| 1. |
- Alfirevic, Ana, et al.
(författare)
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In silico analysis of HLA associations with drug-induced liver injury : use of a HLA-genotyped DNA archive from healthy volunteers
- 2012
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Ingår i: Genome Medicine. - : BioMed Central. - 1756-994X. ; 4:6
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Drug-induced liver injury (DILI) is one of the most common adverse reactions leading to product withdrawal post-marketing. Recently, genome-wide association studies have identified a number of human leukocyte antigen (HLA) alleles associated with DILI; however, the cellular and chemical mechanisms are not fully understood.METHODS: To study these mechanisms, we established an HLA-typed cell archive from 400 healthy volunteers. In addition, we utilized HLA genotype data from more than four million individuals from publicly accessible repositories such as the Allele Frequency Net Database, Major Histocompatibility Complex Database and Immune Epitope Database to study the HLA alleles associated with DILI. We utilized novel in silico strategies to examine HLA haplotype relationships among the alleles associated with DILI by using bioinformatics tools such as NetMHCpan, PyPop, GraphViz, PHYLIP and TreeView.RESULTS: We demonstrated that many of the alleles that have been associated with liver injury induced by structurally diverse drugs (flucloxacillin, co-amoxiclav, ximelagatran, lapatinib, lumiracoxib) reside on common HLA haplotypes, which were present in populations of diverse ethnicity.CONCLUSIONS: Our bioinformatic analysis indicates that there may be a connection between the different HLA alleles associated with DILI caused by therapeutically and structurally different drugs, possibly through peptide binding of one of the HLA alleles that defines the causal haplotype. Further functional work, together with next-generation sequencing techniques, will be needed to define the causal alleles associated with DILI.
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| 2. |
- Assenhöj, Maria, et al.
(författare)
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Protein interaction, monocyte toxicity and immunogenic properties of cerium oxide crystals with 5% or 14% gadolinium, cobalt oxide and iron oxide nanoparticles–an interdisciplinary approach
- 2021
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Ingår i: Nanotoxicology. - : Taylor and Francis Ltd.. - 1743-5390 .- 1743-5404. ; 15:8, s. 1035-1038
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Tidskriftsartikel (refereegranskat)abstract
- Metal oxide nanoparticles are widely used in both consumer products and medical applications, but the knowledge regarding exposure-related health effects is limited. However, it is challenging to investigate nanoparticle interaction processes with biological systems. The overall aim of this project was to improve the possibility to predict exposure-related health effects of metal oxide nanoparticles through interdisciplinary collaboration by combining workflows from the pharmaceutical industry, nanomaterial sciences, and occupational medicine. Specific aims were to investigate nanoparticle-protein interactions and possible adverse immune reactions. Four different metal oxide nanoparticles; CeOx nanocrystals with 5% or 14% Gd, Co3O4, and Fe2O3, were characterized by dynamic light scattering and high-resolution transmission electron microscopy. Nanoparticle-binding proteins were identified and screened for HLA-binding peptides in silico. Monocyte interaction with nanoparticle–protein complexes was assessed in vitro. Herein, for the first time, immunogenic properties of nanoparticle-binding proteins have been characterized. The present study indicates that especially Co3O4-protein complexes can induce both ‘danger signals’, verified by the production of inflammatory cytokines and simultaneously bind autologous proteins, which can be presented as immunogenic epitopes by MHC class II. The clinical relevance of these findings should be further evaluated to investigate the role of metal oxide nanoparticles in the development of autoimmune disease. The general workflow identified experimental difficulties, such as nanoparticle aggregate formation and a lack of protein-free buffers suitable for particle characterization, protein analyses, as well as for cell studies. This confirms the importance of future interdisciplinary collaborations. © 2021 The Author(s).
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| 3. |
- Cederbrant, Karin, et al.
