Human dendritic cells activated with MV130 induce Th1, Th17 and IL‐10 responses via RIPK2 and MyD88 signalling pathways

Recurrent respiratory tract infections (RRTIs) are the first leading cause of community‐ and nosocomial‐acquired infections. Antibiotics remain the mainstay of treatment, enhancing the potential to develop antibiotic resistances. Therefore, the development of new alternative approaches to prevent and treat RRTIs is highly demanded. Daily sublingual administration of the whole heat‐inactivated polybacterial preparation (PBP) MV130 significantly reduced the rate of respiratory infections in RRTIs patients, however, the immunological mechanisms of action remain unknown. Herein, we study the capacity of MV130 to immunomodulate the function of human dendritic cells (DCs) as a potential mechanism that contribute to the clinical benefits. We demonstrate that DCs from RRTIs patients and healthy controls display similar ex vivo immunological responses to MV130. By combining systems biology and functional immunological approaches we show that MV130 promotes the generation of Th1/Th17 responses via receptor‐interacting serine/threonine‐protein kinase‐2 (RIPK2)‐ and myeloid‐differentiation primary‐response gene‐88 (MyD88)‐mediated signalling pathways under the control of IL‐10. In vivo BALB/c mice sublingually immunized with MV130 display potent systemic Th1/Th17 and IL‐10 responses against related and unrelated antigens. We elucidate immunological mechanisms underlying the potential way of action of MV130, which might help to design alternative treatments in other clinical conditions with high risk of recurrent infections.     

Hypotensive reactions: a previously uncharacterized complication of platelet transfusion?

BACKGROUND: In 1993, the American Association of Blood Banks (AABB) received reports of severe hypotensive reactions associated with platelet transfusions. The question arose as to whether these reports were indicative of a previously uncharacterized platelet transfusion reaction. STUDY DESIGN AND METHODS: To further characterize these reactions, the AABB Transfusion Practices Committee developed a series of three questionnaires. The initial questionnaire was sent to all AABB institutional members; the two subsequent questionnaires were sent to those institutions reporting severe and/or unusual platelet transfusion reactions. This report focuses on the 24 responses to the third and most detailed questionnaire, which specifically addressed reactions that were characterized by hypotension and/or unexplained respiratory failure. RESULTS: Of the 24 detailed responses received, 4 were not considered to represent unusual reactions to platelet transfusion, 3 described reactions consistent with a (presumably unrecognized) diagnosis of transfusion-related acute lung injury, and 17 described reactions that were primarily characterized by hypotension. The majority of the hypotensive reactions occurred within 1 hour of the beginning of the transfusion (88%), were associated with respiratory distress (82%), and resolved rapidly after cessation of the transfusion (82%). Eighty-eight percent of implicated components had been white cell reduced by filtration. CONCLUSION: The hypotensive platelet transfusion reactions that were described appear to represent a previously uncharacterized complication of platelet transfusion. However, the nature of the questionnaires used in this investigation does not allow the drawing of firm conclusions as to the frequency or the cause of these reactions.     

Characterization of reactions after transfusion of cellular blood components that are white cell reduced before storage

Background: During the storage of cellular components before transfusion, cytokines that may mediate transfusion reactions are released from white cells (WBCs). Adverse effects of transfused cellular blood components therefore depend not only on the number of residual WBCs in blood components, but also on the timing of WBC reduction. Study Design and Methods: Febrile nonhemolytic transfusion reactions (FNHTRs), allergic reactions, and other reactions were characterized in recipients of 4728 units of red cells (RBCs) and 3405 bags of single-donor apheresis platelets (SDAPs), all of which underwent prestorage WBC reduction. To delineate the impact of prestorage versus poststorage WBC reduction of RBCs on transfusion reactions, these results were compared with reactions occurring after the transfusion to similar recipients of 6447 bags of RBCs that underwent poststorage WBC reduction by bedside filtration and 5197 units of SDAPs that underwent prestorage WBC reduction. The levels of interleukin (IL) 1 beta, IL-6, IL-8, and tumor necrosis factor-alpha (TNF-alpha) were measured in a subset of 20 implicated cellular blood components at the time of transfusion reactions and correlated with the duration of storage before transfusion. Results: The incidence of reactions was greater after transfusions of SDAPs (5.49%) than of RBCs (1.63%). The incidence of FNHTRs after transfusion of RBCs that were WBC reduced before storage (1.1%) was significantly lower (p = 0.0045) than that after transfusion of RBCs that were WBC reduced after storage (2.15%). Although allergic reactions to RBCs that were WBC reduced before storage were also less common (0.41%) than those to RBCs that were WBC reduced after storage (0.51%), the difference was not significant (p = 0.067). At the time of reactions to RBCs and SDAPs that were reduced before storage, the level of IL-6 was negatively correlated (r = -0.54, p = 0.014) with the duration of storage before transfusion, and there was no correlation between the level of either IL-1 beta or IL-8 and the interval before transfusion. TNF-alpha was not detectable in any implicated component. Conclusion: FNHTRs, but not allergic reactions, were less common after transfusion of RBCs that were WBC reduced before storage than after the transfusion of those WBC reduced after storage at the bedside by filtration. The level of IL-6 in implicated cellular blood components that were WBC reduced before storage was inversely correlated with the length of storage before transfusion. Further studies are needed to determine whether the transfusion of cellular blood components that were WBC reduced before storage can both diminish the incidence of adverse reactions and improve outcome.     

