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Sandholm, Kerstin
Publications (10 of 33) Show all publications
Tjernberg, A. R., Woksepp, H., Sandholm, K., Johansson, M., Dahle, C., Ludvigsson, J. F., . . . Nilsson Ekdahl, K. (2019). Celiac disease and complement activation in response to Streptococcus pneumoniae. European Journal of Pediatrics
Open this publication in new window or tab >>Celiac disease and complement activation in response to Streptococcus pneumoniae
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2019 (English)In: European Journal of Pediatrics, ISSN 0340-6199, E-ISSN 1432-1076Article in journal (Refereed) Epub ahead of print
Abstract [en]

Individuals with celiac disease (CD) are at increased risk of invasive pneumococcal disease (IPD). The aim of this study was to explore whether the complement response to Streptococcus pneumoniae differed according to CD status, and could serve as an explanation for the excess risk of IPD in CD. Twenty-two children with CD and 18 controls, born 1999-2008, were included at Kalmar County Hospital, Sweden. The degree of complement activation was evaluated by comparing levels of activation products C3a and sC5b-9 in plasma incubated for 30 min with Streptococcus pneumoniae and in non-incubated plasma. Complement analyses were performed with enzyme-linked immunosorbent assay (ELISA). Pneumococcal stimulation caused a statistically significant increase in C3a as well as sC5b-9 in both children with CD and controls but there was no difference in response between the groups. After incubation, C3a increased on average 4.6 times and sC5b-9 22 times in both the CD and the control group (p = 0.497 and p = 0.724 respectively). Conclusion: Complement response to Streptococcus pneumoniae seems to be similar in children with and without CD and is thus unlikely to contribute to the increased susceptibility to invasive pneumococcal disease in CD.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Coeliac, Pneumococcal, Infection, Innate immunity, MBL
National Category
Immunology
Research subject
Biomedical Sciences, Immunology
Identifiers
urn:nbn:se:lnu:diva-90197 (URN)10.1007/s00431-019-03490-w (DOI)000494392200001 ()31691001 (PubMedID)
Available from: 2019-11-21 Created: 2019-11-21 Last updated: 2019-11-21
Sandholm, K. (2019). Development and evaluation of immunoassays for complement diagnostics. (Doctoral dissertation). Växjö: Linnaeus University Press
Open this publication in new window or tab >>Development and evaluation of immunoassays for complement diagnostics
2019 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Laboratory analyses of human body fluids play an important role in clinical diagnosis. This thesis comprises projects in which various immune assays have been developed and evaluated as complement diagnostics in both plasma and cerebrospinal fluid (CSF). Various methods have been used, such as ELISA, Western blot, flow cytometry, and xMAP technology.

In paper 1, we monitored complement parameters in EDTA-plasma and CSF from patients with suspected neuroborreliosis (NB) by using in-house sandwich ELISAs.  We found significantly elevated levels of C1q, C4, C3, and C3a in CSF, but not in plasma, suggesting that complement plays a role in the intrathecal immune response in NB.

Complement is a main player in early inflammation, and in paper 2, we investigated the role of complement activation in phagocytosis and the release of cytokines and chemokines in response to two clinical isolates: Borrelia afzelii K78 and Borrelia garinii LU59. Our results show that complement activation plays an important role in the initial process of phagocytosis, but not in the subsequent cytokine release that occurs in response to live Borrelia spirochetes. C1q, a valuable biomarker of disease activity in systemic lupus erythematosus (SLE), can be quantitated using a number of different immunochemical techniques.

In paper 3, we developed and validated a magnetic bead-based immunoassay for quantifying C1q in EDTA-plasma and CSF. In contrast to soluble immunoprecipitation assays such as nephelometry and turbidimetry, this new assay was not hampered by the interaction between C1q and detecting antibodies. The novel assay was shown to give a clear correlation between nephritis and SLEDAI score in SLE.

Warfarin is a commonly used but complicated treatment in patients with thrombosis. It reduces the function of vitamin K-dependent coagulation proteins, including protein S, which is a ligand for C4b-binding protein (C4BP). In paper 4, we demonstrated a decrease in various isoforms of C4BP that resulted in a strong complement activation in patients treated with warfarin, but not in patients treated with other anticoagulants.

Taken together, the results from the papers included in this thesis stress the importance of validated assays with high sensitivity and specificity in enabling accurate diagnosis in patients with various inflammatory diseases.

