Longitudinal SARS-CoV-2 Seroprevalence among Employees in Outpatient Care Services in Hamburg.

The risk of SARS-CoV-2 infection is particularly high for healthcare workers during the pandemic. Home care workers visit many different households per shift. Encounters with mostly elderly patients and their relatives increase the potential for the undetected spread of SARS-CoV-2. In order to gain insight into the seroprevalence of SARS-CoV-2 antibodies and possible transmission risks in outpatient care, this follow-up study was conducted with nursing services in Hamburg. The aim was to estimate the dynamics of seroprevalence in this occupational group over a 12-month period, to identify occupation-specific risk factors, and to collect information on the vaccination status of the surveyed nursing staff. Antibody testing for SARS-CoV-2 IgG against the S1 domain (EUROIMUN Analyser I® Lübeck, Germany) was performed on participating healthcare workers with patient contact at a total of four time points within one year from July 2020 to October 2021 (baseline, follow-up after three, six and twelve months). The data were mostly analysed descriptively. Differences in IgG titres were analysed using variance analysis methods, particularly Tukey's range test. The seroprevalence was 1.2% (8/678) at baseline and 1.5% (9/581) at the three-month follow-up (T1). At the second follow-up (T2) after six months, vaccination against SARS-CoV-2 was available from January 2021 onwards. The prevalence rate of positive IgG antibodies relative to the S1 domain of the spike protein test among unvaccinated individuals was 6.5%. At (T3) after twelve months (July to October 2021), 482 participants were enrolled, and 85.7% of the workers were considered fully vaccinated at this time point, while 51 individuals were unvaccinated. The prevalence was 13.7% (7/51). In our study, a low seroprevalence was found among home care workers, which was lower than in our studies conducted in the clinical setting. Therefore, it can be assumed that the occupational risk of infection is rather low for both the nursing staff and the patients/clients cared for in the outpatient setting. The good provision of protective equipment and the high vaccination rate of the staff probably had a positive influence.

Association of the C-terminal 42-peptide fragment of alpha-1 antitrypsin with the severity of ARDS: A pilot study.

BACKGROUND: Acute respiratory distress syndrome is a life-threatening condition with a hospital mortality rate of up to 40%. Biomarkers related to the pathophysiology of ARDS may not only identify patients at risk but may also serve as potential therapeutic targets. This study examined the association between the proteolytic C-terminal 42-peptide fragment of alpha-1 antitrypsin and ARDS severity. METHODS: The 42-peptide fragment and interleukin-6 levels were measured in 21 patients with mild-to-moderate ARDS and 47 patients with moderate-to-severe ARDS on days 1, 3, and 5 after diagnosis/admission to the intensive care unit. To elucidate the association between both biomarkers and the PaO2/FiO2 ratio, the concentrations of both biomarkers were compared between the two groups, and a multivariate regression analysis was performed. RESULTS: The concentrations of both biomarkers were higher in patients with moderate-to-severe ARDS. While the PaO2/FiO2 ratio increased from day 1 to day 3, the concentrations of both biomarkers decreased. Multivariate regression analysis revealed negative associations between the PaO2/FiO2 ratio and both the C-terminal 42-peptide of alpha-1 antitrypsin and interleukin-6 on day 1 (beta: -0.138, p = 0.052; beta: -0.096, p = 0.004) and on day 3 (beta: -0.157, p = 0.045; beta: -0.106, p = 0.043). INTERPRETATION: The C-terminal 42-peptide of alpha-1 antitrypsin is a new biomarker associated with ARDS severity. Its predictive value in identifying patients at risk of developing moderate-to-severe ARDS must be investigated in additional, independent prospective studies.

Multiplex quantification of C-terminal alpha-1-antitrypsin peptides provides a novel approach for characterizing systemic inflammation.

