| 1. |
- Lundström, Annika, et al.
(författare)
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Prognostic Value of Circulating Microvesicle Subpopulations in Ischemic Stroke and TIA
- 2020
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Ingår i: Translational Stroke Research. - : Springer Science and Business Media LLC. - 1868-4483 .- 1868-601X. ; 11:4, s. 708-719
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Tidskriftsartikel (refereegranskat)abstract
- Platelet microvesicles (PMV) have previously been found elevated in acute ischemic stroke (IS) and could be biomarkers for risk of recurrence. PMV surface antigens such as P-selectin and phosphatidylserine (PS) reflect platelet activation and procoagulance. Tissue factor-positive microvesicles (TF+MV) are considered procoagulant, in particular if co-expressing PS. We enumerated MV subpopulations with these surface antigens in a cohort of 211 patients with primarily non-cardioembolic IS or transient ischemic attack (TIA) and investigated their association with long-term outcome. MV concentrations were determined by flow cytometry in the acute and convalescent phase. Primary outcome was a composite of fatal and non-fatal recurrent IS or myocardial infarction. Secondary outcomes were recurrent IS and all-cause mortality. Outcome events were obtained from Swedish registers during a follow-up of 1100 patient years. Concentrations of PS-positive and PS-negative MV populations were elevated in patients compared with healthy controls in both the acute and convalescent phase. PS+TF+PMV displayed pronounced elevations, median fold change 77 in the acute phase (p < 0.0001) but were not associated with outcome, neither were PS+P-selectin(+)PMV. The only subpopulation positively associated with primary outcome was PS-TF+PMV, with adjusted hazard ratio of 1.86 (1.04-3.31,p = 0.036) by Cox regression. Unexpectedly, several MV subpopulations tended to be associated with reduced risk of poor long-term outcome. Our results suggest that PS+TF+PMV may be a promising marker for cerebral ischemia, and that the in vivo generation of PS-MV after IS/TIA warrants further study. Future MV studies should ideally enumerate PS(+)and PS-MV subpopulations separately.
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| 2. |
- Bladh, Oscar, et al.
(författare)
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Comparison of SARS-CoV-2 spike-specific IgA and IgG in nasal secretions, saliva and serum
- 2024
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Ingår i: Frontiers in Immunology. - : FRONTIERS MEDIA SA. - 1664-3224. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Several novel vaccine platforms aim at mucosal immunity in the respiratory tract to block SARS-CoV-2 transmission. Standardized methods for mucosal sample collection and quantification of mucosal antibodies are therefore urgently needed for harmonized comparisons and interpretations across mucosal vaccine trials and real-world data. Methods: Using commercial electrochemiluminescence antibody panels, we compared SARS-CoV-2 spike-specific IgA and IgG in paired saliva, nasal secretions, and serum from 1048 healthcare workers with and without prior infection. Results: Spike-specific IgA correlated well in nasal secretions and saliva (r>0.65, p<0.0001), but the levels were more than three-fold higher in nasal secretions as compared to in saliva (p<0.01). Correlations between the total population of spike-specific IgA and spike-specific secretory IgA (SIgA) were significantly stronger (p<0.0001) in nasal secretions (r=0.96, p<0.0001) as opposed to in saliva (r=0.77, p<0.0001), and spike-specific IgA correlated stronger (p<0.0001) between serum and saliva (r=0.73, p<0.001) as opposed to between serum and nasal secretions (r=0.54, p<0.001), suggesting transudation of monomeric spike specific IgA from the circulation to saliva. Notably, spike-specific SIgA had a markedly higher SARS-CoV-2 variant cross-binding capacity as compared to the total population of spike specific IgA and IgG in both nasal secretions, saliva and serum, (all p<0.0001), which emphasizes the importance of taking potential serum derived monomeric IgA into consideration when investigating mucosal immune responses. Discussion: Taken together, although spike-specific IgA can be reliably measured in both nasal secretions and saliva, our findings imply an advantage of higher levels and likely also a larger proportion of SIgA in nasal secretions as compared to in saliva. We further corroborate the superior variant cross-binding capacity of SIgA in mucosal secretions, highlighting the potential protective benefits of a vaccine targeting the upper respiratory tract.
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| 3. |
- Bladh, Oscar, et al.