(författare)
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Characterization of mercuric mercury (Hg2+)-induced lymphoblasts from patients with mercury allergy and from healthy subjects
- 2000
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Ingår i: Clinical and Experimental Immunology. - : Oxford University Press (OUP). - 0009-9104 .- 1365-2249. ; 121:1, s. 23-30
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Tidskriftsartikel (refereegranskat)abstract
- Hg2+ induces lymphocyte proliferation when added to cell cultures from both healthy and mercury-allergic subjects. Consequently, when measuring DNA synthesis a possible Hg2+-specific response, resulting from proliferating memory cells, cannot be discriminated from a non-allergic response. The mechanism behind this non-allergic response is unknown but a superantigenic effect of Hg2+ has been suggested. In this study, five mercury-allergic patients, with oral lichen planus (OLP) lesions adjacent to dental amalgam and a positive patch test to Hg0, and five healthy subjects without amalgam were examined. The immunophenotype and the T cell receptor Vβ (TCR Vβ) repertoire of Hg2+-induced lymphoblasts as well as the expression of the lymphocyte activation markers CD23 and CD134 were analysed for possible differences between healthy and allergic subjects. The mechanism of Hg2+-induced proliferation was examined by comparing the TCR Vβ expression of Hg- and staphylococcal enterotoxin B (SEB)-activated lymphoblasts, the latter used as a positive superantigen control. It was not possible to discriminate between mercury-allergic and healthy subjects using the immunophenotype or the TCR Vβ profile of the Hg2+-induced lymphoblasts or the expression of CD23 and CD134. However, Hg2+-induced CD4+ lymphoblasts showed a skewing towards Vβ2. This relative increase in Vβ2 was only detected in the CD4+ but not in the CD8+ lymphoblast population. In conclusion, Hg2+ induced a proliferation-dependent skewing towards CD4+ but not CD8+ lymphocytes expressing Vβ2. In this respect Hg2+ differs from the classical bacterial superantigen SEB, which also stimulates unique TCR Vβ families among CD8+ cells.
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| 4. |
- Cederbrant, Karin, et al.
(författare)
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Characterization of primary recall in vitro lymphocyte responses to bacampicillin in allergic subjects
- 2000
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Ingår i: Clinical and Experimental Allergy. - : Wiley. - 0954-7894 .- 1365-2222. ; 30:10, s. 1450-1459
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundAntigen-specific cell lines or clones are often used as models of drug-specific allergy. However, cloning procedures are time consuming, and the repeated antigen stimulation cycles as well as the addition of various growth enhancers may affect the in vivo relevance of these systems.ObjectiveUsing bacampicillin-allergic subjects, we wanted to investigate the applicability of primary recall in vitro lymphocyte responses to characterize type I and type IV allergy. The sensitivity and specificity of LTT (Lymphocyte transformation test), when used as an in vitro diagnostic tool, were also assessed.MethodsA total of 39 patients with symptoms of type I (rhinitis) or type IV (allergic contact dermatitis, ACD) allergy following occupational exposure to bacampicillin, were included. Ten individuals without penicillin allergy or occupational exposure to bacampicillin served as controls. All subjects were LTT tested. Four patients with rhinitis and two patients with ACD were available for studying the immunophenotype and the TCR-Vβ repertoire of bacampicillin induced lymphoblasts as well as the cytokine profiles and expression of the activation markers CD23 and CD134 in primary PBMC cultures.ResultsLTT was positive in 87% and at least one of the skin tests was positive in 85% of the patients with allergic symptoms. 69% of the patients with type I allergies were patch test-positive. Results from LTT and skin test correlated in 87% of the cases. The combined sensitivity of LTT and skin tests was 92%. The specificity of LTT was 90% in healthy controls. Bacampicillin induced lymphoblasts were mainly CD4 + in both ACD and rhinitis patients. The TCR-Vβ profiles of the predominant CD4 + lymphoblasts were heterogeneous with individual skewing towards Vβ2, Vβ3, Vβ5.1 and/or Vβ14. An increased expression of IFNγ was detected in bacampicillin treated PBMC cultures from the ACD but not from rhinitis patients. IL-5 was detected in bacampicillin exposed PBMC cultures from all patients but not from healthy controls. This Th2 environment could also be verified by CD23 and CD134 expression.ConclusionLTT and skin tests are equally sensitive in identifying bacampicillin allergic subjects. When the two tests are combined, the sensitivity increases. The patch test is useful not only for detection of type IV but also for the identification of type I allergies. When using primary PBMC cultures, IFNγ is the most suitable cytokine to discriminate between type I and type IV allergy. IL-5 can possibly be used as a general marker for bacampicillin induced allergy. Thus, primary cell cultures may be considered as an alternative to T-cell lines or clones for the study of drug induced allergy.
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| 5. |
- Cederbrant, Karin, et al.
