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Banfi G, Božič B, Cihan M, Pašalić D, Pennestrì F, Plebani M. Point-of-care testing, near-patient testing and patient self-testing: warning points. Clin Chem Lab Med 2024; 0:cclm-2024-0525. [PMID: 38711414 DOI: 10.1515/cclm-2024-0525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Accepted: 04/28/2024] [Indexed: 05/08/2024]
Abstract
Point-of-care testing (POCT), near-patient testing (NPT) and patient self-tests (PST) are diagnostic examinations performed at the time and place of patient care. While POCT and NPT are performed and analyzed by medical professionals, PST are based on samples and parameters directly collected and analyzed by lay users. These tests are spreading both in high income countries and in low to middle income countries as they are expected to improve healthcare efficiency and equity, by saving resources, releasing pressure from hospitals and reducing logistical barriers. However, accurate multidisciplinary assessment is mandatory to ensure that what they promise is real. We reviewed some important ethical aspects, international standards and regulations. The current risks associated with alternative ways of testing are explained by the principles of respect for patient autonomy and non-maleficence. Further evidence from multidisciplinary assessment is needed to evaluate pros and cons in light of the principles of beneficence and justice. Although POCT or NPT need common regulation and accurate provider training to ensure safe and appropriate interpretation of results, PST needs even more attention as they are subject to direct patient use. Randomized controlled trails including patient education should be conducted in order to provide reliable evidence on clinical outcomes, patient acceptance and cost-effectiveness. Mandatory regulation is needed to avoid harm and EU regulation should help different countries maintain a safe use of devices in a global population of producers and users.
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Affiliation(s)
- Giuseppe Banfi
- IRCCS Istituto Ortopedico Galeazzi, Milan, Italy
- Vita-Salute San Raffaele University, Milan, Italy
| | - Borut Božič
- Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - Murat Cihan
- Faculty of Medicine, Ordu University, Ordu, Türkiye
| | - Daria Pašalić
- Department of Medical Chemistry, Biochemistry and Clinical Chemistry, University of Zagreb School of Medicine, Zagreb, Croatia
| | | | - Mario Plebani
- Laboratory Medicine Unit, Department of Medicine, University of Padua, Padua, Italy
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Lakota K, Švec T, Kveder T, Sodin-Šemrl S, Žigon P, Ambrožič A, Ogrič M, Markez S, Božič B, Tomšič M, Čučnik S. Autoantibodies against dsDNA measured with nonradioactive Farr assay—an alternative for routine laboratories. Clin Rheumatol 2018; 38:353-359. [DOI: 10.1007/s10067-018-4271-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 07/30/2018] [Accepted: 08/20/2018] [Indexed: 10/28/2022]
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Gmeiner T, Horvat N, Kos M, Obreza A, Vovk T, Grabnar I, Božič B. Curriculum Mapping of the Master's Program in Pharmacy in Slovenia with the PHAR-QA Competency Framework. Pharmacy (Basel) 2017; 5:pharmacy5020024. [PMID: 28970436 PMCID: PMC5597149 DOI: 10.3390/pharmacy5020024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 03/14/2017] [Accepted: 04/22/2017] [Indexed: 11/16/2022] Open
Abstract
This article presents the results of mapping the Slovenian pharmacy curriculum to evaluate the adequacy of the recently developed and validated European Pharmacy Competences Framework (EPCF). The mapping was carried out and evaluated progressively by seven members of the teaching staff at the University of Ljubljana's Faculty of Pharmacy. Consensus was achieved by using a two-round modified Delphi technique to evaluate the coverage of competences in the current curriculum. The preliminary results of the curriculum mapping showed that all of the competences as defined by the EPCF are covered in Ljubljana's academic program. However, because most EPCF competences cover healthcare-oriented pharmacy practice, a lack of competences was observed for the drug development and production perspectives. Both of these perspectives are important because a pharmacist is (or should be) responsible for the entire process, from the development and production of medicines to pharmaceutical care in contact with patients. Nevertheless, Ljubljana's graduates are employed in both of these pharmaceutical professions in comparable proportions. The Delphi study revealed that the majority of differences in scoring arise from different perspectives on the pharmacy profession (e.g., community, hospital, industrial, etc.). Nevertheless, it can be concluded that curriculum mapping using the EPCF is very useful for evaluating and recognizing weak and strong points of the curriculum. However, the competences of the framework should address various fields of the pharmacist's profession in a more balanced way.
