta-1b in secondary progressive multiple sclerosis.

OBJECTIVES: Interferon beta-1b has recently become available for the treatment of secondary progressive multiple sclerosis (SPMS). This study aims at estimating the cost-effectiveness of this new treatment that has been shown in a clinical trial to reduce the progression of the disease. Effectiveness is measured as the number of quality-adjusted life-years (QALYs) gained from the reduction in progression. Because the clinical trial period will only capture part of the treatment's effect in terms of QALYs gained, since benefits achieved during the trial will have an effect beyond it, the cost-effectiveness analysis involves modeling over the longer term using complementary data. METHODS: A Markov model with states based on disability expressed by EDSS scores was used. Transition probabilities were calculated directly from clinical trial data for the first 3 years and then extrapolated to 10 years. Mean costs and utilities for each Markov state were calculated from a population-based cross-sectional study in Sweden. RESULTS: The incremental cost per QALY is SEK 342,700 (US $39,250; US $1 = SEK 8.73, March 10, 2000) when all costs (direct, informal care, and indirect) are included (discounted 3%). When indirect costs are excluded, the cost per QALY is SEK 542,000 ($62,100). CONCLUSIONS: Cost-effectiveness analysis in SPMS requires that the effect of treatment beyond clinical trials be included. Also, analysis should be done from a societal perspective, since many of the costs occur outside the healthcare system. The cost-utility ratios estimated in this analysis are at or below the mean threshold value indicated in a recent survey of health economists ($60,000).

Adjuvants, Immunologic↗

PubMed2000

Epidemiological surveillance of Guillain-Barré syndrome in Sweden, 1996-1997. Network members of the Swedish GBS Epidemiology Study Group.

OBJECTIVES: To set up an epidemiological surveillance system of Guillain-Barré syndrome (GBS) in Sweden and to evaluate the pilot practice of the system for 2 years. MATERIAL AND METHODS: A network of neurologists reported incident patients with a GBS diagnosis among a general population of 4.5 million inhabitants in Sweden during 1996 1997. Historical GBS data from the national hospital in-patient registry were used for predicting incidences and controlling under-reporting. RESULTS: One hundred and seventeen cases were reported. No alarm signals were identified during the study period. A re-analysis of data in 1996 revealed: 1) a higher than expected incidence in the population aged below 40 years in January, and 2) 27% under-reporting mainly associated to one hospital and to GBS patients hospitalized outside neurological departments. Threshold values for GBS incidences among the general and selected populations were obtained from corrected data. CONCLUSION: - The Swedish Network for GBS Surveillance can provide immediate support for epidemiological evaluation of suspected outbreaks or increased GBS incidence.

Adult↗

PubMed2000

Linkage analysis of a candidate region in Scandinavian sib pairs with multiple sclerosis reveals linkage to chromosome 17q.

To date, four genome screens have been completed in the demyelinating autoimmune disease multiple sclerosis (MS). Although these screens failed to identify any loci with major effects on susceptibility, several novel regions of potential linkage were suggested, including the long arm of chromosome 17. In order to further pursue this promising region we have investigated six highly polymorphic microsatellite markers in 115 Scandinavian families with MS affected sib pairs. Multipoint linkage analysis revealed a peak maximum likelihood score (MLS) of 0.9 in the region of marker D17S787. Stratifying the results on the basis of HLA-DR2 status showed that the linkage was not limited to families segregating for the HLA-DR2 allele as has previously been suggested. In conclusion, our results further support the proposal that a multiple sclerosis susceptibility locus is contained on chromosome 17q.

Chromosomes, Human, Pair 17↗

PubMed2000

Neutralizing and binding anti-interferon-beta (IFN-beta) antibodies. A comparison between IFN-beta-1a and IFN-beta-1b treatment in multiple sclerosis.

Interferon-beta (IFN-beta) is currently the most commonly used treatment of relapsing-remitting multiple sclerosis (MS). At the time of this study, two preparations of IFN-beta were available, IFN-beta-1a (Avonextrade mark) and IFN-beta-1b (Betaferon(R)), which both can elicit an immune response with the development of anti-IFN-beta antibodies. Direct comparisons between these two preparations regarding antibody frequencies have, however, been difficult to perform, because two different analysis methods measuring partly different biological effects of IFN-beta have been employed. In the present study, binding and neutralizing anti-IFN-beta-1a and -1b antibodies were detected in parallel by an independent, well-acknowledged, interferon research laboratory using an immunoassay and a cytopathic virus inhibition assay. Five per cent of patients treated with IFN-beta-1a intramuscularly (n = 20) had neutralizing antibodies (NABs) compared with 44% of patients treated with IFN-beta-1b subcutaneously (n = 48). A high degree of cross-reactivity between neutralizing anti-IFN-beta-1a and -1b antibodies was observed. No effect of NABs on clinical outcome could be detected in this limited material. Binding anti-IFN-beta antibodies were observed in 20% of IFN-beta-1a treated patients compared with 81% of patients treated with IFN-beta-1b. Only one of 17 patients examined (6%) had detectable titres of binding anti-IFN-beta-1b antibodies in the cerebrospinal fluid (CSF). These data are the first using identical methodology to show that IFN-beta-1a gives rise to fewer NABs than IFN-beta-1b at recommended treatment schedules.

