Extracorporeal photopheresis and the cellular mechanisms: Effects of 8-methoxypsoralen and UVA treatment on red blood cells, platelets and reactive oxygen species.

BACKGROUND AND OBJECTIVES: Extracorporeal photopheresis (ECP) is a widespread cellular therapy for graft-versus-host disease, autoimmune diseases and Sézary disease. One of the main effects of ECP is the apoptosis of leukocytes, but the therapeutic mechanisms are not completely known. The aim of this study was to investigate the effects on red blood cells, platelets and the induction of reactive oxygen species. MATERIALS AND METHODS: We used human cells from healthy blood donors to simulate in vitro the composition in an apheresis bag. Cells were treated with 8-methoxypsoralen (8-MOP) and UVA. Red blood cell stability, platelet activity and induction of reactive oxygen species were analysed. RESULTS: After 8-MOP and UVA treatment, the red blood cells showed high cell integrity with low levels of eryptosis and no increase of free haemoglobin or red blood cell distribution width (RDW). Red blood cell immune-associated antigens CD59 and CD147 were hardly affected by the treatment. Platelet glycoproteins CD41, CD62P and CD63 indicated strong platelet activation after 8-MOP and UVA treatment. Reactive oxygen species were slightly but not significantly induced by the treatment. CONCLUSION: The effect of the ECP therapy is probably not exclusively mediated by leukocytes. Platelet activation is another striking effect caused by the treatment of the apheresis product with 8-MOP/UVA. However, since we could hardly identify any evidence for eryptosis or haemolysis, it is unlikely that red blood cell eryptosis is part of the therapeutic mechanism. Further research on this topic seems to be promising.

Adverse drug reactions following lymphocyte immunotherapy for the treatment of infertility: A retrospective study.

AIM: Unexplained infertility is a major burden for couples who want to have children. Lymphocyte immunotherapy (LIT) could be a therapeutic help for these couples. Although LIT has been carried out for decades, the data on the success of therapy are still controversial and there is hardly information on possible adverse drug reactions. METHODS: In this study, we used a questionnaire to determine the frequency of local and systemic adverse drug reactions in our patients who were treated with LIT between 2017 and 2020 (n = 302). In addition, we asked about pregnancies and/or live births after LIT in a 2-year follow-up (n = 140). RESULTS: Most of the patients reported the occurrence of mild local adverse drug reactions in a period of less than 4 weeks: Over 75% reported moderate erythema, itching or swelling, over 10% erythema, itching or swelling as more pronounced adverse drug reaction. Blistering was specified in 10% of the cases. Serious adverse drug reactions or adverse events were not described. In the follow-up, 69% of our patients stated a pregnancy after LIT, and 50% a life birth. CONCLUSIONS: Overall, LIT represents a well-tolerated therapy for couples with unexplained infertility, however, more evidence is needed on the benefits.

TREM2 expression in the brain and biological fluids in prion diseases.

Triggering receptor expressed on myeloid cells 2 (TREM2) is an innate immune cell surface receptor that regulates microglial function and is involved in the pathophysiology of several neurodegenerative diseases. Its soluble form (sTREM2) results from shedding of the TREM2 ectodomain. The role of TREM2 in prion diseases, a group of rapidly progressive dementias remains to be elucidated. In the present study, we analysed the expression of TREM2 and its main sheddase ADAM10 in the brain of sporadic Creutzfeldt-Jakob disease (sCJD) patients and evaluated the role of CSF and plasma sTREM2 as a potential diagnostic marker of prion disease. Our data indicate that, compared to controls, TREM2 is increased in sCJD patient brains at the mRNA and protein levels in a regional and subtype dependent fashion, and expressed in a subpopulation of microglia. In contrast, ADAM10 is increased at the protein, but not the mRNA level, with a restricted neuronal expression. Elevated CSF sTREM2 is found in sCJD, genetic CJD with mutations E200K and V210I in the prion protein gene (PRNP), and iatrogenic CJD, as compared to healthy controls (HC) (AUC = 0.78-0.90) and neurological controls (AUC = 0.73-0.85), while CSF sTREM2 is unchanged in fatal familial insomnia. sTREM2 in the CSF of cases with Alzheimer's disease, and multiple sclerosis was not significantly altered in our series. CSF sTREM2 concentrations in sCJD are PRNP codon 129 and subtype-related, correlate with CSF 14-3-3 positivity, total-tau and YKL-40, and increase with disease progression. In plasma, sTREM2 is increased in sCJD compared with HC (AUC = 0.80), displaying positive correlations with plasma total-tau, neurofilament light, and YKL-40. We conclude that comparative study of TREM2 in brain and biological fluids of prion diseases reveals TREM2 to be altered in human prion diseases with a potential value in target engagement, patient stratification, and disease monitoring.

