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PurposeBiochemical biomarkers to determine the injury severity and the potential for functional recovery of traumatic spinal cord injury (TSCI) are highly warranted; however, it remains to be clarified whether cerebrospinal fluid (CSF) or peripheral blood (PB) is the ideal sample media. This study aims to measure and compare biomarker concentrations in CSF and PB and to explore associations between biomarker concentrations and injury severity, i.e., American Spinal Injury Association (ASIA) Impairment Scale (AIS) grade, and biomarker concentrations and clinical outcome, i.e., AIS grade improvement and Spinal Cord Independent Measure version III (SCIM-III) score.MethodsFrom 2018 to 2020, we conducted a single-center prospective pilot study of TSCI patients (n=15) and healthy controls (n=15). Sample collection and clinical outcome assessment were performed at median 13 h [IQR: 19], 9 days [IQR: 2], and 148 days [IQR: 49] after TSCI. Concentrations of neuron-specific enolase (NSE); glial fibrillary acid protein (GFAP); neurofilament light chain (NfL); interferon-γ (IFN-γ); interleukin (IL)-1ß, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, and IL-13; and tumor necrosis factor α (TNF-α) were measured and associated to clinical outcomes.ResultsThe biomarker concentrations were higher in CSF than PB. CSF concentrations of GFAP, NSE, IFN-y, TNF-a, IL-2, IL-12p70, IL-4, IL-10, and IL-13 and PB concentrations of GFAP and IFN-y were significantly associated with AIS grade, but not with AIS grade improvement or SCIM-III score.ConclusionsOur results support GFAP as a potential diagnostic biomarker that may be measured in CSF as well as PB. PURPOSE: Biochemical biomarkers to determine the injury severity and the potential for functional recovery of traumatic spinal cord injury (TSCI) are highly warranted; however, it remains to be clarified whether cerebrospinal fluid (CSF) or peripheral blood (PB) is the ideal sample media. This study aims to measure and compare biomarker concentrations in CSF and PB and to explore associations between biomarker concentrations and injury severity, i.e., American Spinal Injury Association (ASIA) Impairment Scale (AIS) grade, and biomarker concentrations and clinical outcome, i.e., AIS grade improvement and Spinal Cord Independent Measure version III (SCIM-III) score.METHODS: From 2018 to 2020, we conducted a single-center prospective pilot study of TSCI patients (n=15) and healthy controls (n=15). Sample collection and clinical outcome assessment were performed at median 13 h [IQR: 19], 9 days [IQR: 2], and 148 days [IQR: 49] after TSCI. Concentrations of neuron-specific enolase (NSE); glial fibrillary acid protein (GFAP); neurofilament light chain (NfL); interferon-γ (IFN-γ); interleukin (IL)-1ß, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, and IL-13; and tumor necrosis factor α (TNF-α) were measured and associated to clinical outcomes.RESULTS: The biomarker concentrations were higher in CSF than PB. CSF concentrations of GFAP, NSE, IFN-y, TNF-a, IL-2, IL-12p70, IL-4, IL-10, and IL-13 and PB concentrations of GFAP and IFN-y were significantly associated with AIS grade, but not with AIS grade improvement or SCIM-III score.CONCLUSIONS: Our results support GFAP as a potential diagnostic biomarker that may be measured in CSF as well as PB.

INTRODUCTION: The regenerative and immunomodulatory properties of multipotent mesenchymal stromal cells (MSCs) make them an intriguing asset for therapeutic applications. An off-the-shelf approach, using pre-expanded cryopreserved allogenic MSCs, bypasses many practical difficulties of cellular therapy. Reconstitution of a MSC product away from cytotoxic cryoprotectants towards a preferred administration solution might be favorable for several indications. Variations in MSC handling accompanied by a non-standardized use of reconstitution solutions complicate a general clinical standardization of MSC cellular therapies. In this study, we aimed to identify a simple and clinically compatible approach for thawing, reconstitution, and post-thaw storage of cryopreserved MSCs.METHODS: Human adipose tissue-derived MSCs were expanded in human platelet lysate (hPL) supplemented culture medium and cryopreserved using a dimethyl sulfoxide (DMSO)-based cryoprotectant. Isotonic solutions (saline, Ringer's acetate and phosphate buffered saline (PBS)) with or without 2% human serum albumin (HSA) were used as thawing, reconstitution, and storage solutions. MSCs were reconstituted to 5 × 10 6 MSCs/mL for evaluating MSC stability. Total MSC numbers and viability were determined using 7-aminoactinomycin D (7-AAD) and flow cytometry. RESULTS: For thawing cryopreserved MSCs the presence of protein was proven to be essential. Up to 50% of MSCs were lost when protein-free thawing solutions were used. Reconstitution and post-thaw storage of MSCs in culture medium and widely used PBS demonstrated poor MSC stability (>40% cell loss) and viability (90% viability with no observed cell loss for at least 4 h. Reconstitution of MSCs to low concentrations was identified as critical. Diluting MSCs to 40% cell loss) and lower viability (CONCLUSION: This study identified a clinically compatible method for MSC thawing and reconstitution that ensures high MSC yield, viability, and stability. The strength of the method lies within the simplicity of implementation which offers an accessible way to streamline MSC therapies across different laboratories and clinical trials, improving standardization in this field.

PURPOSE: Triggering of inflammatory responses and disruption of blood-spinal cord barrier (BSCB) integrity are considered pivotal events in the pathophysiology of traumatic spinal cord injury (TSCI). Yet, these events are poorly understood and described in humans. This study aims to describe inflammatory responses and BSCB integrity in human TSCI.METHODS: Fifteen TSCI patients and fifteen non-TSCI patients were prospectively recruited from Aarhus University Hospital, Denmark. Peripheral blood (PB) and cerebrospinal fluid (CSF) were collected at median day 0 [IQR: 1], median day 9 [IQR: 2], and median day 148 [IQR: 49] after injury. PB and CSF were analyzed for immune cells by flow cytometry, cytokines by multiplex immunoassay, and BSCB integrity by IgG Index.RESULTS: Eleven TSCI patients completed follow-up. Results showed alterations in innate and adaptive immune cell counts over time. TSCI patients had significantly increased cytokine concentrations in CSF at the first and second follow-up, while only concentrations of interleukin (IL)-4, IL-8, and tumor necrosis factor-α remained significantly increased at the third follow-up. In PB, TSCI patients had significantly increased IL-6, IL-8, and IL-10 concentrations and significantly decreased interferon-γ concentrations at the first follow-up. Results further showed increased IgG Index indicative of BSCB disruption in seven TSCI patients at the first follow-up, five TSCI patients at the second follow-up, and two patients at the third follow-up.CONCLUSIONS: Our results suggest that TSCI mainly triggers innate inflammatory responses that resolves over time, although with some degree of non-resolving inflammation, particularly in CSF. Our results cannot confirm BSCB disruption in all TSCI patients.

