Surrogate Marker Research Articles

Measurement of left atrial size as a predictor of severity of illness in sickle cell disease

BackgroundSickle cell disease (SCD) is characterized by microvascular occlusion which leads to multiorgan damage, including left ventricular diastolic dysfunction. Left ventricular diastolic dysfunction has been shown to be an independent risk factor for death in SCD patients. Left atrial dilation (LAD) has been used as a surrogate marker for identification of left ventricular diastolic dysfunction. ObjectiveInvestigate the association of LAD, as determined by echocardiography, with increased disease burden in SCD as reflected by increased emergency department (ED) utilization, increased hemolysis markers, and worsening anemia. MethodsA retrospective cohort study of patients from a single university hospital were selected from a national registry. Age, sickle cell phenotype, echocardiogram findings, ED utilization, baseline hemoglobin, and lab values needed for calculation of hemolytic index were recorded for each patient. Patients were then stratified into two distinct groups based on the presence or absence of LAD to compare ED utilization, baseline hemoglobin and hemolytic index between the two groups. Results129 patients met the criteria for inclusion with 88 having normal left atrial volume and 41 with LAD. There was a higher percentage of high ED utilizers in the LAD group compared to the normal left atrial volume group [34% vs. 17%, p = 0.03]. Average hemoglobin was lower in the LAD group compared with the normal left atrial volume group [mean 8.57 g/dL vs. 9.47 g/dL, p = 0.011]. The mean hemolytic index was higher in the LAD group when compared with the normal left atrial volume group [0.44 vs. −0.21, p < 0.001]. ConclusionsLAD was associated with higher ED utilization, lower hemoglobin level, and more hemolysis in patients with SCD.

Increased expression of formyl peptide receptor-1 by basophils from patients with mastocytosis

BackgroundSymptoms in patients with systemic mastocytosis (SM) are associated with an increase in mast cell burden and release of mast cell-derived mediators. The most frequent presentation of SM is indolent (ISM), with moderate symptoms and prognosis. Basophil numbers in these patients are generally normal. However, when examining basophil activation in patients with ISM, we noted an abnormal response to N-formylmethione-leucyl-phenylalanine (fMLP). ObjectiveTo compare basophil responsiveness to fMLP and anti-IgE in healthy volunteers and patients with ISM and relate findings to fMLP receptor (FPR) expression. MethodsBasophils isolated from peripheral blood of fifteen patients with ISM and fourteen healthy volunteers were stimulated with fMLP or anti-IgE. CD63 expression to assess basophil activation and expression of FPRs were assessed by flow cytometry. ResultsBaseline expression of CD63 on basophils was similar between healthy volunteers and patients with ISM. fMLP induced higher expression of CD63 on basophils from patients with ISM, while responses to anti-IgE were similar between groups. Basophils from patients with ISM also had higher fMLP1 receptor (FPR1) expression, while FPR2 and FPR3 were not detected. fMLP blocked the binding of anti-FPR1 antibody to FPR1, consistent with the conclusion that fMLP signals through FPR1. ConclusionsFMLP-induced basophil activation is higher in patients with ISM which is associated with an increase in FPR1 expression. Further investigation is needed to determine why FPR1 expression is elevated, whether such expression might serve as an additional surrogate marker in the diagnosis of ISM, and whether enhanced responses of basophils to fMPL might have some relationship to unexplained episodes of mediator release.

Clinical and genetic risk factors for progressive fibrosis in metabolic dysfunction-associated steatotic liver disease.

Fibrosis-4 (FIB4) is a recommended noninvasive test to assess hepatic fibrosis among patients with metabolic dysfunction-associated steatotic liver disease (MASLD). Here, we used FIB4 trajectory over time (ie, "slope" of FIB4) as a surrogate marker of liver fibrosis progression and examined if FIB4 slope is associated with clinical and genetic factors among individuals with clinically defined MASLD within the Million Veteran Program Cohort. In this retrospective cohort study, FIB4 slopes were estimated through linear regression for participants with clinically defined MASLD and FIB4 <2.67 at baseline. FIB4 slope was correlated with demographic parameters and clinical outcomes using logistic regression and Cox proportional hazard models. FIB4 slope as a quantitative phenotype was used in a genome-wide association analysis in ancestry-specific analysis and multiancestry meta-analysis using METAL. FIB4 slopes, generated from 98,361 subjects with MASLD (16,045 African, 74,320 European, and 7996 Hispanic), showed significant associations with sex, ancestry, and cardiometabolic risk factors (p < 0.05). FIB4 slopes also correlated strongly with hepatic outcomes and were independently associated with time to cirrhosis. Five genetic loci showed genome-wide significant associations (p < 5 × 10-8) with FIB4 slope among European ancestry subjects, including 2 known (PNPLA3 and TM6SF2) and 3 novel loci (TERT 5.1 × 10-11; LINC01088, 3.9 × 10-8; and MRC1, 2.9 × 10-9). Linear trajectories of FIB4 correlated significantly with time to progression to cirrhosis, with liver-related outcomes among individuals with MASLD and with known and novel genetic loci. FIB4 slope may be useful as a surrogate measure of fibrosis progression.