Plasma YKL-40 in the spectrum of neurodegenerative dementia.

BACKGROUND: Increased plasma YKL-40 has been reported in Alzheimer's disease (AD), but its levels in other neurodegenerative diseases are unknown. Here, we aimed to investigate plasma YKL-40 in the spectrum of neurodegenerative dementias. METHODS: YKL-40 was quantified in the plasma of 315 cases, including healthy controls (HC), neurological disease controls (ND), AD, vascular dementia (VaD), frontotemporal dementia (FTD), sporadic Creutzfeldt-Jakob disease (CJD) and Lewy body dementia (LBD). Diagnostic accuracy in the differential diagnostic context and influence of age and gender was assessed. RESULTS: Highest YKL-40 levels were detected in CJD, followed by LBD, VaD, AD, FTD, ND and HC. YKL-40 was associated to age but not to sex. After controlling for age, YKL-40 was significantly elevated in CJD compared to HC (p < 0.001), ND, AD and VaD (p < 0.01) and in LBD compared to HC (p < 0.05). In CJD, YKL-40 concentrations were significantly higher at late disease stages. CONCLUSIONS: Plasma YKL-40 is significantly elevated in CJD regardless of clinical and genetic parameters, with moderate diagnostic accuracy in the discrimination from control cases. Our study discards a potential use of this biomarker in the differential diagnostic context but opens the possibility to be explored as a marker for CJD monitoring.

The effect of a novel turbulence-controlled suction system in the prevention of hemolysis and platelet dysfunction in autologous surgery blood.

BACKGROUND: Re-transfusion of autologous blood is an important aspect of intraoperative blood management. Hemolysis and platelet dysfunction due to turbulence in the blood suction system strongly impede later usage of suction blood for re-transfusion. The aim of this study was to analyze the effects of a novel surgical-blood suction system with an automatic control setup for minimization of turbulence in the blood flow. METHODS: We compared the turbulence-controlled suction system (TCSS) with a conventional suction system and untreated control blood in vitro. Blood cell counts, hemolysis levels according to free hemoglobin (fHb) and platelet function were analyzed to determine the integrity of the suction blood. RESULTS: In the conventional suction system, we found a strong increase of the fHb levels. In contrast, erythrocyte integrity was almost completely preserved when using the TCSS. We obtained similar results regarding platelet function. The expression of platelet glycoproteins, such as GP IIb/IIIa and P-selectin, native or after stimulation with ADP, were markedly impaired by the conventional system, but not by the TCSS. In addition, platelet aggregometry revealed significant platelet dysfunction in conventional suction blood, but less aggregation impairments were present in blood samples from the TCSS. CONCLUSION: Our findings on an in vitro assessment show major improvements in red blood cell integrity and platelet function of suction blood when using the TCSS compared to a conventional suction system. These results reflect a significant benefit for autologous re-transfusion. We suggest testing the TCSS in surgery for clinical evaluation.

An alternative for extracorporeal photopheresis: 8-methoxypsoralen and UVA-treated leucocytes from allogeneic donors improve graft-versus-host disease in mice.