Normothermic machine perfusion (NMP) of injured kidneys offers the opportunity for interventions to metabolically active organs prior to transplantation. Mesenchymal stromal cells (MSCs) can exert regenerative and anti-inflammatory effects in ischemia-reperfusion injury. The aims of this study were to evaluate the safety and feasibility of MSC treatment of kidneys during NMP using a porcine autotransplantation model, and examine potential MSC treatment-associated kidney improvements up to 14 days posttransplant. After 75 min of kidney warm ischemia, four experimental groups of n = 7 underwent 14 h of oxygenated hypothermic machine perfusion. In three groups this was followed by 240 min of NMP with infusion of vehicle, 10 million porcine, or 10 million human adipose-derived MSCs. All kidneys were autotransplanted after contralateral nephrectomy. MSC treatment did not affect perfusion hemodynamics during NMP or cause adverse effects at reperfusion, with 100% animal survival. MSCs did not affect plasma creatinine, glomerular filtration rate, neutrophil gelatinase-associated lipocalin concentrations or kidney damage assessed by histology during the 14 days, and MSCs retention was demonstrated in renal cortex. Infusing MSCs during ex vivo NMP of porcine kidneys was safe and feasible. Within the short posttransplant follow-up period, no beneficial effects of ex vivo MSC therapy could be demonstrated.

Background.Mesenchymal stromal cell (MSC) therapy may improve renal function after ischemia-reperfusion injury in transplantation. Ex vivo renal intraarterial administration is a targeted delivery method, avoiding the lung vasculature, a known barrier for cellular therapies. In a randomized and blinded study, we tested the feasibility and effectiveness of MSC therapy in a donation after circulatory death autotransplantation model to improve posttransplant kidney function, using an ex vivo MSC delivery method similar to the clinical standard procedure of pretransplant cold graft flush.Methods.Kidneys exposed to 75 minutes of warm ischemia and 16 hours of static cold storage were intraarterially infused ex vivo with 10 million male porcine MSCs (Tx-MSC, n = 8) or vehicle (Tx-control, n = 8). Afterwards, the kidneys were autotransplanted after contralateral nephrectomy. Biopsies an hour after reperfusion confirmed the presence of MSCs in the renal cortex. Animals were observed for 14 days.Results.Postoperatively, peak plasma creatinine was 1230 and 1274 mu mol/L (Tx-controls versus Tx-MSC, P = 0.69). During follow-up, no significant differences over time were detected between groups regarding plasma creatinine, plasma neutrophil gelatinase-associated lipocalin, or urine neutrophil gelatinase-associated lipocalin/creatinine ratio. At day 14, measured glomerular filtration rates were 40 and 44 mL/min, P = 0.66. Renal collagen content and fibrosis-related mRNA expression were increased in both groups but without significant differences between the groups.Conclusions.We demonstrated intraarterial MSC infusion to transplant kidneys as a safe and effective method to deliver MSCs to the graft. However, we could not detect any positive effects of this cell treatment within 14 days of observation.

Naturally occurring antibodies are abundant in human plasma, but their importance in the defense against bacterial pathogens is unclear. We studied the role of the most abundant of such antibodies, the antibody against terminal galactose-α-1,3-galactose (anti-αGal), in the protection against pneumococcal infections (Streptococcus pneumonia). All known pneumococcal capsular polysaccharides lack terminal galactose-α-1,3-galactose, yet highly purified human anti-αGal antibody of the IgG class reacted with 48 of 91 pneumococcal serotypes. Anti-αGal was found to contain multiple antibody subsets that possess distinct specificities beyond their general reactivity with terminal galactose-α-1,3-galactose. These subsets in concert targeted a wide range of microbial polysaccharides. We found that anti-αGal constituted up to 40% of the total antibody reactivity to pneumococci in normal human plasma, that anti-αGal drives phagocytosis of pneumococci by human neutrophils, and that the anti-αGal level was 2-fold lower in patients prone to pneumococcal infections compared to controls. Moreover, during a 48-year period in Denmark, the 48 anti-αGal-reactive serotypes caused fewer invasive pneumococcal infections (n = 10,927) than the 43 non-reactive serotypes (n = 18,107), supporting protection on the population level. Our findings explain the broad-spectrum pathogen reactivity of anti-αGal and support that these naturally occurring polyreactive antibodies contribute significantly to human protective immunity.

BACKGROUND: Adipose tissue-derived stem cells are of great interest because of their properties of immune modulation, tissue regeneration, and multipotent differentiation. To advance development of stem cell-based treatments, determination of the physiologic concentration of adipose tissue-derived stem cells in human adipose tissue is relevant for proper guidance of stem cell treatment dosage, oncologic safety, and evaluation of efficacy.METHODS: A prospective comparative case-control study of 20 patients was conducted to determine the yield of adipose tissue-derived stem cells in periumbilical adipose tissue harvested by the widely used method of aspiration and in structurally intact adipose tissue harvested by excision. Stem cells were isolated using conventional enzymatic digestion and by a method combining enzymatic digestion with mechanical distortion. Stem cell yield was quantified by multicolor flow cytometry and colony-forming capacity.RESULTS: When only the conventional enzymatic digestion was used, no significant difference in adipose tissue-derived stem cell yield was observed. However, when enzymatic digestion was combined with mechanical distortion, twice as many stem cells were isolated from excised adipose tissue compared to aspirated adipose tissue. Inclusion of mechanical distortion significantly increased yield 5-fold in excised adipose tissue and 2-fold in aspirated adipose tissue. Combining enzymatic digestion and mechanical distortion, measured levels of excised adipose tissue reached 140 × 10 (95 percent CI, 62 to 220 × 10) adipose tissue-derived stem cells per gram of adipose tissue that corresponded to 26 × 10 (95 percent CI, 18 to 33 × 10) colony-forming units per gram.CONCLUSIONS: The study indicates that harvesting by aspiration halves the concentration of adipose tissue-derived stem cells in adipose tissue samples when compared to structural intact adipose tissue. Furthermore, the study presents stem cell yield higher than previously described in the current literature.CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Inflammation resulting from ischaemia/reperfusion injury can cause kidney graft dysfunction, increase the risk of delayed graft function and possibly reduce long-term graft survival. Remote ischaemic conditioning may protect against ischaemia/reperfusion injury and mitigate the immunological response to the graft. We investigated the immunological effects of remote ischaemic conditioning on kidney transplantation from deceased donors in the randomized CONTEXT study. Three circulating dendritic cell (DC) subtypes identified in peripheral blood from kidney transplant recipients [myeloid DCs, plasmacytoid DCs and immunoglobulin-like transcript (ILT)3+ DCs] were measured at baseline, days 1, 3 and 5 and 1 and 3 months after transplantation. We also quantified 21 cytokines at baseline, days 1 and 5 and 3 months after transplantation. Neither DC counts nor cytokine levels differed between patients receiving remote ischaemic conditioning and controls; however, several parameters exhibited dynamic and parallel alterations in the two groups over time, reflecting the immunological response to the kidney transplantation and immunosuppression.

