| 1. |
- Tuiskunen-Bäck, Anne, et al.
(author)
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Clinical and genomic characterisation of a fatal Puumala orthohantavirus case with low levels of neutralising antibodies
- 2022
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In: Infectious Diseases. - : Informa UK Limited. - 2374-4235 .- 2374-4243. ; 54:10, s. 766-772
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Journal article (peer-reviewed)abstract
- BACKGROUND: Orthohantaviruses are rodent-borne emerging viruses that cause haemorrhagic fever with renal syndrome (HFRS) in Eurasia and hantavirus pulmonary syndrome in America. Transmission between humans have been reported and the case-fatality rate ranges from 0.4% to 40% depending on virus strain. There is no specific and efficient treatment for patients with severe HFRS. Here, we characterised a fatal case of HFRS and sequenced the causing Puumala orthohantavirus (PUUV).METHODS: PUUV RNA and virus specific neutralising antibodies were quantified in plasma samples from the fatal case and other patients with non-fatal PUUV infection. To investigate if the causing PUUV strain was different from previously known strains, Sanger sequencing was performed directly from the patient's plasma. Biopsies obtained from autopsy were stained for immunohistochemistry.RESULTS: The patient had approximately tenfold lower levels of PUUV neutralising antibodies and twice higher viral load than was normally seen for patients with less severe PUUV infection. We could demonstrate unique mutations in the S and M segments of the virus that could have had an impact on the severity of infection. Due to the severe course of infection, the patient was treated with the bradykinin receptor inhibitor icatibant to reduce bradykinin-mediated vessel permeability and maintain vascular circulation.CONCLUSIONS: Our data suggest that bradykinin receptor inhibitor may not be highly efficient to treat patients that are at an advanced stage of HFRS. Low neutralising antibodies and high viral load at admission to the hospital were associated with the fatal outcome and may be useful for future predictions of disease outcome.
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| 2. |
- Hansson, Magnus, et al.
(author)
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Cystatin C and α-1-Microglobulin Predict Severe Acute Kidney Injury in Patients with Hemorrhagic Fever with Renal Syndrome
- 2020
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In: Pathogens. - : MDPI. - 2076-0817. ; 9:8
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Journal article (peer-reviewed)abstract
- Puumala orthohantavirus causes hemorrhagic fever with renal syndrome (HFRS) characterized by acute kidney injury (AKI), an abrupt decrease in renal function. Creatinine is routinely used to detect and quantify AKI; however, early AKI may not be reflected in increased creatinine levels. Therefore, kidney injury markers that can predict AKI are needed. The potential of the kidney injury markers urea, cystatin C, α1-microglobulin (A1M) and neutrophil gelatinase-associated lipocalin (NGAL) to detect early AKI during HFRS was studied by quantifying the levels of these markers in consecutively obtained plasma (P) and urine samples (U) for 44 HFRS patients. P-cystatin C and U-A1M levels were significantly increased during early HFRS compared to follow-up. In a receiver operating characteristic (ROC) curve analysis, P-cystatin C, U-A1M and P-urea predicted severe AKI with area under the curve 0.72, 0.73 and 0.71, respectively, whereas the traditional kidney injury biomarkers creatinine and U-albumin did not predict AKI. Nearly half of the HFRS patients (41%) fulfilled the criteria for shrunken pore syndrome, which was associated with the level of inflammation as measured by P-CRP. P-cystatin C and U-A1M are more sensitive and earlier markers compared to creatinine in predicting kidney injury during HFRS.
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| 3. |
- Kerkman, Priscilla, et al.