Place, publisher, year, edition, pages
Växjö: Linnaeus University Press, 2019. p. 58
Series
Linnaeus University Dissertations ; 369/2019Linnaeus University Dissertations
Keywords
Immune assays, complement diagnostics, xMAP-technology, C1q, preanalytical factors, method validation
National Category
Immunology in the medical area
Identifiers
urn:nbn:se:lnu:diva-90125 (URN)978-91-89081-14-7 (ISBN)978-91-89081-15-4 (ISBN)
Public defence
2019-12-12, Azur, Hus Vita, Universitetskajen, Kalmar, 09:15 (Swedish)
Opponent
Supervisors
Available from: 2019-11-17 Created: 2019-11-15 Last updated: 2019-11-17Bibliographically approved
Sandholm, K., Persson, B., Skattum, L., Eggertsen, G., Nyman, D., Gunnarsson, I., . . . Nilsson Ekdahl, K. (2019). Evaluation of a Novel Immunoassay for Quantification of C1q for Clinical Diagnostic Use. Frontiers in Immunology, 10, Article ID 7.
Open this publication in new window or tab >>Evaluation of a Novel Immunoassay for Quantification of C1q for Clinical Diagnostic Use
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2019 (English)In: Frontiers in Immunology, ISSN 1664-3224, E-ISSN 1664-3224, Vol. 10, article id 7Article in journal (Refereed) Published
Abstract [en]

Objectives: C1q is a valuable biomarker of disease activity in systemic lupus erythematosus (SLE). The "gold standard" assay, rocket immunoelectrophoresis (RIE), is time-consuming, and thus a shift to soluble immune precipitation techniques such as nephelometry has occurred. However, quantification of C1q with these techniques has been questioned as a result of the antibody binding properties of C1q. In the present work, we have compared results using various techniques (RIE, nephelometry, and ELISA) and have developed and validated a new magnetic bead-based sandwich immunoassay (MBSI). Methods: C1q was quantified by nephelometry and the new sandwich immunoassay in 45 serum samples analyzed using RIE. C1q was also assessed in plasma using RIE and sandwich immunoassay in samples from SLE patients with nephritis (n = 69), SLE patients without nephritis (n = 310) as classified by BILAG score, and matched controls (n = 322). In addition, cerebrospinal fluid (CSF) samples from 31 patients, previously analyzed with ELISA, were also analyzed with the MBSI to test the behavior of this new assay in the lower detection range. Results: We found a strong correlation between the new MBSI, RIE, and ELISA, but not with nephelometry. The MBSI demonstrated lower levels of C1q in SLE patients than in matched controls (p < 0.0001), and patients with nephritis had lower levels than patients without nephritis (p < 0.01). Similarily, RIE showed significant differences between the patient groups (p < 0.0001). An association was also found between the levels of C1q and the SLE disease activity index (SLEDAI). Furthermore, there was good correlation between the values obtained by MBSI and ELISA, in both serum (r = 0.960) and CSF (r = 0.786), underscoring the ability of both techniques to measure low concentrations of C1q with high accuracy. Conclusion: The sandwich immunoassay correlated well with RIE, but soluble immune precipitation techniques, such as nephelometry, did not appear suitable alternatives, since C1q itself, and possibly anti-C1q antibodies, interfered with the measurements. The new sandwich immunoassay is therefore a good replacement for RIE in monitoring SLE disease activity.

Place, publisher, year, edition, pages
Frontiers Media S.A., 2019
Keywords
C1q, immunoassays, plasma, CSF, SLE, nephritis
National Category
Immunology Rheumatology and Autoimmunity
Research subject
Biomedical Sciences, Immunology
Identifiers
urn:nbn:se:lnu:diva-80277 (URN)10.3389/fimmu.2019.00007 (DOI)000456846400001 ()2-s2.0-85061243783 (Scopus ID)
Available from: 2019-02-07 Created: 2019-02-07 Last updated: 2019-11-12Bibliographically approved
Nilsson Ekdahl, K., Mohlin, C., Adler, A., Aman, A., Manivel, V. A., Sandholm, K., . . . Nilsson, B. (2019). Is generation of C-3(H2O) necessary for activation of the alternative pathway in real life?. Paper presented at 17th European Meeting on Complement in Human Disease (EMCHD), 2019, Madrid, SPAIN. Molecular Immunology, 114, 353-361
Open this publication in new window or tab >>Is generation of C-3(H2O) necessary for activation of the alternative pathway in real life?
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2019 (English)In: Molecular Immunology, ISSN 0161-5890, E-ISSN 1872-9142, Vol. 114, p. 353-361Article in journal (Refereed) Published
Abstract [en]

