A K Lefvert

Karolinska Institutet, Solna, Stockholm, Sweden

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Publications (210)898.5 Total impact

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    ABSTRACT: Measurement of inflammatory mediators is an important tool to assess inflammation. We have, therefore, conducted a survey within the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study to evaluate the inter-relationship between soluble CTLA-4 (sCTLA-4) and other inflammatory markers. This is a population-based study, designed to quantify the circulating serum levels of sCTLA-4 and other inflammatory markers such as CRP and pro-inflammatory cytokines and chemokines by in-house ELISA, Immuno-turbidimetry and multiplex ELISA, respectively. A total of 1016 Swedish Caucasians aged 70 years old were recruited. The statistical analysis was performed by ANOVA. The levels of sCTLA-4 were directly related to the levels of pro-inflammatory cytokines such as IL-6, IL-1alpha, IL-1beta, TNF-alpha, IFN-gamma and chemokines such as IL-8. However, the levels of sCTLA-4 were inversely related to the levels of MCP-1. Also, we could not demonstrate any relation between the levels of sCTLA-4 and CRP or soluble adhesion molecules. Circulating sCTLA-4 could be used as a biomarker for inflammation, potentially reflecting dysregulated T lymphocytes.
    Full-text · Article · Mar 2010 · Scandinavian journal of clinical and laboratory investigation
  • Priya Sakthivel · Ricardo Giscombe · Ryan Ramanujam · Ann Kari Lefvert
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    ABSTRACT: Genetic association of programmed cell death-1 (PDCD1) has been implicated in several autoimmune inflammatory disorders. Hence, in this study, our main objective is to evaluate the association of PDCD1 gene to Wegener's granulomatosis (WG). We, thus, analyzed three single nucleotide polymorphisms (SNPs) in PDCD1 gene among WG patients and controls. Further, we quantified circulating serum levels of soluble (s) PD-1 in patients and controls. The methodologies used were ABI Taqman allelic discrimination and restriction fragment length polymorphism for genotyping and in-house ELISA for quantifying sPD-1. Statistical relevance was analyzed by Fischer's exact test. As a result, reduced AA homozygote for SNP in intron-1 was observed, among the patients. However, no association was demonstrated after Bonferroni correction. Also, no differences in genotype and allele frequency were elucidated for SNPs in intron-4 and exon-5. Moreover, we could not demonstrate circulating sPD-1. In conclusion, we show no association of selected SNPs in PDCD1 gene with WG.
    No preview · Article · Jun 2009 · Rheumatology International
  • A.-C. Sundewall · A. K. Lefvert · R. Olsson