(författare)
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Comparison of SARS-CoV-2 spike-specific IgA and IgG in nasal secretions, saliva and serum
- 2024
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Ingår i: Frontiers in Immunology. - : Frontiers Media S.A.. - 1664-3224. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Several novel vaccine platforms aim at mucosal immunity in the respiratory tract to block SARS-CoV-2 transmission. Standardized methods for mucosal sample collection and quantification of mucosal antibodies are therefore urgently needed for harmonized comparisons and interpretations across mucosal vaccine trials and real-world data.Methods: Using commercial electrochemiluminescence antibody panels, we compared SARS-CoV-2 spike-specific IgA and IgG in paired saliva, nasal secretions, and serum from 1048 healthcare workers with and without prior infection.Results: Spike-specific IgA correlated well in nasal secretions and saliva (r>0.65, p<0.0001), but the levels were more than three-fold higher in nasal secretions as compared to in saliva (p<0.01). Correlations between the total population of spike-specific IgA and spike-specific secretory IgA (SIgA) were significantly stronger (p<0.0001) in nasal secretions (r=0.96, p<0.0001) as opposed to in saliva (r=0.77, p<0.0001), and spike-specific IgA correlated stronger (p<0.0001) between serum and saliva (r=0.73, p<0.001) as opposed to between serum and nasal secretions (r=0.54, p<0.001), suggesting transudation of monomeric spike specific IgA from the circulation to saliva. Notably, spike-specific SIgA had a markedly higher SARS-CoV-2 variant cross-binding capacity as compared to the total population of spike specific IgA and IgG in both nasal secretions, saliva and serum, (all p<0.0001), which emphasizes the importance of taking potential serum derived monomeric IgA into consideration when investigating mucosal immune responses.Discussion: Taken together, although spike-specific IgA can be reliably measured in both nasal secretions and saliva, our findings imply an advantage of higher levels and likely also a larger proportion of SIgA in nasal secretions as compared to in saliva. We further corroborate the superior variant cross-binding capacity of SIgA in mucosal secretions, highlighting the potential protective benefits of a vaccine targeting the upper respiratory tract.
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| 4. |
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| 5. |
- Dobilas, Arturas, et al.
(författare)
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Circulating Markers of Neutrophil Extracellular Traps (NETs) in Patients With Ovarian Tumors
- 2022
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Ingår i: Anticancer research. - : Anticancer Research USA Inc.. - 1791-7530 .- 0250-7005. ; 42:2, s. 965-971
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND/AIM: Inflammation is a hallmark of cancer, and the role of neutrophils and neutrophil extracellular traps (NETs) in cancer and cancer-associated thrombosis has attracted a lot of interest. The NET-specific marker H3Cit has been found to be elevated in the plasma of patients with malignancies, suggesting NETs markers as novel cancer biomarkers. This study aimed to determine the levels of NETs markers (H3Cit and dsDNA) in the plasma of women with adnexal masses. PATIENTS AND METHODS: Peripheral blood samples were obtained from 199 patients admitted for primary surgery of adnexal masses. Patients were grouped according to tumor type and stage. Plasma levels of H3Cit-DNA, dsDNA, and CA125 were quantified. RESULTS: Plasma levels of H3Cit-DNA and dsDNA were not elevated in women with borderline or malignant ovarian tumors compared with those of the benign group. Increased levels of CA125 were found in the borderline and ovarian cancer group (ptrend<0.001). In Cox regression analysis, CA125 levels dichotomized at 326 IU/ml (median) were associated with worse overall survival (HR=1.9; 95%CI=1.03-3.36; p=0.038). No differences were found in the survival analyses of malignant ovarian tumors by analyzing the dsDNA and H3Cit-DNA levels. CONCLUSION: There is no association between NETs markers and ovarian tumors.
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| 6. |
- Havervall, Sebastian, et al.