(author)
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Generation of plasma cells and CD27-IgD- B cells during hantavirus infection is associated with distinct pathological findings
- 2021
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In: Clinical & Translational Immunology (CTI). - : John Wiley & Sons. - 2050-0068. ; 10
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Journal article (peer-reviewed)abstract
- Objective: Human hantavirus infections can cause haemorrhagic fever with renal syndrome (HFRS). The pathogenic mechanisms arenot fully understood, nor if they affect the humoral immune system. The objective of this study was to investigate humoral immune responses to hantavirus infection and to correlate them to the typical features of HFRS: thrombocytopenia and transient kidney dysfunction.Methods: We performed a comprehensive characterisation of longitudinal antiviral B-cell responses of 26 hantavirus patients and combined this with paired clinical data. In addition, we measured extracellular adenosine triphosphate (ATP)and its breakdown products in circulation and performed in vitro stimulations to address its effect on B cells.Results: We found that thrombocytopenia was correlated to an elevated frequency of plasmablasts in circulation. In contrast, kidney dysfunction was indicative of an accumulation of CD27-IgD- B cells and CD27/low plasmablasts. Finally, we provide evidence that high levels of extracellular ATP and matrix metalloproteinase 8 can contribute to shedding of CD27 during human hantavirus infection.Conclusion: Our findings demonstrate that thrombocytopenia and kidneydysfunction associate with distinctly different effects on the humoral immune system. Moreover, hantavirus-infectedindividuals have significantly elevated levels of extracellular ATP incirculation.
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| 4. |
- Pettersson, Lisa, et al.
(author)
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Viral load and humoral immune response in association with disease severity in Puumala hantavirus-infected patients-implications for treatment
- 2014
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In: Clinical Microbiology and Infection. - : Wiley-Blackwell. - 1198-743X .- 1469-0691. ; 20:3, s. 235-241
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Journal article (peer-reviewed)abstract
- Hantaviruses are the causative agents of haemorrhagic fever with renal syndrome (HFRS) in Eurasia and of hantavirus cardiopulmonary syndrome (HCPS) in the Americas. The case fatality rate varies between different hantaviruses and can be up to 40%. At present, there is no specific treatment available. The hantavirus pathogenesis is not well understood, but most likely, both virus-mediated and host-mediated mechanisms are involved. The aim of the present study was to investigate the association among Puumala hantavirus (PUUV) viral RNA load, humoral immune response and disease severity in patients with HFRS. We performed a study of 105 PUUV-infected patients that were followed during the acute phase of disease and for up to 1-3 months later. Fifteen of the 105 patients (14%) were classified as having moderate/severe disease. A low PUUV-specific IgG response (p <0.05) and also a higher white blood cell count (p <0.001) were significantly associated with more severe disease. The PUUV RNA was detected in a majority of patient plasma samples up to 9 days after disease onset; however, PUUV RNA load or longevity of viraemia were not significantly associated with disease severity. We conclude that a low specific IgG response was associated with disease severity in patients with HFRS, whereas PUUV RNA load did not seem to affect the severity of HFRS. Our results raise the possibility of passive immunotherapy as a useful treatment for hantavirus-infected patients.
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| 5. |
- Rankin, Gregory, et al.
(author)
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MMP9 Associates with Endothelial Glycocalyx Degradation During Haemorrhagic Fever with Renal Syndrome
- 2019
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In: Journal of Vascular Research. - : S. Karger. - 1018-1172 .- 1423-0135. ; 56, s. 35-35
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Journal article (other academic/artistic)abstract
- Introduction: Haemorrhagic fever with renal syndrome (HFRS) is characterized by fever, hypotension, vascular leakage, thrombocytopenia and renal failure. HFRS in Sweden is caused by the Puumala hantavirus and is spread by viral-infested droppings from bank voles. The health care system has little to offer these patients since there is no antiviral treatment and as of yet there is no vaccine prophylaxis available. We previously showed that a marker of endothelial glycocalyx degradation (Syndecan-1) was associated with disease severity and disseminated intravascular coagulation during HFRS (Connolly-Andersen et al., 2014, Open Forum Infect Dis.).Methods: We analysed the levels of other endothelial glycocalyx degradation markers (heparan sulfate, soluble thrombomodulin, albumin), a potential “sheddase”: Matrix Metalloproinase 9 (MMP9) and neutrophil activation/tissue damage (neutrophil gelatinase-associated lipocalin, NGAL) in patient plasma from 44 HFRS patients collected consecutively following disease onset. We used the generalized estimating equation to analyse the association between endothelial glycocalyx degradation, MMP9 levels, neutrophil activation/tissue damage and HFRS disease outcome (need for oxygen, transfusion with blood components, need for intensive care unit (ICU) treatment and renal damage).Results: 44 HFRS patients were included in this study (29 females (66%)); need for oxygen: 11 (25%); transfusion with blood components: 3 (7%) and stay at ICU: 2 (5%)). The levels of MMP9 were significantly associated with all markers of endothelial glycocalyx degradation. Neutrophil activation/tissue damage (NGAL) was also significantly associated with MMP9 and endothelial glycocalyx degradation markers (apart from albumin (p = 0.053). In addition degradation of endothelial glycocalyx associated with HFRS disease outcome.Conclusion: Degradation of the endothelial glycocalyx could be a potential mechanism of HFRS pathogenesis, and potentially MMP9 could contribute to degradation of the endothelial glycocalyx
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| 6. |
- Schmedes, Clare M., et al.