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Affiliation(s)
- Tanja Gmeiner
- Faculty of Pharmacy, University of Ljubljana, Askerčeva 7, 1000 Ljubljana, Slovenia.
| | - Nejc Horvat
- Faculty of Pharmacy, University of Ljubljana, Askerčeva 7, 1000 Ljubljana, Slovenia.
| | - Mitja Kos
- Faculty of Pharmacy, University of Ljubljana, Askerčeva 7, 1000 Ljubljana, Slovenia.
| | - Aleš Obreza
- Faculty of Pharmacy, University of Ljubljana, Askerčeva 7, 1000 Ljubljana, Slovenia.
| | - Tomaž Vovk
- Faculty of Pharmacy, University of Ljubljana, Askerčeva 7, 1000 Ljubljana, Slovenia.
| | - Iztok Grabnar
- Faculty of Pharmacy, University of Ljubljana, Askerčeva 7, 1000 Ljubljana, Slovenia.
| | - Borut Božič
- Faculty of Pharmacy, University of Ljubljana, Askerčeva 7, 1000 Ljubljana, Slovenia.
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Mally M, Božič B, Hartman SV, Klančnik U, Mur M, Svetina S, Derganc J. Controlled shaping of lipid vesicles in a microfluidic diffusion chamber. RSC Adv 2017. [DOI: 10.1039/c7ra05584f] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The chemical environment around flaccid lipid vesicles, i.e., the osmotic conditions and the concentration of membrane-shaping molecules, is regulated only by diffusion without any hydrodynamic flow.
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Affiliation(s)
- M. Mally
- Institute of Biophysics
- Faculty of Medicine
- University of Ljubljana
- Ljubljana
- Slovenia
| | - B. Božič
- Institute of Biophysics
- Faculty of Medicine
- University of Ljubljana
- Ljubljana
- Slovenia
| | - S. Vrhovec Hartman
- Institute of Biophysics
- Faculty of Medicine
- University of Ljubljana
- Ljubljana
- Slovenia
| | - U. Klančnik
- Institute of Biophysics
- Faculty of Medicine
- University of Ljubljana
- Ljubljana
- Slovenia
| | - M. Mur
- Institute of Biophysics
- Faculty of Medicine
- University of Ljubljana
- Ljubljana
- Slovenia
| | - S. Svetina
- Institute of Biophysics
- Faculty of Medicine
- University of Ljubljana
- Ljubljana
- Slovenia
| | - J. Derganc
- Institute of Biophysics
- Faculty of Medicine
- University of Ljubljana
- Ljubljana
- Slovenia
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Artenjak A, Omersel J, Ahlin Grabnar P, Mlinarič-Raščan I, Shoenfeld Y, Sodin-Semrl S, Božič B, Čučnik S. Oxidatively altered IgG with increased immunoreactivity to β2-glycoprotein I and its peptide clusters influence human coronary artery endothelial cells. Lupus 2015; 24:448-62. [PMID: 25801888 DOI: 10.1177/0961203314561073] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Oxidative stress has been shown to play a role in modifying antibodies in favor of higher auto-immunoreactivity. We studied the immunoreactivity of oxidized IgG (oxIgG) to β2-glycoprotein I (β2GPI), six peptide sequences corresponding to amino acid clusters on its different domains, to determine their effects on human coronary artery endothelial cells (HCAEC). Human IgG was purified from seven donors, electro-oxidized and checked for immunoreactivity and avidity to β2GPI and to peptides by ELISA. Conformational stability and antibody-antigen complex formation of oxIgG was analyzed by fluorescence spectroscopy and dynamic light scattering. Resting and activated sub-confluent HCAEC were stimulated with oxIgG or IgG. Secreted cytokines were measured by ELISA. Immunoreactivity of seven oxIgG samples increased to 7.5-fold against β2GPI and to 3.8-fold against six peptides as compared to IgG. oxIgG showed low avidity "properties." Conformational changes and exposure of protein hydrophobic regions were confirmed by an elevation in fluorescence (2.4- to 5.0-fold) on bis-ANS dye binding to oxIgG. oxIgG significantly elevated the release of GROα and IL-8 in resting and activated states of HCAEC. Oxidation alters IgG in favor of autoreactivity toward whole β2GPI and corresponding peptides on different domains of β2GPI and could lead to dysfunction of arterial endothelium by upregulation of chemokines.