    No preview · Article · Apr 2009 · Acta Neurologica Scandinavica

  • No preview · Article · Apr 2009 · Acta Neurologica Scandinavica
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    ABSTRACT: In order to investigate the potential involvement of PTPN22 R620W in the pathogenesis of myasthenia gravis (MG), we performed a case-control study including 409 Swedish MG patients and 1557 normal controls. The W620 variant was significantly overrepresented in patients (odds ratio, 1.52; 95% confidence interval, 1.21-1.90; p=0.00027). Incubation of patient (n=100) derived PBMC cells with the autoantigen, the acetylcholine receptor, resulted in a significantly higher number of cells producing anti-AChR antibodies and IL-2 in W620 carriers, suggesting that PTPN22 W620 may be a loss-of-function variant in MG.
    No preview · Article · Aug 2008 · Journal of Neuroimmunology
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    ABSTRACT: Myasthenia gravis (MG) is an autoimmune disease characterized by muscle weakness induced by autoantibodies against the acetylcholine receptor. CTLA-4 (CD152) plays an inhibitory role in the immune response and has been suggested to be involved in the pathophysiology of MG. In this study, we focused on alternative CTLA-4 mRNA expression in PBMCs from MG patients. We defined two new isoforms of CTLA-4 mRNA that arise due to alternative splicing. By semi-quantitative RT-PCR analysis, we observed a lower expression of sCTLA-4 mRNA relative to the membrane form in MG patients. In addition, the MG patients had lower levels of sCTLA-4 mRNA in PBMCs compared to healthy controls, as assessed by real-time PCR. One of the spliced isoforms (LCTLA-4) was more prevalent in MG patients compared to healthy controls. The alternative splicing was not associated with sex, thymectomy, serum levels of anti-AChR, immunosuppressive treatment or the four CTLA-4 gene polymorphisms analyzed. This study reveals an abnormal spectrum of mRNA expression of CTLA-4 in MG patients, which marks the importance of studying gene expression of alternative splicing.
    No preview · Article · Jul 2008 · Clinical Immunology
  • M Kakoulidou · R Pirskanen-Matell · A K Lefvert
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    ABSTRACT: To measure clinical and immunological parameters in a patient with myasthenia gravis (MG) treated with antibodies against CD25 (basiliximab, Simulect). Patient and methods - Injections of basiliximab were given repeatedly together with cyclosporin A and corticosteroids for 9 months to a patient with severe MG. Her muscle function score was monitored and the immunological parameters were followed using ELISA, flow cytometry and radioimmunoassay. The patient improved moderately and corticosteroid treatment could be withdrawn. The percentage of activated CD4+ T cells decreased during treatment, while that of 'naïve' T cells increased. The serum levels of sCD28, sCD152, sCD80, sCD86 and IL-10 decreased. The treatment was stopped due to repeated infections. Treatment with basiliximab appears to be suitable only for severely ill patients who do not respond to conventional treatments. However, careful monitoring of side effects is necessary.
    No preview · Article · Apr 2008 · Acta Neurologica Scandinavica
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    ABSTRACT: The key role of an inhibitory receptor, Programmed Death-1, has been evaluated in 273 patients with autoimmune myasthenia gravis. At the genetic level, SNP's genotyping showed no significant association to the disease. Gene expressions in patients were not different from that in controls. Interestingly, at the cell-surface protein level, there were significant elevated levels of PD-1 on T cells and its ligand PD-L1 on monocytes in the patients compared to controls. However, we could not demonstrate any secreted soluble forms of PD-1 among the patients and controls. Thus, our study shows PD-1 might have a natural regulatory property behind MG.
    No preview · Article · Feb 2008 · Journal of Neuroimmunology
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    X B Wang · R Pirskanen · R Giscombe · A K Lefvert
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    ABSTRACT: The molecular mechanisms underlying the regulation of the CD152 (CTLA-4) gene are largely unknown. Two single nucleotide polymorphisms (SNPs) located in the promoter region are suspected to contribute to the pathogenesis of myasthenia gravis (MG) through regulation of gene expression. SETTING, SUBJECTS AND DESIGN: One hundred and sixty-five unrelated Swedish-Caucasian patients with MG (103 females and 62 males, age 17 to 92 years) and 148 ethnically matched healthy individuals were studied. Gene typing of two SNPs (T/C(-1772) and A/G(-1661)) and quantification of soluble CD152 were performed in the patients. Besides the association studies, the function of these two SNPs is characterized. We present new genetic associations of two SNPs in the CD152 gene with human MG. These SNPs located in the promoter region are involved in transcriptional binding activity for Nuclear Factor I (NF-1) and c/EBPbeta, as demonstrated using chromatin immunoprecipitation and electromobility shift assay. MG patients with the T/C(-1772) polymorphism have elevated levels of sCD152 in sera. The two SNPs in the promoter region are associated with MG and might cause abnormal alternative splicing and affect the expression of CD152, thereby contributing to the pathogenesis of MG.
    Full-text · Article · Feb 2008 · Journal of Internal Medicine
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    M Kakoulidou · R Giscombe · X Zhao · A K Lefvert · X Wang
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    ABSTRACT: CD80 is a costimulatory factor mainly expressed on the surface of activated monocytes, B cells and dendritic cells. In this study, we demonstrate that 24% of healthy individuals have soluble forms of CD80, sCD80, in their serum. The concentration of sCD80 ranged from 0 to 1 mg/l. At the mRNA level, we detected a spliced form s1CD80 (771 bp), in unstimulated monocytes and B cells, while another form named s2CD80 (489 bp) was expressed in activated T cells as well as in freshly isolated and activated monocytes. s1CD80 lacks the transmembrane domain, and the IgC-like domain plus the transmembrane domain are spliced out of s2CD80. We also present data demonstrating that recombinant s1CD80 binds to recombinant CD152-Ig and CD28-Ig. It can also bind to T cells, preferentially to activated T cells. Recombinant sCD80 had immunomodulatory effects shown by its inhibition of the mixed lymphocyte reaction and inhibition of T-cell proliferation. sCD80 in human serum adds a new member to the family of soluble receptors, implying a network of soluble costimulatory factors with functional relevance. The inhibitory effect of the recombinant protein on T-cell activation makes it a possible candidate for treatment of diseases associated with hyperactivated T cells.
    Full-text · Article · Dec 2007 · Scandinavian Journal of Immunology
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    ABSTRACT: The costimulatory factors CD28, CD80, CD86 and CD152 needed to start and turn off an immune response are present as membrane receptors and soluble proteins. There was no difference in the serum levels of soluble costimulatory molecules in 153 healthy controls and 118 patients with myasthenia gravis. However, we could confirm that the soluble forms of ICAM-1 and CD25 were increased in patients. The concentrations of the soluble costimulatory proteins seemed to be rather constant in individual patients, despite changes in clinical presentation. Thus, the soluble costimulatory factors do not seem to constitute reliable markers for disease activity in myasthenia gravis.
    No preview · Article · May 2007 · Journal of Neuroimmunology
  • M Kakoulidou · S Bjelak · R Pirskanen · A K Lefvert
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    ABSTRACT: To measure clinical and immunological parameters in a patient with myasthenia gravis (MG) treated with antibodies against tumour necrosis factor-alpha (infliximab, Remicade). A patient with severe MG received repeated injections of infliximab. His muscle function score was monitored and the immunological parameters were followed using enzyme-linked immunosorbent assay, flow cytometry and radioimmunoassay. The patient improved in muscle fatigability tests and the levels of antibodies against the acetylcholine receptor decreased during treatment. The activation marker human leucocyte antigen-DR on CD4(+) T cells also decreased. Treatment with infliximab might be beneficial for patients with severe MG but demands careful monitoring of possible serious side-effects.
    No preview · Article · May 2007 · Acta Neurologica Scandinavica
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    P Sakthivel · V Shively · M Kakoulidou · W Pearce · AK Lefvert
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    ABSTRACT: The T cell co-stimulatory factors CD28 and CTLA-4 and their ligands CD80 and CD86 occur as receptors on T cells and antigen-presenting cells and also in soluble forms in the circulation. We determined the levels of soluble co-stimulatory molecules in patients with abdominal aortic aneurysm (AAA) and normal individuals. We further correlated these soluble co-stimulatory molecules to other clinical parameters of importance such as age of the patient, presence of hypertension, size of the aneurysm and levels of matrix metalloproteinases-9 and C-reactive protein. This case-control study was designed to quantify the circulating levels of soluble co-stimulatory molecules by an in-house enzyme linked immunosorbent assay. A total of 314 subjects participated in the study including 100 patients and 214 normal controls. The statistical analysis was performed by Mann-Whitney test and Spearman's correlation rank test. Our results show increased plasma levels of sCD28, sCD86 (P = 0.0001) and decreased plasma levels of sCTLA-4 (P = 0.0018) in the patients compared with normal individuals. The levels of these factors were not related to the age of the patient, size of aneurysm or levels of C-reactive protein in plasma. There was, however, a significant inverse relationship between the concentrations of sCTLA-4 and sCD80 with matrix metalloproteinase-9. We suggest that soluble co-stimulatory molecules serve as biomarkers for the estimation of immune activation in AAA patients.
    Preview · Article · Apr 2007 · Journal of Internal Medicine
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    ABSTRACT: See also Santagostino E. Can the genetic profile predict inhibitor development in hemophilia A? This issue, pp 261–2.
    Full-text · Article · Jan 2007 · Journal of Thrombosis and Haemostasis
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    Full-text · Article · Jan 2007 · Journal of Genetics