Background and aims Allergic rhinitis (AR), allergic conjunctivitis (AC), and asthma are characterized by activation of the immune system. The aim of this study was to explore the long-term association between AR, AC, asthma, and specific immunoglobulin E (IgE) and blood platelet and leukocyte differential counts. Material and methods In the Danish Blood Donor Study, 14,440 participants from Central Denmark Region had platelet and leukocyte differential counts available and completed a questionnaire regarding AR, AC, and asthma. Of these participants, 8485 were tested for IgE to inhalation allergens. Results The prevalence of AR, AC, asthma, and IgE sensitization was 19%, 15%, 9%, and 29%, respectively. AR, AC, asthma, wheeze, and IgE sensitization was associated with increased blood eosinophil concentration even in IgE sensitized participants who did not report any allergy or asthma. The strongest associations were observed for participants with current disease. We found no differences in eosinophil concentration between months without symptoms and months with symptoms of AR and asthma. Conclusion AR, AC, asthma, wheezing, and IgE sensitization to inhalation allergens are associated with increased eosinophil concentration. This may reflect a persistent inflammation even in periods without symptomatic disease.

BACKGROUND: For unknown reasons, HIV-2 is less pathogenic than HIV-1, and HIV-2-induced immunodeficiency may be different from that caused by HIV-1. Previous immunological studies have hinted at possible shifts in both T-cell and B-cell subsets, which we aimed to characterize further. METHODS: From an HIV clinic in Guinea-Bissau, 63 HIV-2, 83 HIV-1, and 26 HIV-negative participants were included. All HIV-infected participants were ART-naive. The following cell subsets were analysed by flow cytometry; T cells (maturation and activation), regulatory T cells, and B cells (maturation and activation). RESULTS: After standardizing for sex, age, and CD4 T-cell count HIV-2 had 0.938 log10 copies/ml lower HIV RNA levels than the HIV-1-infected patients. Whereas T-cell maturation and regulatory T-cell profiles were similar between patients, HIV-2-infected patients had higher proportions of CD8CD28 and lower proportions of CD8PD-1+ T cells than HIV-1-infected patients. This finding was independent of HIV RNA levels. HIV-2 was also associated with a more preserved proportion of naive B cells. CONCLUSION: HIV-2 is characterized by lower viral load, and lower T-cell activation, which may account for the slower disease progression.

Background Do prescription drugs with anti-inflammatory properties such as nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, and statins increase the risk of postoperative bleeding measured with RBC transfusion in elderly hip fracture surgery patients? Study design and methods Using the Danish Multidisciplinary Hip Fracture Database, 74,791 patients aged 65 years or older with surgery-treated hip fracture were identified during 2005-2016, and their use of NSAIDs, corticosteroids, and statins was ascertained. For each drug, patients were categorized as nonusers (no prescription ≤365 days prior to surgery), former users (one prescription 91-365 days), and current users (one prescription ≤90 days). Information on surgical treatment, transfusion, other medication and comorbidities were collected using Danish nationwide registries. A log-binomial model was used to estimate relative risks for RBC transfusion within 7 days of surgery and corresponding 95% confidence intervals. Adjustments were made for patient- and surgery-related factors. Results Former and current users of NSAIDs, corticosteroids, and statins accounted for 22%, 10%, and 24%, respectively. Current users of NSAIDs had an increased adjusted relative risk of transfusion (1.07; confidence interval, 1.04-1.10) compared to nonusers. There was no association between current users of corticosteroids and statins and risk of transfusion. Conclusion NSAID use within 90 days of a hip fracture surgery was associated with an increased risk of RBC transfusion. Thus, current use of NSAIDs can be associated with an increased risk of postoperative bleeding, but we cannot rule out the influence of confounding.

Serological assays for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are needed to support clinical diagnosis and epidemiological investigations. Recently, assays for large-scale detection of total antibodies (Ab), immunoglobulin G (IgG), and IgM against SARS-CoV-2 antigens have been developed, but there are limited data on the diagnostic accuracy of these assays., Serological assays for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are needed to support clinical diagnosis and epidemiological investigations. Recently, assays for large-scale detection of total antibodies (Ab), immunoglobulin G (IgG), and IgM against SARS-CoV-2 antigens have been developed, but there are limited data on the diagnostic accuracy of these assays. This study was a Danish national collaboration and evaluated 15 commercial and one in-house anti-SARS-CoV-2 assays in 16 laboratories. Sensitivity was evaluated using 150 samples from individuals with asymptomatic, mild, or moderate COVID-19, nonhospitalized or hospitalized, confirmed by nucleic acid amplification tests (NAAT); samples were collected 13 to 73 days either from symptom onset or from positive NAAT (patients without symptoms). Specificity and cross-reactivity were evaluated in samples collected prior to the SARS-CoV-2 epidemic from >586 blood donors and patients with autoimmune diseases, cytomegalovirus or Epstein-Barr virus infections, and acute viral infections. A specificity of ≥99% was achieved by all total-Ab and IgG assays except one, DiaSorin Liaison XL IgG (97.2%). Sensitivities in descending order were Wantai ELISA total Ab (96.7%), CUH-NOVO in-house ELISA total Ab (96.0%), Ortho Vitros total Ab (95.3%), YHLO iFlash IgG (94.0%), Ortho Vitros IgG (93.3%), Siemens Atellica total Ab (93.2%), Roche Elecsys total Ab (92.7%), Abbott Architect IgG (90.0%), Abbott Alinity IgG (median 88.0%), DiaSorin Liaison XL IgG (median 84.6%), Siemens Vista total Ab (81.0%), Euroimmun/ELISA IgG (78.0%), and Snibe Maglumi IgG (median 78.0%). However, confidence intervals overlapped for several assays. The IgM results were variable, with the Wantai IgM ELISA showing the highest sensitivity (82.7%) and specificity (99%). The rate of seropositivity increased with time from symptom onset and symptom severity.