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Affiliation(s)
- A Artenjak
- Department of Rheumatology, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - J Omersel
- The chair of Clinical Biochemistry, Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - P Ahlin Grabnar
- The chair of Pharmaceutical Technology, Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - I Mlinarič-Raščan
- The chair of Clinical Biochemistry, Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - Y Shoenfeld
- The Zabludowicz Center for Autoimmune Diseases, Sheba Medical Center, Tel-Hashomer, Israel
| | - S Sodin-Semrl
- Department of Rheumatology, University Medical Centre Ljubljana, Ljubljana, Slovenia Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Koper, Slovenia
| | - B Božič
- Department of Rheumatology, University Medical Centre Ljubljana, Ljubljana, Slovenia The chair of Clinical Biochemistry, Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - S Čučnik
- Department of Rheumatology, University Medical Centre Ljubljana, Ljubljana, Slovenia
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Artenjak A, Locatelli I, Brelih H, Simonič DM, Ulcova-Gallova Z, Swadzba J, Musial J, Iwaniec T, Stojanovich L, Conti F, Valesini G, Avčin T, Cohen Tervaert JW, Shoenfeld Y, Blank M, Ambrožič A, Sodin-Semrl S, Božič B, Čučnik S. Immunoreactivity and avidity of IgG anti-β2-glycoprotein I antibodies from patients with autoimmune diseases to different peptide clusters of β2-glycoprotein I. Immunol Res 2015; 61:35-44. [PMID: 25395339 DOI: 10.1007/s12026-014-8578-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The pathogenicity of antibodies against β2-glycoprotein I (anti-β2GPI) depends on multiple factors such as subclass type, epitope binding and avidity. Due to their large heterogeneity, their impact on antiphospholipid syndrome (APS) onset is still not fully clarified. We studied the binding characteristics of IgG anti-β2GPI with known avidity from sera of 201 autoimmune patients (87 with APS, 67 with APS associated with systemic lupus erythematosus (SLE), 47 with only SLE) to six β2GPI peptides corresponding to amino acid clusters on domains I-II, II, III and III-IV by indirect ELISA and evaluated their association with clinical features of APS. Peptides A (LKTPRV; domain I-II), B (KDKATF; domain IV) and C (TLRVYK; domain III) were derived from a hexapeptide phage display library previously shown to react with pathogenic monoclonal anti-β2GPI. Peptides D (NGPANSK; domain III), E (YNPLWFV; domain II) and F (KMDGNHP; domain III-IV) represent surface amino acid clusters on β2GPI. The percentage of patients positive for peptides were observed as follows: 30.3% for peptide D, 28.90% for B, 25.9% for C, 24.9% for E, 24.4% for F and 10.0% for A. The anti-peptide antibodies in studied serum samples were predominantly of heterogeneous avidity, followed by law avidity anti-peptide antibodies, whereas only a few were of high avidity. Positive and negative correlations were found between several anti-peptide antibodies and the rate of thrombosis. Our results indicated diverse reactivity of IgG anti-β2GPI to different epitopes on β2GPI. Classification of IgG anti-β2GPI into subgroups regarding epitope specificity and avidity could represent an additional tool in understanding their pathogenicity in APS.
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Affiliation(s)
- A Artenjak
- Lek Pharmaceuticals d.d., Sandoz Biopharmaceuticals Mengeš, Kolodvorska 27, 1234, Menges, Slovenia
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Zager U, Kveder T, Cučnik S, Božič B, Lunder M. Anti-β2-glycoprotein I paratopes and β2-glycoprotein I epitopes characterization using random peptide libraries. Autoimmunity 2014; 47:438-44. [PMID: 24819195 DOI: 10.3109/08916934.2014.914176] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Studies concerning interactions between anti-β2-glycoprotein I antibodies (anti-β2GPI) and β2-glycoprotein I (β2GPI) suggest relevance of charge interactions and hydrogen bonds. However, paratope of diagnostically and clinically relevant anti-β2GPI and epitope characteristics of β2GPI, still remain unclear. The aim of our study was to determine paratope characteristics of various anti-β2GPI antibodies and epitope characteristics of β2GPI using phage display. Monoclonal IgG anti-β2GPI, purified polyclonal high avidity and low avidity IgG anti-β2GPI derived from plasma of APS patients were used to screen phage display libraries. The affinity and competition ability of selected clones were evaluated. Various heptapeptides presenting putative paratopes of anti-β2GPI and specific heptapeptides presenting putative epitopes of β2GPI were determined. Epitope presenting peptides bind to the respective anti-β2GPI and consequently interrupt antibody-antigen interaction. The amino acid composition of selected peptides confirmed the importance of hydrogen bonds and charge interactions in the binding of anti-β2GPI to the antigen. Epitopes recognized by high avidity anti-β2GPI predominately contain hydrogen bond forming side chains, while in low avidity anti-β2GPI epitope the charged side chains prevail. The alignment of selected sequences to three-dimensional antigen structure revealed that polyclonal high avidity anti-β2GPI recognize native epitopes that are accessible regardless of β2GPI's conformation whereas the epitope recognized by low avidity anti-β2GPI is cryptic and cannot be accessed when β2GPI takes the closed plasma conformation.