  • No preview · Article · Dec 2006 · Annals of the New York Academy of Sciences
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    ABSTRACT: To describe two patients with myasthenia gravis (MG) and prolactinoma and analyze the associations between MG and prolactin (PRL) levels. Two case reports and a case-control study of PRL levels in 192 patients with MG. The Immunological Research Laboratory, Center for Molecular Medicine, Department of Medicine and the Department of Neurology, Karolinska Institutet, Stockholm, Sweden; St Petersburg Medical Academy for Postgraduate Studies, and St Petersburg State Medical Pediatric Academy, Russia. Two women with MG and thymic hyperplasia accompanied by prolactinomas are described. The levels of plasma PRL were raised in 101 women with MG, but not in 91 men. There was an association between high PRL levels and high levels of autoantibodies against the acetylcholine receptor. There is an association of MG with raised levels of PRL in women. PRL has stimulating effects on immune activation and the increased levels might thus be implied in the pathophysiology of MG.
    No preview · Article · Dec 2006 · Acta Neurologica Scandinavica
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    R Giscombe · X B Wang · M Kakoulidou · AK Lefvert
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    ABSTRACT: Wegener's granulomatosis (WG) is a chronic inflammatory disease characterized by granulomatosis inflammation, systemic vasculitis and glomerulonephritis. In patients, the peripheral T cells are characterized by mono/oligoclonal CD4+/CD8+ T-cell AV/BV receptor expansions, with aberrant expression of activation markers. This study was designed to characterize the phenotypic differences between the expanded and nonexpanded T-cell populations. Expression of markers for activation, costimulation and adhesion molecules was examined. As earlier studies have shown aberrant expression of CD28/CD152, we also analysed the expression of another costimulatory system, the tumour necrotic factor receptor (TNFR) superfamily proteins. Fluorocrome-conjugated monoclonal antibodies and flow cytometry was used to analyse the expression of the different markers on the surface of the expanded and nonexpanded subsets of T cells. The Karolinska Hospital and Karolinska Institutet in Stockholm, Sweden. Nine patients with WG (six men and three women) had 16 TCRAV/BV CD4+/CD8+ expanded populations that were characterized. The expanded TCRA/BV CD4+ and CD8+ cells had lower percentages of cells expressing CD28 and higher of those expressing CD152 (CTLA-4). The expanded CD4+ population had more cells expressing HLA-DR, CD57 and CCR5 (CD195), whilst the expression of CD25 was present on fewer of the expanded cells. The expanded CD8+ population contained more cells expressing CD137 (4-1BB), CD137 (4-1BBL), CD30 (Ki-1), CD40 and CD134 (OX40). There were marked differences in the phenotypes of expanded and nonexpanded T-cell populations.
    Full-text · Article · Oct 2006 · Journal of Internal Medicine
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    ABSTRACT: Inhibitory regulatory functions of B7-H3 and B7-H4 regarding T-cell activation have been reported recently. Little is known about the significance of human B7-H3 and B7-H4 expression in non-small-cell lung cancer (NSCLC), and we conducted the present study to address this issue in cell lines and tumor tissue from 70 patients. B7-H3 is over-expressed by all six NSCLC cell lines on both mRNA and protein level. B7-H4 is only transcripted by one cell line in which an alternatively spliced form was discovered. In tumor tissues, expression of B7-H3 and B7-H4 was found both on the cell membrane and in the cytoplasm. Thirty-seven percent of the specimens expressed B7-H3 and 43% B7-H4. The number of T infiltrating lymphoid cells (TILs) in the tumor tissues that expressed B7-H3 or B7-H4 was much lower than those who did not. There was a significant positive relation between the expression of B7-H3 and B7-H4, and high B7-H3 or B7-H4 expression was significantly more common in cases with lymph node metastasis. These observations suggest the contribution of B7-H3 and B7-H4 to immune dysfunction and tumor progression in NSCLC patients. B7-H3 and B7-H4 may be an important target for diagnosis and/or therapy of NSCLC.
    No preview · Article · Sep 2006 · Lung Cancer
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    Zhao Xiaoyan · R Pirskanen · V Malmstrom · AK Lefvert
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    ABSTRACT: Myasthenia gravis (MG) is commonly regarded as the prototype of an antibody-mediated, organ-specific autoimmune disease. Antibodies against the acetylcholine receptor (AChR) on the muscle endplate trigger its typical clinical manifestations of weakness and fatiguability. T-B cell interactions are thought to play a crucial role in the pathogenesis of MG. OX40 (CD134), a costimulatory molecule that is expressed on activated CD4+ T-cells, might contribute to the development or pathogenesis of immune-mediated diseases such as rheumatoid arthritis and graft-versus-host disease. In the present study, we investigated the expression of OX40 on CD4+ T-cells from patients with MG and healthy individuals. Results from 36 MG patients and 28 healthy controls revealed that more freshly isolated CD4+ T-cells from MG patients expressed OX40 than cells from healthy individuals. High levels of antibodies against the AChR, thymic hyperplasia and onset at an early age were associated with elevated expression of OX40. Upon activation by various concentrations of anti-CD3 antibodies, CD4+ T-cells from MG patients showed a tendency toward higher levels of OX40 expression than cells from healthy individuals. Given the role of OX40 in the immune system, we conclude that OX40 might contribute to the development of MG.
    Preview · Article · Feb 2006 · Clinical & Experimental Immunology