BACKGROUND AND OBJECTIVE: Extracorporeal photopheresis (ECP) is an important immune tolerance inducing therapy for graft-versus-host disease (GvHD). However, a sufficient number of ECP cycles cannot be performed in patients with severe GvHD and contraindications for apheresis. Allogeneic sources of leucocytes for use as ECP treatment would be of great benefit. Therefore, this study aimed to test the therapeutic potential of novel sources of leucocytes for ECP. MATERIALS AND METHODS: Graft-versus-host disease mice were treated with ECP using therapeutic cells from different allogeneic sources. Splenocytes were incubated with 8-methoxypsoralen (8-MOP), irradiated with UVA light and injected into GvHD mice as a model for ECP. RESULTS: The therapy with 8-MOP/UVA-treated cells from healthy mice of the bone marrow transplantation (BMT) donor strain reduced the GvHD symptoms, at least in a model of chronic GvHD. In the acute GvHD model, 8-MOP/UVA-treated cells from the BMT donor or recipient strain did not show significant improvements in GvHD symptoms or survival time. Pre-activation of cells by mixed lymphocyte reactions before 8-MOP/UVA treatment also failed to result in significant differences in survival time or GvHD score. In contrast, ECP with third-party 8-MOP/UVA-treated cells from a HLA-mismatched donor resulted in a mean survival time of 37 days compared to 21 days in the control group. CONCLUSION: In our analysis of novel allogeneic leucocyte sources for ECP, we could demonstrate that the source of the 8-MOP/UVA-treated cells is crucial. The underlying immunologic effect of allogeneic 8-MOP/UVA-treated cells needs to be investigated in future studies.

Prediction of graft-versus-host disease: a biomarker panel based on lymphocytes and cytokines.

Graft-versus-host disease (GvHD) still belongs to the major challenges after allogeneic hematopoietic stem cell transplantation (HSCT). Immune-suppressive therapy against GvHD is a double-edged sword due to risk of infections and relapse. The ability to adapt prophylactic treatment according to the probability of severe GvHD would be an essential advantage for the patients. We analyzed different biomarkers for their potential to predict the development of GvHD in 28 patients who underwent allogeneic HSCT. Blood was taken once directly after hematopoietic engraftment. In this study, patients were monitored for 12 months after HSCT for the occurrence of acute GvHD or acute/chronic GvHD overlap syndrome. Soluble IL-2 receptor and CD4/CD8 T cell ratio were independently associated with the occurrence of GvHD in the observation period. However, the largest area under the receiver operating characteristic curve with 0.90 was observed when a 5-parameter biomarker score based on CD4+ T cells, CD8+ T cells, CD19- CD21+ precursor B cells, CD4/CD8 T cell ratio, and soluble IL-2 receptor was used to predict GvHD. In addition, CD8+ T cell levels above 2.3% of all mononuclear cells after engraftment may predict relapse-free survival at least for 12 months. In summary, we found a new biomarker panel for prediction of GvHD which is featured by established laboratory assays and high statistical significance. In order to introduce the biomarker panel into routine clinical protocols, we suggest performing a larger multi-center study.

In vitro effects of different 8-methoxypsoralen treatment protocols for extracorporeal photopheresis on mononuclear cells.

Extracorporeal photopheresis (ECP) is an important second-line therapy for graft-versus-host disease. A central therapeutic mechanism is the induction of immune tolerance through apoptosis in patient's leukocytes, caused by ex vivo incubation with 8-methoxypsoralen (8-MOP) and subsequent UVA irradiation. We hypothesized that different 8-MOP incubation times and an additional 8-MOP removal step could influence the apoptosis kinetics of leukocytes in general and in particular could lead to different apoptotic levels in the leukocyte subpopulations. After 8-MOP/UVA treatment of human leukocytes, cells were cultured and the percentage of annexin V positive cells from several leukocyte subpopulations was determined. Only regulatory T cells (Tregs) were relatively resistant to 8-MOP/UVA induced apoptosis. When cells were incubated for 30 minutes with 8-MOP prior to UVA exposure, higher percentages of annexin V positive cells were detected on day 1 and day 2 after treatment. Removal of 8-MOP after UVA exposure caused no significant changes in the apoptosis kinetics during the 72 h culture period compared with unwashed cells. The results of our in vitro study indicate that it could be possible to adjust the apoptosis kinetics via modulation of the 8-MOP incubation time. In further in vivo studies it should be elucidated to which extent different apoptosis kinetics influence the therapeutic effect of ECP since steady-state apoptosis levels are probably important for establishing a long lasting immune tolerance. Furthermore we found that Tregs, according to their well-known tolerogenic function, are more resistant to apoptosis after 8-MOP/UVA treatment compared to GvHD inducing T cell populations.

Dendritic polyglycerol sulfate attenuates murine graft-versus-host disease.