In the alternative pathway (AP) an amplification loop is formed, which is strictly controlled by various fluid-phase and cell-bound regulators resulting in a state of homeostasis. Generation of the "C3b-like" C3(H2O) has been described as essential for AP activation, since it conveniently explains how the initial fluid-phase AP convertase of the amplification loop is generated. Also, the AP has a status of being an unspecific pathway despite thorough regulation at different surfaces. During complement attack in pathological conditions and inflammation, large amounts of C3b are formed by the classical/lectin pathway (CP/LP) convertases. After the discovery of LP's recognition molecules and its tight interaction with the AP, it is increasingly likely that the AP acts in vivo mainly as a powerful amplification mechanism of complement activation that is triggered by previously generated C3b molecules initiated by the binding of specific recognition molecules. Also in many pathological conditions caused by a dysregulated AP amplification loop such as paroxysmal nocturnal hemoglobulinuria (PNH) and atypical hemolytic uremic syndrome (aHUS), C3b is available due to minute LP and CP activation and/or generated by non-complement proteases. Therefore, C3(H2O) generation in vivo may be less important for AP activation during specific attack or dysregulated homeostasis, but may be an important ligand for C3 receptors in cell-cell interactions and a source of C3 for the intracellular complement reservoir.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Complement system, C-3(H2O), Conformation, Analysis, Proteases, Alternative pathway
National Category
Immunology
Research subject
Biomedical Sciences, Immunology
Identifiers
urn:nbn:se:lnu:diva-89867 (URN)10.1016/j.molimm.2019.07.032 (DOI)000490625600041 ()31446306 (PubMedID)
Conference
17th European Meeting on Complement in Human Disease (EMCHD), 2019, Madrid, SPAIN
Available from: 2019-10-31 Created: 2019-10-31 Last updated: 2019-10-31Bibliographically approved
Mohlin, C., Sandholm, K., Kvanta, A., Nilsson Ekdahl, K. & Johansson, K. (2018). A model to study complement involvement in experimental retinal degeneration.. Upsala Journal of Medical Sciences, 123(1), 28-42
Open this publication in new window or tab >>A model to study complement involvement in experimental retinal degeneration.
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2018 (English)In: Upsala Journal of Medical Sciences, ISSN 0300-9734, E-ISSN 2000-1967, Vol. 123, no 1, p. 28-42Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: The complement system (CS) plays a role in the pathogenesis of a number of ocular diseases, including diabetic retinopathy (DR), glaucoma, uveitis, and age-related macular degeneration (AMD). Given that many of the complex eye-related degenerative diseases have limited treatment opportunities, we aimed to mimic the in vivo retinal degenerative process by developing a relevant co-culture system.

METHOD AND MATERIALS: The adult porcine retina was co-cultured with the spontaneously arising human retinal pigment epithelial cells-19 (ARPE-19).

RESULTS: Inflammatory activity was found after culture and included migrating microglial cells, gliosis, cell death, and CS activation (demonstrated by a minor increase in the secreted anaphylotoxin C3a in co-culture). CS components, including C1q, C3, C4, soluble C5b-9, and the C5a receptor, were expressed in the retina and/or ARPE cells after culture. C1q, C3, and CS regulators such as C4 binding protein (C4BP), factor H (CFH), and factor I (CFI) were secreted after culture.

DISCUSSION: Thus, our research indicates that this co-culturing system may be useful for investigations of the CS and its involvement in experimental neurodegenerative diseases.

Place, publisher, year, edition, pages
Taylor & Francis, 2018
Keywords
AMD, RPE, complement system, ocular diseases, retina
National Category
Immunology in the medical area
Research subject
Biomedical Sciences, Immunology
Identifiers
urn:nbn:se:lnu:diva-71489 (URN)10.1080/03009734.2018.1431744 (DOI)000428060300004 ()29436895 (PubMedID)2-s2.0-85041902488 (Scopus ID)
Available from: 2018-03-12 Created: 2018-03-12 Last updated: 2019-08-29Bibliographically approved
Labriere, C., Kondori, N., Caous, J. S., Boomgaren, M., Sandholm, K., Nilsson Ekdahl, K., . . . Svenson, J. (2018). Development and evaluation of cationic amphiphilic antimicrobial 2,5-diketopiperazines. Paper presented at 7th International Meeting on Antimicrobial Peptides, AUG 25-27, 2017, Univ Copenhagen, Copenhagen, DENMARK. Journal of Peptide Science, 24(7), Article ID UNSP e3090.
Open this publication in new window or tab >>Development and evaluation of cationic amphiphilic antimicrobial 2,5-diketopiperazines
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2018 (English)In: Journal of Peptide Science, ISSN 1075-2617, E-ISSN 1099-1387, Vol. 24, no 7, article id UNSP e3090Article in journal (Refereed) Published
Abstract [en]

