Is having sex with other men a risk factor for transfusion-transmissible infections in male blood donors in Western countries?: a systematic review

Background : Although increased prevalence of transfusion transmissible infections (TTI) among “men who have sex with men” (MSM) has been well documented, the exclusion of MSM as blood donors is contested. The aim of this systematic review is to find studies that describe the risk of TTI in MSM blood donors. Methods : We searched MEDLINE, Embase, The Cochrane Central Register of Controlled Trials, Cinahl, and Web of Science, and used GRADE for determining evidence quality. We included studies comparing MSM and non-MSM blood donors (or people eligible to give blood), living in areas most relevant for our Blood Service. Results : Out of 18 987 articles, 14 observational studies were included. Two studies directly compared MSM with non-MSM donors showing that MSM donors have a statistically significant higher risk of HIV-1 infections. In one of these studies it was shown that this was related to recent (< 12 months) MSM contact. In two additional studies no evidence was shown in favour of a certain deferral period for MSM. Ten studies, applying permanent deferral for MSM, compared infected versus non-infected donors. One study found that MSM is a statistically significant risk factor for HIV-1 infection in blood donors. For other TTI such as HBV or HCV, an increased risk of infection could not be demonstrated, because the precision of the results was affected by the low numbers of donors with MSM as risk factor, or because of risk of bias in the included studies. All studies included low level evidence, because of risk of bias and imprecision of the results. Conclusions : High-quality studies investigating the risk of TTI in MSM who donate blood are scarce. The available evidence suggests a link between MSM blood donors and HIV-1 infection, but is too limited to be able to unambiguously/clearly recommend a certain deferral policy

Microfluidic flow chambers using reconstituted blood to model hemostasis and platelet transfusion in vitro

Blood platelets prepared for transfusion gradually lose hemostatic function during storage. Platelet function can be investigated using a variety of (indirect) in vitro experiments, but none of these is as comprehensive as microfluidic flow chambers. In this protocol, the reconstitution of thrombocytopenic fresh blood with stored blood bank platelets is used to simulate platelet transfusion. Next, the reconstituted sample is perfused in microfluidic flow chambers which mimic hemostasis on exposed subendothelial matrix proteins. Effects of blood donation, transport, component separation, storage and pathogen inactivation can be measured in paired experimental designs. This allows reliable comparison of the impact every manipulation in blood component preparation has on hemostasis. Our results demonstrate the impact of temperature cycling, shear rates, platelet concentration and storage duration on platelet function. In conclusion, this protocol analyzes the function of blood bank platelets and this ultimately aids in optimization of the processing chain including phlebotomy, transport, component preparation, storage and transfusion

Psoralen and ultraviolet A light treatment directly affects phosphatidylinositol 3-kinase signal transduction by altering plasma membrane packing

Psoralen and ultraviolet A light (PUNTA) are used to kill pathogens in blood products and as a treatment of aberrant cell proliferation in dermatitis, cutaneous T-cell lymphoma, and graft versus-host disease. DNA damage is well described, but the direct effects of PUVA on cell signal transduction are poorly understood. Because platelets are anucleate and contain archetypal signal transduction machinery, they are ideally suited to address this. Lipidomics on platelet membrane extracts showed that psoralen forms adducts with unsaturated carbon bonds of fatty acyls in all major phospholipid classes after PUVA. Such adducts increased lipid packing as measured by a blue shift of an environment-sensitive fluorescent probe in model liposomes. Furthermore, the interaction of these liposomes with lipid order-sensitive proteins like amphipathic lipid-packing sensor and a-synuclein was inhibited by PUVA. In platelets, PUVA caused poor membrane binding of Akt and Bruton's tyrosine kinase effectors following activation of the collagen glycoprotein VI and thrombin protease-activated receptor (PAR) 1. This resulted in defective Akt phosphorylation despite unaltered phosphatidylinositol 3,4,5-trisphosphate levels. Downstream integrin activation was furthermore affected similarly by PUVA following PAR1 (effective half-maximal concentration (EC), 8.4 +/- 1.1 versus 4.3 +/- 1.1 mu M) and glycoprotein VI (EC50, 1.61 +/- 0.85 versus 0.26 +/- 0.21 mu g/ml) but not PAR4 (EC50, 50 +/- 1 versus 58 +/- 1 mu m) signal transduction. Our findings were confirmed in T-cells ftom graft-versus-host disease patients treated with extracorporeal photopheresis, a form of systemic PUVA. In conclusion, PUVA increases the order of lipid phases by covalent modification of phospholipids, thereby inhibiting membrane recruitment of effector kinases