C-terminal peptides (CAAPs) of the highly abundant serine protease alpha-1-antitrypsin (A1AT) have been identified at various lengths in several human materials and have been proposed to serve as putative biomarkers for a variety of diseases. CAAPs are enzymatically formed and these enzymatic activities are often associated with excessive immune responses (e.g. sepsis, allergies). However, most of those CAAPs have been either detected using in vitro incubation experiments or in human materials which are not easily accessible. To gain a comprehensive understanding about the occurrence and function of CAAPs in health and disease, a LC-MS/MS method for the simultaneous detection of nine CAAPs was developed and validated for human plasma (EDTA and lithium-heparin) and serum. Using this newly developed method, we were able to detect and quantify five CAAPs in healthy individuals thereby providing an initial proof for the presence of C36, C37, C40 and C44 in human blood. Concentrations of four CAAPs in a clinical test cohort of patients suffering from sepsis were significantly higher compared to healthy controls. These results reveal that in addition to C42 other fragments of A1AT seem to play a crucial role during systemic infections. The proposed workflow is simple, rapid and robust; thus this method could be used as diagnostic tool in routine clinical chemistry as well as for research applications for elucidating the diagnostic potential of CAAPs in numerous diseases. To this end, we also provide an overview about the current state of knowledge for CAAPs identified in vitro and in vivo.

Vitamin D receptor expression and serum 25(OH)D concentration inversely associates with burden of neurofibromas.

Vitamin D and its receptor may play a role in preventing tumor development and progression. As such antineoplastic effects are expected to be weak and to act over long periods, conditions with increased tumor incidence, such as the neurofibromatosis type 1 (NF1), provide suitable study models. We previously found an inverse correlation of serum 25(OH)D concentration with number of neurofibromas in NF1. Here we aim to further explore the role of the vitamin D receptor. A total of 141 adult NF1 patients were included in the study. For 101 of them, serum vitamin 25(OH)D data were available. From 87 patients, blood samples were obtained in PaxGene tubes containing a reagent to stabilize RNA immediately. mRNA of the vitamin D receptor (VDR) gene (coding for the vitamin D receptor) was measured by means of RT-PCR. Correlation of laboratory data with NF1-related tumors was statistically evaluated. Vitamin D receptor in NF1-tumors was examined by means of immunohistochemistry using an antibody against the vitamin D1 receptor. The number of dermal neurofibromas was significantly inversely correlated with VDR mRNA level and with serum 25(OH)D concentration in NF1 patients. In contrast, plexiform neurofibroma and malignant peripheral nerve sheath tumor did not correlate with these two parameters. Immunostaining did not detect vitamin D receptor in NF1-tumors. Both vitamin D and its receptor may play a role in suppressing the development of neurofibromas. Sustaining 25(OH)D at an adequate level may contribute to controlling neurofibromas and possibly also other tumors. This is especially important for individuals with lower expression of VDR.

Loss of complex O-glycosylation impairs exocrine pancreatic function and induces MODY8-like diabetes in mice.

Cosmc is ubiquitously expressed and acts as a specific molecular chaperone assisting the folding and stability of core 1 synthase. Thus, it plays a crucial role in the biosynthesis of O-linked glycosylation of proteins. Here, we show that ablation of Cosmc in the exocrine pancreas of mice causes expression of truncated O-glycans (Tn antigen), resulting in exocrine pancreatic insufficiency with decreased activities of digestive enzymes and diabetes. To understand the molecular causes of the pleiotropic phenotype, we used Vicia villosa agglutinin to enrich Tn antigen-modified proteins from Cosmc-KO pancreatic lysates and performed a proteomic analysis. Interestingly, a variety of proteins were identified, of which bile salt-activated lipase (also denoted carboxyl-ester lipase, Cel) was the most abundant. In humans, frameshift mutations in CEL cause maturity-onset diabetes of the young type 8 (MODY8), a monogenic syndrome of diabetes and pancreatic exocrine dysfunction. Here, we provide data suggesting that differentially O-glycosylated Cel could negatively affect beta cell function. Taken together, our findings demonstrate the importance of correct O-glycan formation for normal exocrine and endocrine pancreatic function, implying that aberrant O-glycans might be relevant for pathogenic mechanisms of the pancreas.