Background Allergic rhinitis (AR), allergic conjunctivitis (AC), and asthma composing multiple phenotypes and improved understanding of these phenotypes and their respective risk factors are needed. Objectives The objective of this study was to define the prevalence of AR, AC, and asthma and their association with allergen-specific immunoglobulin E (sIgE) sensitization in a large cohort of blood donors and identify risk factors. Methods From the nationwide population-based Danish Blood Donor Study, 52,976 participants completed an electronic questionnaire including AR, AC, asthma, allergic predisposition, and childhood residence. Of these, 25,257 were additionally tested for sIgE to inhalation allergens (Phadiatop). Results The prevalence of sIgE sensitization, AR, AC, and asthma was 30%, 19%, 15%, and 9%, respectively. The youngest birth cohorts had the highest prevalence of sIgE sensitization and symptoms of asthma, AR, and AC, and for asthma, they apparently experienced symptoms at an earlier age. The sIgE sensitization was positively associated with male sex. The sIgE seroprevalence was higher in participants with both AR and AC (ARC) than in participants with either AR or AC. Allergic predisposition and sIgE sensitization increased the risk of the diseases, while farm upbringing was associated with reduced prevalence of ARC, however, only in sIgE sensitized participants. Conclusion Birth year, childhood residence, sIgE sensitization, and allergic predisposition were associated with asthma, AR, and AC prevalence. Individuals with self-reported ARC represent a primarily sIgE-positive phenotype, while those with either AR or AC represent more diverse phenotypes. Background: Allergic rhinitis (AR), allergic conjunctivitis (AC), and asthma composing multiple phenotypes and improved understanding of these phenotypes and their respective risk factors are needed. Objectives: The objective of this study was to define the prevalence of AR, AC, and asthma and their association with allergen-specific immunoglobulin E (sIgE) sensitization in a large cohort of blood donors and identify risk factors. Methods: From the nationwide population-based Danish Blood Donor Study, 52,976 participants completed an electronic questionnaire including AR, AC, asthma, allergic predisposition, and childhood residence. Of these, 25,257 were additionally tested for sIgE to inhalation allergens (Phadiatop). Results: The prevalence of sIgE sensitization, AR, AC, and asthma was 30%, 19%, 15%, and 9%, respectively. The youngest birth cohorts had the highest prevalence of sIgE sensitization and symptoms of asthma, AR, and AC, and for asthma, they apparently experienced symptoms at an earlier age. The sIgE sensitization was positively associated with male sex. The sIgE seroprevalence was higher in participants with both AR and AC (ARC) than in participants with either AR or AC. Allergic predisposition and sIgE sensitization increased the risk of the diseases, while farm upbringing was associated with reduced prevalence of ARC, however, only in sIgE sensitized participants. Conclusion: Birth year, childhood residence, sIgE sensitization, and allergic predisposition were associated with asthma, AR, and AC prevalence. Individuals with self-reported ARC represent a primarily sIgE-positive phenotype, while those with either AR or AC represent more diverse phenotypes.

Supplemental Digital Content is available in the text., Background. In an era where global kidney shortage has pushed the field of transplantation towards using more marginal donors, modified kidney preservation techniques are currently being reviewed. Some techniques require further optimization before implementation in full scale transplantation studies. Using a porcine donation after circulatory death kidney model, we investigated whether initial kidney hemodynamics improved during normothermic machine perfusion if this was preceded by a short period of oxygenated hypothermic machine perfusion (oxHMP) rather than static cold storage (SCS). Methods. Kidneys subjected to 75 minutes of warm ischemia were randomly assigned to either SCS (n = 4) or SCS + oxHMP (n = 4), with a total cold storage time of 240 minutes. Cold preservation was followed by 120 minutes of normothermic machine perfusion with continuous measurement of hemodynamic parameters and renal function. Results. oxHMP preserved kidneys maintained significantly lower renal resistance throughout the normothermic machine perfusion period compared to SCS kidneys (P

BackgroundThe pandemic due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has tremendous consequences for our societies. Knowledge of the seroprevalence of SARS-CoV-2 is needed to accurately monitor the spread of the epidemic and also to calculate the infection fatality rate (IFR). These measures may help the authorities to make informed decisions and adjust the current societal interventions. Blood donors comprise approximately 4.7% of the similarly aged population of Denmark and blood is donated in all areas of the country. The objective of this study was to perform real-time seroprevalence surveying among blood donors as a tool to estimate previous SARS-CoV-2 infections and the population based IFR.MethodsAll Danish blood donors aged 17-69 years giving blood April 6 to 17 were tested for SARS-CoV-2 immunoglobulin M and G antibodies using a commercial lateral flow test. Antibody status was compared between areas and an estimate of the IFR was calculated. The seroprevalence was adjusted for assay sensitivity and specificity taking the uncertainties of the test validation into account when reporting the 95% confidence intervals (CI).ResultsThe first 9,496 blood donors were tested and a combined adjusted seroprevalence of 1.7% (CI: 0.9-2.3) was calculated. The seroprevalence differed across areas. Using available data on fatalities and population numbers a combined IFR in patients younger than 70 is estimated at 82 per 100,000 (CI: 59-154) infections.ConclusionsThe IFR was estimated to be slightly lower than previously reported from other countries not using seroprevalence data. The IFR, including only individuals with no comorbidity, is likely several fold lower than the current estimate. This may have implications for risk mitigation. We have initiated real-time nationwide anti-SARS-CoV-2 seroprevalence surveying of blood donations as a tool in monitoring the epidemic.

Identification of risk factors for contracting and developing serious illness following infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is of paramount interest. Here, we performed a retrospective cohort analysis of all Danish individuals tested for SARS-CoV-2 between 27 February 2020 and 30 July 2020, with a known ABO and RhD blood group, to determine the influence of common blood groups on virus susceptibility. Distribution of blood groups was compared with data from nontested individuals. Participants (29% of whom were male) included 473 654 individuals tested for SARS-CoV-2 using real-time polymerase chain reaction (7422 positive and 466 232 negative) and 2 204 742 nontested individuals, accounting for ∼38% of the total Danish population. Hospitalization and death from COVID-19, age, cardiovascular comorbidities, and job status were also collected for confirmed infected cases. ABO blood groups varied significantly between patients and the reference group, with only 38.41% (95% confidence interval [CI], 37.30-39.50) of the patients belonging to blood group O compared with 41.70% (95% CI, 41.60-41.80) in the controls, corresponding to a relative risk of 0.87 (95% CI, 0.83-0.91) for acquiring COVID-19. This study identifies ABO blood group as a risk factor for SARS-CoV-2 infection but not for hospitalization or death from COVID-19.

Background The renal endothelium is a prime target for ischemia-reperfusion injury (IRI) during donation and transplantation procedures. Mesenchymal stromal cells (MSC) have been shown to ameliorate kidney function after IRI. However, whether this involves repair of the endothelium is not clear. Therefore, our objective is to study potential regenerative effects of MSC on injured endothelial cells and to identify the molecular mechanisms involved. Methods Human umbilical vein endothelial cells (HUVEC) were submitted to hypoxia and reoxygenation and TNF-α treatment. To determine whether physical interaction or soluble factors released by MSC were responsible for the potential regenerative effects of MSC on endothelial cells, dose-response experiments were performed in co-culture and transwell conditions and with secretome-deficient MSC. Results MSC showed increased migration and adhesion to injured HUVEC, mediated by CD29 and CD44 on the MSC membrane. MSC decreased membrane injury marker expression, oxidative stress levels, and monolayer permeability of injured HUVEC, which was observed only when allowing both physical and paracrine interaction between MSC and HUVEC. Furthermore, viable MSC in direct contact with injured HUVEC improved wound healing capacity by 45% and completely restored their angiogenic capacity. In addition, MSC exhibited an increased ability to migrate through an injured HUVEC monolayer compared to non-injured HUVEC in vitro. Conclusions These results show that MSC have regenerative effects on injured HUVEC via a mechanism which requires both physical and paracrine interaction. The identification of specific effector molecules involved in MSC-HUVEC interaction will allow targeted modification of MSC to apply and enhance the therapeutic effects of MSC in IRI.