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Affiliation(s)
- Urška Zager
- Department of Rheumatology, University Medical Centre Ljubljana , Ljubljana , Slovenia and
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van Beers JJBC, Schwarte CM, Stammen-Vogelzangs J, Oosterink E, Božič B, Pruijn GJM. The rheumatoid arthritis synovial fluid citrullinome reveals novel citrullinated epitopes in apolipoprotein E, myeloid nuclear differentiation antigen, and β-actin. ACTA ACUST UNITED AC 2013; 65:69-80. [PMID: 23044660 DOI: 10.1002/art.37720] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 09/20/2012] [Indexed: 11/10/2022]
Abstract
OBJECTIVE To generate a catalog of citrullinated proteins that are present in the synovia of patients with rheumatoid arthritis (RA) and to elucidate their relevance for the anti-citrullinated protein antibody response in RA. METHODS Polypeptides isolated from the synovial fluid of patients with RA were identified by mass spectrometry. Three proteins (apolipoprotein E [Apo E], myeloid nuclear differentiation antigen [MNDA], and β-actin) were studied in more detail, using immunoprecipitation and Western blotting. The presence of autoantibodies to synthetic peptides derived from these proteins in sera from patients with RA, sera from patients with other diseases, and sera from healthy control subjects was studied by enzyme-linked immunosorbent assay (ELISA). RESULTS RA synovial fluid samples displayed several distinct patterns of citrullinated proteins. Using mass spectrometry, (fragments of) 192 proteins were identified, including 53 citrullinated proteins, some of which contained multiple citrullinated residues. In addition to previously reported citrullinated proteins in RA synovia (e.g., vimentin and fibrinogen), a series of novel citrullinated proteins, including Apo E, MNDA, β-actin, and cyclophilin A, was identified. Immunoprecipitation experiments confirmed the citrullination of Apo E and MNDA. ELISAs demonstrated the presence of autoreactive citrullinated epitopes in Apo E, MNDA, and β-actin. CONCLUSION Synovial fluid samples from the inflamed joints of patients with RA contain many citrullinated proteins. Citrullinated Apo E, MNDA, and β-actin are novel antigens identified in RA synovial fluid, and only a limited number of their citrullinated epitopes are targeted by the immune system in RA.
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Affiliation(s)
- Joyce J B C van Beers
- Nijmegen Center for Molecular Life Sciences and Institute for Molecules and Materials, Radboud University Nijmegen, Nijmegen, The Netherlands
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Žigon P, Čučnik S, Ambrožič A, Šemrl SS, Kveder T, Božič B. Antibodies to phosphatidylserine/prothrombin complex as an additional diagnostic marker of APS? Lupus 2012; 21:790-2. [DOI: 10.1177/0961203312444173] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Antiprothrombin antibodies can be measured by ELISA using either a prothrombin/phosphatidylserine complex (aPS/PT) or prothrombin alone (aPT) as antigen. We aimed to compare the clinical features of autoimmune patients with avidity of aPS/PT and determine the diagnostic efficiency of aPS/PT and aPT for assessing antiphospholipid syndrome (APS). aPS/PT were of low ( n = 9), heterogeneous ( n = 31) and high ( n = 8) avidity out of 48 cases. None of the samples with low avidity were positive in aPT ELISA. Among patients with heterogeneous or high avidity aPS/PT, there was a significantly greater number of patients with APS as compared to patients with low avidity (38/39 vs. 7/9; p < 0.05). No SLE patients had high avidity antiprothrombin antibodies.
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Affiliation(s)
- P Žigon
- University Medical Centre, Department of Rheumatology, Slovenia
| | - S Čučnik
- University Medical Centre, Department of Rheumatology, Slovenia
| | - A Ambrožič
- University Medical Centre, Department of Rheumatology, Slovenia
| | - S Sodin Šemrl
- University Medical Centre, Department of Rheumatology, Slovenia
| | - T Kveder
- University Medical Centre, Department of Rheumatology, Slovenia
| | - B Božič
- University Medical Centre, Department of Rheumatology, Slovenia
- University of Ljubljana, Faculty of Pharmacy, Slovenia
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Čučnik S, Kveder T, Artenjak A, Gallova ZU, Swadzba J, Musial J, Iwaniec T, Stojanovich L, Alessandri C, Valesini G, Avčin T, Tervaert JWC, Rozman B, Božič B. Avidity of anti-β2-glycoprotein I antibodies in patients with antiphospholipid syndrome. Lupus 2012; 21:764-5. [DOI: 10.1177/0961203312440057] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Antibodies against β2-glycoprotein I (anti-β2GPI) are one of the hallmarks of the antiphospholipid syndrome (APS). However, they are heterogenic regarding their epitope specificity, pathogenic mechanisms and their avidity. In the current study we present some outstanding issues about avidity of anti-β2GPI antibodies. Our results confirmed that high avidity anti-β2GPI are associated with thrombosis and APS, while in low avidity anti-β2GPI group non-APS (predominantly systemic lupus erythematosus) patients prevailed.
