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Biomedical subjects

J Sieper

Publications and source records attributed to J Sieper.

At least 19 recordsLinked to original sources
PubMed2002

Treatment of active ankylosing spondylitis with infliximab: a randomised controlled multicentre trial.

UNLABELLED: BACKGROUND Treatment options for patients with ankylosing spondylitis are few. We aimed to assess the effectiveness of infliximab, an antibody to tumour necrosis factor (TNF)-alpha, in treatment of such patients. METHODS: In this 12-week placebo-controlled multicentre study, we randomly assigned 35 patients with active ankylosing spondylitis to intravenous infliximab (5 mg/kg) and 35 to placebo at weeks 0, 2, and 6. One patient in the infliximab group was withdrawn from the study. Our primary outcome was regression of disease activity of at least 50%. To assess response, we used validated clinical criteria from the ankylosing spondylitis assessment working group, including disease activity (BASDAI), functional indices (BASFI), metrology (BASMI), and quality of life (short form 36). Analyses were done by intention to treat. FINDINGS: 18 (53%) of 34 patients on infliximab had a regression of disease activity at week 12 of at least 50% compared with three (9%) of 35 on placebo (difference 44% [95% CI 23-61], p<0.0001). Function and quality of life also improved significantly on infliximab but not on placebo (p<0.0001 and p<0.0001, respectively). Treatment with infliximab was generally well tolerated, but three patients had to stop treatment because of systemic tuberculosis, allergic granulomatosis of the lung, or mild leucopenia. INTERPRETATION: Our results show that treatment with infliximab is effective in patients with active ankylosing spondylitis. Since there are some potentially serious adverse effects, we recommend that this treatment mainly be used in co-operation with rheumatological centres.

Adult↗
PubMed2002

[Epidemiology and patient management in the area of spondyloarthritis].

Within the group of inflammatory rheumatic diseases, spondyloarthropathy is the most common diagnosis after rheumatoid arthritis. Its prevalence was long underestimated. Ankylosing spondylitis (AS) and undifferentiated spondyloathropathy (uSpA) are the most common subgroups in western countries. There are still difficulties in diagnosis especially of the early forms of the spondyloarthropathies. Data of socioeconomics and therapeutic options are limited. In more recent times, researchers have started to investigate the burden of disease and the socioeconomic aspects. Better diagnostic options are available and promising new therapeutic agents, especially TNF-alpha blocking agents, have been investigated. However, further studies are urgently needed for this underestimated group of diseases and are currently being performed inside the German rheumatology network.

Adolescent↗
PubMed2001

Identification of HLA-B27-restricted peptides from the Chlamydia trachomatis proteome with possible relevance to HLA-B27-associated diseases.

The association of HLA-B27 with ankylosing spondylitis and reactive arthritis is the strongest one known between an MHC class I Ag and a disease. We have searched the proteome of the bacterium Chlamydia trachomatis for HLA-B27 binding peptides that are stimulatory for CD8(+) cells both in a model of HLA-B27 transgenic mice and in patients. This was done by combining two biomathematical computer programs, the first of which predicts HLA-B27 peptide binding epitopes, and the second the probability of HLA-B27 peptide generation by the proteasome system. After preselection, immunodominant peptides were identified by Ag-specific flow cytometry. Using this approach we have identified for the first time nine peptides derived from different C. trachomatis proteins that are stimulatory for CD8(+) T cells. Eight of these nine murine-derived peptides were recognized by cytotoxic T cells. The same strategy was used to identify B27-restricted chlamydial peptides in three patients with reactive arthritis. Eleven peptides were found to be stimulatory for patient-derived CD8(+) T cells, of which eight overlapped those found in mice. Additionally, we applied the tetramer technology, showing that a B27/chlamydial peptide containing one of the chlamydial peptides stained CD8(+) T cells in patients with Chlamydia-induced arthritis. This comprehensive approach offers the possibility of clarifying the pathogenesis of B27-associated diseases.

Animals↗
PubMed2001

[Glucocorticoid-induced osteoporosis].

