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A Svejgaard

Publications and source records attributed to A Svejgaard.

At least 37 records · Page 2Linked to original sources
PubMed2001

Post-induction residual leukemia in childhood acute lymphoblastic leukemia quantified by PCR correlates with in vitro prednisolone resistance.

Most prognostic factors in childhood acute lymphoblastic leukemia (ALL) are informative for groups of patients, whereas new approaches are needed to predict the efficacy of chemotherapy for the individual patient. The residual leukemia following 4 weeks of induction therapy with prednisolone, vincristine, doxorubicin and i.t. methotrexate and the in vitro resistance to prednisolone, vincristine, and doxorubicin were measured in 30 boys and 12 girls with B (n = 34) or T lineage (n = 8) ALL. The residual leukemia was quantified after 2 (MRD-D15, n = 29) and 4 weeks (MRD-PI, n = 42) of induction therapy with a precise and reproducible clone-specific PCR technique. The median MRD-D15 and MRD-PI were 0.50% (75% range 0.0088.1%) and 0.014% (75% range 0.001-2.0%), respectively, and these levels correlated significantly (n = 29, rs = 0.75, P < 0.001). Both the MRD-D15 and the MRD-PI were related to the age of the patient (MRD-D15: rs= 0.48, P= 0.009; MRD-PI: rs = 0.45, P = 0.003). Patients with T lineage ALL had higher MRD-PI than those with B lineage ALL (median MRD-PI: 0.5% vs 0.01%, P = 0.05). The median LC50 (concentration lethal to 50% of cells) for prednisolone was 2.3 microg/ml (75% range 0.05-668). Both MRD-D15 and MRD-PI correlated significantly with the in vitro resistance to prednisolone (MRD-D15: rs = 0.41, P = 0.03; MRD-PI: rs = 0.39, P = 0.01); but not to in vitro vincristine or doxorubicin resistance. The correlations between MRD and in vitro prednisolone resistance were even more pronounced when B cell precursor and T cell leukemia were analyzed separately (B cell precursor ALL: MRD-PI vs prednisolone LC50: n = 33, rs = 0.47, P = 0.006; T cell ALL: MRD-PI vs prednisolone resistance: n = 8, rs = 0.84, P = 0.009). After a median follow-up of 5.0 years (75% range 3.2-6.9) eight patients have relapsed. All of the 21 patients with a MRD-PI < or =0.5% and a prednisolone LC50 < or =10 microg/ml have remained in remission whereas the 7 year event-free survival for the remaining 20 patients was 0.45 +/- 0.16 (P= 0.002) Prospective studies in childhood ALL are needed to clarify whether combined monitoring of in vitro drug resistance and residual leukemia early during chemotherapy could offer new ways to classify patients and stratify the intensity of therapy.

Adolescent↗
PubMed2001

Interferon-alpha induces transient suppressors of cytokine signalling expression in human T cells.

The suppressors of cytokine signalling (SOCS) proteins comprise a newly identified family of negative feedback regulators of cytokine signalling. SOCS expression is differentially induced upon cytokine stimulation in different cell types. Here we show that interferon-alpha (IFNalpha) is a potent inducer of SOCS expression in human T cells, as high expression of CIS, SOCS-1, SOCS-2, and SOCS-3 was detectable after IFNalpha stimulation. After 4 h of stimulation, CIS, SOCS-1, and SOCS-3 expression had returned to baseline levels, whereas SOCS-2 expression had not declined. In contrast, after IL-2 induction neither CIS, SOCS-1, nor SOCS-2 expression levels declined after 6 h. In conclusion, we provide the first evidence that IFNalpha induces SOCS expression in human T cells. Moreover, we show that IFNalpha and IL-2 induce distinct patterns of expression kinetics, suggesting that dynamic changes in cytokine sensitivity might be mediated via induction of SOCS expression with different kinetics in T cells.

CD4-Positive T-Lymphocytes↗
PubMed2001

Oligonucleotide fishing for STAT6: cross-talk between IL-4 and chemokines.

Signal transducer and activator of transcription 6 (STAT6) is essential for the biological activities of interleukin-4 (IL-4) and the development of allergic responses in mice. Here we report on a sensitive and specific assay for STAT6 activation in response to IL-4. We took advantage of double-stranded oligonucleotide probes containing a STAT6-binding gene-sequence from the promotor of the immunoglobulin heavy chain germline epsilon transcript to study the IL-4-induced DNA binding of STAT6. Using these probes, we show that repeated adjacent STAT6-binding sites result in enhanced STAT6-DNA binding. Moreover, the distance between the binding sites is critical for STAT-DNA binding, i.e. STAT6 binding is decreased at distances above 20 nucleotides between neighbouring binding sites. Using this assay to study cross-talk between IL-4 and chemokines, we provide evidence that MIP-1beta and MIG inhibit IL-4-induced STAT6 activation, whereas other chemokines and cytokines do not. In conclusion, our data show that oligonucleotide fishing is a supplementary tool for studying cytokine cross-talk at a genomic level.