Geriatric assessment and biomarkers in patients with metastatic breast cancer receiving first-line mono-chemotherapy: Results from the randomized phase III PELICAN trial.

OBJECTIVES: To determine predictive/prognostic factors for patients with metastatic breast cancer (MBC) receiving first-line monochemotherapy using biomarker analysis and geriatric assessment (GA). MATERIALS AND METHODS: Karnofsky Performance Status (KPS) and GA as clinical parameters, and prognostic inflammatory and nutritional index (PINI), and Glasgow prognostic score (GPS) as biomarkers were analyzed for association with clinical outcome within the randomized phase III PEg-LIposomal Doxorubicin vs. CApecitabin iN MBC (PELICAN) trial of first-line pegylated liposomal doxorubicin (PLD) or capecitabine. RESULTS: Of 210 patients, 38% were >65years old. GA (n=152) classified 74% as fit, 10% as compromised, and 16% as frail. Biomarkers showed no age dependency. In multivariate analysis (n=70) KPS, GA, cumulative illness rating scale-geriatrics (CIRS-G), and GPS were significantly associated with time to progression, and KPS, CIRS-G, and instrumental activities of daily living (IADL) from GA, and PINI showed a significant correlation with overall survival. CONCLUSION: GA evaluation was feasible. KPS significantly correlated with efficacy outcomes. Items of a GA and biomarkers of inflammation and nutrition may have prognostic significance in patients with MBC.

Thrombin generation in a patient with an acquired high-titre factor V inhibitor.

The management of patients with acquired factor V inhibitors is challenging, because their bleeding risk is highly variable and only poorly correlated with routine coagulation tests. Furthermore, there is no standardized treatment for bleeding control or inhibitor eradication. An 84-year-old white man underwent uneventful surgery for a ruptured intracerebral haemangioma. There were no perioperative coagulation abnormalities. Eight weeks after surgery, however, the prothrombin and the activated partial thromboplastin times were found to be maximally prolonged without signs of acute haemorrhage. A factor V inhibitor of 212 Bethesda units was diagnosed. We used a fluorogenic real-time thrombin generation assay with low concentrations of tissue factor (TF) to analyse the factor V inhibitor for interference with coagulation in platelet-poor plasma. Compared with three bleeding patients with acquired haemophilia A and severely deficient thrombin generation, total thrombin generation capacity was similar in the patient and healthy controls. However, the lag phase was significantly prolonged, suggesting a defect in the initiation/amplification, but not in the propagation phase of TF-triggered thrombin generation. This defect could be fully reproduced by purified patient IgG and largely corrected by ex-vivo addition of activated prothrombin complex concentrate, but not recombinant human FVIIa. Addition of normal platelets to the patient's plasma resulted in a pronounced shortening of the lag phase, suggesting that platelet-derived factor V can escape the inhibitor. Our findings offer an explanation for the absence of spontaneous bleeding in this patient and support the concept of platelet transfusions for the management of acute haemorrhages in patients with acquired factor V inhibitors.

Differences of 25-hydroxyvitamin D3 concentrations in children and adults with neurofibromatosis type 1.

OBJECTIVES: Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder, frequently associated with reduced bone mineral density. Serum 25-hydroxyvitamin D3 concentrations in NF1 adults are lower than in healthy controls in autumn respectively winter and are inversely correlated with the number of dermal neurofibromas. We investigated 25-hydroxyvitamin D3 levels in children and adults with neurofibromatosis type 1 in winter and summer and compared them to healthy controls to get more pathogenic insights in vitamin D3 metabolism in NF1 patients. DESIGN AND METHODS: NF1 patients were clinically examined and serum 25-hydroxyvitamin D3 concentrations were measured in 58 NF1 adults and 46 children in winter as well as in summer and compared to sex-, age- and month-matched controls. RESULTS: 52 adults suffered from 10 to 5000 dermal neurofibromas, whereas none of the children presented neurofibromas. 25-Hydroxyvitamin D3 increased from winter to summer (mean: 21.0 to 46.5nmol/l) in NF1 adults. This increase was even larger (p=0.0001) than in healthy controls (mean: 50.5 to 60.5nmol/l). However, there were no differences of 25-hydroxyvitamin D3 concentrations in NF1 children and healthy controls both in winter and in summer. CONCLUSIONS: Only adults with NF1 showed lower 25-hydroxyvitamin D3 levels in winter and summer, which are unlikely due to impaired UV-dependent dermal synthesis, but rather might be caused by an accelerated catabolism.