Protocol and rationale of the Australian multicentre registry for serial cardiac computed tomography angiography (ARISTOCRAT): a prospective observational study of the natural history of pericoronary adipose tissue attenuation and radiomics.

Vascular inflammation plays a crucial role in the development of atherosclerosis and atherosclerotic plaque rupture resulting in acute coronary syndrome (ACS). Pericoronary adipose tissue (PCAT) attenuation quantified from routine coronary computed tomography angiography (CCTA) has emerged as a promising non-invasive imaging biomarker of coronary inflammation. However, a detailed understanding of the natural history of PCAT attenuation is required before it can be used as a surrogate endpoint in trials of novel therapies targeting coronary inflammation. This article aims to explore the natural history of PCAT attenuation and its association with changes in plaque characteristics. The Australian natuRal hISTOry of periCoronary adipose tissue attenuation, RAdiomics and plaque by computed Tomographic angiography (ARISTOCRAT) registry is a multi-centre observational registry enrolling patients undergoing clinically indicated serial CCTA in 9 centres across Australia. CCTA scan parameters will be matched across serial scans. Quantitative analysis of plaque and PCAT will be performed using semiautomated software. The primary endpoint is to explore temporal changes in patient-level and lesion-level PCAT attenuation by CCTA and their associations with changes in plaque characteristics. Secondary endpoints include evaluating: (I) impact of statin therapy on PCAT attenuation and plaque characteristics; and (II) changes in PCAT attenuation and plaque characteristics in specific subgroups according to sex and risk factors. ARISTOCRAT will further our understanding of the natural history of PCAT attenuation and its association with changes in plaque characteristics. This study has been prospectively registered with the Australia and New Zealand Clinical Trials Registry (ACTRN12621001018808).

The Prodrug DHED Delivers 17β-Estradiol into the Retina for Protection of Retinal Ganglion Cells and Preservation of Visual Function in an Animal Model of Glaucoma.

We report a three-pronged phenotypic evaluation of the bioprecursor prodrug 10β,17β-dihydroxyestra-1,4-dien-3-one (DHED) that selectively produces 17β-estradiol (E2) in the retina after topical administration and halts glaucomatous neurodegeneration in a male rat model of the disease. Ocular hypertension (OHT) was induced by hyperosmotic saline injection into an episcleral vein of the eye. Animals received daily DHED eye drops for 12 weeks. Deterioration of visual acuity and contrast sensitivity by OHT in these animals were markedly prevented by the DHED-derived E2 with concomitant preservation of retinal ganglion cells and their axons. In addition, we utilized targeted retina proteomics and a previously established panel of proteins as preclinical biomarkers in the context of OHT-induced neurodegeneration as a characteristic process of the disease. The prodrug treatment provided retina-targeted remediation against the glaucomatous dysregulations of these surrogate endpoints without increasing circulating E2 levels. Collectively, the demonstrated significant neuroprotective effect by the DHED-derived E2 in the selected animal model of glaucoma supports the translational potential of our presented ocular neuroprotective approach owing to its inherent therapeutic safety and efficacy.