Animals↗
PubMed2001

Analysis of an interferon-gamma gene dinucleotide-repeat polymorphism in Nordic multiple sclerosis patients.

The proinflammatory cytokine interferon (IFN)-gamma has been shown to influence the course of multiple sclerosis (MS). The IFN-gamma (IFNG) contains a multiallelic dinucleotide repeat in intron 1. To investigate whether alleles at this locus influence susceptibility to MS, we performed linkage and familial association analyses on 100 sibling pairs from four Nordic countries, and case-control association analysis on 220 intermediately disabled sporadic MS patients and 266 controls. To determine the effect of the polymorphism on disease outcome, we compared genotype frequencies in the most and least disabled octiles of a total cohort of 913 cases. We also measured IFN-gamma mRNA levels in unstimulated peripheral blood mononuclear cells from 46 MS patients and 27 controls grouped according to IFNG intron 1 genotype. Both nonparametric linkage analysis and transmission disequilibrium testing of the 100 sibling pairs produced negative results. Genotype frequencies for intermediate-MS patients did not differ significantly from those for controls; nor did genotype frequencies in the benign-MS octile differ significantly from those in the severe-MS octle. Comparison of IFN-gamma mRNA levels in genotype-conditioned subgroups revealed no significant differences. Thus, alleles at the IFNG intron 1 dinucleotide repeat appear to affect neither MS susceptibility and severity nor IFN-gamma mRNA expression in vivo.

Case-Control Studies↗
PubMed2001

The influence of mannose binding lectin polymorphisms on disease outcome in early polyarthritis. TIRA Group.

OBJECTIVE: To determine whether variant alleles of the mannose binding lectin (MBL) gene causing low serum concentrations of MBL are associated with increased susceptibility to rheumatoid arthritis (RA) and erosive outcome in an inception cohort of patients with early polyarthritis. METHODS: MBL and HLA-DRB1 alleles were determined by polymerase chain reaction in 68 Danish patients with incident early polyarthritis observed for one year. The associations between MBL and specific HLA-DRB1 genotypes and disease outcomes were analyzed. RESULTS: Among the patients with early polyarthritis 7.4% (5/68) and 41.2% (28/68) were homozygous and heterozygous for MBL variant alleles, compared with 2.8% (7/250) and 34.4% (86/250) of healthy controls (p = 0.09), while the corresponding figures in the patients with RA were 10% (5/50) and 42% (21/50) (p = 0.03), and in the patients with erosive RA 18.8% (3/16) and 35.3% (6/16), respectively (p = 0.004). Patients with early polyarthritis homozygous for MBL variant alleles had an increased risk of having erosive RA at inclusion by a factor of 4.7 (p = 0.02) and after one year by a factor of 3.6 (p = 0.04). MBL deficiency was associated with increased levels of C-reactive protein (CRP) and IgM rheumatoid factor (RF) at inclusion (p < 0.05). HLA-DRB1 alleles were not found to be associated with disease outcome. CONCLUSION: MBL variant alleles appear to be weak susceptibility markers for RA, and patients with early polyarthritis and homozygous for MBL structural variant alleles have a higher risk of developing early erosive RA. These findings, together with the positive association between MBL variant alleles and the increased serum levels of IgM RF and CRP, point at the MBL gene as a relevant locus in the pathophysiology of RA.

Adult↗
PubMed2000

CXC chemokine receptor 3 expression on CD34(+) hematopoietic progenitors from human cord blood induced by granulocyte-macrophage colony-stimulating factor: chemotaxis and adhesion induced by its ligands, interferon gamma-inducible protein 10 and monokine induced by interferon gamma.