Osteoporosis due to steroid therapy is one of the most frequent and serious adverse events of antirheumatic therapy. The greatest loss of bone occurs during the 1st year of steroid intake, with the largest loss in the spine. Up to 50% of the patients, mostly postmenopausal women, suffer vertebral fractures. The prevalence of osteoporosis in 60-year-old patients with rheumatoid arthritis (RA) is more than double compared to the normal population. There are more risk factors other than age, gender, and menopause. Independent from the underlying disease, glucocorticoid therapy is associated with a high risk of osteoporosis development. Among the clinical manifestations of osteoporosis, fractures of the vertebrae, hips, and ribs are the most common. In clinical practice, bone density measurements are mostly performed with the dual-energy X-ray absorptiometry (DXA) technique. Since prevalent vertebral fractures are strongly predictive of new fractures, X-rays of the lumbar and thoracic spine are indicated in patients who are scheduled to receive steroid therapy for > 3 months. The value of serologic bone markers has not yet been clearly established. On the basis of these risks and the high prevalence of already manifest osteoporosis, there is a clear indication for osteoprotective therapy in RA. Bisphosphonates and active vitamin D metabolites play an important role for therapy and prophylaxis of steroid-induced osteoporosis. In rheumatology it is often necessary to administer bisphosphonates intravenously due to the disability of the patients. The clear necessity for prophylaxis and therapy of steroid-induced osteoporosis must be stressed. Efforts should be intensified to ensure even more consistent application in daily practice. Doctors should treat their steroid patients on the basis of the clear-cut indications for intervention despite budget problems.

Absorptiometry, Photon↗
PubMed2001

[Current status of therapeutic approaches in spondyloarthropathies].

Anti-TNF therapy seems to be highly effective in AS. Based on the available results, this treatment seems to be at least as effective as in RA. Furthermore, because no other treatments are available for AS--in contrast to RA or psoriatic arthritis--infliximab might even become a first-line immuno-suppressive treatment in patients with severe, active AS. A dosage of 5 mg/kg seems to be required and intervals between 6-12 weeks seem to be necessary depending on the disease activity. It remains to be shown what the long-term effects are, whether the patients benefit from long-term therapy and whether radiological progression and ankylosis can be stopped. Allergy, lupus-like diseases and tuberculosis are rare side effects which need to be addressed. At first glance, the possible benefits of anti-TNF therapy seem to outweigh these shortcomings.

Antibodies, Monoclonal↗
PubMed2001

Regulation of expression of cytokines and growth factors in osteoarthritic cartilage explants.

Osteoarthritis (OA) is a degenerative joint disease characterised by the breakdown of the extracellular matrix of chondrocytes in the affected joints. Cytokines and growth factors which are known to play a role in the synthesis and degradation of cartilage matrix have been shown to be upregulated in osteoarthritic cartilage. This upregulation resulted in two different phenotypes, overexpressing either TNF-alpha and IL-6 or IL-1beta, TGFbeta1, IL-4 and IL-10. To investigate the hierarchy among growth factors and cytokines involved in cartilage metabolism, we analysed osteoarthritic cartilage explants for their responses to human recombinant (rh) cytokines and growth factors. The cytokine expression patterns of the explants before and after in vitro culture were compared by immunohistological staining of cartilage sections. We found a coordinate expression of TNF-alpha and IL-6 on the one hand, and of IL-1beta, TGFbeta1, IL-4 and IL-10 on the other. Although TNF-alpha and IL-6 stimulated each other's expression, they downregulated TGF beta1, IL-4 and IL-10 or IL-1beta, TGF beta1 and IFNdelta, respectively. IL upregulated the expression of TGF beta1, IL-4 and IL-10, and jointly these four cytokines and growth factors downregulated IL-6. Both of the expression patterns described for OA cartilage can be explained by these regulatory mechanisms. Interestingly, no cytokine efficiently downregulated TNF-alpha, and even though IL-1beta is upregulated in one of the OA phenotypes, none of the growth factors and cytokines tested--except for IL-1beta itself--seemed capable of mediating this upregulation. This unresponsiveness to cytokine stimulation might hint at a genetic cause for the elevated expression in the respective phenotypes.

Aged↗
PubMed2001

Pathogenesis of reactive arthritis.

There is good evidence that bacteria persist in vivo in patients with reactive arthritis (ReA). While Chlamydia seem to hide inside the joint, other areas such as gut mucosa or lymph nodes seem to be more likely places for Salmonella and Yersinia. T-helper (Th) 1 cells secreting cytokines such as IFN gamma and TNF alpha are crucial for an effective elimination of these bacteria. An inhibited Th1-response could be demonstrated in ReA, probably contributing to bacterial persistence. While HLA-B27 is found in only approximately 50% of patients with acute ReA, HLA-B27 seems to be crucial for the development of features typical with chronic spondyloarthropathy, such as sacroiliitis. Among several hypotheses to explain the interaction of bacteria with HLA-B27, the most likely seems to be that until now unknown bacterial or self- antigens were presented by HLA-B27 to CD8(+) T-cells. An important site where the immunopathology takes place seems to be at the insertion of tendons and ligaments at bone. Because antibiotics have failed so far in the treatment of ReA immunomodulatory therapies, based on a better understanding of the pathogenesis, alone or in combination with antibiotics might be an option for the future.