Ultraviolet C light pathogen inactivation treatment of platelet concentrates preserves integrin activation but affects thrombus formation kinetics on collagen in vitro

BACKGROUND: Ultraviolet (UV) light illumination in the presence of exogenously added photosensitizers has been used to inactivate pathogens in platelet (PLT) concentrates for some time. The THERAFLEX UV-C system, however, illuminates PLT concentrates with UV-C light without additional photoactive compounds. In this study residual PLT function is measured in a comprehensive paired analysis of UV-C-treated, gamma-irradiated, and untreated control PLT concentrates. STUDY DESIGN AND METHODS: A pool-and-split design was used with buffy coat-derived PLT concentrates in 65% SSP+ additive solution. Thrombus formation kinetics in microfluidic flow chambers onto immobilized collagen was investigated with real-time video microscopy. PLT aggregation, membrane markers, and cellular metabolism were determined concurrently. RESULTS: Compared to gamma-treated and untreated controls, UV-C treatment significantly affected thrombus formation rates on Days 5 and 7, not Day 2. PLT degranulation (P-selectin) and PLT apoptosis (annexin V binding) was slightly but significantly increased from Day 2 on. UV-C treatment moreover induced integrin αIIb β3 conformational changes reminiscent of activation. However, subsequent integrin activation by either PAR1-activating hexapeptide (PAR1AP) or convulxin was unaffected. This was confirmed by PLT aggregation studies induced with collagen, PAR1AP, and ristocetin at two different agonist concentrations. Finally, UV-C slightly increased lactic acid production rates, resulting in significantly decreased pH on Days 5 and 7, but never dropped below 7.2. CONCLUSION: UV-C pathogen inactivation treatment slightly but significantly increases PLT activation markers but does not profoundly influence activatability nor aggregation. The treatment does, however, attenuate thrombus formation kinetics in vitro in microfluidic flow chambers, especially after storage

The contribution of von Willebrand factor-GPIbα interactions to persistent aggregate formation in apheresis platelet concentrates

BACKGROUND AND OBJECTIVES: Apheresis platelet concentrates sometimes contain persistent aggregates (PA). Because apheresis involves extracorporeal circulation, we hypothesized that interactions between GPIbα and von Willebrand factor (VWF) underlie their origin. MATERIALS AND METHODS: Platelets in donations with PA were compared to aggregate-free (AF) controls. Flow cytometry was used to determine platelet bound VWF. Degranulation was measured using P-selectin expression in flow cytometry and cytokine release using immunosorbent assays. Platelet adhesion to VWF was assessed in hydrodynamic flow and real-time video microscopy. RESULTS: Platelets in PA concentrates had significantly more (P = 0·009, n ≥ 8) bound VWF compared to AF platelets, but differences in VWF concentration, VWF collagen binding, activated VWF or GPIbα expression were not found. Degranulation was higher (P = 0·030, n = 7) in PA than AF concentrates on day 1 of storage, but adhesion to immobilized VWF under hydrodynamic flow conditions was normal at that moment. On day 6, however, significantly less VWF adhesion (P = 0·009, n ≥ 6) was found for PA platelets compared to AF, indicating accelerated storage lesion in PA products. In a model that mimicks PA formation by chemically induced binding of VWF to platelets, we found that degranulation, phosphatidylserine expression and metabolism did not differ with paired controls at any time during subsequent storage. CONCLUSION: Accelerated storage lesion is found in concentrates with PA, but this cannot be explained solely by increased platelet bound VWF following apheresis. Therefore, additional stressors are probably responsible for the increases observed in platelet degranulation and storage lesion in products with PA

Persistent aggregates in apheresis platelet concentrates are commonly collected from donors with a history of aggregate donation

Platelet apheresis sometimes causes persistent aggregates (PA). This study (n = 211) shows that changing the apheresis settings to reach fixed product volumes instead of yields does not influence PA incidence, even though PA products on average contain more platelets than controls. Furthermore, logistic regression was used to model if PA can be predicted on the basis of certain predonation parameters. PA donation history was the only parameter retained, proving a strong determinant of predictability [AUC = 0.735 (SE = 0.022)]. Consequently, donations from a donor with previous PA history are 7.8 times more likely to contain PA than from a donor without preceding history

A microfluidic flow chamber model for platelet transfusion and hemostasis measures platelet deposition and fibrin formation in real-time