(författare)
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Antibody responses after a single dose of ChAdOx1 nCoV-19 vaccine in healthcare workers previously infected with SARS-CoV-2
- 2021
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Ingår i: EBioMedicine. - : Elsevier BV. - 2352-3964. ; 70
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Tidskriftsartikel (refereegranskat)abstract
- Background: Recent reports demonstrate robust serological responses to a single dose of messenger RNA (mRNA) vaccines in individuals previously infected with SARS-CoV-2. Data on immune responses following a single-dose adenovirus-vectored vaccine expressing the SARS-CoV-2 spike protein (ChAdOx1 nCoV-19) in individuals with previous SARS-CoV-2 infection are however limited, and current guidelines recommend a two-dose regimen regardless of preexisting immunity. Methods: We compared RBD-specific IgG and RBD-ACE2 blocking antibodies against SARS-CoV-2 wild type and variants of concern following two doses of the mRNA vaccine BNT162b2 in SARS-CoV-2 naive healthcare workers (n=65) and a single dose of the adenovector vaccine ChAdOx1 nCoV-19 in 82 healthcare workers more than (n=45) and less than (n=37) 11 months post mild SARS-CoV-2 infection at time of vaccination. Findings: The post-vaccine levels of RBD-specific IgG and neutralizing antibodies against the SARS-CoV-2 wild type and variants of concern including Delta lineage 1.617.2 were similar or higher in participants receiving a single dose of ChAdOx1 nCoV-19 vaccine post SARS-CoV-2 infection (both more than and less than 11 months post infection) compared to SARS-CoV-2 naive participants who received two doses of BNT162b2 vaccine. Interpretation: Our data support that a single dose ChAdOx1 nCoV-19 vaccine that is administered up to at least 11 months post SARS-CoV-2 infection serves as an effective immune booster. This provides a possible rationale for a single-dose vaccine regimen. (C) 2021 The Author(s). Published by Elsevier B.V.
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| 7. |
- Havervall, Sebastian, et al.
(författare)
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Impact of SARS-CoV-2 infection on vaccine-induced immune responses over time
- 2022
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Ingår i: Clinical & Translational Immunology (CTI). - : Wiley. - 2050-0068. ; 11:4
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To determine the long-term impact of prior SARS-CoV-2 infection on immune responses after COVID-19 vaccination. Methods. Using longitudinally collected blood samples from the COMMUNITY study, we determined binding (WHO BAU mL(-1)) and neutralising antibody titres against ten SARS-CoV-2 variants over 7 months following BNT162b2 in SARS-CoV-2-recovered (n = 118) and SARS-CoV-2-naive (n = 289) healthcare workers with confirmed prior SARS-CoV-2 infection. A smaller group with (n = 47) and without (n = 60) confirmed prior SARS-CoV-2 infection receiving ChAdOx1 nCoV-19 was followed for 3 months. SARS-CoV-2-specific memory T-cell responses were investigated in a subset of SARS-CoV-2-naive and SARS-CoV-2-recovered vaccinees. Results. Vaccination with both vaccine platforms resulted in substantially enhanced T-cell responses, anti-spike IgG responses and neutralising antibodies effective against ten SARS-CoV-2 variants in SARS-CoV-2-recovered participants as compared to SARS-CoV-2-naive participants. The enhanced immune responses sustained over 7 months following vaccination. Conclusion. These findings imply that prior SARS-CoV-2 infection should be taken into consideration when planning booster doses and design of current and future COVID-19 vaccine programmes.
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| 8. |
- Lauren, Ida, et al.
(författare)
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Long-term SARS-CoV-2-specific and cross-reactive cellular immune responses correlate with humoral responses, disease severity, and symptomatology
- 2022
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Ingår i: Immunity, Inflammation and Disease. - : John Wiley & Sons. - 2050-4527. ; 10:4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Cellular immune memory responses post coronavirus disease 2019 (COVID-19) have been difficult to assess due to the risks of contaminating the immune response readout with memory responses stemming from previous exposure to endemic coronaviruses. The work herein presents a large-scale long-term follow-up study investigating the correlation between symptomology and cellular immune responses four to five months post seroconversion based on a unique severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific peptide pool that contains no overlapping peptides with endemic human coronaviruses. Methods: Peptide stimulated memory T cell responses were assessed with dual interferon-gamma (IFN gamma) and interleukin (IL)-2 Fluorospot. Serological analyses were performed using a multiplex antigen bead array. Results: Our work demonstrates that long-term SARS-CoV-2-specific memory T cell responses feature dual IFN gamma and IL-2 responses, whereas cross-reactive memory T cell responses primarily generate IFN gamma in response to SARS-CoV-2 peptide stimulation. T cell responses correlated to long-term humoral immune responses. Disease severity as well as specific COVID-19 symptoms correlated with the magnitude of the SARS-CoV-2-specific memory T cell response four to five months post seroconversion. Conclusion: Using a large cohort and a SARS-CoV-2-specific peptide pool we were able to substantiate that initial disease severity and symptoms correlate with the magnitude of the SARS-CoV-2-specific memory T cell responses.