CXC chemokine receptor 3 (CXCR3), which is known to be expressed predominately on memory and activated T lymphocytes, is a receptor for both interferon gamma (IFN-gamma)-inducible protein 10 (gamma IP-10) and monokine induced by IFN-gamma (Mig). We report the novel finding that CXCR3 is also expressed on CD34(+) hematopoietic progenitors from human cord blood stimulated with granulocyte-macrophage colony-stimulating factor (GM-CSF) but not on freshly isolated CD34(+) progenitors. Freshly isolated CD34(+) progenitors expressed low levels of CXCR3 messenger RNA, but this expression was highly up-regulated by GM-CSF, as indicated by a real-time quantitative reverse transcriptase-polymerase chain reaction technique. gamma IP-10 and Mig induced chemotaxis of GM-CSF-stimulated CD34(+) progenitors by means of CXCR3, since an anti-CXCR3 monoclonal antibody (mAb) was found to block gamma IP-10-induced and Mig-induced CD34(+) progenitor chemotaxis. These chemotactic attracted CD34(+) progenitors are colony-forming units-granulocyte-macrophage. gamma IP-10 and Mig also induced GM-CSF-stimulated CD34(+) progenitor adhesion and aggregation by means of CXCR3, a finding confirmed by the observation that anti-CXCR3 mAb blocked these functions of gammaIP-10 and Mig but not of chemokine stromal cell-derived factor 1 alpha. gamma IP-10-induced and Mig-induced up-regulation of integrins (CD49a and CD49b) was found to play a crucial role in adhesion of GM-CSF-stimulated CD34(+) progenitors. Moreover, gamma IP-10 and Mig stimulated CXCR3 redistribution and cellular polarization in GM-CSF-stimulated CD34(+) progenitors. These results indicate that CXCR3-gamma IP-10 and CXCR3-Mig receptor-ligand pairs, as well as the effects of GM-CSF on them, may be especially important in the cytokine/chemokine environment for the physiologic and pathophysiologic events of differentiation of CD34(+) hematopoietic progenitors into lymphoid and myeloid stem cells, subsequently immune and inflammatory cells. These processes include transmigration, relocation, differentiation, and maturation of CD34(+) hematopoietic progenitors. (Blood. 2000;96:1230-1238)

Antigens, CD34↗
PubMed2000

Visualization of myelin basic protein (MBP) T cell epitopes in multiple sclerosis lesions using a monoclonal antibody specific for the human histocompatibility leukocyte antigen (HLA)-DR2-MBP 85-99 complex.

Susceptibility to multiple sclerosis (MS) is associated with the human histocompatibility leukocyte antigen (HLA)-DR2 haplotype, suggesting that major histocompatibility complex class II-restricted presentation of central nervous system-derived antigens is important in the disease process. Antibodies specific for defined HLA-DR2-peptide complexes may therefore be valuable tools for studying antigen presentation in MS. We have used phage display technology to select HLA-DR2-peptide-specific antibodies from HLA-DR2-transgenic mice immunized with HLA-DR2 molecules complexed with an immunodominant myelin basic protein (MBP) peptide (residues 85-99). Detailed characterization of one clone (MK16) demonstrated that both DR2 and the MBP peptide were required for recognition. Furthermore, MK16 labeled intra- and extracellular HLA-DR2-MBP peptide complexes when antigen-presenting cells (APCs) were pulsed with recombinant MBP. In addition, MK16 inhibited interleukin 2 secretion by two transfectants that expressed human MBP-specific T cell receptors. Analysis of the structural requirement for MK16 binding demonstrated that the two major HLA-DR2 anchor residues of MBP 85-99 and the COOH-terminal part of the peptide, in particular residues Val-96, Pro-98, and Arg-99, were important for binding. Based on these results, the antibody was used to determine if the HLA-DR2-MBP peptide complex is presented in MS lesions. The antibody stained APCs in MS lesions, in particular microglia/macrophages but also in some cases hypertrophic astrocytes. Staining of APCs was only observed in MS cases with the HLA-DR2 haplotype but not in cases that carried other haplotypes. These results demonstrate that HLA-DR2 molecules in MS lesions present a myelin-derived self-peptide and suggest that microglia/macrophages rather than astrocytes are the predominant APCs in these lesions.

Amino Acid Sequence↗
PubMed2000

Competitive PCR for quantification of minimal residual disease in acute lymphoblastic leukaemia.

A very precise and reproducible polymerase chain reaction (PCR) method was developed in order to quantify minimal residual disease (MRD) in children with acute lymphoblastic leukaemia (ALL). A clone-specific competitor was constructed by introducing a restriction site in a PCR product identical to parts of the highly specific rearranged T-cell receptor delta (TCR-delta), T-cell receptor gamma (TCR-gamma), or immunoglobulin heavy chain (IgH) genes of the malignant clone. Using primers located externally to the restriction site the competitor and the DNA from the malignant clone will be amplified under identical conditions. After restriction enzyme cleavage, the PCR products originating from the competitor and the malignant clone can be distinguished by size in a gel electrophoresis step and the amount of residual disease can be determined. The method is very sensitive with a detection limit of at least one malignant cell in 10(5) normal cells. This method may be used for treatment stratification based on the early response to antileukaemic therapy.

Adolescent↗
PubMed2000

The association of variant mannose-binding lectin genotypes with radiographic outcome in rheumatoid arthritis.