Efficacy and selectivity of nilotinib on NF1-associated tumors in vitro.

Neurofibromatosis type 1 is a tumor suppressor gene disorder which predisposes patients to cutaneous neurofibromas, plexiform neurofibromas (PNFs) and malignant peripheral nerve sheath tumors (MPNSTs) among other neoplasias and manifestation. In this study, we examined the efficiency of nilotinib on PNF-derived Schwann cells and on cells of established MPNST lines in vitro. Nilotinib treatment for 10 days led to decreased proliferation, viability and vitality of the cells with 50 % inhibitory concentration (IC50) for proliferation varying from 3.1 to 9.0 µM. We further addressed selectivity of the drug for tumor cells by simultaneously examining its efficacy on tumor cells (Schwann cells) and non-tumor cells (fibroblasts) from the same tumor. For four out of the six PNFs studied, IC50 was lower in Schwann cells than in fibroblasts for all parameters measured (proliferation, vitality and viability), indicating good drug selectivity. In addition, nilotinib induced apoptosis and suppressed collagenase activity. Our results suggest that nilotinib may provide a treatment option for some PNFs and MPNSTs and our in vitro model of comparative treatment on tumor and non-tumor cells may provide a prototype of preclinical drug screening system toward personalized treatment.

Effect of vitamin D3 treatment on bone density in neurofibromatosis 1 patients: a retrospective clinical study.

OBJECTIVES: We have previously demonstrated reduced bone density and an increased incidence of 25-hydroxy vitamin D3 (25-OH D3) deficiency in adults with neurofibromatosis 1 (NF1) compared to healthy controls. Vitamin D3 is a cheap, safe, and effective supplement in the general population, but its value in NF1 patients has not been demonstrated. This study investigates the therapeutic potential of oral vitamin D3 on bone mineral density (BMD) in NF1 patients with vitamin D3 deficiency. METHODS: We measured serum 25-OH D3, parathyroid hormone, calcium, and bone alkaline phosphatase concentrations, urinary deoxypyridinoline concentrations, and BMD in 35 adults with NF1. Nineteen patients received vitamin D3 supplementation for 2 years, six patients received supplementation for 1 year and 10 patients received no supplementation. Supplementation was administered in a dose that maintained the serum 25-OH D3 level above 30 µg/l. BMD was measured again at 1 and 2 years, and biochemical assessments of bone metabolism were measured at least every half year during therapy. RESULTS: Treated subjects had significantly reduced loss of BMD, as measured by T score at the hip (p=0.011) and lumbar spine (p=0.022). The effect on hip BMD was apparent at 1 year in comparison to baseline (p=0.02) and was greater at 2 years in comparison to measurements at 1 year (p=0.02). CONCLUSIONS: Vitamin D3 supplementation improves BMD in adult NF1 patients. Further studies are needed to elucidate the mechanisms responsible for reduced BMD in NF1 patients.

Hyaluronan in intra-operative edema of NF1-associated neurofibromas.