EPM2AIP1 immunohistochemistry is inadequate as a surrogate marker for MLH1 promoter hypermethylation testing in colorectal cancer

MLH1 promoter hypermethylation (MPH) analysis is an essential step in the universal tumor testing algorithm for Lynch syndrome, the most common inherited predisposition to colorectal cancer (CRC). MPH usually indicates sporadic CRC. EPM2AIP1 gene shares the same promoter as MLH1, therefore MPH should also silence EPM2AIP1 transcription leading to loss of protein expression on immunohistochemistry (IHC). It has been previously reported that EPM2AIP1 IHC can be used as a surrogate for MPH in endometrial cancer. Our goal was to evaluate the feasibility of EPM2AIP1 IHC as a surrogate for MPH in CRC. 101 microsatellite instable CRC cases were selected, including 19 cases from whole tumor sections and 82 cases from tissue microarrays. 74 cases were with MPH and 27 without MPH. All 74 cases with MPH showed absent MLH1 by IHC, but only 47 (64%) exhibited loss of expression of EPM2AIP1. Of the 27 cases without MPH, 9 (33%) cases had unexpected loss of EPM2AIP1 expression. Of note, 10 cases were MLH1-mutated Lynch syndrome without MPH, and 2 of these cases showed unexpected loss of EPM2AIP1 staining. Of the 6 cases with double somatic mutations of MLH1 gene (without MPH), only 4 cases demonstrated intact expression of EPM2AIP1 as expected. Taken together, EPM2AIP1 loss was 64% sensitive and 67% specific for MPH, with an accuracy of 64%. We conclude that, unless stain quality improves with different clones or platforms, EPM2AIP1 IHC will likely not be useful as a surrogate test for MPH in CRC.

Impact of opioid analgesics on survival in cancer patients receiving immune checkpoint inhibitors

PurposeThis study aimed to assess the effects of concurrent opioid analgesic (OA) use with immune checkpoint inhibitors (ICIs) on progression-free survival (PFS) and overall survival (OS).MethodsIn this observational retrospective study, we included advanced cancer patients who received ICIs at Hacettepe University Hospital’s Department of Medical Oncology between June 2018 and January 2023.ResultsOur study included 375 recurrent or metastatic cancer patients treated with ICIs in the first, second line, or beyond. There were no significant differences between the OA-treated and OA-untreated groups regarding median age, age group, gender, primary tumor location, ICI type, or the presence of baseline liver and lung metastases. However, the OA-treated group exhibited a significantly higher proportion of patients who had received three or more prior treatments before initiating ICIs (p = 0.015). OA-Untreatment was significantly correlated with prolonged mPFS (6.83 vs. 4.30 months, HR 0.59, 95% CI 0.44–0.79, p < 0.001) and mOS (17.05 vs. 7.68 months, HR 0.60, 95% CI 0.45–0.80, p < 0.001).ConclusionsOur study demonstrates an association between the concurrent use of OAs and reduced OS and PFS in patients treated with ICIs. While OA treatment serves as a surrogate marker for higher disease burden, it may also suggest a potential biological relationship between opioids and immunotherapy efficacy.

Mild Systemic Inflammation Increases Erythrocyte Fragility.

There is growing evidence that inflammation impairs erythrocyte structure and function. We assessed the impact of mild systemic inflammation on erythrocyte fragility in three different settings. In order to investigate causation, erythrocyte osmotic fragility was measured in mice challenged with a live attenuated bacterial strain to induce low-grade systemic inflammation; a significant increase in erythrocyte osmotic fragility was observed. To gather evidence that systemic inflammation is associated with erythrocyte fragility in humans, two observational studies were conducted. First, using a retrospective study design, the relationship between reticulocyte-based surrogate markers of haemolysis and high-sensitivity C-reactive protein was investigated in 9292 healthy participants of the UK Biobank project. Secondly, we prospectively assessed the relationship between systemic inflammation (measured by the urinary neopterin/creatinine ratio) and erythrocyte osmotic fragility in a mixed population (n = 54) of healthy volunteers and individuals with long-term medical conditions. Both human studies were in keeping with a relationship between inflammation and erythrocyte fragility. Taken together, we conclude that mild systemic inflammation increases erythrocyte fragility and may contribute to haemolysis. Further research is needed to assess the molecular underpinnings of this pathway and the clinical implications in inflammatory conditions.