Graft-versus-host disease (GvHD) is a severe immune reaction commonly occurring after hematopoietic stem cell transplantation. The outcome of patients who do not respond to the currently used immunosuppressive drugs is poor, thus there is an urgent need for the evaluation of new therapies. Heparin has a well-known anti-inflammatory effect and heparin analogues with a low anticoagulant effect are interesting candidates as new anti-inflammatory drugs. We explored the therapeutic potential of dendritic polyglycerol sulfates (dPGS), a novel class of heparin derivatives, on murine acute GvHD in vivo. The therapeutic effect of dPGS on murine GvHD was more intense after intravenous application compared to subcutaneous injection. An increased survival rate and improved clinical scores were observed in mice treated with 5 mg/kg once a week. In these animals, there was a reduction in the percentage of CD4(+) and CD8(+) T cells, which are the main effectors of GvHD. In addition, dPGS treatment decreased the number of tumor necrosis factor alpha (TNFα)-producing T cells. Increasing the dose of dPGS reversed the positive effect on survival as well as the clinical score, which indicates a small therapeutic range. Here, we report for the first time that dPGS have a significant immunosuppressive in vivo effect in a mouse model of severe acute GvHD. Therefore, we propose to study dPGS as promising candidates for the development of potential new drugs in the treatment of steroid-refractory GvHD patients first in larger animals and later in humans.

Circulating Endothelial Cells Expressing the Angiogenic Transcription Factor Krüppel-Like Factor 4 are Decreased in Patients with Coronary Artery Disease.

OBJECTIVE: The zinc finger transcription factor KLF4 is known to control diverse EC functions. METHODS: The functional role of KLF4 for angiogenesis and its association with CAD was examined in HUVECs and human CECs. RESULTS: In two different angiogenesis assays, siRNA-mediated KLF4 downregulation impaired HUVEC sprouting and network formation. Conversely, KLF4 overexpression increased HUVEC sprouting and network formation. Similar findings were observed after incubation of HUVECs with CdM from KLF4 cDNA-transfected cells, suggesting a role of paracrine factors for mediating angiogenic KLF4 effects. In this regard, VEGF expression was increased in KLF4-overexpressing HUVECs, whereas its expression was reduced in HUVECs transfected with KLF4 siRNA. To examine the relevance of our in vitro findings for human endothelial dysfunction, we analyzed the expression of KLF4 in CECs of patients with stable CAD. Flow cytometry analyses revealed decreased numbers of KLF4-positive CECs in peripheral blood from CAD patients compared to healthy controls. CONCLUSIONS: Our findings suggest that KLF4 may represent a potential biomarker for EC dysfunction. In the future, (therapeutic) modulation of KLF4 may be useful in regulating EC function during vascular disease processes.

In vitro and in vivo effects of human monocytes and their subsets on new vessel formation.

OBJECTIVE: Human monocytes can be divided into CD16(-) monocytes and CD16(+) monocytes. Studies in mice suggested differential effects of monocyte subsets during new vessel formation. METHODS: The functional role of human monocyte subsets in neovascularization processes was investigated. For in vivo experiments, nude mice underwent unilateral hindlimb ischemia surgery before being injected with either total monocytes, CD16(-) monocytes or CD16(+) monocytes isolated from healthy individuals. RESULTS: In vitro, cytokine array analysis demonstrated that monocytes release numerous angiogenic cytokines, some of which were differentially expressed in monocyte subsets. Sprout length was enhanced in EC spheroids being cultured in conditioned medium obtained from total monocytes and, to a lesser extent, also in supernatants of CD16(-) monocytes. Laser Doppler perfusion imaging up to day 28 after surgery revealed a trend toward improved revascularization in mice treated with monocytes, but no significant differences between monocyte subsets. Histological analyses four weeks after surgery showed an increased arteriole size in mice having received CD16(+) monocytes, whereas the number of capillaries did not significantly differ between groups. CONCLUSIONS: Our findings suggest additive and differential effects of monocyte subsets during neovascularization processes, possibly due to an altered secretion of angiogenic factors and their paracrine capacity to stimulate new vessel formation.

Hemostatic radiotherapy in clinically significant tumor-related bleeding: excellent palliative results in a retrospective analysis of 77 patients.

