Can We Use Blood Biomarkers as Entry Criteria and for Monitoring Drug Treatment Effects in Clinical Trials? A Report from the EU/US CTAD Task Force.

In randomized clinical trials (RCTs) for Alzheimer's Disease (AD), cerebrospinal fluid (CSF) and positron emission tomography (PET) biomarkers are currently used for the detection and monitoring of AD pathological features. The use of less resource-intensive plasma biomarkers could decrease the burden to study volunteers and limit costs and time for study enrollment. Blood-based markers (BBMs) could thus play an important role in improving the design and the conduct of RCTs on AD. It remains to be determined if the data available on BBMs are strong enough to replace CSF and PET biomarkers as entry criteria and monitoring tools in RCTs.

Blood Biomarkers from Research Use to Clinical Practice: What Must Be Done? A Report from the EU/US CTAD Task Force.

Timely and accurate diagnosis of Alzheimer's disease (AD) in clinical practice remains challenging. PET and CSF biomarkers are the most widely used biomarkers to aid diagnosis in clinical research but present limitations for clinical practice (i.e., cost, accessibility). Emerging blood-based markers have the potential to be accurate, cost-effective, and easily accessible for widespread clinical use, and could facilitate timely diagnosis. The EU/US CTAD Task Force met in May 2022 in a virtual meeting to discuss pathways to implementation of blood-based markers in clinical practice. Specifically, the CTAD Task Force assessed: the state-of-art for blood-based markers, the current use of blood-based markers in clinical trials, the potential use of blood-based markers in clinical practice, the current challenges with blood-based markers, and the next steps needed for broader adoption in clinical practice.

[Collision tumor]. / Kollisionstumor.

A 65-year-old woman presented with a painless, partially pigmented and partially hyperkeratotic tumorous lesion on the lower eye lid. Histopathologic findings of the wedge resection showed a collision tumor of a highly differentiated squamous cell carcinoma and a fibrosing basal cell carcinoma. Collision tumors involving these two components are rare, particularly in the periocular region.

Preclinical and Clinical Development of ABBV-8E12, a Humanized Anti-Tau Antibody, for Treatment of Alzheimer's Disease and Other Tauopathies.

Tau neurofibrillary tangles are found in the brains of patients suffering from Alzheimer's disease and other tauopathies. The progressive spreading of tau pathology from one brain region to the next is believed to be caused by extracellular transsynaptic transmission of misfolded tau between neurons. Preclinical studies have shown that antibodies against tau can prevent this transfer of misfolded tau between cells. Thus, antibodies against tau have the potential to stop or slow the progression of tau pathology observed in human tauopathies. To test this hypothesis, a humanized anti-tau antibody (ABBV-8E12) was developed and a phase 1 clinical trial of this antibody has been completed. The double-blind, placebo-controlled phase 1 study tested single doses of ABBV-8E12 ranging from 2.5 to 50 mg/kg in 30 patients with progressive supranuclear palsy (PSP). ABBV-8E12 was found to have an acceptable safety profile with no clinically concerning trends in the number or severity of adverse events between the placebo and dosed groups. Pharmacokinetic modelling showed that the antibody has a plasma half-life and cerebrospinal fluid:plasma ratio consistent with other humanized antibodies, and there were no signs of immunogenicity against ABBV-8E12. Based on the acceptable safety and tolerability profile of single doses of ABBV-8E12, AbbVie is currently enrolling patients into two phase 2 clinical trials to assess efficacy and safety of multiple doses of ABBV-8E12 in patients with early Alzheimer's disease or PSP.

Bacterial load of conditioned pressure ulcers is not a predictor for early flap failure in spinal cord injury.

OBJECTIVES: Pressure ulcers impose a major lifetime medical problem to patients with high-grade spinal cord injury (SCI). For patients with stages 3-4 pressure ulcers, plastic surgery is often the only remaining treatment option. Despite considerable flap failure rates of around 30%, only sparse knowledge exists on predictors for flap failure. Hence, identification of predictors for flap failures is needed. METHODS: We prospectively enrolled 38 SCI patients with stages 3-4 pressure ulcers scheduled for plastic surgery. Preoperative wound swabs, intraoperative tissue samples and postoperative drainage liquids were microbiologically analyzed. In multivariable logistic regression analyses, bacterial loads of deep tissue cultures of intraoperative samples as well as other clinical variables were analyzed with respect to the prediction of flap failures. RESULTS: The flap failure rate was 27.5%. Bacterial loads of deep tissue cultures were not predictive for flap failure, neither was the colonization with a specific bacterial strain. We observed a considerable fluctuation of microbiological environment from initial swab cultures, intraoperative samples and postoperative drainage fluids. Antibioprophylaxis was sufficient in only 75% of deep tissue cultures and 69% of drainage fluids. Insufficient antibioprophylaxis was associated with a higher flap failure rates (odds ratio 6.3, confidence interval 1.2-41.0). CONCLUSION: After inpatient wound conditioning, bacterial load analysis of intraoperative wound tissue cultures is ineffective in order to predict flap failure rates in SCI patients with stages 3-4 pressure ulcers after flap surgery. Instead, insufficient antibioprophylaxis might be a factor contributing to flap failure.