(author)
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Circulating extracellular vesicle tissue factor activity during orthohantavirus infection is associated with intravascular coagulation
- 2020
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In: Journal of Infectious Diseases. - : Oxford University Press. - 0022-1899 .- 1537-6613. ; 222:8, s. 1392-1399
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Journal article (peer-reviewed)abstract
- BACKGROUND: Puumala (PUUV) orthohantavirus causes hemorrhagic fever with renal syndrome (HFRS). HFRS patients have an activated coagulation system with increased risk of disseminated intravascular coagulation (DIC) and venous thromboembolism (VTE). The aim of the study was to determine if circulating extracellular vesicle tissue factor (EVTF) activity levels associates with DIC and VTE (grouped as intravascular coagulation) in HFRS patients.METHODS: Longitudinal samples were collected from 88 HFRS patients. Patients were stratified into groups of those with intravascular coagulation (n=27) and those who did not (n=61). We measured levels of circulating EVTF activity, fibrinogen, activated partial prothrombin time, prothrombin time international normalized ratio, D-dimer, tissue plasminogen activator (tPA), plasminogen activator inhibitor 1 (PAI-1) and platelets.RESULTS: Plasma EVTF activity was transiently increased during HFRS. Levels of EVTF activity significantly associated with plasma tPA and PAI-1, suggesting endothelial cells as a potential source. Patients with intravascular coagulation had significantly higher peak EVTF activity levels compared to those who did not. The peak EVTF activity value predicting intravascular coagulation was 0.51 ng/L with 63% sensitivity and 61% specificity with AUC 0.63 (95% CI 0.51 - 0.76), p-value 0.046.CONCLUSIONS: Increased circulating EVTF activity during HFRS is associated with intravascular coagulation.
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| 7. |
- Thunberg, Therese, 1977-
(author)
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Study of pathogenesis and immune response in human Puumala virus infection
- 2013
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Doctoral thesis (other academic/artistic)abstract
- Hantaviruses can cause two severe human diseases: hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS). Hantaviruses are spread to humans mainly through inhalation of infectious virions, secreted from infected rodents. The human diseases are characterized by an increased capillary leakage syndrome. Hantaviruses are known to infect endothelial cells, but they are non-cytopathogenic. The mechanism behind human disease is not well understood, but an overactive immune response is implicated in the pathogenesis. The aim of my thesis has been to investigate parts of innate and adaptive immune responses in Puumala virus-infected patients.In paper I we found a sex difference in the cytokine profile during acute infection. Females had significantly higher plasma levels of IL-9, FGF-2, GM-CSF and lower levels of IL-8 and IP-10 compared to males. These differences may affect the activation and function of the immune response.In paper II we studied the phenotype and kinetics of NK cells. We observed that CD56dim NK cells were elevated during acute infection and that these, predominantly NKG2C+ NK cells, remained elevated for at least two months after symptom debut. Our novel finding of a prolonged NK cell response, implicates that NK cells may possess adaptive immunity features. In paper III we observed a vigorous cytotoxic T cell (CTL) response during acute infection, which contracted in parallel with decrease in viral load. The CTL response was not balanced by an increase in regulatory T cells. The T cells expressed inhibitory immunoregulatory receptors, known to dampen intrinsic T cell activity. In paper IV, we found that a low IgG response in patients was significantly associated with more severe disease, while the viral load did not affect the outcome. Our findings support the use of passive immunization as a treatment alternative for hantavirus-infected patients.In conclusion, my thesis contributes to an increased knowledge about the immune response in hantavirus-infected patients. The findings, combined with future studies, will hopefully lead to a better understanding of the pathogenesis and possible treatment alternatives.