BACKGROUND: Significant bleeding of tumor sites is a dreaded complication in oncological diseases and often results in clinical emergencies. Besides basic local and interventional procedures, an urgent radiotherapeutic approach can either achieve a bleeding reduction or a bleeding stop in a vast majority of patients. In spite of being used regularly in clinical practice, data reporting results to this therapy approach is still scarce. METHODS: We retrospectively analyzed 77 patients treated for significant tumor-related bleeding at our clinic between 2000 and 2021, evaluating treatment response rate, hemoglobin levels, hemoglobin transfusion necessity, administered radiotherapy dose and overall survival. RESULTS: Response rate in terms of bleeding stop was 88.3% (68/77) in all patients and 95.2% (60/63) in the subgroup, wherein radiotherapy (RT) was completed as intended. Hemoglobin transfusions decreased during treatment in a further subgroup analysis. Median overall survival (OS) was 3.3 months. Patients with primary tumors (PT) of the cervix (carcinoma of the cervix, CC) or endometrium (endometrioid carcinoma, EDC) and patients receiving the full intended RT dose showed statistically significant better OS in a multivariable cox regression model. Median administered dose was 39 Gy, treatment related acute toxicity was considerably low. CONCLUSIONS: Our data show an excellent response rate with a low toxicity profile when administering urgent radiotherapy for tumor related clinically significant bleeding complications. Nonetheless, treatment decisions should be highly individual due to the low median overall survival of this patient group.

Low vitamin D and elevated immunoreactivity against Epstein-Barr virus before first clinical manifestation of multiple sclerosis.

OBJECTIVE: Vitamin D deficiency and Epstein-Barr virus (EBV) infection may be associated with the development of multiple sclerosis (MS). We investigated serum 25-hydroxyvitamin D (25-OH-D) levels and anti-EBV immunoreactivity in 25 individuals before the first clinical manifestation of MS. PATIENTS AND METHODS: 56 serum samples of 25 individuals who had donated blood prior to the first clinical MS manifestation (clinically isolated syndrome (CIS)) (four male subjects, 21 female subjects, mean age 31.5 years at time of pre-CIS blood sampling; mean age at disease onset 33.4 years) were available, covering an interval of 7.3 years-2 months (mean 31.5 months) before CIS. In 18 of 25 patients serum samples were also obtained after established diagnosis of MS. Longitudinal age- and gender-matched healthy blood donors (four male subjects, 21 female subjects, 39 samples, mean age 32.5 years) served as controls. Serum 25-OH-D was measured by isotope dilution-liquid chromatography-tandem mass spectrometry. 25-OH-D levels were deconvoluted using published seasonal coefficients from a German population. Immunoglobulin G (IgG) against Epstein-Barr virus nuclear antigen-1 (EBNA1) were assessed using commercially available ELISA. RESULTS: Low 25-OH-D levels were observed during the 24-month pre-CIS interval (47.8 (32.5-77.2) nmol/l, median (IQR); healthy controls: 81.6 (57.7-98.5), p=0.004, however, still higher than after established diagnosis (24.5 (13.7-47.7), p<0.0001 compared with controls). IgG against EBNA1 during the 36-month pre-CIS interval was increased (185.9 (91.2-460.0) IU/ml, median (IQR); healthy controls 63.7 (29.5-121.6), p=0.002). CONCLUSIONS: Low vitamin D and remote EBV infection may be associated with clinical MS breakthrough within 2-3 years.

Plasma Lipocalin 2 in Alzheimer's disease: potential utility in the differential diagnosis and relationship with other biomarkers.