Inter-reader reproducibility of a radiographic grading system for usual interstitial pneumonitis validates its use as a surrogate endpoint in clinical trials

AbstractBackgroundThe primary purpose of this study was to assess the interreader reliability of a grading system for UIP based on the quantification of normal lung. This grading system considers each of the following lung regions: right upper and middle lobes, right lower lobe, left upper lobe, and left lower lobe. Each is assigned a grade based on the following: 0: 0% normal lung; 1: 1–49% normal lung; 2: 50–74% normal lung; 3: 75–89% normal lung; 4: 90–99% normal lung; 5: 100% normal lung. The secondary purpose was to compare the grades rendered by non-cardiothoracic subspecialty trained radiologists to grades established by cardiothoracic radiologists, which were considered the gold standard.MethodsChest CT images of patients were obtained by searching the radiology record system for the terms “usual interstitial pneumonia” and “UIP”. Each case was confirmed by radiologist review; pathology was not assessed given the small fraction of cases that underwent biopsy due to the high risk of complications in patients with fibrotic lung disease. Two cardiothoracic radiologists evaluated each CT and reached a consensus grade. Two different radiologists who were not subspecialty trained in cardiothoracic radiology independently graded each case. Spearman correlation analysis was performed to compare the two reader's grades as well as each reader's grade independently to the gold standard score.ResultsOur analysis demonstrated a strongly positive statistically significant interreader correlation coefficient (RS) = 0.7062, P &lt; 0.001. Our analysis of each reader compared to the gold standard demonstrated an Rs = 0.77559, P &lt; 0.001 and an RS = 0.69958, P &lt; 0.001 for readers 1 and 2, respectively, both representing statistically significant strongly positive correlations.ConclusionsThese results demonstrate strong interreader reproducibility and show that radiologists without subspecialty training in cardiothoracic radiology render grades that correlate strongly with those given by cardiothoracic radiologists. These findings support the use of this grading system for UIP both to monitor clinical progression and as a surrogate endpoint for antifibrotic drug trials.

A proteomic signature of healthspan.

The focus of aging research has shifted from increasing lifespan to enhancing healthspan to reduce the time spent living with disability. Despite significant efforts to develop biomarkers of aging, few studies have focused on biomarkers of healthspan. We developed a proteomics-based signature of healthspan (healthspan proteomic score (HPS)) using data from the UK Biobank Pharma Proteomics Project (53,018 individuals and 2920 proteins). A lower HPS was associated with higher mortality risk and several age-related conditions, such as COPD, diabetes, heart failure, cancer, myocardial infarction, dementia, and stroke. HPS showed superior predictive accuracy for these outcomes compared to chronological age and biological age measures. Proteins associated with HPS were enriched in hallmark pathways such as immune response, inflammation, cellular signaling, and metabolic regulation. Our findings demonstrate the validity of HPS, making it a valuable tool for assessing healthspan and as a potential surrogate marker in geroscience-guided studies.

Triglyceride-glucose index as a potential predictor of major adverse cardiovascular and cerebrovascular events in patients with coronary heart disease complicated with depression.

Triglyceride-glucose (TyG) index is a surrogate marker of insulin resistance and metabolic abnormalities, which is closely related to the prognosis of a variety of diseases. Patients with both CHD and depression have a higher risk of major adverse cardiovascular and cerebrovascular events (MACCE) and worse outcome. TyG index may be able to predict the adverse prognosis of this special population. The retrospective cohort study involved 596 patients with both CHD and depression between June 2013 and December 2023. The primary outcome endpoint was the occurrence of MACCE, including all-cause death, stroke, MI and emergent coronary revascularization. The receiver operating characteristic (ROC) curve, Cox regression analysis, Kaplan-Meier survival analysis, and restricted cubic spline (RCS) analysis were used to assess the correlation between TyG index and MACCE risk of in patients with CHD complicated with depression. With a median follow-up of 31 (15-62) months, MACCE occurred in 281(47.15%) patients. The area under the ROC curve of TyG index predicting the risk of MACCE was 0.765(0.726-0.804) (P<0.01). Patients in the high TyG index group(69.73%) had a significantly higher risk of developing MACCE than those in the low TyG index group(23.63%) (P<0.01). The multifactorial RCS model showed a nonlinear correlation (nonlinear P<0.01, overall P<0.01), with a critical value of 8.80 for the TyG index to predict the occurrence of MACCE. The TyG index was able to further improve the predictive accuracy of MACCE. TyG index is a potential predictor of the risk of MACCE in patients with CHD complicated with depression.

Radiation and chemo-sensitizing effects of DNA-PK inhibitors are proportional in tumors and normal tissues.