Background Remote ischaemic conditioning (RIC) is currently being explored as a non-invasive method to attenuate ischaemia/reperfusion injuries in organs. A randomised clinical study (CONTEXT) evaluated the effects of RIC compared to non-RIC controls in human kidney transplants. Methods RIC was induced prior to kidney reperfusion by episodes of obstruction to arterial flow in the leg opposite the transplant using a tourniquet (4 × 5 min). Although RIC did not lead to clinical improvement of transplant outcomes, we explored whether RIC induced molecular changes through precision analysis of CONTEXT recipient plasma and kidney tissue samples by high-resolution tandem mass spectrometry (MS/MS). Results We observed an accumulation of muscle derived proteins and altered amino acid metabolism in kidney tissue proteomes, likely provoked by RIC, which was not reflected in plasma. In addition, MS/MS analysis demonstrated transient upregulation of several acute phase response proteins (SAA1, SAA2, CRP) in plasma, 1 and 5 days post-transplant in RIC and non-RIC conditions with a variable effect on the magnitude of acute inflammation. Conclusions Together, our results indicate sub-clinical systemic and organ-localised effects of RIC.

Objectives This study aimed to characterize the association between HLA alleles and ANCA-associated vasculitis (AAV) in a genetically homogeneous population, and to analyse the contribution of specific HLA molecule amino acid sequences to the risk of AAV. Methods We included 187 Danish patients with AAV and 1070 healthy controls. All were HLA typed at two-field resolution. The association of HLA alleles to PR3- or MPO-AAV was analysed. The contribution of the dominant molecular motifs of the HLA-DPB1 molecule to the risk of AAV was investigated by association studies that included specific amino acid sequences of the hypervariable regions in exon 2. Results Ninety-four percent of patients with PR3-AAV were carriers of HLA-DPB1*04:01 while all patients with PR3-AAV were carriers of an HLA-DPB1*04 allele, and 85% were homozygous. This was significantly more than in the control group (P < 0.0001). The association was even stronger when HLA-DPB1*04:02 and -DPB1*23:01 were included. HLA-DPB1*04:01, -DPB1*04:02 and -DPB1*23:01 share amino acids in positions 8–9, 69, 76 and 84–87 within the hypervariable regions, but only positions 69 and 84–87 contributed significantly to the disease risk. HLA-DRB1*15 was associated with an increased risk of developing PR3-AAV, while HLA-DRB1*04, -DRB1*07 and -DQB1*03 were associated with a reduced risk of kidney involvement in PR3-AAV. MPO-AAV was only weakly associated with HLA class I alleles. Conclusion PR3-AAV is strongly associated with the HLA-DPB1 alleles HLA-DPB1*04:01, -DPB1*04:02 and -DPB1*23:01, which share amino acid sequences crucial for the peptide-binding groove.

Background & Aim Renal endothelium is damaged by ischemia reperfusion injury (IRI) during transplantation as a result of the hypoxic metabolism and the resumption of oxygen supply after reperfusion. It has been shown that mesenchymal stromal cells (MSC) are effective in enhancing kidney function after IRI. However, the cellular targets and mechanisms of action behind MSC effects are still poorly understood. Therefore, our objective was to evaluate the role of MSC in repairing injured endothelium as it is the first tissue with which they interact after infusion and to determine the specific interactions involved in this process. The role of physical communication and cytokine secretion in the reparative action of MSC was studied as well as its molecular mechanisms. Methods, Results & Conclusion Human umbilical vein endothelial cells (HUVEC) were submitted to hypoxic and inflammatory insult (TNF-a). This increased the expression of activation molecules such as CD54, CD62e and HLA-II on HUVEC's cell surface. Consequently, an increase of almost 20% in the adherence of MSC to HUVEC was observed in comparison to untreated HUVEC. Moreover, an increase of around 20% in the migratory capacity of MSC towards injured HUVEC was observed. MSC showed a 15 to 20% increase in their ability to transmigrate through injured HUVEC monolayers. Once MSC were in contact with HUVEC, the oxidative stress of HUVEC decreased as observed by a decrease in reactive oxygen species levels, their proliferative status improved and MSC restored the angiogenic potential to levels close to those from healthy HUVEC. To determine whether physical interaction or soluble factors released by MSC are fundamental for MSC regenerative capacity, a Boyden chamber system experiment was performed and we observed that both were required to achieve the full reparative effect of MSC. Moreover, we observed an increase in the expression of CD44 and CD29 adhesion molecules on MSC membrane after co-culture with injured HUVEC, as well as their ligands CD62e and CD106 on HUVEC membrane. We conclude that MSC are able to repair the injury caused by ischemic and inflammatory injury on HUVEC via a mechanism that requires both physical and paracrine interaction between MSC and HUVEC. We are currently studying the specific effector molecules involved in MSC and HUVEC cell-to-cell interaction which will allow targeted modification to improve the regenerative effects of MSC therapy.

Antibodies of the IgG class to terminal Galα3Gal (IgG anti-αGal) is abundant in human plasma and are reported to bind most sepsis-causing Gram-negative bacteria. However, these seminal findings, made more than two decades ago, have not been reexamined. Our aim was to assess IgG anti-αGal´s pathogen reactivity. We affinity purified IgG anti-αGal from a therapeutic grade normal human IgG pool applying two rounds of positive selection with Galα3Gal-coupled beads and included removal of column matrix reactive antibodies. The purified antibodies were rigorously characterized in terms of specificity and purity in various solid-phase immunoassays. We used flow cytometry to study reactivity against 100 consecutive clinical isolates diagnosed as cause of sepsis in humans. We found that the purified IgG anti-αGal displays high specificity for Galα3Gal. Also, IgG anti-αGal at 5 mg/L bound 56 out of 100 pathogens with predilection for Gram-positive bacteria binding 39 out of 52 strains. We confirm that although IgG anti-αGal comprise a small fraction of the human antibody pool (~0.1%), these antibodies targets an impressively large part of pathogens causing invasive disease.