OBJECTIVE: To investigate the possible association of mannose-binding lectin (MBL) genotypes with the outcome of rheumatoid arthritis (RA). METHODS: MBL genotypes and plasma concentrations were retrospectively determined in 140 RA patients who were selected from a major cohort followed up prospectively for up to 32 years. RESULTS: MBL-insufficient patients (those with 2 defective structural MBL alleles or with 1 defective allele combined with a low-expression variant of the normal allele) had unfavorable outcomes. The relative risk of a severe radiographic outcome event (30% of maximum radiographic destruction, or an RE30) was 3.1 (95% confidence interval 1.8-5.1) in the MBL-insufficient group versus the MBL-competent group (P < 0.0001). An RE30 occurred in 50% of MBL-competent patients within 17 years, while such an event occurred 9 years earlier in MBL-insufficient patients (i.e., within 8 years) (P < 0.0001). During the first 15 years, there was a significant trend toward lower hemoglobin levels (P < 0.04), higher erythrocyte sedimentation rates (P < 0.02), and a higher number of swollen joints (P < 0.05) in the MBL-insufficient group. CONCLUSION: MBL genotypes giving rise to MBL insufficiency are highly significant risk factors for fast progression of radiographic joint destruction.

Adolescent↗
PubMed2000

HLA DRB1*1501 and intrathecal inflammation in multiple sclerosis.

CD4 T cells are considered to be pivotal in the pathogenesis of multiple sclerosis (MS), and the human leukocyte antigen (HLA) haplotype associated with DRB1*1501 confers susceptibility to MS in patients of Northern European descent. Some previous studies have suggested an association of DRB1*1501 with T- and B-cell reactivity to specific myelin protein peptides, other studies suggested an association with enhanced cytokine production or intrathecal immunoglobulin (Ig) synthesis. In order to further assess the role of DRB1*1501 in the pathogenesis of MS, we studied intrathecal inflammation and T-cell phenotypes in patients with possible onset symptoms or clinically definite MS. Presence of DRB1*1501 was associated with higher levels of cerebrospinal fluid (CSF) inflammation as assessed by IgG synthesis levels and higher levels of matrix metalloproteinase-9 activity. DRB1*1501-positive patients also had a lower percentage of T cells in CSF expressing HLA-DR without co-expressing CD25. These findings suggest that enhanced intrathecal inflammation and an altered T-cell activation status may be of importance in conferring the DRB1*1501-associated susceptibility to MS.

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

Two edged role of mannose binding lectin in rheumatoid arthritis: a cross sectional study.

OBJECTIVE: We investigated whether polymorphisms in the gene of mannose binding lectin (MBL) may be associated with onset of rheumatoid arthritis (RA), and whether MBL in conjunction with aggregated agalactosyl IgG (IgG-G0) may be associated with clinical and paraclinical variables. METHODS: MBL genotypes and serum concentrations were measured by polymerase chain reaction and ELISA in 189 patients with established RA. Binding of purified MBL to IgG-G0 in serum was assessed and clinical and paraclinical variables were recorded. RESULTS: The median age at onset of RA in the 3 genotypes (normal: A/A, hetero: A/0, and homozygous: 0/0 for variant alleles) was 54.1 (n = 108), 47.0 (n = 68), and 38.4 years (n = 13), respectively (p = 0.01). The frequency of variant alleles in patients with onset below the median age (50.8 yrs) was 0.32, but was 0.17 in patients with onset above 50.8 years (p = 0.003) and 0.20 in 250 controls (p = 0.001). Stratification according to erosion score (no, small, large) revealed an increasing tendency among the different groups in binding of MBL to IgG-G0, increased Health Assessment Questionnaire score, and acute phase reactants in A/A individuals, while no difference was seen among carriers of variant alleles. This effect was most pronounced in those with late onset RA. CONCLUSION: Presence of MBL variant alleles was associated with early onset of RA. MBL deficiency may, therefore, accelerate the disease. However, in patients with late onset and advanced disease our results indicate that the A/A type may be associated with additional inflammation different from that seen in carriers of variant alleles.

Adult↗
PubMed2000

A molecule basis for the HLA association in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a common chronic autoimmune disease that primarily affects the joints. The etiology of RA is unknown, and the pathogenesis is only poorly defined. One of the few clues to the understanding of the pathogenesis of RA is the observation that the disease is associated with genes in the major histocompatibility complex (MHC). Recent structural and functional studies provide molecular insight into the role of MHC genes in RA susceptibility. This insight provides an important basis for further understanding of the disease mechanism, generation of humanized animal models for RA, and the development of new immunomodulatory drugs with a minimum of unwanted side effects.

Animals↗