Publication Stats

6k Citations
898.50 Total Impact Points


  • 1977-2010
    • Karolinska Institutet
      • • Center for Molecular Medicine - CMM
      • • Department of Medicine, Huddinge
      • • Department of Clinical Chemistry
      Solna, Stockholm, Sweden
  • 1985-2009
    • Sahlgrenska University Hospital
      Goeteborg, Västra Götaland, Sweden
  • 1978-2008
    • Karolinska University Hospital
      • • Center for Molecular Medicine (CMM)
      • • Department of Hematology, Immunology, and HIV
      • • Department of Oncology
      • • Department of Clinical Chemistry
      Tukholma, Stockholm, Sweden
  • 2002
    • Umeå University
      Umeå, Västerbotten, Sweden
  • 1998
    • Queen's University Belfast
      Béal Feirste, Northern Ireland, United Kingdom
  • 1976-1997
    • Södersjukhuset
      Tukholma, Stockholm, Sweden
  • 1994
    • Laboratory for Molecular Infection Medicine Sweden
      Umeå, Västerbotten, Sweden
  • 1988
    • Hebrew University of Jerusalem
      • Department of Pathology
      Jerusalem, Jerusalem District, Israel
  • 1981-1984
    • University of Geneva
      • Department of Biochemistry
      Genève, Geneva, Switzerland
  • 1982
    • Copenhagen University Hospital
      København, Capital Region, Denmark