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| 9. |
- Mangsbo, Sara, 1981-, et al.
(författare)
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An evaluation of a FluoroSpot assay as a diagnostic tool to determine SARS-CoV-2 specific T cell responses
- 2021
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 16:9
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Tidskriftsartikel (refereegranskat)abstract
- Numerous assays evaluating serological and cellular responses have been developed to characterize immune responses against SARS-CoV-2. Serological assays are both cost- and time-effective compared to cellular assays, but cellular immune responses may provide a diagnostic value to determine previous SARS-CoV-2 infection in seronegative individuals. However, potential cross-reactive T cell responses stemming from prior encounters with human coronaviruses (HCoVs) may affect assay specificity. In this study, we evaluated the specificity and sensitivity of a SARS-CoV-2 IFN-gamma Release Assay (IGRA) based on the FluoroSpot method employing commercially available SARS-CoV-2-specific peptide pools, as well as an in-house designed SARS-CoV-2 peptide pool restricted to 5 amino acid stretches or less aligning with endemic HCoVs. Blood samples were obtained from healthcare workers (HCW) 5-6 months post SARS-CoV-2 spike (S) IgG and nucleocapsid (N) IgG dual seroconversion (n = 187) and HCW who had been S IgG and N IgG dual seronegative at repeated occasions, including the current sampling time point (n = 102). In addition, samples were obtained 4 to 5 months post infection from 55 polymerase chain reaction (PCR)-confirmed COVID-19 patients. Assay specificity and sensitivity were calculated with serology as a reference standard for HCW. The in-house generated peptide pool displayed a specificity of 96.1%, while the commercially available peptide pools displayed specificities of 80.4% and 85.3%, respectively. Sensitivity was higher in a cohort of previously hospitalized COVID-19 patients (96.4% and 84.0% for the commercially available peptide pools and 92.7% for the in-house generated peptide pool) compared to the HCW cohort (92.0% and 66.8% for the commercially available peptide pools and 76.0% for the in-house generated peptide pool). Based on these findings, the individual diagnostic value of T cell immune responses against SARS-CoV-2 currently appears to be limited but remain an important research tool ahead.
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| 10. |
- Marking, Ulrika, et al.
(författare)
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Duration of SARS-CoV-2 Immune Responses Up to Six Months Following Homologous or Heterologous Primary Immunization with ChAdOx1 nCoV-19 and BNT162b2 mRNA Vaccines
- 2022
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Ingår i: Vaccines. - : MDPI AG. - 2076-393X. ; 10:3, s. 359-
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Tidskriftsartikel (refereegranskat)abstract
- Heterologous primary immunization against SARS-CoV-2 is part of applied recommendations. However, little is known about duration of immune responses after heterologous vaccine regimens. To evaluate duration of immune responses after primary vaccination with homologous adeno-vectored ChAdOx1 nCoV-19 vaccine (ChAd) or heterologous ChAd/BNT162b2 mRNA vaccine (BNT), anti-spike-IgG and SARS-CoV-2 VOC-neutralizing antibody responses were measured in 354 healthcare workers (HCW) at 2 weeks, 3 months, 5 months and 6 months after the second vaccine dose. T-cell responses were investigated using a whole blood interferon gamma (IFN-gamma) release assay 2 weeks and 3 months post second vaccine dose. Two hundred and ten HCW immunized with homologous BNT were enrolled for comparison of antibody responses. In study participants naive to SARS-CoV-2 prior to vaccination, heterologous ChAd/BNT resulted in 6-fold higher peak anti-spike IgG antibody titers compared to homologous ChAd vaccination. The half-life of antibody titers was 3.1 months (95% CI 2.8-3.6) following homologous ChAd vaccination and 1.9 months (95% CI 1.7-2.1) after heterologous vaccination, reducing the GMT difference between the groups to 3-fold 6 months post vaccination. Peak T-cell responses were stronger in ChAd/BNT vaccinees, but no significant difference was observed 3 months post vaccination. SARS-CoV-2 infection prior to vaccination resulted in substantially higher peak GMTs and IFN-gamma levels and enhanced SARS-CoV-2 specific antibody and T cell responses over time. Heterologous primary SARS-CoV-2 immunization with ChAd and BNT elicits a stronger initial immune response compared to homologous vaccination with ChAd. However, although the differences in humoral responses remain over 6 months, the difference in SARS-CoV-2 specific T cell responses are no longer significant three months after vaccination.
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