Adjuvants, Immunologic↗

PubMed2000

Decreased mRNA expression of TNF-alpha and IL-10 in non-stimulated peripheral blood mononuclear cells in myasthenia gravis.

Myasthenia gravis (MG) is characterized by T cell-dependent autoantibodies to the acetylcholine receptor on the post-synaptic membrane of the neuromuscular junction. The production of autoantibodies is regulated by T cells via cytokines. To investigate the involvement of interferon gamma (IFN-gamma), tumour necrosis factor alpha (TNF-alpha), interleukin-4 (IL-4) and interleukin-10 (IL-10) in MG, the mRNA levels of these cytokines in peripheral blood mononuclear cells without stimulation in vitro were quantified by competitive reverse transcription polymerase chain reaction technique. The mRNA level of TNF-alpha was significantly lower (P = 0.0004) in the overall group of MG patients compared with controls. IL-10 was also lower in MG patients (P = 0.008), most markedly in non-thymectomized patients (P = 0.016). There were no significant differences in IFN-gamma and IL-4 between patients and healthy controls, but the mRNA levels of IL-4 in non-thymectomized patients was significantly lower than in controls (P = 0.02) and in thymectomized patients (P = 0.03). These results, reflecting the in vivo expression pattern of these cytokines in the periphery, suggest an altered cytokine expression at the systemic level in MG.

Adult↗

PubMed2000

Clinical epidemiology of Guillain-Barré syndrome in adults in Sweden 1996-97: a prospective study.

We described clinical manifestations, outcomes, prognostic indicators and clinico-epidemiological subgroups for 53 adult patients with Guillain-Barré syndrome (GBS) in Sweden during the period 1996-97. These patients were identified from a population of 2.8 million inhabitants and prospectively followed up for one year by a network of neurologists. An additional 10 cases, of whom five were adults who had not been prospectively followed up, were not included in the analyses. At 6 months after onset 80% of the patients could walk without aid, while at 1 year 46% were fully recovered, 42% had mild residual signs or symptoms, 4% had moderate and 6% severe disabilities, and 2% had died. Intravenous human immunoglobulin or plasmapheresis were used in 72% of the patients. The sum of the Medical Research Council (MRC) score at nadir was found as the only significant predictor for residual signs at 1 year in a multivariate model. Three subgroups, with different clinico-epidemiological characteristics, were identified by using cluster analysis. In conclusion, GBS in Sweden is frequently preceded by a respiratory infection, is often treated with immunomodulatory therapies, and exhibits a high recovery rate and a low fatality rate.

Adult↗

PubMed2000

Interferon-beta treatment for patients with multiple sclerosis: the patients' perceptions of the side-effects.

The aims of this study were to investigate (i) the self-reported frequency and intensity of systemic side-effects and their impact on the daily lives of patients suffering from Multiple Sclerosis (MS) and undergoing interferon-beta therapy and (ii) the self-reported frequency and perceptions of any local-tissue reactions. Forty patients aged 22 - 59 years (27 females) with relapsing/remitting MS were consecutively recruited for the study (17 on interferon-beta-1a and 23 on interferon-beta-1b). Two self-administered questionnaires were used before and after 1, 4, 8 and 16 weeks of therapy. The interferon therapy was found to be associated with flu-like symptoms. Most systemic side-effects were reported to be mild and to have little impact on the patients' daily lives. Asthenia and fatigue were more often rated as moderate or severe. The most frequently reported local-tissue side-effects were redness and local pain at the injection sites. A considerable inter-individual variation was found among patients regarding the perceptions of both the systemic and local side-effects. This suggests that it is of importance to identify early those patients who may need more support or other interventions to maintain a successful compliance. Multiple Sclerosis (2000) 6 349 - 354

Activities of Daily Living↗

PubMed2000

Incidence of Guillain-Barré syndrome in Sweden 1996.

We describe the incidence of Guillain-Barré syndrome (GBS) in Sweden in 1996. Information of incident GBS patients was mainly collected by a multicentre network of 18 neurologists prospectively monitoring a general population with 4.48 million inhabitants across the country and complemented with data from the national hospital in-patient registry. GBS diagnoses for all patients were validated by neurologists. While 53 patients with GBS were identified by the network neurologists from the study population, the other 20 GBS patients were recognized after carefully reviewing the registered data. There were 44 (60%) male patients and 29 (40%) female patients and the mean age at onset for all patients was 48.6 (SD 24.3) years. The GBS incidence, age-adjusted to the European standard population, was 1.51 (95% CI 1.18-1.90) per 100 000 person-years in 1996, higher in males and increased with age. When compared with selected studies, the GBS incidence in Sweden is moderately high, and the variation of GBS incidence in Europe seems to be small.

Adolescent↗

PubMed1999

[Place of residence determines access to interferon-beta therapy in MS. Less than 15 per cent of patients are treated--big differences between the counties].