(författare)
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Cytokine production, lymphocyte proliferation and T-cell receptor Vbeta expression in primary peripheral blood mononuclear cell cultures from nickel-allergic individuals
- 2003
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Ingår i: International Archives of Allergy and Immunology. - : S. Karger AG. - 1018-2438 .- 1423-0097. ; 132:4, s. 373-379
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Tidskriftsartikel (refereegranskat)abstract
- Background: Clinical history and patch test constitute the two cornerstones in the diagnosis of nickel (Ni) allergy. Due to technical and interpretative limits of the patch test, the in vitro lymphocyte transformation test (LTT) has been developed for confirming contact allergy, however, most studies show an overlap in lymphocyte proliferation between Ni-allergic and nonallergic subjects using the LTT. The aim of this study was to see if the secretion of cytokines, especially interleukin (IL)-10 and IL-17, or the use of T-cell receptor (TCR) V▀ families in Ni-stimulated primary peripheral blood mononuclear cell (PBMC) cultures might be more useful for discriminating between allergic and nonallergic subjects. Methods: Ni2+-stimulated primary PBMC cultures derived from female subjects diagnosed as Ni-allergic (n = 5) or nonallergic (n = 5) on the basis of a positive or negative patch test were assessed for cell proliferation by tritiated thymidine incorporation and for production of interferon-?, IL-4, IL-10 and IL-17 in the culture supernatant by ELISA. The immunophenotype and TCR-V▀ family affiliation of the Ni2+-induced lymphoblasts were determined by flow cytometry. Results: Lymphocytes from Ni-allergic individuals challenged with a high and a low concentration of Ni showed significantly higher cell proliferation than lymphocytes from nonallergic individuals, but all subjects showed a positive LTT result (stimulation index>2). We found a significantly higher release of IL-10 in Ni2+-treated cultures from Ni-allergic compared with nonallergic subjects that provided better separation between individuals in the two groups than did lymphocyte proliferation. The proliferating lymphoblasts were predominantly CD4+, and in 2 of the 5 Ni-allergic subjects, but in none of the 5 nonallergic subjects, the CD4+ lymphoblasts showed a dominance of TCR-V▀17. Conclusions: Determination of IL-10 production in primary PBMC cultures is a potentially promising in vitro method for discrimination of Ni allergy in females, as compared with cell proliferation. Copyright ⌐ 2003 S. Karger AG, Basel.
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| 6. |
- Cederbrant, Karin, et al.
(författare)
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IL-10 production in primary PBMC cultures : an in vitro marker for nickel allergy?
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Nickel (Ni) is one of the most known contact allergens and at present, patch test and clinical history constitute the two cornerstones in the diagnostic procedure. Since the patch test is inherited with in vivo provocation and subjective interpretation of the test result, a non-invasive in vitro method with objective interpretation of the test result has long been searched for. Unfortunately, in vitro diagnosis of Ni- allergy is hampered by the fact that Ni2+ is able to trigger in vitro proliferative responses in lymphocytes from both Ni-allergic and non-allergic subjects. This constitutes a problem when LTT (lymphocyte transformation test), the most frequently used in vitro test as a complement in the diagnosis of contact allergy, is considered for Ni allergy. However, other parameters in the in vitro response might be more useful. In this study, Ni2+-stimulated primary PBMC-cultures derived from Ni-allergic and non-allergic subjects were assessed for IFN-γ, IL-4, IL-10 and IL-17. Also, Ni2+ induced lymphoblasts from such cultures were characterized by their immunophenotype and T-cell receptor Vß-affiliation.We found a significantly higher release of IL-10 in Ni2+ treated cultures from allergic than from non-allergic subjects. The Ni2+-induced lymphoblasts from both groups were predominantly CD4+. Two of the allergic patients (n=5) showed a skewing towards TCR-Vß17, a Vß family earlier associated with Ni-allergy. A significant increase in CD134 and CD23 expression indicated that Ni2+ activates B-cells in vitro. In conclusion, IL-10 seems to be a promising marker for Ni-allergy using primary PBMC cultures. Further, flow cytometric screening of Ni2+ induced lymphoblasts can detect expanded TCR-Vß families that may be used for preparation of Ni-specific T cell clones.
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| 7. |
- Cederbrant, Karin, et al.