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Affiliation(s)
- S Čučnik
- University Medical Centre, Department of Rheumatology, Ljubljana, Slovenia
| | - T Kveder
- University Medical Centre, Department of Rheumatology, Ljubljana, Slovenia
| | - A Artenjak
- University Medical Centre, Department of Rheumatology, Ljubljana, Slovenia
| | - Z Ulcova Gallova
- Charles University, Medical School, Department of Gynecology and Obstetrics, Plzen- Lochotin, Czech Republic
| | - J Swadzba
- Jagiellonian University Medical College, Department of Medicine, Krakow, Poland
| | - J Musial
- Jagiellonian University Medical College, Department of Medicine, Krakow, Poland
| | - T Iwaniec
- Jagiellonian University Medical College, Department of Medicine, Krakow, Poland
| | - L Stojanovich
- Bezhanijska Kosa, University Medical Centre, Belgrade University, Serbia
| | - C Alessandri
- Sapienza University of Rome, Dipartimento di Medicina Interna e Specialità Mediche, Rome, Italy
| | - G Valesini
- Sapienza University of Rome, Dipartimento di Medicina Interna e Specialità Mediche, Rome, Italy
| | - T Avčin
- University Medical Centre, University Children’s Hospital Ljubljana, Department of Allergology, Rheumatology and Clinical Immunology, Ljubljana, Slovenia
| | - JW Cohen Tervaert
- Maastricht University Medical Center, Division of Clinical and Experimental Immunology, Department of Internal Medicine, Maastricht, the Netherlands
| | - B Rozman
- University Medical Centre, Department of Rheumatology, Ljubljana, Slovenia
| | - B Božič
- University Medical Centre, Department of Rheumatology, Ljubljana, Slovenia
- University in Ljubljana, Faculty of Pharmacy, Chair for Clinical Biochemistry, Ljubljana, Slovenia
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Raijmakers R, van Beers JJBC, El-Azzouny M, Visser NFC, Božič B, Pruijn GJM, Heck AJR. Elevated levels of fibrinogen-derived endogenous citrullinated peptides in synovial fluid of rheumatoid arthritis patients. Arthritis Res Ther 2012; 14:R114. [PMID: 22584083 PMCID: PMC3446491 DOI: 10.1186/ar3840] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 03/28/2012] [Accepted: 05/14/2012] [Indexed: 02/04/2023] Open
Abstract
Introduction Rheumatoid arthritis (RA) is an autoimmune disease characterized by inflammation of the joints and the presence of autoantibodies directed against proteins containing the non-standard arginine-derived amino acid citrulline. The protein fibrinogen, which has an essential role in blood clotting, is one of the most prominent citrullinated autoantigens in RA, particularly because it can be found in the inflamed tissue of affected joints. Here, we set out to analyze the presence of citrullinated endogenous peptides in the synovial fluid of RA and arthritic control patients. Methods Endogenous peptides were isolated from the synovial fluid of RA patients and controls by filtration and solid phase extraction. The peptides were identified and quantified using high-resolution liquid chromatography-mass spectrometry. Results Our data reveal that the synovial fluid of RA patients contains soluble endogenous peptides, derived from fibrinogen, containing significant amounts of citrulline residues and, in some cases, also phosphorylated serine. Several citrullinated peptides are found to be more abundantly present in the synovial fluid of RA patients compared to patients suffering from other inflammatory diseases affecting the joints. Conclusions The increased presence of citrullinated peptides in RA patients points toward a possible specific role of these peptides in the immune response at the basis of the recognition of citrullinated peptides and proteins by RA patient autoantibodies.
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Affiliation(s)
- Reinout Raijmakers
- Biomolecular Mass Spectrometry and Proteomics Group, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University and Netherlands Proteomics Centre, Padualaan 8, Utrecht, 3584 CH, The Netherlands.
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12
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Žager U, Lunder M, Hodnik V, Anderluh G, Čučnik S, Kveder T, Božič B. Significance of K(L/V)WX(I/L/V)P Epitope of the B2Gpi in Its (Patho)Physiologic Function. EJIFCC 2011; 22:118-24. [PMID: 27683401 PMCID: PMC4975316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
β2-glycoprotein I (β2GPI) is a major autoantigen of autoimmune thrombophilia, known as the antiphospholipid syndrome. The exact mechanism underlying the β2GPI's involvement in the disease is not fully elucidated, as it is not its physiological role. We used random phage peptide library to identify sequences binding to β2GPI. Obtained K(L/V)WX(I/L/V)P motif, primarily designated as target unrelated, was confirmed as the selective binder of β2GPI. Based on this motif we confirmed the previously suggested role of polar residues in β2GPI interactions, and identified some already known and some new putative β2GPI binding proteins. The latter can help to further elucidate β2GPI's (patho)physiological role.