Arthritis, Reactive↗
PubMed2001

New treatment options in spondyloarthropathies: increasing evidence for significant efficacy of anti-tumor necrosis factor therapy.

Tumor necrosis factor-alpha is a major effector and regulatory cytokine, which seems to have an outstanding position in rheumatic and other inflammatory states. Because TNF-alpha has been detected in the inflamed gut and sacroiliac joints of patients with chronic inflammatory bowel diseases and spondyloarthritides, like ankylosing spondylitis, there was need for studies of the efficacy of the modern biologic anti-TNF agents infliximab and etanercept in these diseases. Infliximab is approved for the treatment of Crohn disease. In addition, there are now also positive data for infliximab in the treatment of ankylosing spondylitis and for etanercept and infliximab in the treatment of psoriatic arthritis.

Antibodies, Monoclonal↗
PubMed2001

Low T cell production of TNFalpha and IFNgamma in ankylosing spondylitis: its relation to HLA-B27 and influence of the TNF-308 gene polymorphism.

OBJECTIVE: To test the hypothesis that ankylosing spondylitis (AS) is a T helper cell type 2 polarised disease by quantifying the T cell cytokines interferon gamma (IFNgamma), interleukin 4 (IL4), tumour necrosis factor alpha (TNFalpha), and IL10 at the single cell level in patients with AS in comparison with healthy HLA-B27 negative and HLA-B27 positive controls. METHODS: Peripheral blood mononuclear cells from 65 subjects (25 HLA-B27 positive patients with active AS, 18 healthy HLA-B27 positive controls, and 22 healthy HLA-B27 negative controls) were stimulated with phorbol myristate acetate/ionomycin for six hours, surface stained for CD3 and CD8, intracellularly stained for the cytokines IFNgamma, TNFalpha, IL4, and IL10, and analysed by flow cytometry. TNFalpha production was related to the genotype of the TNFalpha promoter at the -308 and -238 polymorphisms. RESULTS: In peripheral blood the percentage of TNFalpha+ T cells was significantly lower in HLA-B27 positive patients with AS (median 5.1% for CD4+ T cells) than in healthy HLA-B27 negative controls (median 9.5%; p=0.008). Surprisingly, the percentage of TNFalpha+ T cells was also significantly lower in healthy HLA-B27 positive controls (median 7.48%) than in healthy HLA-B27 negative controls (p=0.034). Furthermore, the percentage of IFNgamma+ T cells was lower in patients with AS and in healthy HLA-B27 positive controls than in healthy HLA-B27 negative controls (p=0.005 and p=0.003, respectively). The percentage of IL10+/CD8+ T cells was higher in patients with AS than in both control groups. In HLA-B27 positive subjects, TNF1/2 heterozygosity at -308 (n=6) was associated with a higher percentage of TNFalpha+ T cells than TNF1/1 homozygosity (n=25; median 9.97% v 5.11% for CD4+ T cells; p=0.017). In contrast, in HLA-B27 negative controls (n=18) there was no such genotype/phenotype correlation (median 9.4% v 10.6%). CONCLUSIONS: The lower T cell production of TNFalpha and IFNgamma shown at the single cell level in HLA-B27 positive patients with AS and healthy HLA-B27 positive controls may contribute to the increased susceptibility of HLA-B27 positive subjects to develop AS. Preliminary genotype-phenotype correlations suggest that in HLA-B27 positive subjects TNF2 at -308 or a linked gene results in higher TNFalpha production and, therefore, might be a marker for a protective haplotype.

Adult↗
PubMed2001

Low incidence of reactive arthritis in children following a salmonella outbreak.

OBJECTIVES: To assess the incidence of reactive arthritis (ReA) in an outbreak of salmonella infection in a large cohort of children in Germany. METHODS: A few days after the salmonella outbreak all parents of affected children and all paediatricians and general practitioners in the region were provided with detailed information about the possibility of ReA. Six weeks after the outbreak a telephone call was made to all general practitioners and paediatricians to identify patients with ReA. Ten weeks after the outbreak a questionnaire assessing symptoms of ReA was mailed to all parents, and after a period of 4 months paediatricians and general practitioners were contacted again to search for additional unreported cases of ReA. RESULTS: Of the 286 children (age range 11 months to 9 years) with diarrhoea and stool cultures positive for Salmonella enteritidis lysotype 8/7, not a single case of arthritis was reported over the 4 month period. However, six children (2%) had arthralgia of various duration (1 day to 6 weeks) with a single recurrence in one child. The joint pattern was oligoarticular and lower limb joints (knee/ankle) were affected exclusively. CONCLUSION: The incidence of ReA after salmonella infection in children appears to be very low which may be related to differences in the immune response between children and adults.

Arthritis, Reactive↗