The regenerative capacities of mesenchymal stromal cells (MSCs) make them suitable for renal regenerative therapy. The most common delivery route of MSC is through intravenous infusion, which is associated with off-target distribution. Renal intra-arterial delivery offers a targeted therapy, but limited knowledge is available regarding the fate of MSCs delivered through this route. Therefore, we studied the efficiency and tissue distribution of MSCs after renal intra-arterial delivery to a porcine renal ischemia-reperfusion model. MSCs were isolated from adipose tissue of healthy male pigs, fluorescently labeled and infused into the renal artery of female pigs. Flow cytometry allowed MSC detection and quantification in tissue and blood. In addition, quantitative polymerase chain reaction was used to trace MSCs by their Y-chromosome. During infusion, a minor number of MSCs left the kidney through the renal vein, and no MSCs were identified in arterial blood. Ischemic and healthy renal tissues were analyzed 30 min and 8 h after infusion, and 1-4 × 104 MSCs per gram of tissue were detected, predominantly, in the renal cortex, with a viability >70%. Confocal microscopy demonstrated mainly glomerular localization of MSCs, but they were also observed in the capillary network around tubuli. The infusion of heat-inactivated (HI) MSCs, which are metabolically inactive, through the renal artery showed that HI-MSCs were distributed in the kidney in a similar manner to regular MSCs, suggesting a passive retention mechanism. Long-term MSC survival was analyzed by Y-chromosome tracing, and demonstrated that a low percentage of the infused MSCs were present in the kidney 14 days after administration, while HI-MSCs were completely undetectable. In conclusion, renal intra-arterial MSC infusion limited off-target engraftment, leading to efficient MSC delivery to the kidney, most of them being cleared within 14 days. MSC retention was independent of the metabolic state of MSC, indicating a passive mechanism.

Metformin is today the first choice treatment for type‐2 diabetes, but has also protective effects in several renal disease models. Previously, we have demonstrated that the protective effects in response to unilateral ureteral obstruction (UUO) are independent of organic cation transporters (OCTs), the transporters responsible for the metformin uptake into the renal cells. The mechanisms behind the renoprotective effects are incompletely understood, but our previous results indicate that the renoprotective effects at least partly could be dependent on actions of metformin outside the renal cells. In this study, we investigate whether the renoprotective effects of metformin can be mediated via systemic immunomodulatory actions. We demonstrated that metformin can affect the immune system in the kidney as well as in the peripheral blood and spleen following UUO. UUO kidneys showed infiltration of immune cells including monocytes, B cells, and T cells, but metformin limited infiltration of all cell types. UUO animals had increased spleen sizes, but this increase was attenuated by metformin. Metformin treatment surprisingly resulted in a higher proportion of monocytes with infiltratory capacity 7 days after UUO. Other studies have suggested that metformin regulates monocyte maturation through signal transducer and activator of transcription 3 (STAT3) activation, as also indicated by our results. In conclusion, our results demonstrate that metformin limits the infiltration of immune cells into the kidney, as well as modulates immune cell composition at a systemic level.

Background: This pilot study aimed to maintain acceptable animal welfare in the development of a porcine autotransplantation model with severe and incremental renal ischemic injury, a model for usage in future intervention studies. Secondary aims were to develop and test methods to collect blood and urine without the need to restrain or use sedative and avoid transportation to optimize welfare of the pig. Methods: Kidneys from 7 female pigs were subjected to incremental durations of warm ischemia (WI) 30, 45, or 75 minutes by left renal artery and vein clamping. After static cold storage, contralateral nephrectomy was performed, and the injured graft was autotransplanted and animals observed for 14 days. Animal welfare was assessed and recorded using a structured scoring sheet before and 4 days after the kidney autotransplantation. Furthermore, blood samples were drawn daily the first week and every second day the following week using a semi-central venous catheter. An ostomy bag around the genitals was tested for urine collection. Measured glomerular filtration rate was calculated using renal clearance of chromium-51-labeled ethylenediamine tetraacetic acid on day 14. Results: None of the 7 animals died during the follow-up. The animal welfare was moderately affected when applying 75 minutes of WI (n = 2), and for that reason WI was not further increased. Pigs with lower WI had no observed welfare issues. With 75 minutes of WI peak, plasma creatinine was 1486 and 1317 µmol/L, reached on day 4. Lowest glomerular filtration rate levels were observed in the pigs with 75 minutes of WI. Conclusions: WI up to 75 minutes caused the intended severely impaired renal function without significantly compromising animal welfare. Blood and urine was collected postoperatively without sedation of the pigs or use of a metabolic cage.

Ischemic preconditioning (IPC) has been protective against ischemia-reperfusion injury (IRI), but the underlying mechanism is poorly understood. We examined whether IPC modulates the early inflammatory response after IRI. Nineteen healthy males participated in a randomised crossover trial with and without IPC before IRI. IPC and IRI were performed by cuff inflation on the forearm. IPC consisted of four cycles of five minutes followed by five minutes of reperfusion. IRI consisted of twenty minutes followed by 15 min of reperfusion. Blood was collected at baseline, 0 min, 85 min and 24 h after IRI. Circulating monocytes, T-cells subsets and dendritic cells together with intracellular activation markers were quantified by flow cytometry. Luminex measured a panel of inflammation-related cytokines in plasma. IRI resulted in dynamic regulations of the measured immune cells and their intracellular activation markers, however IPC did not significantly alter these patterns. Neither IRI nor the IPC protocol significantly affected the levels of inflammatory-related cytokines. In healthy volunteers, it was not possible to detect an effect of the investigated IPC-protocol on early IRI-induced inflammatory responses. This study indicates that protective effects of IPC on IRI is not explained by direct modulation of early inflammatory events.

CD46 is an important immune regulatory receptor with dual functions, however, the CD46 isoform distribution and the effect of CD46 activation on the cytokine production in monocytes and monocyte-derived dendritic cells (moDCs) is unclear. Here, we show that CD46 activation of moDCs downregulates LPS-induced CXCL-10 expression, while the expression of CXCL-10 in monocytes is unaffected. Furthermore, the differentiation of moDCs induces a switch towards dominance of CYT-2 isoforms of CD46. These data indicate that CD46 activation exerts different functions in monocytes and moDCs and this correlates with a switch in CD46 isoform expression upon differentiation of moDCs.

