Monitoring Blood Supply in Germany: A Regulatory Perspective.

Background and Objectives: A sufficient supply of safe, high-quality blood components for transfusion is essential to the healthcare system in Germany. The requirements for the current reporting system are laid down in the German Transfusion Act. The present work elaborates on the advantages and limitations of the current reporting system and investigates the feasibility of a pilot project that collects specific data on blood supply based on weekly reports. Materials and Methods: Selected data on blood collection and supply from 2009 to 2021 derived from the §21 German Transfusion Act database were examined. In addition, a pilot study over a period of 12 months was conducted on a voluntary basis. The number of red blood cell (RBC) concentrates was documented and stock availability was calculated weekly. Results: From 2009 to 2021, the annual number of RBC concentrates decreased from 4.68 to 3.43 million, the per capita distribution decreased from 58 to 41 RBC concentrates per 1,000 inhabitants. These figures did not change significantly during the COVID-19 pandemic. The data of the 1-year pilot project represented 77% of the released RBC concentrates in Germany. Percentage share of O RhD positive RBC concentrates fluctuated between 35% and 22% and for O RhD negative concentrates between 17% and 5%. The availability of O RhD positive RBC concentrate stocks varied between 2.1 and 7.6 days. Conclusion: The data presented shows a decrease in annual RBC concentrate sales over an 11-year period and no further change over the past 2 years. A weekly monitoring of blood components detects acute problems in RBC provision and supply. Close monitoring seems helpful but should be combined with a nationwide supply strategy.

Reduction of Platelet Outdating and Shortage by Forecasting Demand With Statistical Learning and Deep Neural Networks: Modeling Study.

BACKGROUND: Platelets are a valuable and perishable blood product. Managing platelet inventory is a demanding task because of short shelf lives and high variation in daily platelet use patterns. Predicting platelet demand is a promising step toward avoiding obsolescence and shortages and ensuring optimal care. OBJECTIVE: The aim of this study is to forecast platelet demand for a given hospital using both a statistical model and a deep neural network. In addition, we aim to calculate the possible reduction in waste and shortage of platelets using said predictions in a retrospective simulation of the platelet inventory. METHODS: Predictions of daily platelet demand were made by a least absolute shrinkage and selection operator (LASSO) model and a recurrent neural network (RNN) with long short-term memory (LSTM). Both models used the same set of 81 clinical features. Predictions were passed to a simulation of the blood inventory to calculate the possible reduction in waste and shortage as compared with historical data. RESULTS: From January 1, 2008, to December 31, 2018, the waste and shortage rates for platelets were 10.1% and 6.5%, respectively. In simulations of platelet inventory, waste could be lowered to 4.9% with the LASSO and 5% with the RNN, whereas shortages were 2.1% and 1.7% with the LASSO and RNN, respectively. Daily predictions of platelet demand for the next 2 days had mean absolute percent errors of 25.5% (95% CI 24.6%-26.6%) with the LASSO and 26.3% (95% CI 25.3%-27.4%) with the LSTM (P=.01). Predictions for the next 4 days had mean absolute percent errors of 18.1% (95% CI 17.6%-18.6%) with the LASSO and 19.2% (95% CI 18.6%-19.8%) with the LSTM (P<.001). CONCLUSIONS: Both models allow for predictions of platelet demand with similar and sufficient accuracy to significantly reduce waste and shortage in a retrospective simulation study. The possible improvements in platelet inventory management are roughly equivalent to US $250,000 per year.

Convalescent plasma treatment of critically ill intensive care COVID-19 patients.