Human mucosal CD4+ T cells but not blood CD4+ T cells respond vigorously towards CD28 engagement.

Human lamina propria T lymphocytes (LPT) possess functional properties profoundly different from those of peripheral blood T lymphocytes (PBT). While they are characterized by a low proliferative response to T cell receptor (TCR)/CD3 stimulation in vitro their responsiveness to activation through the 'co-stimulatory' CD2-receptor is enhanced when compared to PBT. In this study, we demonstrate that engagement of another co-stimulatory receptor on both LPT and PBT, namely CD28, by a single monoclonal antibody (mAb), respectively, strongly activates the former but not the latter through a PI3-kinase dependent signalling pathway leading to the production of inflammatory cytokines such as interleukin (IL)-2, tumour necrosis factor (TNF)-α, interferon (IFN)-γ and granulocyte-macrophage colony-stimulating factor (GM-CSF). In addition to the high sensitivity of LPT to CD2 stimulation, this finding supports the notion that 'non-specific/innate' mechanisms to activate T lymphocytes play a predominant role vis-à-vis'TCR driven/adaptive' responses in the intestinal mucosa. Furthermore, it suggests that results from preclinical tests for therapeutic antibodies performed with human blood derived T cells are probably insufficient to predict reactivities of tissue-resident immune cells, which--given their quantitative predominance--may critically determine the in-vivo response to such compounds.

Monitoring of plasma levels of activated protein C using a clinically applicable oligonucleotide-based enzyme capture assay.

BACKGROUND: Human-activated protein C (APC) is a serine protease with anticoagulant, anti-inflammatory and cytoprotective functions. This feature renders APC to be a promising vascular-inflammatory biomarker. OBJECTIVE: The aim of the present study was the development and validation of a technique that allows the measurement of APC plasma levels under practical laboratory conditions. METHODS/PATIENTS: Based on the APC-binding ssDNA aptamer HS02-52G we developed an oligonucleotide-based enzyme capture assay (OECA) that quantifies aptamer-captured APC through hydrolysis rates of a fluorogenic peptide substrate. After optimization of pre-analytical conditions, plasma APC levels were measured in healthy individuals and patients undergoing hip replacement surgery. RESULTS AND CONCLUSION: A combination of APC-OECA with an aprotinin-based quenching strategy allowed APC analysis with a limit of detection as low as 0.022 ± 0.005 ng mL(-1) (0.39 ± 0.10 pmol L(-1)) and a limit of quantification of 0.116 ± 0.055 ng mL(-1) (2.06 ± 0.98 pmol L(-1)). While APC plasma levels in healthy individuals fell below the quantifiable range of the APC-OECA platform, levels substantially increased in patients undergoing hip replacement surgery reaching peak values of up to 12 ng mL(-1) (214 pmol L(-1)). When normalized to the amount of thrombin generated, interindividual variabilities in the APC generating capacity were observed. In general, with a turn-around time from blood sampling to generation of test results of < 7 h, the APC-OECA platform allows sensitive and rapid determination of circulating APC levels under pathological conditions.

Up-regulation of the phosphoinositide 3-kinase pathway in human lamina propria T lymphocytes.

Human intestinal lamina propria T lymphocytes (LPT), when investigated ex vivo, exhibit functional properties profoundly different from those of peripheral blood T lymphocytes (PBT). One prominent feature represents their enhanced sensitivity to CD2 stimulation when compared to PBT. Given that LPT are hyporesponsive to T cell receptor (TCR)/CD3 stimulation, an alternative activation mode, as mimicked by CD2 triggering in vitro, may be functional in mucosal inflammation in vivo. This study provides insight into signalling events associated with the high CD2 responsiveness of LPT. When compared to PBT, LPT show an increased activation of the phosphoinositide 3/protein kinase B/glycogen synthase kinase 3beta (PI3-kinase/AKT/GSK-3beta) pathway in response to CD2 stimulation. Evidence is provided that up-regulation of this pathway contributes to the enhanced CD2-induced cytokine production in LPT. Given the importance of TCR-independent stimulation for the initiation of intestinal immune responses analysis of signalling pathways induced by 'co-stimulatory' receptors may provide valuable information for therapeutic drug design.