The tumor suppressor disorder neurofibromatosis type 1 (NF1) is associated with development of multiple neurofibromas which may grow intraneurally as plexiform neurofibromas (PNF) or intracutaneously (CNF). Upon surgery neurofibromas may show prominent swelling hindering skin-edge approximation. To assess whether the water binding glycosaminoglycan hyaluronan is involved in intra-operative swelling, 51 neurofibromas from 33 NF1-patients were investigated. Hyaluronan was histologically demonstrated and was quantified by ELISA. Molecular weight of hyaluronan was determined by gel filtration. Further, hyaluronan content was measured in cultivated Schwann cells and fibroblasts. Clinically, 67% of PNF were associated with moderate or severe intra-operative swelling, whereas only 36% of CNF showed this feature. Significantly higher levels of hyaluronan content were found in PNF compared to CNF (P < 0.05). Mast cell density did not correlate with any of the parameters. Molecular weight of hyaluronan in PNF and CNF ranged from higher than 106 Da to approximately 105 Da. Fibroblasts produced less hyaluronan than Schwann cells. The findings support the view that hyaluronan plays an important role in intra-operative swelling in neurofibroma surgery.

Determination of hemolysis thresholds by the use of data loggers in pneumatic tube systems.

BACKGROUND: Pneumatic tube systems (PTSs) for the transport of blood samples are regaining popularity in medical centers after earlier reports that their use could introduce preanalytical distortions such as hemolysis and changes in blood gases. METHODS: We drew duplicate blood samples from 30 volunteers. One sample was hand transported, and the other sample was transported through a PTS together with a mini-data logger that provided continuous measurements of temperature, humidity, pressure, and acceleration. After transport the samples were analyzed at the same time. We looked for possible relationships of the transport method and the parameters measured by the data loggers with differences in hematological parameters, standard clinical chemistry analyses, blood coagulation, erythrocyte sedimentation rate, and blood gas analysis. RESULTS: There were no significant differences in temperature, humidity, and pressure between the methods of transport, but we observed significant differences in 3-axis accelerations. The combined effect of these forces could be described by the right-tailed area under the vector sum acceleration distribution. Our data show that this area correlated with PTS speed and that PTS speed and the area under the curve exhibited a direct relation to the degree of hemolysis. CONCLUSIONS: Assessment of 3-axis acceleration by use of data loggers can be used to identify preanalytical deviations that result from the transportation of blood samples in PTSs. Our approach could be used for the evaluation and regular control of PTSs without the need for repeated blood drawing and laboratory analyses.

Tandem affinity depletion: a combination of affinity fractionation and immunoaffinity depletion allows the detection of low-abundance components in the complex proteomes of body fluids.

Protein biomarker discovery in the low concentration range of human body fluids requires the enrichment of the proteins of interest. Here we report on a tandem affinity strategy: In the first step, we isolated a human plasma glyco-subproteome of healthy individuals by wheat germ agglutinin (WGA) lectin affinity chromatography. In the second step, the proteins of this subproteome were used to raise antibodies in llama (Lama glama). The heavy-chain fraction of the llama antibodies was used to deplete from the WGA lectin binding fraction all proteins normally found in human plasma. In this way, we selectively enriched the glycoprotein, CEA, a known cancer marker which had been spiked into normal plasma. As a proof of concept, we applied this method to the analysis of plasma sample from colon cancer patients. We could demonstrate the selective enrichment of CEA by a factor of 600-800.

Integrated analysis of the cerebrospinal fluid peptidome and proteome.

Cerebrospinal fluid (CSF) is the only body fluid in direct contact with the brain and thus is a potential source of biomarkers. Furthermore, CSF serves as a medium of endocrine signaling and contains a multitude of regulatory peptides. A combined study of the peptidome and proteome of CSF or any other body fluid has not been reported previously. We report confident identification in CSF of 563 peptide products derived from 91 precursor proteins as well as a high confidence CSF proteome of 798 proteins. For the CSF peptidome, we use high accuracy mass spectrometry (MS) for MS and MS/MS modes, allowing unambiguous identification of neuropeptides. Combination of the peptidome and proteome data suggests that enzymatic processing of membrane proteins causes release of their extracellular parts into CSF. The CSF proteome has only partial overlap with the plasma proteome, thus it is produced locally rather than deriving from plasma. Our work offers insights into CSF composition and origin.

Comparison of three commercial assays for the measurement of 17alpha-hydroxyprogesterone (17alpha-OHPR): limitations of the quality control system.