BACKGROUND: Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may be life-threatening, and specific antiviral drugs are currently not available. However, first studies indicated that convalescent plasma treatment might improve the clinical outcome of coronavirus disease 2019 (COVID-19) patients. STUDY DESIGN AND METHODS: In the current study, we investigated the efficacy of convalescent plasma treatment in eight COVID-19 patients. All the patients were critically ill, and seven of them were SARS-CoV-2 RNA-positive when starting treatment. SARS-CoV-2-specific antibodies were determined by an enzyme-linked immunosorbent assay detecting immunoglobulin G (IgG) antibodies against the S1 protein (Euroimmun), and the neutralizing titers were determined with a cell-culture-based neutralization assay. Plasma treatment started between 4 and 23 days after the onset of symptoms. The patients were usually treated by three plasma units, each containing 200-280 ml, which was applied at day 1, 3, and 5. RESULTS: Donor sera had on average lower IgG antibody ratios and neutralizing titers than the COVID-19 patients before the onset of treatment (median ratio of 5.8 and neutralizing titer of 1:320 vs. 7.5 and 1:640, respectively). Nevertheless, we observed an increase of antibody ratios in seven and of neutralizing titers in five patients after treatment; which did, however, not correlate with patient survival. Plasma treatment was effective in three patients, but five deceased despite treatment. Patients who deceased had a later treatment onset than survivors and finally died from multiple organ failure. CONCLUSION: Our data indicate that the efficacy of convalescent plasma treatment of critically ill COVID-19 patients who already had developed strong antiviral immune responses and organ complications is limited.

Blood donor screening for West Nile virus (WNV) revealed acute Usutu virus (USUV) infection, Germany, September 2016.

Between 1 June and 31 December 2016, 13,023 blood donations from the University Hospital Aachen in Germany were routinely screened for West Nile virus (WNV) RNA using the cobas TaqScreen WNV Test. On 28 September 2016, one blood donor was tested positive. Subsequent analysis revealed an acute Usutu virus (USUV) infection. During the ongoing USUV epizootics in Germany, blood transfusion services, public health authorities and clinicians should be aware of increased human USUV infections.

Iron Parameters Determine the Prognosis of Critically Ill Patients.

OBJECTIVE: Because iron is both an essential and toxic micronutrient influencing the development of microbial infections, we evaluated the usefulness of iron parameters as outcome predictors in ICU patients. DESIGN: Prospective clinical single-center non-interventional study. SETTING: General internal medicine ICU; German University hospital. PATIENTS: One hundred and twelve septic and 43 nonseptic ICU patients, 156 healthy blood donors. MEASUREMENTS AND MAIN RESULTS: Serum iron parameters at admission were correlated with short and long term mortality in ICU subjects. Both hepcidin and ferritin concentrations were significantly elevated in ICU patients compared with blood donors and were the highest in septic patients. On the contrary, serum iron and transferrin levels were decreased in ICU subjects with lowest values among septic patients. Hepcidin values correlated with ferritin levels, and serum iron correlated strongly with transferrin saturation. A moderate correlation of hepcidin, ferritin, and transferrin with inflammatory parameters was noted. Both short- and long-term survivors displayed higher ferritin/transferrin levels and lower transferrin saturation. In Kaplan-Meier analyses, low iron levels (cutoff 10.5 µmol/mL), low transferrin saturation (cutoff 55%), and high serum transferrin concentrations (cutoff 1.6 g/L) were associated with short- and long-term survival. In the subgroup of septic ICU subjects, low iron levels and transferrin saturation went along with a nonlethal outcome. CONCLUSIONS: Our findings demonstrate that parameters of iron metabolism, particularly transferrin saturation, that reflect serum iron availability, are strong outcome predictors in ICU patients. These data suggest that a failure of iron homeostasis with increased iron availability in serum occurs in lethally ill ICU patients and should trigger prospective clinical trials evaluating the usefulness of iron-chelating therapy in critical illness and sepsis.

[Risk Assessment of Single-Donor (Apheresis) Platelet Concentrates and Pooled Whole-Blood-Derived Platelet Concentrates]. / Bewertung von Apherese- und Pool-Thrombozytenkonzentraten.

According to the risk estimates of the Robert-Koch-Institute (RKI) and the Paul Ehrlich-Institute (PEI) an equivalence cannot be assumed to exist between the two different platelet preparations. Differences between single-donor (apheresis) platelet concentrates (ATK) and pooled whole-blood-derived platelet concentrates (PTK) result from donor populations, donation intervals, and preparation techniques. There are no prospective randomized studies with regard to the clinical efficacy, which would unambiguously demonstrate equivalence of the therapeutic efficacy of PTK (buffy coat method) in comparison to ATK. The German Association of Blood Transfusion Services (StKB) points out that, due to the non-equivalence of PTK and ATK, it is incumbent on the transfusion physician to select the platelet concentrate, make the appropriate disclosures, and assume treatment responsibility. Proper compensation for ATK and PTK must be ensured by the health insurance companies, whereby a special indication for the selection of either PTK or ATK is not given. Exceptions are patients with known HLA antibodies in which only selected platelet concentrates may be administered. Otherwise, no indication exists in the selection of the different platelet concentrates (Article is in German).