Signaling through the JAK/STAT pathway, recent advances and future challenges.

Investigation into the mechanism of cytokine signaling led to the discovery of the JAK/STAT pathway. Following the binding of cytokines to their cognate receptor, signal transducers and activators of transcription (STATs) are activated by members of the janus activated kinase (JAK) family of tyrosine kinases. Once activated, they dimerize and translocate to the nucleus and modulate the expression of target genes. During the past several years significant progress has been made in the characterization of the JAK/STAT signaling cascade, including the identification of multiple STATs and regulatory proteins. Seven STATs have been identified in mammals. The vital role these STATs play in the biological response to cytokines has been demonstrated through the generation of murine 'knockout' models. These mice will be invaluable in carefully elucidating the role STATs play in regulating the host response to various stresses. Similarly, the solution of the crystal structure of two STATs has and will continue to facilitate our understanding of how STATs function. This review will highlight these exciting developments in JAK/STAT signaling.

Acute abdomen in infants of adolescent mothers: diagnostic challenges.

Caring for children of adolescent parents presents unique challenges. Because adolescent parents may lack parenting skills and knowledge of medical terminology, symptoms of life-threatening illnesses may be misinterpreted. We present two cases of unexpected acute abdomen in young infants with adolescent mothers. The first case involves midgut volvulus, which was discovered during a routine newborn visit. The second case, involving pyloric stenosis, presented a clinical management challenge when the adolescent mother refused diagnostic studies.

Lipid disorders: justification of methods and goals of treatment.

Dyslipidemia is a major risk factor for coronary heart disease (CHD). While some uncertainty exists about the clinical significance of improving high-density lipoprotein cholesterol and triglyceride levels, large primary- and secondary-prevention studies aimed at lowering low-density lipoprotein cholesterol levels with statins have convincingly reduced CHD events and total mortality. Despite the strong clinical evidence and widely publicized treatment guidelines, many hyperlipidemic patients receive inadequate lipid-lowering treatment. This failure to achieve clinical treatment goals may be due to poor physician adherence to treatment guidelines, patient noncompliance, and the presence of concomitant medical conditions that modify typical hyperlipidemia management. This review considers the challenges and available strategies to optimize lipid management in patients at risk for CHD.

ABCs of cardiovascular disease risk management.

The past 20 years have witnessed a marked decline in morbidity and mortality from cardiovascular disease. This decline has been due in large part to advances in coronary risk factor modification and a better understanding of the atherosclerotic process. Compelling scientific and clinical trial evidence proves that comprehensive risk factor modification extends patient survival and reduces cardiovascular and cerebrovascular events. This article reviews the ABCs of optimal medical and lifestyle management in patients with documented atherosclerotic vascular disease as well as in those adults who are at increased risk for the development of cardiovascular disease, based on contemporary clinical trial evidence.

Thiol-mediated redox regulation of intestinal lamina propria T lymphocytes.

Intestinal lamina propria T lymphocytes (LP-Ts) have a markedly low proliferative potential both in vivo and in vitro. Here, we have identified that the capacity of antigen-presenting cells to release cysteine upon receptor-ligand interactions represents a critical parameter for proliferation of LP-Ts. The availability of cysteine is limiting for the intracellular production of glutathione, which in turn is essential for cell cycle progression. When cysteine is provided either directly or by addition of the reducing agent 2-mercaptoethanol to cystine-containing culture medium, proliferation of LP-T is fully restored. Importantly, coculture with peripheral blood monocytes that easily take up cystine, reduce cystine, and secrete cysteine also restores reactivity of LP-Ts to T cell receptor/CD3 stimulation. In marked contrast, lamina propria macrophages lack this capacity to elaborate cysteine, and thereby secure physiological unresponsiveness to antigen exposure in the intestinal microenvironment. The well-documented local recruitment of blood monocytes in inflammatory bowel disease (IBD) may thus represent an important parameter underlying hyperresponsiveness of T cells, an essential component of the pathogenesis of IBD.

In situ expression of interleukin-10 in noninflamed human gut and in inflammatory bowel disease.