(författare)
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In vitro Lymphocyte Proliferation as Compared to Patch Test Using Gold, Palladium and Nickel
- 1997
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Ingår i: International Archives of Allergy and Immunology. - : S. Karger AG. - 1018-2438 .- 1423-0097. ; 112:3, s. 212-217
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Tidskriftsartikel (refereegranskat)abstract
- Background: A conventional lymphocyte transformation test (LTT) was compared to the commercially available MELISA® (memory lymphocyte immuno-stimulation assay), a lymphoproliferative assay that has been suggested to be a valuable instrument for the diagnosis of metal allergy. Sensitivity and specificity of the two assays were calculated using a patch test as a reference method.Methods: 34 patients were patch-tested for gold sodium thiosulfate, palladium chloride and nickel sulfate, and the lymphocyte proliferation to these metals was tested in vitro using mononuclear cells from peripheral blood.Results: No significant differences regarding sensitivity and specificity were found between MELISA and conventional LTT. The sensitivity varied between 55 and 95% and the specificity between 17 and 79%.Conclusions: The low specificity of the two in vitro assays suggests that they are not useful for diagnosis of contact allergy to the metals gold, palladium and nickel, since a large number of false-positive results will be obtained.
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| 8. |
- Cederbrant, Karin, et al.
(författare)
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In vitro Lymphoproliferative Assays with HgCl2 Cannot Identify Patients with Systemic Symptoms Attributed to Dental Amalgam
- 1999
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Ingår i: Journal of Dental Research. - : SAGE Publications. - 0022-0345 .- 1544-0591. ; 78:8, s. 1450-1458
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Tidskriftsartikel (refereegranskat)abstract
- Dental amalgam is suspected, by some exposed individuals, to cause various systemic psychological, sensory, and neurological symptoms. Since not all amalgam-bearers experience such reactions, an individual characteristic—for example, a susceptible immune system—might explain these conditions. In vitro lymphocyte proliferation is a valuable tool in the diagnosis of allergy. With HgCl2 as the antigen, however, the test is hampered, because Hg2+ can cause unspecific lymphocyte proliferation, optimal at 1.4 to 9.5 μg HgCl2/mL. Recently, the use of suboptimal HgCl2 concentrations (≤ 0.5 μg/mL) has been suggested to circumvent these problems. The main aim of this study was to investigate whether patients with systemic symptoms alleged to result from the presence of dental amalgam differ from healthy controls, with reference to in vitro lymphoproliferative responses to HgCl2 ≤ 0.5 μg/mL. Three different test protocols—lymphocyte transformation test (LTT) in micro- and macro-cultures, and the memory lymphocyte immunostimulation assay (MELISA®)—were used. Other immune parameters—such as a standard patch test for dental materials, the number of T- and B-lymphocytes, monocytes, granulocytes, and NK cells in peripheral blood, allergic symptoms, and predisposition-were also investigated. Twenty-three amalgam patients, 30 healthy blood donors with amalgam, ten healthy subjects without amalgam, and nine patients with oral lichen planus (OLP) adjacent to dental amalgam and a positive patch test to Hg0 were tested. None of the investigated immune parameters revealed any significant differences between amalgam patients and controls. The sensitivity of in vitro lymphocyte proliferation ranged from 33 to 67%, with the OLP patients as a positive control group, and the specificity from 0 to 70% for healthy controls with a negative patch test to Hg°. Thus, despite the use of HgCl2 ≤ 0.5 μg/mL, a high frequency of positive results was obtained among healthy subjects with or without dental amalgam. Consequently, in vitro lymphocyte proliferation with HgCl2 cannot be used as an objective marker for mercury allergy in dental amalgam-bearers.