Both pathogenic bacteria and fungi are developing resistance to common antimicrobial treatment at an alarming rate. To counteract this development, it is of essence to develop new classes of antimicrobial agents. One such class is antimicrobial peptides, most of which are derived from the innate immune system. In this study, a series of novel 2,5-diketopiperazines were designed, synthesized, and evaluated for their antimicrobial abilities. The compounds were designed to probe the pharmacophore dictated for short linear mimics of antimicrobial cationic peptides, and as such, the compounds contain a range of cationic and hydrophobic functionalities. Several of the prepared compounds displayed high antimicrobial activities toward bacteria and also against human pathogenic fungi. Of particular interest was the high activity toward fungal strains with an inherent increased resistance toward conventional antifungal agents. The most effective compounds displayed inhibition of Candida glabrata and Candida krusei growth at concentrations between 4 and 8 mu g/mL, which is comparable to commercial antifungal agents in use. Structure activity relationship studies revealed a similar dependence on cationic charge and the volume of the hydrophobic bulk as for linear cationic antimicrobial peptides. Finally, the hemolytic activity of selected compounds was evaluated, which revealed a potential to produce active compounds with attenuation of unwanted hemolysis. The findings highlight the potential of cyclic cationic amphiphilic peptidomimetics as a class of promising compounds for the treatment of infections caused by microorganisms with an increased resistance to conventional antimicrobial agents.

Place, publisher, year, edition, pages
John Wiley & Sons, 2018
Keywords
2, 5-diketopiperazine, antifungal agents, antimicrobial, Candida krusei, MRSA, structure-activity relationship
National Category
Biochemistry and Molecular Biology
Research subject
Natural Science, Biomedical Sciences
Identifiers
urn:nbn:se:lnu:diva-77499 (URN)10.1002/psc.3090 (DOI)000440144700005 ()29845683 (PubMedID)2-s2.0-85047664224 (Scopus ID)
Conference
7th International Meeting on Antimicrobial Peptides, AUG 25-27, 2017, Univ Copenhagen, Copenhagen, DENMARK
Available from: 2018-08-31 Created: 2018-08-31 Last updated: 2019-08-29Bibliographically approved
Nilsson Ekdahl, K., Persson, B., Mohlin, C., Sandholm, K., Skattum, L. & Nilsson, B. (2018). Interpretation of Serological Complement Biomarkers in Disease. Frontiers in Immunology, 9, Article ID 2237.
Open this publication in new window or tab >>Interpretation of Serological Complement Biomarkers in Disease
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2018 (English)In: Frontiers in Immunology, ISSN 1664-3224, E-ISSN 1664-3224, Vol. 9, article id 2237Article, review/survey (Refereed) Published
Abstract [en]

Complement systemaberrations have been identified as pathophysiological mechanisms in a number of diseases and pathological conditions either directly or indirectly. Examples of such conditions include infections, inflammation, autoimmune disease, as well as allogeneic and xenogenic transplantation. Both prospective and retrospective studies have demonstrated significant complement-related differences between patient groups and controls. However, due to the low degree of specificity and sensitivity of some of the assays used, it is not always possible to make predictions regarding the complement status of individual patients. Today, there are three main indications for determination of a patient's complement status: (1) complement deficiencies (acquired or inherited); (2) disorders with aberrant complement activation; and (3) C1 inhibitor deficiencies (acquired or inherited). An additional indication is to monitor patients on complement-regulating drugs, an indication which may be expected to increase in the near future since there is now a number of such drugs either under development, already in clinical trials or in clinical use. Available techniques to study complement include quantification of: (1) individual components; (2) activation products, (3) function, and (4) autoantibodies to complement proteins. In this review, we summarize the appropriate indications, techniques, and interpretations of basic serological complement analyses, exemplified by a number of clinical disorders.