Donor age of human platelet lysate affects proliferation and differentiation of mesenchymal stem cells.

The regenerative potential declines upon aging. This might be due to cell-intrinsic changes in stem and progenitor cells or to influences by the microenvironment. Mesenchymal stem cells (MSC) raise high hopes in regenerative medicine. They are usually culture expanded in media with fetal calf serum (FCS) or other serum supplements such as human platelet lysate (HPL). In this study, we have analyzed the impact of HPL-donor age on culture expansion. 31 single donor derived HPLs (25 to 57 years old) were simultaneously compared for culture of MSC. Proliferation of MSC did not reveal a clear association with platelet counts of HPL donors or growth factors concentrations (PDGF-AB, TGF-ß1, bFGF, or IGF-1), but it was significantly higher with HPLs from younger donors (<35 years) as compared to older donors (>45 years). Furthermore, HPLs from older donors increased activity of senescence-associated beta-galactosidase (SA-ßgal). HPL-donor age did not affect the fibroblastoid colony-forming unit (CFU-f) frequency, immunophenotype or induction of adipogenic differentiation, whereas osteogenic differentiation was significantly lower with HPLs from older donors. Concentrations of various growth factors (PDGF-AB, TGF-ß1, bFGF, IGF-1) or hormones (estradiol, parathormone, leptin, 1,25 vitamin D3) were not associated with HPL-donor age or MSC growth. Taken together, our data support the notion that aging is associated with systemic feedback mechanisms acting on stem and progenitor cells, and this is also relevant for serum supplements in cell culture: HPLs derived from younger donors facilitate enhanced expansion and more pronounced osteogenic differentiation.

Peripheral CD34+ cells and the risk of in-stent restenosis in patients with coronary heart disease.

In-stent restenosis represents the major limitation of percutaneous coronary revascularization. The underlying neointimal hyperplasia mainly consists of smooth muscle cells (SMCs), which can be derived from bone marrow cells. We hypothesized that changes in the peripheral progenitor cell counts after coronary stenting may predict the development of restenosis. We prospectively studied men with atherosclerotic coronary artery disease who had undergone successful elective stenting of solitary target lesions (n = 17). Peripheral blood samples were drawn at baseline (before stenting) and 1 day after stenting. The CD34+ cell count was determined by flow cytometry. Follow-up quantitative coronary angiography was performed after 8.1 +/- 2.6 months. Except for longer primary lesions in patients with angiographic restenosis, no significant differences in patient and lesion characteristics were seen. The rate of restenosis (75% vs 11%, p = 0.015) and the extent of diameter stenosis at follow-up (56.9 +/- 26.9% vs 26.5 +/- 16.5%, p = 0.012) were higher in patients with a postprocedural increase in CD34+ cells than in those with a decrease in CD34+ cells. Postprocedural CD34+ cell counts were increased in patients with restenosis but decreased in those without restenosis (p = 0.002). A robust correlation was seen between the change in CD34+ cells and late lumen loss (r = 0.65, p <0.005). In a multivariate regression model, the change in CD34+ cells, lesion length, and preprocedural minimal lumen diameter independently predicted for late lumen loss. In conclusion, an increase in circulating CD34+ cells after coronary stenting constitutes an independent risk factor predicting in-stent restenosis and may be suggestive of their involvement in neointimal hyperplasia.

Effect of propofol on adhesion of activated platelets to leukocytes in human whole blood.