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| 8. |
- Waltraud, Schrottmaier, et al.
(author)
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Direct and indirect effects of Puumala hantavirus on platelet function
- 2024
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In: Thrombosis Research. - 0049-3848 .- 1879-2472. ; 233, s. 41-54
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Journal article (peer-reviewed)abstract
- Thrombocytopenia is a cardinal symptom of hantavirus-induced diseases including Puumala virus (PUUV)-induced hemorrhagic fever with renal syndrome (HFRS), which is associated with impaired platelet function, bleeding manifestations and augmented thrombotic risk. However, the underlying mechanisms causing thrombocytopenia and platelet hypo-responsiveness are unknown. Thus, we investigated the direct and indirect impact of PUUV on platelet production, function and degradation. Analysis of PUUV-HFRS patient blood revealed that platelet hypo-responsiveness in PUUV infection was cell-intrinsic and accompanied by reduced platelet-leukocyte aggregates (PLAs) and upregulation of monocyte tissue factor (TF), whereas platelet vasodilator-stimulated phosphoprotein (VASP) phosphorylation was comparable to healthy controls. Plasma CXCL4 levels followed platelet count dynamics throughout disease course. PUUV activated both neutrophils and monocytes in vitro, but platelet desialylation, degranulation and GPIIb/IIIa activation as well as PLA formation and endothelial adhesion under flow remained unaltered in the presence of PUUV. Further, MEG-01 megakaryocytes infected with PUUV displayed unaltered polyploidization, expression of surface receptors and platelet production. However, infection of endothelial cells with PUUV significantly increased platelet sequestration. Our data thus demonstrate that although platelet production, activation or degradation are not directly modulated, PUUV indirectly fosters thrombocytopenia by sequestration of platelets to infected endothelium. Upregulation of immunothrombotic processes in PUUV-HFRS may further contribute to platelet dysfunction and consumption. Given the pathophysiologic similarities of hantavirus infections, our findings thus provide important insights into the mechanisms underlying thrombocytopenia and highlight immune-mediated coagulopathy as potential therapeutic target.
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| 9. |
- Wigren, Julia, et al.
(author)
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At-home sampling to meet geographical challenges for serological assessment of SARS-CoV-2 exposure in a rural region of northern Sweden, March to May 2021 : a retrospective cohort study
- 2023
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In: Eurosurveillance. - : European Centre for Disease Control and Prevention (ECDC). - 1025-496X .- 1560-7917. ; 28:13
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Journal article (peer-reviewed)abstract
- Background: The current SARS-CoV-2 pandemic has highlighted a need for easy and safe blood sampling in combination with accurate serological methodology. Venipuncture for testing is usually performed by trained staff at healthcare centres. Long travel distances to healthcare centres in rural regions may introduce a bias of testing towards relatively large communities with closer access. Rural regions are therefore often not represented in population-based data.Aim: The aim of this retrospective cohort study was to develop and implement a strategy for at-home testing in a rural region of Sweden during spring 2021, and to evaluate its role to provide equal health care for its inhabitants.Methods: We developed a sensitive method to measure antibodies to the S-protein of SARS-CoV-2 and optimised this assay for clinical use together with a strategy of at-home capillary blood sampling.Results: We demonstrated that our ELISA gave comparable results after analysis of capillary blood or serum from SARS-CoV-2-experienced individuals. We demonstrated stability of the assay under conditions that reflected temperature and humidity during winter or summer. By assessment of capillary blood samples from 4,122 individuals, we could show both feasibility of the strategy and that implementation shifted the geographical spread of testing in favour of rural areas.Conclusion: Implementation of at-home sampling enabled citizens living in remote rural areas access to centralised and sensitive laboratory antibody tests. The strategy for testing used here could therefore enable disease control authorities to get rapid access to information concerning immunity to infectious diseases, even across vast geographical distance.
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