Interferon-beta (IFNB) is the first agent to be registered in Sweden for modifying disease course in multiple sclerosis (MS). A nationwide survey uncovered a tenfold variation between counties in the prescribing of IFNB. About 10% of patients received treatment in a few counties, while in most the figure was even smaller. No correlation was found between sales of IFNB and numbers of neurologists in the respective counties. Patients should receive treatment according to national medical guidelines, regardless of place of residence.

Drug Costs↗

PubMed1999

Multiple sclerosis is associated with high levels of circulating dendritic cells secreting pro-inflammatory cytokines.

Recent evidence emphasises a pivotal role for dendritic cells (DC) in the control of immunity by priming and tolerising T cells. DC capture and process antigens, express co-stimulatory molecules, migrate to lymphoid organs and secrete cytokines to initiate immune responses. In multiple sclerosis (MS), autoreactive T cells are proposed to play a pathogenic role by secreting pro-inflammatory cytokines, but studies on DC are lacking. To evaluate the involvement of DC in patients with MS, a modified procedure was used to prepare DC from blood of patients with MS and healthy subjects. DC were found to be potent stimulators of T cells in allogeneic and, to a lesser extent, in autologous mixed leukocyte reaction (MLR). Enzyme-linked immunospot (ELISPOT) assays were adopted to determine levels of IFN-gamma, TNF-alpha, IL-6 and IL-10 secreting DC vs. mononuclear cells (MNC). Proportionally more DC than MNC secreted IFN-gamma and IL-10 in both MS and healthy subjects. Patients with MS had higher levels of IFN-gamma, TNF-alpha and IL-6 secreting DC than healthy subjects. The differences for IFN-gamma and TNF-alpha secreting cells were confined to the subgroup of untreated MS patients and not observed in the subgroup examined during ongoing treatment with IFN-beta. Circulating DC secreting pro-inflammatory cytokines may represent another focus for the study of both immuno-pathogenesis and therapeutic interventions in MS.

Adult↗

PubMed1999

Bilateral subdural haematomas following lumbar puncture in three haematopoietic stem cell transplant recipients.

Between 1990 and 1996, three patients (1.1%), all with CML, among 272 patients with haematological malignancies, developed bilateral subdural haematomas (SDH) after treatment with i.t. MTX before HSCT in our unit. Since October 1996, we have given i.t. MTX only to patients at increased risk of CNS leukaemia such as ALL and AML M4 or M5. We suggest that intrathecal treatment before HSCT should only be given to patients at increased risk of CNS leukaemia.

Adult↗

PubMed1999

Multiple sclerosis: levels of interleukin-10-secreting blood mononuclear cells are low in untreated patients but augmented during interferon-beta-1b treatment.

The cytokine interleukin (IL)-10 has immune response down-regulatory properties, which include suppression of the synthesis of pro-inflammatory cytokines such as interferon (IFN)-gamma and of major histocompatibility complex (MHC) class II expression on monocytes. To further elucidate the involvement of IL-10 in multiple sclerosis (MS), an enzyme-linked immunospot assay was adopted to enumerate IL-10-secreting mononuclear cells (MNC) in peripheral blood. IFN-gamma secreting MNC were detected in parallel. Levels of IL-10-secreting cells were lower in patients with MS compared with other neurological diseases (OND) and healthy subjects. This difference was seen only in patients with untreated MS, and not in those undergoing treatment with IFN-beta-1b. No differences were observed when subgrouping the patients with MS regarding clinical phase (exacerbation, remission, secondary progression), duration of MS or disability status. Levels of IFN-gamma-secreting blood MNC did not differ in patients with MS, irrespective of treatment with IFN-beta-1b, compared with OND and healthy subjects. Patients with MS, but not the two groups of controls, had elevated numbers of IL-10- and IFN-gamma-secreting cells upon stimulation with MBP compared with culture in the absence of antigen. The data suggest that IL-10 is decreased in MS and that treatment resulting in its up-regulation beneficially influence the disease.

Adult↗

PubMed1999

High numbers of perforin mRNA expressing CSF cells in multiple sclerosis patients with gadolinium-enhancing brain MRI lesions.

Enhanced expression of pro- and anti-inflammatory cytokines is a common finding in MS, but attempts to correlate cytokine expression with disease activity have produced conflicting results. In this paper, gadolinium-(Gd-)enhancing lesions on brain MRI were used as markers for active inflammation in patients with MS not treated with any immunomodulatory drugs. In parallel, in situ hybridization was used to detect blood and cerebrospinal fluid (CSF) mononuclear cells (MNC) expressing cytokine mRNA. An association was observed between numbers of perforin mRNA expressing CSF MNC and numbers of Gd-enhancing brain MRI lesions. Perforin mRNA expressing CSF MNC were not detected in any of the patients lacking active lesions on brain MRI. The expression of tumor necrosis factor-alpha, interleukin-10 (IL-10) and IL-12 mRNA in CSF MNC did not differ between MS patients with and without active MRI lesions. Based on the present finding, a role for perforin in the disruption of the blood-brain barrier in MS can be hypothesized.

Adult↗