OBJECTIVE: To investigate the effect of propofol and its solvent Intralipid on the adhesion of activated platelets to leukocytes in vitro. DESIGN AND SETTING: Prospective study in an experimental laboratory. PARTICIPANTS: Sixteen healthy volunteers. INTERVENTIONS: Whole blood was incubated for 60 min with propofol (4, 40 micro g/ml), an equal volume of Intralipid 10% or phosphate-buffered saline (PBS). After stimulation with adenosine-5-diphosphate (ADP) platelet-leukocyte adhesion and platelet surface expression of P-selectin, GPIb and fibrinogen-binding to platelets were evaluated by flow cytometry. MEASUREMENTS AND RESULTS: The 4 micro g/ml concentration of propofol did not alter binding of platelets to leukocytes, expression of P-selectin, GPIb and fibrinogen binding to platelets. The 40 micro g/ml concentration of propofol reduced spontaneous and ADP-induced formation of platelet-neutrophil conjugates compared with PBS and the equal volume of Intralipid. In addition, binding of ADP-activated platelets to monocytes were also inhibited by 40 micro g/ml propofol. Following incubation with propofol, platelets showed reduced binding of fibrinogen in the unstimulated and ADP-stimulated blood samples as well as a lower percentage of platelets with bound fibrinogen. Effects dependent on the solvent Intralipid were enhanced adhesion of platelets to monocytes in comparison with propofol (40 micro g/ml) and PBS. CONCLUSION: In clinically used concentrations, propofol does not alter the adhesion of platelets to leukocytes in vitro. At ten-fold anesthetic concentration propofol reduced the formation of platelet-neutrophil and platelet-monocyte conjugates. We suggest that this effect is due to an inhibition of fibrinogen-binding to platelets by propofol. These effects were all independent of the propofol carrier Intralipid.

Xenon preserves neutrophil and monocyte function in human whole blood.

PURPOSE: Most volatile anesthetics are known to inhibit the oxidative and phagocytic function of neutrophils. In the present study, we investigated the effect of xenon on phagocytosis and respiratory burst activity of neutrophils and monocytes in human whole blood. METHODS: Heparinized whole blood from 22 healthy volunteers was incubated for 60 min in the presence of 65% xenon. Sixty-five percent nitrous oxide was used as a positive control to prove the reliability of our in vitro system. Phagocytosis of fluorescein isothiocyanate labelled, opsonized Escherichia coli (E. coli) by neutrophils and monocytes was measured using flow cytometry. After induction with either N-formyl-methionyl-leucyl-phenylalanine (FMLP), phorbol-12-myristate-13-acetate or opsonized E. coli, respiratory burst activity was assessed by measuring the oxidation of dihydrorhodamine 123 to rhodamine 123 with a flow cytometer. RESULTS: Exposure of human whole blood to xenon increased the percentage of neutrophils showing phagocytosis (94 +/- 3% vs 92 +/- 4%; P < 0.01), and the amount of ingested bacteria (P < 0.01). Respiratory burst activity in neutrophils and monocytes was not affected by xenon. Nitrous oxide significantly reduced the percentage of neutrophils showing respiratory burst after FMLP stimulation. Furthermore, E. coli-induced stimulation resulted in a decreased number of reacting neutrophils (84 +/- 15% vs 95 +/- 5%; P < 0.05) and monocytes (70 +/- 22% vs 83 +/- 11%; P < 0.05) as well as a reduced production of hydrogen peroxide in both cell lines compared to control. CONCLUSION: In contrast to nitrous oxide, xenon preserves neutrophil and monocyte antibacterial capacity in vitro.

The effect of isoflurane on neutrophil selectin and beta(2)-integrin activation in vitro.

UNLABELLED: Isoflurane is reported to reduce ischemia-reperfusion injury. Lower expression of CD11b may be responsible for attenuated postischemic neutrophil adhesion to vascular endothelium. However, neutrophil adhesion to vascular endothelium is a multistep process involving several selectins and beta(2)-integrins. Therefore, we assessed whether isoflurane affects the activation of the selectins P-selectin glycoprotein ligand-1 (PSGL-1) and L-selectin and the beta(2)-integrins CD11a and CD11b. Whole blood was incubated for 60 min with 0.5 or 1 minimum alveolar anesthetic concentration (MAC) isoflurane. After incubation, neutrophils were activated with N-formyl-methionyl-leucyl-phenylalanine (FMLP) or phorbol-12-myristate-13-acetate (PMA). Activation of adhesion molecules was evaluated via flow cytometry, and 1 MAC isoflurane reduced the expression of CD11a in the unstimulated samples. After stimulation with FMLP and PMA, shedding of L-selectin was lower in the presence of isoflurane. Furthermore, 1 MAC isoflurane reduced FMLP-induced activation of CD11a and CD11b compared with unexposed blood samples. These results demonstrate that isoflurane affects the activation of three adhesion molecules involved in the multistep process of neutrophil recruitment. First, isoflurane inhibits the activation of L-selectin, which mediates the neutrophil tethering and rolling on the vascular endothelium. Second, isoflurane attenuates the activation of both beta(2)-integrins-CD11a and CD11b-which mediate firm adhesion and transendothelial migration. IMPLICATIONS: Adhesion of neutrophils to endothelial cells in reperfusion injury is mediated by different adhesion molecules. This study indicates that the inhibiting effect of isoflurane on neutrophil recruitment may be mediated by a decreased activation of the L-selectin and by attenuation of the activation of the beta(2)-integrins CD11a and CD11b.