Background: High dose chemotherapy (HDT) burdens patients with a high risk of serious infections while neutropenic. The role of host antibodies as risk factors for infections is unclear. Our aim was to investigate if pre-HDT levels of IgG antibodies against terminal Galα3Gal (anti-αGal) predict infections. Anti-αGal is reported to be the most abundant antibody in human plasma and is able to recognize most sepsis-causing Gram-negative bacteria. The antibody exerts poor complement activation, which promotes pathogen survival by blocking access of more effective complement activators. This may be particularly problematic in neutropenic patients. Thus, we hypothesized that patients with high anti-αGal serum concentrations are particularly prone to suffer infections following HDT. Methods: We conducted a clinical cohort study on patients ≥16 years receiving HDT with autologous stem cell transplantation for myelomatosis (MM) or non-Hodgkin lymphoma (NHL) at Department of Hematology, Aarhus University Hospital, Denmark from 25 November 2009 through 26 June 2015. Of eligible patients (N=308), we excluded previous transplanted (N=14), those without a pre-HDT serum sample available for anti-αGal quantification (N=115), and recipients of plasma transfusion/IgG substitutions within 90 days before the pre-HDT serum sample and until end of follow-up (N=9). All included received prophylactic antimicrobial therapy (levofloxacin and fluconazol) and filgrastim. Serum anti-αGal was quantified using an in-house Time-resolved Immuno-Fluoremetric Assay. We ascertained infectious episodes within 30 days following the date of autologous stem cell re-infusion through review of all medical charts and data retrieval from the laboratory information systems, blinded for anti-αGal concentrations. Infectious episodes were defined as fever (≥38.5°C) or hypothermia ( 21 mg/L preceded by at least 24 hours without any of these. We used a Cox proportional hazards model to investigate the association between anti-αGal concentrations and risk of infection, with adjustment for total plasma IgG concentrations, ABO blood group, comorbidity, and underlying disease (MM or NHL) in the adjusted hazard ratios (HR). Optimum cutoff for dichotomizing was determined from ROC analysis applying Youden´s J statistic and groups were compared by Kaplan-Meier method. Results: We included 170 patients (MM, 55%; males, 58%; median age 62 years). Severe neutropenia was transient in all, with blood neutrophils increasing to above 500/µL on median day 11 (range 8-18). We identified one infectious episode in 103 patients (61%) and two episodes in six (3.5%) patients. The infectious episodes began during severe neutropenia in 92% of the patients. The infection types were fever of unknown origin (FUO) (72%), pneumonia (19%), catheter related (4.3%), typhlitis (1.7%), C. difficile colitis (1.7%), and hypothermia of unknown origin (0.87%). None died from infections. Pre-HDT serum was collected on median day -31 (range -142- -16). Anti-αGal was detectable in all but one sample, averaging 0.51 mg/dL (range: 0.016-12). Overall, anti-αGal concentrations predicted infectious episodes (all types), crude HR 1.2 (95% confidence interval (CI) 1.1-1.4), adjusted HR 1.1 (95% CI: 1.0-1.3). Using anti-αGal at 1.3 mg/dL as cut-off, we identified that patients with higher concentrations (N=41) experienced considerably increased risk of infectious episodes (crude estimates): all types, HR 1.7 (95% CI: 1.3-3.2); FUO, HR 2.0 (95%CI: 1.5-4.5); and pneumonia HR 2.1 (95%CI: 0.83-8.7). Discussion: We found that high anti-αGal serum concentrations predict an increased risk of infection after HDT. These findings support that anti-αGal may critically enhance pathogen-survival in the neutropenic host. Studies of other cohorts and mechanistic studies are required. Our findings may pave the way for future optimized risk stratification and therapeutic measures. Disclosures No relevant conflicts of interest to declare.

BACKGROUND: HIV-2 may slow progression of a subsequently acquired HIV-1 infection through cross-neutralizing antibodies and polyfunctional CD8 T cells. We hypothesized that HIV-1/2 dually infected patients compared with HIV-1-infected patients had more preserved immune maturation subsets and less immune activation of T and B cells. METHODS: ART-naive patients with HIV-1 (n = 83) or HIV-1/2 dual (n = 27) infections were included in this cross-sectional study at an HIV clinic in Guinea-Bissau. Peripheral blood mononuclear cells (PBMCs) were analyzed by flow cytometry according to T-cell maturation and activation, regulatory T-cell fraction, and B-cell maturation and activation. RESULTS: HIV-1/2 dually infected patients had lower levels of HIV-1 RNA compared with patients with HIV-1 infection, but the levels of total HIV RNA (HIV-1 and HIV-2) were similar in the two patient groups. T-cell maturation, and proportions of regulatory T cells (FoxP3+) were also similar in the two groups. HIV-1/2 dually infected patients had higher proportions of CD4 and CD8 T cells positive for the activation marker CD38, but there was no difference in other T-cell activation markers (CD28, CTLA-4, PD-1). HIV-1/2 dually infected patients also had higher proportions of IgM-only B cells and plasmablasts. CONCLUSION: HIV-1/2 was not associated with less immune perturbations than for HIV-1 infection.

The detection of donor-specific antibodies (DSAs) is a cornerstone in the immunological risk assessment prior to organ transplantation. The detection methods have developed rapidly during the last decade, and the evidence for clinical interpretation of results obtained by solid phase immunoassays (SPI) is slowly accumulating. Nevertheless, technical limitations and theoretical concerns still mean that "expert opinions" govern clinical decision-making when results of bead-based arrays are applied in immunological risk assessment prior to transplantation. This article underlines the prognostic value of SPI in the immunized recipient of an organ transplant while cautioning uncritical clinical interpretation of mean fluorescence intensity (MFI) as a quantitative parameter in organ transplantation based on documented as well as theoretical shortcomings of the method. The role of SPI-based detection of anti-HLA antibodies in clinical transplantation diagnostics is summarized and put into perspective of the Sensitization in Transplantation: Assessment of Risk (STAR) working group report 2017.

Common variable immunodeficiency (CVID) is a heterogeneous primary immunodeficiency disease, leading to recurrent bacterial airway infections and often also autoimmune complications. To shed light on the regulatory lymphocytes from these patients, we analyzed the levels of regulatory B (pro-B10) cell and regulatory T (Treg) cell subpopulations in PBMCs from twenty-six patients diagnosed with CVID using multi-color flowcytometry. Pro-B10 cells were induced by 48h in vitro stimulation prior to analysis. Suppressor function was measured on a subset of patients with splenomegaly and autoimmune complications. The levels of regulatory B and T cells were correlated to clinical manifestations, including autoimmunity, splenomegaly and CVID EUROclass subgroups. We demonstrate a significant association between elevated levels of pro-B10 cells, decreased levels of Tregs and autoimmune phenomena in CVID patients. The finding of marked abnormalities in regulatory lymphocyte populations contribute to our understanding of the pathogenesis of CVID and potentially be valuable in the clinical management and treatment of patients.

Background: Enumeration of stem cells is essential in the management of peripheral blood stem cell (PBSC) harvest. An alternative to the gold standard flow cytometric CD34+ stem cell count is the fully automated hematopoietic stem cell (HPC) count on the Sysmex XN hematology analyzer. Materials and methods: Eighty-nine patients and healthy stem cell donors who underwent PBSC harvest were included in the study. Stem cells were enumerated in pre-harvest peripheral blood and the apheresis yield by both flow cytometric CD34+ stem cell enumeration and by the Sysmex XN HPC count. Results: The Sysmex HPC concentration overestimated the CD34+ stem cell concentration by a ratio of 1.3 in average. The agreement between the two methods was poor at concentration 43.5 HPC/μL, where PBSC harvest can be initiated. And a negative cut off

Novel HLA-B alleles HLA-B*53:01:17 and HLA-B*58:83 are described in two patients from Guinea-Bissau.