BACKGROUND: Lipocalin-2 is a glycoprotein that is involved in various physiological and pathophysiological processes. In the brain, it is expressed in response to vascular and other brain injury, as well as in Alzheimer's disease in reactive microglia and astrocytes. Plasma Lipocalin-2 has been proposed as a biomarker for Alzheimer's disease but available data is scarce and inconsistent. Thus, we evaluated plasma Lipocalin-2 in the context of Alzheimer's disease, differential diagnoses, other biomarkers, and clinical data. METHODS: For this two-center case-control study, we analyzed Lipocalin-2 concentrations in plasma samples from a cohort of n = 407 individuals. The diagnostic groups comprised Alzheimer's disease (n = 74), vascular dementia (n = 28), other important differential diagnoses (n = 221), and healthy controls (n = 84). Main results were validated in an independent cohort with patients with Alzheimer's disease (n = 19), mild cognitive impairment (n = 27), and healthy individuals (n = 28). RESULTS: Plasma Lipocalin-2 was significantly lower in Alzheimer's disease compared to healthy controls (p < 0.001) and all other groups (p < 0.01) except for mixed dementia (vascular and Alzheimer's pathologic changes). Areas under the curve from receiver operation characteristics for the discrimination of Alzheimer's disease and healthy controls were 0.783 (95%CI: 0.712-0.855) in the study cohort and 0.766 (95%CI: 0.627-0.905) in the validation cohort. The area under the curve for Alzheimer's disease versus vascular dementia was 0.778 (95%CI: 0.667-0.890) in the study cohort. In Alzheimer's disease patients, plasma Lipocalin2 did not show significant correlation with cerebrospinal fluid biomarkers of neurodegeneration and AD-related pathology (total-tau, phosphorylated tau protein, and beta-amyloid 1-42), cognitive status (Mini Mental Status Examination scores), APOE genotype, or presence of white matter hyperintensities. Interestingly, Lipocalin 2 was lower in patients with rapid disease course compared to patients with non-rapidly progressive Alzheimer's disease (p = 0.013). CONCLUSIONS: Plasma Lipocalin-2 has potential as a diagnostic biomarker for Alzheimer's disease and seems to be independent from currently employed biomarkers.

Tandem high-dose therapy in relapsed and refractory B-cell lymphoma: results of a prospective phase II trial of myeloablative chemotherapy, followed by escalated radioimmunotherapy with (131)I-anti-CD20 antibody and stem cell rescue.

A phase II trial evaluated safety, feasibility and efficacy of a sequential tandem approach combining myeloablative BEAM chemotherapy and autologous stem cell transplantation (ASCT) with myeloablative radioimmunotherapy (HD-RIT), with (131)I-anti-CD20 antibody ((131)I-rituximab), followed by a second ASCT in patients with relapsed or refractory CD20+ B-cell lymphoma. According to protocol, 16 patients with relapsed (n = 14) and refractory (n = 2) CD20+ B-cell lymphoma received salvage therapy with rituximab and Dexa-BEAM, followed by BEAM (HD chemotherapy) and high-dose myeloablative radioimmunotherapy 2-6 months after BEAM. Nine of 16 patients received HD-RIT; seven patients were excluded before HD-RIT because of toxicity or progressive disease. Disease histologies were follicular lymphoma (FL) grades 1 and 2 (n = 4), transformed follicular (FL 3b; n = 6), diffuse large B-cell (DLBCL; n = 4), mantle cell (n = 1) and marginal zone lymphoma (n = 1). After a median follow-up of 50.4 months for OS and 39.7 months for progression-free survival (PFS), estimated 4-year OS and PFS were 67% and 64%, respectively. The estimated 4-year OS and PFS for patients with FL were 80% and 78%, respectively. Toxicity was significant, including one fatal outcome due to pneumonitis. Tandem transplants consisting of HD chemotherapy followed by HD-RIT with (131)I-coupled anti-CD20 are manageable and effective but toxic treatment modalities for relapsed poor prognosis CD20+ B-NHL.

Needle EMG induced muscle bleeding complication after guideline approved discontinuation of anticoagulation.

INTRODUCTION: Needle electromyography (EMG) is an essential part of electrodiagnosis (EDX) in neuromuscular disorders. As in all invasive procedures there is a risk of bleeding complications, but which is rare according to the current literature. Controlled, prospective studies that include patients under anticoagulation or antiplatelet therapy are lacking and would be difficult to conduct. CASE REPORTS: We describe two patients with no history of coagulopathy who developed an intramuscular hematoma after needle EMG. They had been under therapeutic anticoagulation but this had been discontinued, and their standard coagulation parameters had returned to normal prior to the EMG. One patient was found to have a rare genetic defect in thromboxane synthesis with associated markedly impaired platelet aggregation, while no obvious cause of the bleeding was found in the second patient. However, it could have been due to an unexpectedly strong anticoagulatory response to the oral anticoagulant apixaban. CONCLUSION: One must be aware of the increased risk of bleeding events in patients with therapeutic anticoagulation. These can occur even when the recommendations regarding discontinuation of anticoagulant drugs for the procedure have been followed. The patient must be actively questioned for ongoing use of NSAIDs, and if pain therapy is required alternatives with no antiplatelet activity should be given. A larger data pool of adverse EMG events would aid in risk assessment and decision making.