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Affiliation(s)
- Urška Žager
- Department of Rheumatology, University Medical Centre Ljubljana, SI-1000 Ljubljana, Slovenia
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13
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Zager U, Lunder M, Božič B. Using phage display in autoimmunity research. Acta Chim Slov 2011; 58:742-754. [PMID: 24061124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023] Open
Abstract
Autoimmune diseases affect approximately 3% of the population and are a significant cause of morbidity and mortality. Therefore, they are the focus of vivid research aimed at the delineation of pathology, more efficient diagnosis and therapy. Phage display is a simple methodology markedly useful in studying protein-protein interactions which are the driving forces of (patho)physiological processes, including autoimmunity. The commercially available phage display peptide libraries allow the characterization and identification of antibody-antigen and receptor-ligand binding sites, thus providing basic insight into the pathological network. Through the phage display of antibody's, receptor's or ligand's protein domains it is possible to produce various self-specificities that have already been proven useful in the therapy of autoimmune diseases. Phage antibody display libraries are able to reprint the in vivo autoimmune response which significantly facilitates structural and functional analyses of auto-reactive antibodies and assessing their role in disease pathology. The aim of this review was an overview of the versatile applications of phage display technology to determine their potential advantages in studying autoimmune diseases and to critically categorize and analyze the usefulness of phage displays towards understanding pathology and towards development of improved diagnostic tools. Above all its focus was on targeted therapy.
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Čučnik S, Kveder T, Ulcova GZ, Swadzba J, Musial J, Valesini G, Avčin T, Rozman B, Božič B. The avidity of anti-β2-glycoprotein I antibodies in patients with or without antiphospholipid syndrome: a collaborative study in the frame of the European forum on antiphospholipid antibodies. Lupus 2011; 20:1166-71. [DOI: 10.1177/0961203311406308] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Objective. The objective of this study was to extend the findings of the preliminary study by measuring the avidity of IgG anti-β2-glycoprotein I antibodies (anti-β2-GPI) on a larger group of patients with primary or secondary antiphospholipid syndrome (APS) and anti-β2-GPI positive patients without APS in the frame of the European Forum on antiphospholipid antibodies (aPL). Methods. Serum from 137 patients with primary APS, APS associated with autoimmune diseases, and patients with autoimmune diseases other than APS from five EU rheumatology centres were tested for anti-β2-GPI antibodies. The 109 patients who were sera positive for anti-β2-GPI by the in-house anti-β2-GPI enzyme-linked immunosorbent assay (ELISA) at the Immunology Laboratory, UMC Ljubljana were selected for further testing on avidity with chaotropic anti-β2-GPI ELISA. Results. High, low and heterogeneous avidity IgG anti-β2-GPI was found in 32/109, 17/109 and 60/109 patients respectively. Significantly more patients with APS were in the high avidity than in the low avidity anti-β2-GPI group, while the opposite was observed for non-APS (both p < 0.001). The most common clinical feature among patients with high avidity anti-β2-GPI was thrombosis, mainly due to venous thrombosis ( p < 0.01 and p < 0.001, versus low avidity anti-β2-GPI group). Conclusion. Patients with or without APS had anti-β2-GPI of high, low or heterogeneous avidity. High avidity anti-β2-GPI was associated with thrombosis and APS, while in the low avidity anti-β2-GPI group non-APS (predominantly SLE) patients prevailed. Determination of anti-β2-GPI avidity should be considered in the analytical strategies for further differentiation of patients with anti-β2-GPI antibodies.
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Affiliation(s)
- S Čučnik
- University Medical Centre, Department of Rheumatology, Ljubljana, Slovenia
| | - T Kveder
- University Medical Centre, Department of Rheumatology, Ljubljana, Slovenia
| | - GZ Ulcova
- Charles University, Medical School, Department of Gynaecology and Obstetrics, Plzen, LOCHOTIN, 30604 Czech Republic
| | - J Swadzba
- Jagiellonian University Medical College, Department of Medicine, Krakow, Poland
| | - J Musial
- Jagiellonian University Medical College, Department of Medicine, Krakow, Poland
| | - G Valesini
- University of Roma La Sapienza, Division of Rheumatology, Rome, Italy
| | - T Avčin
- University Medical Centre, University Children’s Hospital Ljubljana, Department of Allergy, Rheumatology and Clinical Immunology, Ljubljana, Slovenia
| | - B Rozman
- University Medical Centre, Department of Rheumatology, Ljubljana, Slovenia
| | - B Božič