Highlights • Activation of CD46 induces rapid down-modulation of CD46 expression on the surface of CD8+ T cells. • CD46 co-stimulation potently induces CD8+ T cell proliferation. • CD46 co-stimulation does not induce a switch to IL-10 production in CD8+ T cells, as is known for CD4+ T cells. • CD46 co-stimulation predominantly expands IFN-γ-producing CD8+ T cells., Similar to CD4+ T cells, precursor CD8+ T cells are thought to depend on a co-stimulatory signal through CD28 for proliferation and differentiation into effector cells. CD46 is another co-stimulatory receptor that promotes differentiation of CD4+ T-helper cells type 1 (Th1 cells) into a regulatory phenotype with a switch from IFN-γ towards IL-10-secretion over time. Whether CD46 exerts a similar function on CD8+ T cells remains to be fully elucidated. Here, we demonstrate that CD46 co-stimulation induced secretion of IFN-γ as well as expansion of IFN-γ-secreting CD8+ T cells. In contrast to CD46 co-stimulation of CD4+ T cells, CD8+ T cells did not differentiate into a regulatory IL-10-secreting phenotype. This demonstrates that CD46 is a co-stimulatory receptor on CD8+ T cells, and that it exerts separate functions during CD4+ and CD8+ T-cell differentiation.

Objectives: HIV-2 is endemic in West Africa and is characterized by lower transmissibility because of lower viral load, and HIV-2-infected persons usually have a slower progression to AIDS. The mechanisms behind the slower disease progression are unknown. The main objective was to identify specific HLA class I and II alleles that may influence the disease progression of HIV-2 infection. Design: Cohort follow-up study. Methods: We used high-resolution HLA typing of DNA from 437 antiretroviral naive HIV-2-infected patients from the Bissau HIV Cohort, Guinea-Bissau, to identify HLA alleles with an influence on HIV-2 disease progression. The effect of HLA-type on viral load and CD4 + cell count was assessed initially by ranksum-test and t-test, followed by adjusted logistic regression and multivariable linear regression analysis, respectively. Results: Three alleles (HLA-B ∗ 58:01, HLA-DPB1 ∗ 10:01 and HLA-DRB1 ∗ 11:01) were associated with lower possibility of detectable baseline plasma viral load (P = 0.002, P = 0.044 and P = 0.033, respectively), and no alleles were associated with higher possibility of detectable plasma viral load. HLA-DPB1 ∗ 10:01 and HLA-DRB1 ∗ 11:01 were in linkage disequilibrium (P = 0.047). Patients with heterozygous HLA types in all their HLA class I loci or in one or two loci were not more likely to have undetectable viral load compared with patients that were homozygous in all their class I loci after adjusting for sex and CD4 + cell count (P = 0.93 and P = 0.88, respectively). Conclusion: The three alleles HLA-B ∗ 58:01, HLA-DPB1 ∗ 10:01 and HLA-DRB1 ∗ 11:01 may protect against HIV-2 disease progression towards AIDS.

DQB1*06:276 differs from DQB1*06:03:01:01 by amino acid substitutions p.T71A, p.G74S, and p.L75V in exon 2.

Background Several frequently used prescription drugs may affect bleeding risk. We investigated use of aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), selective serotonin reuptake inhibitors (SSRIs), and statins and risk of postoperative red blood cell transfusion in breast cancer patients. Methods Using Danish population-based registries, we identified a cohort of women who underwent surgery for primary breast cancer (n = 22,238) during 2005–2012 and ascertained their use of aspirin, NSAIDs, SSRIs, and statins. For each drug, patients were categorized as users if they filled ≥1 prescription in the 60 days prior to surgery. We calculated the 14-day risk of red blood cell transfusion and relative risks (RRs) with 95% confidence intervals (CIs), comparing users with nonusers for each drug and adjusting for age, cancer stage, and Charlson Comorbidity Index score. Results In our cohort, 1385 (6.2%) women were aspirin users, 1794 (8.0%) were NSAID users, 1110 (4.9%) were SSRI users, and 2053 (9.1%) were statin users. The overall risk of red blood cell transfusion was 1.3%. The 14-day risk of RBC transfusion was 3.5% among aspirin users versus 1.1% among aspirin nonusers (adjusted RR = 1.9, 95% CI: 1.4–2.7), and 1.8% among SSRI users versus 1.2% among SSRI nonusers (adjusted RR = 1.2, 95% CI: 0.7–1.9). Red blood cell transfusion risk was increased among NSAID users, but not in a sensitivity analysis with a 30-day exposure window. Red blood cell transfusion risk was not increased among SSRI and statin users. Conclusions Primary breast cancer surgery confers a low risk of RBC transfusion. Still, use of aspirin and possibly NSAIDs, but not SSRIs and statins, is associated with increased red blood cell transfusion. This increased risk is not explained by differences in age, stage, or comorbidity level. Electronic supplementary material The online version of this article (doi:10.1186/s13058-017-0926-2) contains supplementary material, which is available to authorized users.

BACKGROUND: It is well known that obesity complicates the course of several diseases. However, it is unknown whether obesity affects the risk of infection among healthy individuals.METHODS: We included 37,808 healthy participants from the Danish Blood Donor Study, who completed a questionnaire on health-related items. Obesity was defined as a body mass index ≥ 30 kg/m. Infections among participants were identified by relevant ICD-10 codes in the Danish National Patient Register and Anatomical Therapeutic Chemical (ATC) codes in the Danish Prescription Register. Multivariable Cox proportional hazards analysis with age as the underlying timescale was used as the statistical model.RESULTS: During 113,717 person-years of observation, 1,233 participants were treated for infection at a hospital. Similarly, during 58,411 person-years of observation, 15,856 participants filled at least one prescription of antimicrobials. Obesity was associated with risk of hospital-based treatment for infection (women: hazard ratio [HR] = 1.5, 95% confidence interval [CI] = 1.1, 1.9; men: HR = 1.5, 95% CI = 1.2, 1.9). For specific infections, obesity was associated with increased risk of abscesses (both sexes), infections of the skin and subcutaneous tissue (men), and respiratory tract infections and cystitis (women). Similarly, obesity was associated with filled prescriptions of antimicrobials overall (women: HR = 1.22, 95% CI = 1.14, 1.30; men: HR = 1.23, 95% CI: 1.15, 1.33) and particularly with phenoxymethylpenicillin, macrolides, dicloxacillin and flucloxacillin, and broad-spectrum penicillins.CONCLUSIONS: In a large cohort of healthy individuals, obesity was associated with risk of infection. This result warrants further studies of metabolism and the immune response.

Influenza can cause significant morbidity and mortality in renal transplant recipients especially with a high rate of lower respiratory disease. Annual influenza vaccination is therefore recommended to renal transplant recipients. We report the first three cases of acute kidney injury in renal transplant recipients following influenza vaccination that all led to graft loss. They all had different native diseases and were all vaccinated in the same season of 2009-10. The time span from vaccination to decline of kidney function is shorter than the time to diagnosis since the three patients only had blood tests every 3 months or when symptoms became severe. These reports do not justify a change of current recommendations regarding influenza vaccination in renal transplant recipients, but they support the continued attention and registration of vaccinations to monitor side effects.