Place, publisher, year, edition, pages
Frontiers Media S.A., 2018
Keywords
complement, deficiency, activation products, functional test, complement regulatory drugs
National Category
Immunology
Research subject
Biomedical Sciences, Immunology
Identifiers
urn:nbn:se:lnu:diva-78739 (URN)10.3389/fimmu.2018.02237 (DOI)000448107500001 ()2-s2.0-85055834488 (Scopus ID)
Available from: 2018-11-08 Created: 2018-11-08 Last updated: 2019-08-29Bibliographically approved
Mohlin, C., Petrus-Reurer, S., Lanner, F., Sandholm, K., Nilsson, P. H., Nilsson, B. & Nilsson Ekdahl, K. (2018). Is the polarized secretion of complement factor H of importance in age-related macular degeneration?. Paper presented at Annual Meeting of the Association-for-Research-in-Vision-and-Ophthalmology (ARVO), APR 29-MAY 03, 2018, Honolulu, HI. Investigative Ophthalmology and Visual Science, 59(9)
Open this publication in new window or tab >>Is the polarized secretion of complement factor H of importance in age-related macular degeneration?
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2018 (English)In: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 59, no 9Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
ASSOC RESEARCH VISION OPHTHALMOLOGY INC, 2018
National Category
Ophthalmology
Research subject
Natural Science, Optometry
Identifiers
urn:nbn:se:lnu:diva-78425 (URN)000442932806149 ()
Conference
Annual Meeting of the Association-for-Research-in-Vision-and-Ophthalmology (ARVO), APR 29-MAY 03, 2018, Honolulu, HI
Available from: 2018-10-22 Created: 2018-10-22 Last updated: 2018-11-16Bibliographically approved
Mohlin, C., Petrus-Reurer, S., Lanner, F., Sandholm, K., Kvanta, A., Nilsson, B. & Nilsson Ekdahl, K. (2017). Complement system proteins in human embryonic stem cell-derived retinal pigment epithelial cells co-cultured with or without porcine retina. Paper presented at 16th European Meeting on Complement in Human Disease (EMCHD), SEP 08-12, 2017, Copenhagen, DENMARK. Molecular Immunology, 89, 162-163
Open this publication in new window or tab >>Complement system proteins in human embryonic stem cell-derived retinal pigment epithelial cells co-cultured with or without porcine retina
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2017 (English)In: Molecular Immunology, ISSN 0161-5890, E-ISSN 1872-9142, Vol. 89, p. 162-163Article in journal, Meeting abstract (Other academic) Published
National Category
Immunology
Research subject
Biomedical Sciences, Immunology
Identifiers
urn:nbn:se:lnu:diva-68148 (URN)10.1016/j.molimm.2017.06.132 (DOI)000410014500107 ()
Conference
16th European Meeting on Complement in Human Disease (EMCHD), SEP 08-12, 2017, Copenhagen, DENMARK
Available from: 2017-10-02 Created: 2017-10-02 Last updated: 2018-11-16Bibliographically approved
Mohlin, C., Sandholm, K., Nilsson Ekdahl, K. & Nilsson, B. (2017). The link between morphology and complement in ocular disease. Paper presented at 16th European Meeting on Complement in Human Disease (EMCHD), SEP 08-12, 2017, Copenhagen, DENMARK. Molecular Immunology, 89, 84-99
Open this publication in new window or tab >>The link between morphology and complement in ocular disease
2017 (English)In: Molecular Immunology, ISSN 0161-5890, E-ISSN 1872-9142, Vol. 89, p. 84-99Article, review/survey (Refereed) Published
Abstract [en]

The complement system is a vital component of the immune-priveliged human eye that is always active at a low-grade level, preventing harmful intraocular injuries caused by accumulation of turnover products and controlling pathogens to preserve eye homeostasis and vision. The complement system is a double-edged sword that is essential for protection but may also become harmful and contribute to eye pathology. Here, we review the evidence for the involvement of complement system dysregulation in age-related macular degeneration, glaucoma, uveitis, and neuromyelitis optica, highlighting the relationship between morphogical changes and complement system protein expression and regulation in these diseases. The potential benefits of complement inhibition in age-related macular degeneration, glaucoma, uveitis, and neuromyelitis optica are abundant, as are those of further research to improve our understanding of complement-mediated injury in these diseases.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Complement, Eye, Morphology, Age-related macular degeneration, Glaucoma, Uveitis, Neuromyelitis optica
National Category
Immunology
Research subject
Biomedical Sciences, Immunology
Identifiers
urn:nbn:se:lnu:diva-71382 (URN)10.1016/j.molimm.2017.05.028 (DOI)000410014500010 ()28622910 (PubMedID)2-s2.0-85020678968 (Scopus ID)
Conference
16th European Meeting on Complement in Human Disease (EMCHD), SEP 08-12, 2017, Copenhagen, DENMARK
Available from: 2018-03-05 Created: 2018-03-05 Last updated: 2019-08-29Bibliographically approved
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