Diagnostic and prognostic value of plasma neurofilament light and total-tau in sporadic Creutzfeldt-Jakob disease.

BACKGROUND: Blood neurofilament light (Nfl) and total-tau (t-tau) have been described to be increased in several neurological conditions, including prion diseases and other neurodegenerative dementias. Here, we aim to determine the accuracy of plasma Nfl and t-tau in the differential diagnosis of neurodegenerative dementias and their potential value as prognostic markers of disease severity. METHODS: Plasma Nfl and t-tau were measured in healthy controls (HC, n = 70), non-neurodegenerative neurological disease with (NND-Dem, n = 17) and without dementia syndrome (NND, n = 26), Alzheimer's disease (AD, n = 44), Creutzfeldt-Jakob disease (CJD, n = 83), dementia with Lewy bodies/Parkinson's disease with dementia (DLB/PDD, n = 35), frontotemporal dementia (FTD, n = 12), and vascular dementia (VaD, n = 22). Biomarker diagnostic accuracies and cutoff points for the diagnosis of CJD were calculated, and associations between Nfl and t-tau concentrations with other fluid biomarkers, demographic, genetic, and clinical data in CJD cases were assessed. Additionally, the value of Nfl and t-tau predicting disease survival in CJD was evaluated. RESULTS: Among diagnostic groups, highest plasma Nfl and t-tau concentrations were detected in CJD (fold changes of 38 and 18, respectively, compared to HC). Elevated t-tau was able to differentiate CJD from all other groups, whereas elevated Nfl concentrations were also detected in NND-Dem, AD, DLB/PDD, FTD, and VaD compared to HC. Both biomarkers discriminated CJD from non-CJD dementias with an AUC of 0.93. In CJD, plasma t-tau, but not Nfl, was associated with PRNP codon 129 genotype and CJD subtype. Positive correlations were observed between plasma Nfl and t-tau concentrations, as well as between plasma and CSF concentrations of both biomarkers (p < 0.001). Nfl was increased in rapidly progressive AD (rpAD) compared to slow progressive AD (spAD) and associated to Mini-Mental State Examination results. However, Nfl displayed higher accuracy than t-tau discriminating CJD from rpAD and spAD. Finally, plasma t-tau, but not plasma Nfl, was significantly associated with disease duration, offering a moderate survival prediction capacity. CONCLUSIONS: Plasma Nfl and t-tau are useful complementary biomarkers for the differential diagnosis of CJD. Additionally, plasma t-tau emerges as a potential prognostic marker of disease duration.

SARS-CoV-2 mutations acquired in mink reduce antibody-mediated neutralization.

Transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from humans to farmed mink has been observed in Europe and the US. In the infected animals, viral variants arose that harbored mutations in the spike (S) protein, the target of neutralizing antibodies, and these variants were transmitted back to humans. This raised concerns that mink might become a constant source of human infection with SARS-CoV-2 variants associated with an increased threat to human health and resulted in mass culling of mink. Here, we report that mutations frequently found in the S proteins of SARS-CoV-2 from mink are mostly compatible with efficient entry into human cells and its inhibition by soluble angiotensin-converting enzyme 2 (ACE2). In contrast, mutation Y453F reduces neutralization by an antibody with emergency use authorization for coronavirus disease 2019 (COVID-19) therapy and sera/plasma from COVID-19 patients. These results suggest that antibody responses induced upon infection or certain antibodies used for treatment might offer insufficient protection against SARS-CoV-2 variants from mink.

Apoptosis induction by miR-19b inhibition: does it show therapeutic potential for leukemia?

High levels of miR-19 play an important role in malignant diseases of the hematopoietic system. Therefore the treatment with corresponding microRNA antagonists seems to be an interesting therapeutic approach. We found a significant increase of apoptosis in Jurkat cells which were transfected with a miR-19b inhibitor. The rise of apoptosis in transfected human monocuclear cells (MNCs) was significant as well, but the unspecific miRNA control induced apoptosis in MNCs to a similar extend. A closer look at the MNC subpopulations revealed higher specific apoptosis in B cells whereas T cell apoptosis was lower and induced by unspecific miRNA interference.