ImprintSeq,a novel tool to interrogate DNA methylation at human imprinted regions and diagnose multilocus imprinting disturbance

PurposeDisruptions of genomic imprinting are associated with congenital imprinting disorders (CIDs) and other disease states, including cancer. CIDs are most often associated with altered methylation at imprinted differentially methylated regions (iDMRs). In some cases, multiple iDMRs are affected causing multilocus imprinting disturbances (MLIDs). The availability of accurate, quantitative, and scalable high-throughput methods to interrogate multiple iDMRs simultaneously would enhance clinical diagnostics and research.MethodsWe report the development of a custom targeted methylation sequencing panel that covered most relevant 63 iDMRs for CIDs and the detection of MLIDs. We tested it in 70 healthy controls and 147 individuals with CIDs. We distinguished loss and gain of methylation per differentially methylated region and classified high and moderate methylation alterations.ResultsAcross a range of CIDs with a variety of molecular mechanisms, ImprintSeq performed at 98.4% sensitivity, 99.9% specificity, and 99.9% accuracy (when compared with previous diagnostic testing). ImprintSeq was highly sensitive for detecting MLIDs and enabled diagnostic criteria for MLID to be proposed. In a child with extreme MLID profile a probable genetic cause was identified.ConclusionImprintSeq provides a novel assay for clinical diagnostic and research studies of CIDs, MLIDs, and the role of disordered imprinting in human disease states.     

ABCG2/BCRP: Specific and Nonspecific Modulators

Multidrug resistance (MDR) in cancer cells is the development of resistance to a variety of structurally and functionally nonrelated anticancer drugs. This phenomenon has become a major obstacle to cancer chemotherapy seriously affecting the clinical outcome. MDR is associated with increased drug efflux from cells mediated by an energy‐dependent mechanism involving the ATP‐binding cassette (ABC) transporters, mainly P‐glycoprotein (ABCB1), the MDR‐associated protein‐1 (ABCC1), and the breast cancer resistance protein (ABCG2). The first two transporters have been widely studied already and reviews summarized the results. The ABCG2 protein has been a subject of intense study since its discovery as its overexpression has been detected in resistant cell lines in numerous types of human cancers. To date, a long list of modulators of ABCG2 exists and continues to increase. However, little is known about the clinical consequences of ABCG2 modulation. This makes the design of novel, potent, and nontoxic inhibitors of this efflux protein a major challenge to reverse MDR and thereby increase the success of chemotherapy. The aim of the present review is to describe and highlight specific and nonspecific modulators of ABCG2 reported to date based on the selectivity of the compounds, as many of them are effective against one or more ABC transport proteins.     

Dietary Management of Blood Glucose in Medical Critically Ill Overweight and Obese Patients: An Open‐Label Randomized Trial

Background: Enteral nutrition (EN) increases hyperglycemia due to high carbohydrate concentrations while providing insufficient protein. The study tested whether an EN formula with very high‐protein‐ and low‐carbohydrate‐facilitated glucose control delivered higher protein concentrations within a hypocaloric protocol. Methods: This was a multicenter, randomized, open‐label clinical trial with parallel design in overweight/obese mechanically ventilated critically ill patients prescribed 1.5 g protein/kg ideal body weight/day. Patients received either an experimental very high‐protein (37%) and low‐carbohydrate (29%) or control high‐protein (25%) and conventional‐carbohydrate (45%) EN formula. Results: A prespecified interim analysis was performed after enrollment of 105 patients (52 experimental, 53 control). Protein and energy delivery for controls and experimental groups on days 1–5 were 1.2 ± 0.4 and 1.1 ± 0.3 g/kg ideal body weight/day (P = .83), and 18.2 ± 6.0 and 12.5 ± 3.7 kcals/kg ideal body weight/day (P < .0001), respectively. The combined rate of glucose events outside the range of >110 and ≤150 mg/dL were not different (P = .54, primary endpoint); thereby the trial was terminated. The mean blood glucose for the control and the experimental groups were 138 (?SD 108, +SD 177) and 126 (?SD 99, +SD 160) mg/dL (P = .004), respectively. Mean rate of glucose events >150 mg/dL decreased (Δ = ?13%, P = .015), whereas that of 80–110 mg/dL increased (Δ = 14%, P = .0007). Insulin administration decreased 10.9% (95% CI, ?22% to 0.1%; P = .048) in the experimental group relative to the controls. Glycemic events ≤80 mg/dL and rescue dextrose use were not different (P = .23 and P = .53). Conclusions: A very high‐protein and low‐carbohydrate EN formula in a hypocaloric protocol reduces hyperglycemic events and insulin requirements while increasing glycemic events between 80–110 mg/dL.     

How many calories are necessary during critical illness?

Several nutritional alternatives exist to provide critically ill patients sufficient calories to meet metabolic demands. Intuitively, investigators, nutritionists, and clinicians have pursued the goal of providing high-calorie nutrition support, believing that this would improve outcomes. There is little evidence, however, that meeting caloric goals is of significant benefit. In fact, accumulating data suggest that feeding patients below previously described caloric goals is associated with better outcomes, including decreases in hospital stay, ventilator dependence, use of antibiotics, and even mortality. This suggests that permissive underfeeding could replace the paradigm of meeting measured caloric goals. Prospective evidence to support adoption of permissive underfeeding is lacking, however. Appropriate clinical studies are necessary to prove its safety and efficacy.