The measurement of 17alpha-hydroxyprogesterone (17alpha-OHPR) is of value for the diagnosis and management of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency. In the central laboratory from 2000 to 2002, we observed, using the assay from the manufacturer DSL, an elevation of the moving average of 17alpha-OHPR concentrations and a number of adrenocorticotropic hormone (ACTH) stimulation tests despite the lack of any changes to the internal and external quality control, of which the criteria were continuously fulfilled. We studied a population of n=49 patients for the measurement of 17alpha-OHPR, with and without extraction, to evaluate the quality of different commercially available radioimmunoassays. The internal and external quality controls were successful in determining 17alpha-OHPR. An excellent measurement and correlation of 17alpha-OHPR was expressed with the assay from the manufacturer IBL without extraction and from the manufacturer DSL with extraction. The quantitative determination of 17alpha-OHPR requires adequate specificity and accuracy of the 17alpha-OHPR radioimmunoassays. The results show that internal and external quality control systems are not sufficient to resolve analytical problems described in this study.

Expression of cytosolic and membrane associated tissue transglutaminase in rat hepatic stellate cells and its upregulation during transdifferentiation to myofibroblasts in culture.

Transdifferentiation of hepatic stellate cells (HSC) to collagen producing myofibroblasts (MFB) is a principal event in liver fibrogenesis. In our studies we investigated if tissue transglutaminase (tTG) from these cell types may play a role in liver fibrosis. Separation of cytosol and membrane components showed membrane associated tTG and during transdifferentiation an upregulation of total tTG on mRNA and protein level was found, but no modulation during stimulation with TGF-beta1. In HSC and fully differentiated MFB a significant amount of the total tTG synthesised during transdifferentiation is found to be membrane-associated whereas the remaining portion is cytosol-associated and only very little is found within the extracellular matrix (ECM). The data implicate that tTG in this cell type seems to play an important role in liver fibrogenesis.

Ruthenium(II)-tris-bipyridine/titanium dioxide codoped zeolite Y photocatalysts: II. Photocatalyzed degradation of the model pollutant 2,4-xylidine, evidence for percolation behavior.

A considerably arduous test of a novel class of composite materials consisting of [Ru(bpy)3]2+ and TiO2 codoped zeolites Y is presented here. The [Ru(bpy)3]2+ and TiO2 codoped zeolites Y served as photocatalysts in the oxidation of the model compounds 2,4-dimethylaniline (2,4-xylidine) by H2O2 in an acidic aqueous medium. Zeolite-embedded TiO2 (nano)particles play an important role in the degradation mechanism. The first step in this complex mechanism is the photoelectron transfer from photoexcited [Ru(bpy)3]2+*, located inside the supercage of zeolite Y, to a neighboring TiO2 nanoparticle. During this electron transfer process, electron injection into the conduction band of TiO2 is achieved. The second decisive step is the reaction of this electron with H2O2, which was previously chemisorbed at the surface-region of the TiO2 nanoparticles. In this reaction, a TiO2 bound hydroxyl radical (TiO2-HO.) is created. This highly reactive intermediate initiates then the oxidation of 2,4-xylidine, which enters the zeolites framework in its protonated form (Hxyl+). The formation of 2,4-dimethylphenol as first detectable reaction product indicated that this oxidation proceeds via an electron transfer mechanism. Furthermore, [Ru(bpy)3]3+, which was created in the initiating photoelectron transfer reaction between [Ru(bpy)3]2+* and TiO2, also takes place in the oxidation of Hxyl+. [Ru(bpy)3]2+ is recycled in that reaction, which also belongs to the group of electron transfer reactions. In addition to the primary steps of this particular Advanced Oxidation Process (AOP), the dependence of the efficiency of the 2,4-xylidine degradation as a function of the [Ru(bpy)3]2+ and TiO2 loadings of the zeolite Y framework is also reported here. The quenching of [Ru(bpy)3]2+* by H2O2 as well as the photocatalytic activity of the [Ru(bpy)3]2+ and TiO2 codoped zeolite Y catalysts both follow a distinct percolation behavior in dependence of their TiO2 content.