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| 9. |
- Cederbrant, Karin, 1964-
(författare)
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The Primary Lymphocyte Culture in the Diagnosis of Drug- and Metal-Induced Allergy
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Drugs and metals are examples of xenobiotics that can induce hypersensitivity in humans. These adverse reactions are classified as allergy if repeated exposure leads to the same type of clinical manifestation. Together with the clinical history, the skin test is the most commonly used test for the diagnosis of allergic disease. However, in vivo testing per se has drawbacks such as the risk of potentiation of the allergy or even sensitisation to a given test substance. For this reason in vitro testing is an attractive diagnostic alternative since it does not involve any exposure of the test subject to the allergen.The lymphocyte transformation test (LTT) has been used to complement the diagnosis of allergy to drugs and metals for more than thirty years. The principle behind this test is to show the presence of allergen-specific memory lymphocytes in peripheral blood, which is a sine qua non of a true allergy. LTT reveals the proliferation of such cells by showing DNA synthesis as the uptake of 3H-thymidine in primary PBMC (peripheral blood mononuclear cell) cultures treated with the allergen. However, LIT has not yet been generally accepted as a stand-alone test in the diagnosis of allergy. One reason for this is that different chemical properties of the allergens may lead to either false positive or false negative LTT responses.In the present study we investigated allergy to the drug bacampicillin and to the metals Au, Pd, Ni and Hg. Three different protocols for LTT: LIT in micro cultures (LTT-micro), LTT in macro cultures (LTT-macro) and memory lymphocyte immunostimulation assay (MELISA) were compared using a skin test or clinical history as reference methods. LTI showed a sensitivity of 87% and a specificity of 90% when used in the diagnosis of allergy to bacampicillin. When allergy to Au, Pd, Ni and Hg was investigated, the sensitivity was 33- 95% and the specificity 0-79%. There were no significant differences between the test protocols, except that MELISA showed a significantly higher specificity than LTT-micro and LTT-macro when Hg2+ was used as antigen. Even so, this specificity was only 70%, which would result in 30 of 100 healthy subjects receiving a false diagnosis of Hg allergy when using the MELISA protocol. Ni2+ also induced high numbers of false-positive LTI responses, 77-85% patch-test negative subjects showed positive results to these metals. However, group comparisons showed a significantly higher proliferation intensity in allergic than in nonallergic groups for all allergens except Hg2+. Furthermore, only 56% of patients with verified allergy to mercury showed a positive MELISA, a sensitivity that is unacceptably low.Following these findings, we investigated whether other endpoints than DNA synthesis could be used to discriminate allergic from healthy subjects, using primary PBMC cultures with Hg2+ or Ni2+ as a model system. Analysis of the T-cell receptor Vß profiles of lymphoblasts induced by these metal ions showed individual patterns, and there was no difference between healthy and allergic groups. However, the fraction of CD4+/Vß2+ cells correlated significantly with the proliferation intensity induced by Hg2+ in patients with a verified Hg allergy but not in non-allergic controls. Interestingly, such a correlation was not seen with CD8+/Nß2+ cells. This indicates that Hg2+ does not function as a superantigen, since classical superantigens also stimulate CD8+ lymphocytes. When Ni2+ was used as antigen we found significantly higher IL-10 production in allergic than in non-allergic subjects, despite no significant difference in proliferation intensity between these two groups.In conclusion, the LTT test is useful for the diagnosis of allergy to bacampicillin. Regarding Au, Pd and Ni the LIT has low validity and can only be used to discriminate groups of allergic from non-allergic individuals. LTT with Hg2+ and Ni2+ is not useful for the diagnosis of allergy to these metals since a high fraction of non-allergic individuals show positive results, irrespective of the test protocol used. This thesis calls for further studies on the usefulness of in vitro IL-10 production for the diagnosis of Ni allergy as well as on the specificity of in vitro induced CD4+N~2+ lymphoblasts from Hg allergic subjects.
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| 10. |
- Christiansen Clifford, Jenny, et al.
(författare)
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Interferon-gamma secreted from peripheral blood mononuclear cells as a possible diagnostic marker for allergic contact dermatitis to gold
- 2006
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873 .- 1600-0536. ; 55:2, s. 101-112
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Tidskriftsartikel (refereegranskat)abstract
- 10% of patch-tested patients have a positive reaction to gold. Most lack clinical symptoms, but allergic contact dermatitis (ACD) to gold is increasing. In this study, 77 dermatological outpatients were divided into 3 groups depending on epicutaneous patch test outcomes: a group positive to gold (EPI+), a group negative to gold (EPI-), and a group with irritant reactions to gold (EPI-IR). Lymphocytes were stimulated in vitro with gold sodium thiosulfate. Proliferation was assessed using the lymphocyte transformation test (LTT), and cytokine secretion was assessed using a multibead array (Luminex; Linco Research Inc., St. Charles, MO, USA), in order to evaluate whether an in vitro method with high diagnostic accuracy could be devised. The EPI+ group showed a significantly increased secretion of interferon (IFN)-gamma, interleukin (IL)-2, and IL-13 and also showed a significantly higher stimulation indexes for LTT, compared to the other 2 subject groups. Sensitivity and specificity were calculated for all methods individually and combined, but IFN-gamma assessment alone was the most accurate method for identifying ACD to gold, with sensitivity and specificity of 81.8% and 82.1%, respectively. This method also identified 87.5% of the EPI-IR subjects as non-allergic. Therefore, assessment of secretion of IFN-gamma should be a valuable complement to patch test for diagnosing gold allergy.
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