A dysregulated secretion of contra-inflammatory cytokines such as interleukin-10 (IL-10) could play a role in the pathogenesis of inflammatory bowel disease (IBD). We have investigated the expression of IL-10 in gut tissues from patients with Crohn's disease (CD), ulcerative colitis (UC) and controls by mRNA in situ hybridization and immunohistochemistry. Intestinal epithelial cells were found to express IL-10 mRNA and IL-10 protein in all of the tissues investigated without any major differences in the expression patterns. However, compared with noninflamed gut, significantly increased numbers of mononuclear cells (MNCs) producing IL-10 were present in inflamed gut, both in CD and UC. This cytokine was expressed most prominently by inflammatory infiltrates enriched in macrophages, although T cells seem to contribute to its production as well. Elevated IL-10 expression in IBD was mainly detected in the submucosa, whereas IL-10 production by lamina propria cells remained comparably low. In contrast, the expression of IL-1beta mRNA was preferentially increased in the lamina propria. Our data argue against a general deficiency in IL-10 production in IBD. The results suggest rather that the local production of IL-10 by mucosal MNCs in IBD is insufficient to down-regulate pro-inflammatory cytokines such as IL-1beta in the lamina propria compartment.

T cells of the human intestinal lamina propria are high producers of interleukin-10.

BACKGROUND AND AIM: Some of the recently observed functional features characteristic of immunocompetent cells residing in the human intestinal lamina propria could be mediated by interleukin-10 (IL-10). To investigate the role of IL-10 in the human intestinal mucosa, the regulation of IL-10 production by lamina propria T lymphocytes (LPL-T) was determined and compared with that of peripheral blood T lymphocytes (PBL-T). METHODS: Following activation by using different stimuli, IL-10 release by LPL-T and PBL-T into the supernatant was measured by enzyme linked immunosorbent assay (ELISA). In parallel, cell growth was determined by [3H]-thymidine incorporation. RESULTS: Neither LPL-T nor PBL-T release IL-10 constitutively. Triggering through CD2 or the T cell receptor (TCR)/CD3 complex in the presence of autologous monocytes induces significantly greater IL-10 secretion by LPL-T than by PBL-T. Engagement of the CD45 receptor enhances IL-10 release and proliferation of CD2 triggered CD45RO+ PBL-T. In contrast, it reduces CD2 induced IL-10 production by LPL-T without altering cell growth significantly. CONCLUSIONS: Activated LPL-T release relatively high amounts of IL-10. Enhanced IL-10 production by activated LPL-T, in comparison with activated PBL-T, is not only related to the presence of a higher proportion of CD45RO+ T cells in the intestinal lamina propria, but is also caused by increased sensitivity of LPL-T to CD2 co-stimulation. The differential responsiveness of LPL-T, compared with PBL-T, to CD45 engagement demonstrates that CD45 could be involved in the altered CD2 reactivity of LPL-T.

Meningiomas: the decision not to operate.

In a consecutive series of 100 patients diagnosed with meningiomas, we advised 12 patients not to have surgery, and followed them from 3.3 to 12.8 years (mean, 8.8 years). The two determinants of this decision were either absence of related neurologic symptoms or signs and concern about high operative risk of neurologic impairment. Serial imaging studies showed meningioma growth in only one of the 12 unoperated patients and only one had convincing progression of neurologic impairment.

Hepatobiliary excretion of bile acids and rose bengal in streptozotocin-induced and genetic diabetic rats.

Divergent opinions regarding the effect of streptozotocin- (STZ) induced diabetes on bile flow rate may be due to the differing lengths of time after STZ administration at which bile flow was measured. Also, the biliary excretion of bile acids can influence the canalicular transport of several organic anions. Therefore, the hepatic clearance of the bile acid-dependent organic anion rose bengal was studied over a 30-day period in STZ-induced insulin-dependent Sprague-Dawley diabetic rats with elevated bile acid pools and in fatty noninsulin-dependent diabetic and lean Wistar rats. Excretion of total bile acids and rose bengal was higher in diabetic rats than in Sprague-Dawley control or lean or fatty Wistar rats. Depletion of bile acids for 10 hr in the 30-day STZ rat prevented the increased excretion of rose bengal. Bile flow rates in fatty and lean Wistar rats were similar to that in Sprague-Dawley controls. Increased bile acid excretion 7 and 14 days after STZ was not accompanied by the expected significant increase in bile flow, reflecting decreased bile acid-independent bile flow, regardless of method of calculation of bile flow (per g liver or per kg body weight). By 30 days, there were significant increases in bile acid excretion and bile flow. The increased clearance of rose bengal 7 days after STZ indicates that pathophysiological changes in the hepatocyte begin soon after the initiation of diabetes. Studies of taurocholate uptake into liver plasma membrane vesicles indicated that the maximal velocity of transport across the basolateral membrane was increased with no change in Km. This change was not observed in vesicles from insulin-treated diabetic rats. Therefore, studies employing STZ need to allow time for STZ toxicity to be overcome and for the pathology of diabetes to become established, to accurately reflect the diabetic condition.