Effect of halothane and isoflurane on binding of ADP- and TRAP-6- activated platelets to leukocytes in Whole blood.

BACKGROUND: Adhesion of activated platelets to neutrophils and monocytes has an important role in the regulation of inflammatory processes. This study investigates whether halothane and isoflurane affect binding of activated platelets to leukocytes in human whole blood. METHODS: Citrated whole blood was incubated for 60 min with either 1 or 2 minimum alveolar concentration (MAC) halothane or isoflurane. After stimulation with adenosine-5-diphosphate (ADP) or the thrombin receptor agonist protein TRAP-6, platelet-leukocyte adhesion and surface expression of CD62P on platelets were evaluated by flow cytometry. RESULTS: Halothane led to an inhibition of agonist-induced adhesion of activated platelets to neutrophils and monocytes. One MAC halothane reduced the formation of TRAP-6-induced platelet-monocyte conjugates. After exposure to 2 MAC halothane, agonist-induced platelet-monocyte and platelet-neutrophil adhesion were inhibited. Surface expression of CD62P on ADP- and TRAP-6-stimulated platelets were significantly reduced after 1 and 2 MAC halothane. After 2 MAC isoflurane, the authors observed an increase of the percentage of lymphocytes with bound platelets after activation with ADP. The percentage of neutrophils with bound platelets after activation with ADP or TRAP-6 was also increased in this group. Two MAC isoflurane led to an increase of the percentage of platelets expressing CD62P in the unstimulated and TRAP-6 stimulated samples, and of the amount of CD62P epitopes on the surface of platelets in the ADP-stimulated samples. CONCLUSION: This study indicates that halothane inhibits, whereas isoflurane enhances, adhesion of agonist-activated platelets to leukocytes. Interaction of both anesthetics with the expression of CD62P on platelets contribute to theses effects.

[Macular hole surgery: experience with autologous platelet concentrate and indocyanine green-assisted internal limiting membrane peeling]. / Chirurgie des idiopathischen Makulaforamens: Erfahrungen mit autologem Thrombozytenkonzentrat und Indocyaningrünapplikation.

BACKGROUND: To report on our clinical experience with autologous platelet concentrate and indocyanine green(ICG)-assisted internal limiting membrane (ILM) peeling in macular hole surgery. PATIENTS AND METHODS: Standard 3-port vitrectomy was performed in 107 eyes of 101 patients (m: f = 27 : 74; mean age 60 +/- 9, range 30 - 80 years) with idiopathic macular hole stages II - IV. After fluid/air exchange, autologous platelet concentrate was applied (1.9 +/- 0,1 x 10(8) thrombocytes). ILM peeling, which was preceded by ICG staining in 19 eyes, was performed in 34 patients. RESULTS: After one procedure, anatomic success (hole closure) could be achieved in 85 % (n = 68), 75 % (n = 27) and 100 % (n = 3) of the eyes with stage II, III and IV holes, respectively. The mean visual acuity improved by 1 line. The overall initial closure rate of 82 % could be further enhanced to 96 % with a second procedure. In eyes pretreated with ICG, an initial rate of hole closure in 94 % and an improvement of visual acuity by 2 lines was observed. CONCLUSION: Autologous platelet concentrate appears to be a safe and reliable adjunct to improve the anatomical outcome of conventional macular hole surgery. Functional results can be further enhanced by ICG-assisted ILM peeling