Microfluidic models of hemostasis assess platelet function under conditions of hydrodynamic shear, but in the presence of anticoagulants, this analysis is restricted to platelet deposition only. The intricate relationship between Ca2+-dependent coagulation and platelet function requires careful and controlled recalcification of blood prior to analysis. Our setup uses a Y-shaped mixing channel, which supplies concentrated Ca2+/Mg2+ buffer to flowing blood just prior to perfusion, enabling rapid recalcification without sample stasis. A ten-fold difference in flow velocity between both reservoirs minimizes dilution. The recalcified blood is then perfused in a collagen-coated analysis chamber, and differential labeling permits real-time imaging of both platelet and fibrin deposition using fluorescence video microscopy. The system uses only commercially available tools, increasing the chances of standardization. Reconstitution of thrombocytopenic blood with platelets from banked concentrates furthermore models platelet transfusion, proving its use in this research domain. Exemplary data demonstrated that coagulation onset and fibrin deposition were linearly dependent on the platelet concentration, confirming the relationship between primary and secondary hemostasis in our model. In a timeframe of 16 perfusion min, contact activation did not take place, despite recalcification to normal Ca2+ and Mg2+ levels. When coagulation factor XIIa was inhibited by corn trypsin inhibitor, this time frame was even longer, indicating a considerable dynamic range in which the changes in the procoagulant nature of the platelets can be assessed. Co-immobilization of tissue factor with collagen significantly reduced the time to onset of coagulation, but not its rate. The option to study the tissue factor and/or the contact pathway increases the versatility and utility of the assay

Lessons for Employing Participatory Design When Developing Care for Young People with Cancer: A Qualitative Multiple-Case Study

Purpose: Participatory design (PD) is a collective creative design process involving designers and nondesigners. There is limited reporting on the experience of using PD for adolescent and young adult (AYA) care. This study summarizes lessons from employing PD to develop care for AYAs with cancer. Methods: A qualitative multiple-case study method was conducted of three PD processes addressing food (FfC), intimacy and sexuality (I&S), and integrative medicine (IM) in caring for AYAs with cancer. Results: Local key stakeholders, who were exposed to a problem and had not been successful at solving it individually, were recruited to ‘‘dream’’ together. Through this synergy, a shared understanding of the problem and a joint mission emerged to find a solution. PD tools were used to develop a problem definition. An open mind and explorative research helped to understand the problems, and stakeholders were managed such that idea-sharing and learning were enabled. Designers translated ideas into prototypes. The PD process was prolonged due to the hierarchical hospital environment, business considerations, and additionally required evidence. The FfC program produced an effective new food service for the whole hospital. The I&S initiative developed a podcast, two articles, and a prototype website. The IM project developed a pilot study. Conclusions: For a PD process to successfully develop care for AYAs, one needs to use designers and skilled people, PD tools, and an open-ended approach to visualize an

Promoting Handwashing and Sanitation Behaviour Change in Low- and Middle-Income Countries: A Mixed-Method Systematic Review

This systematic review shows which promotional approaches are effective in changing handwashing and sanitation behaviour and which implementation factors affect the success or failure of such interventions. The authors find that promotional approaches can be effective in terms of handwashing with soap, latrine use, safe faeces disposal and open defecation. No one specific approach is most effective. However, several promotional elements do induce behaviour change. Different barriers and facilitators that influence implementing promotional approaches should be carefully considered when developing new policy, programming, practice, or research in this area

Development and validation of a standardized double-blind, placebo-controlled food challenge matrix for raw hazelnuts

Background: Double-blind, placebo-controlled food challenge (DBPCFC) is considered the gold standard for food allergy diagnosis. However, this test is rarely performed routinely in clinical practice because of various practical issues, e.g. the lack of a standardized matrix preparation. The aim of this study was to develop and validate a convenient DBPCFC matrix, that can easily be implemented in daily clinical practice. The focus of this study was the blinding of hazelnuts, whereby the hazelnuts retained as much as possible their allergenicity and could be mixed homogenously in low-doses to the matrices. Methods: A basophil-activation test (BAT), microbial tests and an LC-MS/MS test were performed to assess respectively the allergenicity of the used hazelnuts, the microbial stability of the novel developed matrices and the homogeneity of the hazelnuts in the matrices. A sensory test was conducted to validate the blinding of the hazelnuts in the matrices. A pilot DBPCFC study included eight patients as proof of concept. Results: The BAT-test gave the first insights concerning the retained allergenicity of the hazelnuts. The microbial safety could be assured after 12 months of storage. Sufficient masking was assessed by several sensory tests. Homogeneous hazelnut distribution could be achieved for the different hazelnut concentrations. The DBPCFC's results showed diverse allergic responders (from no reactions to distinct objective symptoms). Conclusion: A novel stable and validated DBPCFC matrix using raw hazelnuts has been developed that allows easy preparation in a standardized way for convenient use in daily clinical practice