- University Medical Centre, Department of Rheumatology, Ljubljana, Slovenia
- University in Ljubljana, Faculty of Pharmacy, Chair for Clinical Biochemistry, Ljubljana, Slovenia
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Žigon P, Ambrožič A, Čučnik S, Kveder T, Rozman B, Božič B. Modified phosphatidylserine-dependent antiprothrombin [corrected] ELISA enables identification of patients negative for other antiphospholipid antibodies and also detects low avidity antibodies. Clin Chem Lab Med 2011; 49:1011-8. [PMID: 21574879 DOI: 10.1515/cclm.2011.162] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Two approaches for detecting anti-prothrombin antibodies have been described. The first detects antibodies against prothrombin alone and the second, phos-phatidylserine-dependent antiprothrombin antibodies. The latter more often correlate with clinical manifestations of antiphospholipid syndrome and with lupus anticoagulant activity. METHODS In order to increase the capacity of antibody binding, we modified the previously described phosphatidylser-ine-dependent antiprothrombin ELISA and determined their avidity. We examined 203 patients with systemic autoimmune diseases and 222 blood donors. RESULTS Our modification resulted in a greater intensity of antibody binding to prothrombin on phosphatidylserine-coated plate surfaces compared to the previously described method. By changing ELISA conditions, we were able to detect with one assay the two, presumably different, populations of antiprothrombin antibodies. Diagnostic specificities of both ELISAs for antiphospholipid syndrome were similar (92.5% vs. 93.1%), while the sensitivity of the modified phosphatidylserine-dependent antiprothrombin ELISA was significantly higher than the anti-prothrombin alone ELISA (59% vs. 25%). Low avidity antiprothrombin antibodies were only detected in the modified phosphatidylserine-dependent antiprothrombin ELISA. Four percent of patients with positive phosphatidylserine-dependent antiprothrombin antibodies, showing clinical manifestations of antiphospholipid syndrome, were negative for all other antiphospholipid antibodies. The risk for antiphospholipid syndrome increased with the number of antiphospholipid antibody positivity. CONCLUSIONS We conclude that antibodies detected with a modified phosphatidylserine-dependent antiprothrombin ELISA could improve the diagnosis of antiphospholipid syndrome by offering additional information on the risk for thrombosis, especially in patients negative for other antiphospholipid antibodies.
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Affiliation(s)
- Polona Žigon
- Immunology Laboratory, Department of Rheumatology, University Medical Centre, Ljubljana, Slovenia.
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Irman Š, Škarabot M, Muševič I, Rozman B, Božič B. Thrombomodulatory Effect of Anti-B2-Glycoprotein I Antibodies on Crystalline Annexin A5 on Phospholipid Bilayers, as Observed by Atomic Force Microscopy. EJIFCC 2011; 21:81-93. [PMID: 27683378 PMCID: PMC4975317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Antibodies against β2-glycoprotein I are a subset of very heterogeneous family of antiphospholipid antibodies. It is well recognised that anti-β2-glycoprotein I antibodies are the main pathogenic players in the autoimmune disease known as antiphospholipid syndrome. Many mechanisms have been proposed through which these autoantibodies could cause microplacental, arterial or venous thrombosis. One of the suggested mechanisms is an antiphospholipid antibody-mediated disruption of annexin A5 protective crystalline shield on negatively charged phospholipid membranes. In current report the study of β2-glycoprotein I, anti-β2-glycoprotein I antibodies and annexin A5 interactions was performed on in vitro model of planar solid-supported phospholipid bilayers and visualized by atomic force microscopy. Planar phospholipid bilayers comprised 30 % L-α-phosphatidylserine and 70 % L-α-phosphatidylcholine. For the study of interactions 10 mg/l annexin A5, 0.15 g/l β2-glycoprotein I, 10 g/l of IgG fraction from healthy blood donor, 10 g/l of IgG fraction from a patient with anti-β2-glycoprotein I antibodies and 0.4 g/l of isolated IgG anti-β2-glycoprotein I antibodies from the same patients in Hepes buffered saline with 1.5 mM Ca2+ were used. We confirmed the clustering of β2-glycoprotein I on planar phospholipid bilayers. We also found that in the presence of annexin A5, β2-glycoprotein I does not bind to planar phospholipid bilayers. However, when adding the anti-β2-glycoprotein I antibodies, the growth of β2-glycoprotein I-anti-β2-glycoprotein I antibodies complexes in the presence of incompletely crystallized annexin A5 on planar phospholipid bilayers was observed. Results confirm the possible thrombomodulatory activity of anti-β2-glycoprotein antibodies through their effect on crystalline annexin A5. In addition, the hypothesis that the presence of possibly pathologic antigen-antibody pair itself is not sufficient to start the pathological process is confirmed and visualized for the first time.
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Affiliation(s)
- Špela Irman
- University Medical Centre, Division of Internal Medicine, Department of Rheumatology, Vodnikova cesta 61, SI-1000 Ljubljana, Slovenia
| | - Miha Škarabot
- Jožef Stefan Institute, Department of Condensed matter physics, Jamova cesta 39, SI-1000 Ljubljana, Slovenia,University in Ljubljana, Faculty of Mathematics and Physics, Jadranska 19, SI-1000 Ljubljana, Slovenia
| | - Igor Muševič
- Jožef Stefan Institute, Department of Condensed matter physics, Jamova cesta 39, SI-1000 Ljubljana, Slovenia,University in Ljubljana, Faculty of Mathematics and Physics, Jadranska 19, SI-1000 Ljubljana, Slovenia
| | - Blaž Rozman
- University Medical Centre, Division of Internal Medicine, Department of Rheumatology, Vodnikova cesta 61, SI-1000 Ljubljana, Slovenia
| | - Borut Božič
- University Medical Centre, Division of Internal Medicine, Department of Rheumatology, Vodnikova cesta 61, SI-1000 Ljubljana, Slovenia,University in Ljubljana, Faculty of Pharmacy, Chair for Clinical Biochemistry, Aškerčeva cesta 7, SI-1000 Ljubljana, Slovenia,* Prof. Borut Božič, University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, SI-1000 Ljubljana, Slovenia. +386 1 4769502, +386 1 4769512,
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Žigon P, Ambrožič A, Čučnik S, Kveder T, Rozman B, Božič B. Modified phosphatidylserine-dependent antiprothrombin ELISA enables identification of patients negative for other antiphospholipid antibodies and also detects low avidity antibodies. Clin Chem Lab Med 2011. [DOI: 10.1515/cclm.2011.699] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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18
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Irman S, Skarabot M, Muševič I, Rozman B, Božič B. The use of atomic force microscopy to study the pathologic effects of anti-annexin autoantibodies. J Autoimmun 2010; 36:98-105. [PMID: 21185149 DOI: 10.1016/j.jaut.2010.11.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Revised: 11/15/2010] [Accepted: 11/25/2010] [Indexed: 11/29/2022]
Abstract
Patients with recurrent pregnancy loss and a history of thrombotic events have often been noted to have autoantibodies directed at annexin A5. However, the relationship of these autoantibodies to immunopathology is still unknown, although it has been proposed that they have a direct effect on the function of annexin A5. Annexin A5 may be a significant immunological target with pathologic implications. Essentially, annexin A5 is an anticoagulant protein that crystallizes over negatively charged phospholipid surfaces and thereby blocks them from availability for coagulation reactions. To address this issue, we have taken advantage of our expertise with atomic force microscopy and studied anti-annexin A5 autoantibodies isolated from patients and focused on the ability of these antibodies to influence annexin A5 crystallization on planar mica-supported phospholipid bilayers. We report herein that such antibodies from patients, but not controls, produced a significant disruption of incomplete annexin A5 crystalline shield on phospholipid bilayer. In addition, the IgG fraction isolated from such patients significantly decreased the velocity of annexin A5 crystallization. Atomic force microscopy is a powerful tool to study the pathologic mechanisms of autoantibodies and the data herein reflect the potential of anti-annexin A5 antibodies that produce pathology in a number of varied but overlapping clinical conditions, including autoimmune thrombosis and antiphospholipid syndrome.
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Affiliation(s)
- Spela Irman
- University Medical Centre, Division of Internal Medicine, Department of Rheumatology, Vodnikova cesta 61, SI-1000 Ljubljana, Slovenia.
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Omersel J, Jurgec I, Čučnik S, Kveder T, Rozman B, Sodin-Šemrl S, Božič B. Autoimmune and proinflammatory activity of oxidized immunoglobulins. Autoimmun Rev 2008; 7:523-9. [DOI: 10.1016/j.autrev.2008.04.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Kveder T, Božič B. The Quality Assurance and Organization of Autoantibody Laboratory. EJIFCC 2006; 17:118-128. [PMID: 29760640 PMCID: PMC5938687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Tanja Kveder
- Department of Rheumatology, University Medical Centre, 1000 Ljubljana, Slovenia
| | - Borut Božič
- University of Ljubljana, Faculty of Pharmacy, Chair for Clinical Biochemistry, Ljubljana, Slovenia
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22
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Božič B, Rozman B. Apoptosis and Autoimmunity. EJIFCC 2006; 17:69-74. [PMID: 29760634 PMCID: PMC5938681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Borut Božič
- University of Ljubljana, Faculty of Pharmacy, Chair for Clinical Biochemistry, Ljubljana, Slovenia
| | - Blaž Rozman
- University Medical Centre, Department of Rheumatology, Immunology Laboratory
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Božič B. Diabetes and Autoimmunity. EJIFCC 2002; 13:164-169. [PMID: 30349433 PMCID: PMC6195778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Svetina S, Božič B, Žekš B. A mechanism for the establishment of polar cell morphology based on the cytoskeleton-derived forces exerted on the cell boundary. European Biophysics Journal 1998. [DOI: 10.1007/s002490050185] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Svetina S, Božič B, Song J, Waugh RE, Žekš B. Phospholipid Membrane Local and Non-Local Bending Moduli Determined by Tether Formation from Aspirated Vesicles. Springer Proceedings in Physics 1992. [DOI: 10.1007/978-3-642-84763-9_29] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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