Inhibitors of DNA-PK sensitize cancers to radiotherapy and DNA-damaging chemotherapies, with candidates in clinical trials. However, the degree to which DNA-PK inhibitors also sensitize normal tissues remains poorly characterized. In this study we compare tumor growth control and normal tissue sensitization following DNA-PK inhibitors in combination with radiation and etoposide. FaDu tumor xenografts implanted in mice were treated with 10 - 15Gy irradiation ± 3 - 100 mg/kg AZD7648. A dose-dependent increase in time to tumor volume doubling following AZD7648 was proportional to an increase in toxicity scores of the overlying skin. Similar effects were seen in the intestinal jejunum, tongue and FaDu tumor xenografts of mice assessed for proliferation rates at 3.5 days after treatment with etoposide or 5Gy whole body irradiation ± DNA-PK inhibitors AZD7648 or peposertib (M3814). Additional organs were examined for sensitivity to DNA-PK inhibitor activity in ATM-deficient mice, where DNA-PK activity is indicated by surrogate marker γH2AX. Inhibition was observed in heart, brain, pancreas, thymus, tongue and salivary glands of ATM-deficient mice treated with the DNA-PK inhibitors relative to radiation alone. Similar reductions are also seen in ATM-deficient FaDu tumor xenografts where both pDNA-PK and γH2AX staining could be performed. Conclusions: DNA-PK inhibitor-mediated sensitization to radiation and DNA-damaging chemotherapy is not limited to tumor tissues, but also extends to normal tissues sustaining DNA damage. These data are useful for interpretation of the sensitizing effects of DNA damage repair inhibitors, where a therapeutic index showing greater cell-killing effects on cancer cells is crucial for optimal clinical translation.

The role of a radiopaque peri-rectal hydrogel spacer in aiding accurate daily image-guidance for prostate stereotactic radiotherapy.

Precise patient positioning with image guidance (IGRT) is essential for safe prostate radiotherapy. We present the first report of utilizing a CT-visible hydrogel spacer, used to decrease rectal radiation dose, as a surrogate fiducial marker to aid in daily IGRT with cone-beam CT (CBCT) in stereotactic radiotherapy (SABR) for prostate cancer. Prior to CT simulation, patients underwent placement of three intraprostatic gold fiducial markers and radiopaque hydrogel spacer per standard practice. At treatment, after initial setup, a CBCT was acquired and fused to the planning CT based on 3-dimensional matching of the spacer. A second alignment was then performed based on the fiducial markers. The six directional shifts (three linear and three rotational) were recorded, and the differences compared. 140 individual fractions across 41 consecutive patients were evaluated. Mean/median differences between hydrogel spacer-based and fiducial-based alignment in linear (vertical, longitudinal, lateral) and rotational (rotation, pitch, roll) shifts were 0.9/0.6mm, 0.8/0.5mm, and 0.6/0.4mm, and 0.38/0, 0.62/0, and 0.35/0 degrees, respectively. No difference was observed in 9.9%, 22.9%, and 22.14% of linear shifts, and 65.7%, 65%, and 66.4% rotational shifts, respectively. Significantly smaller differences were observed in the latter 70 fractions vs. the former, and results were consistent across evaluators. For precise daily IGRT with CBCT for prostate SABR, alignment using a radiopaque hydrogel spacer was highly comparable to intraprostatic fiducial markers. This represents the first report supporting an additional indication of IGRT for a CT-visible hydrogel spacer, to further enhance treatment accuracy and potentially obviate the need for the additional fiducial marker procedure.

Selenium levels and their association with thyroid autoimmunity and severe preeclampsia in pregnancy: Insights from a prospective ideal breast milk cohort study.

This study aimed to assess selenium status in South Korean pregnant women and its impact on maternal thyroid function and pregnancy outcomes. 'Ideal Breast Milk (IBM) Cohort Study' included 367 pregnant women out of 442 participants and categorized into three groups based on plasma selenium levels: deficient (< 70 μg/L), suboptimal (70-99 μg/L), and optimal (≥ 100 μg/L). During the second or third trimester, various blood parameters, including selenium, thyroid-stimulating hormone, free T4, free T3, and anti-thyroid peroxidase antibody levels, were measured. Thyroid parenchymal echogenicity was assessed as another surrogate marker for thyroid autoimmunity using ultrasonography. The median plasma selenium was 98.8 (range: 46.7-206.4) μg/L, and 30 individuals (8%) were categorized as deficient, while 164 (45%) were classified in the suboptimal group. Selenium deficiency was associated with markers of autoimmune thyroiditis, including positive anti-thyroid peroxidase antibody results (13.3 (deficient) vs 4.6 (optimal) %, P = 0.031) and thyroid parenchymal heterogeneity on ultrasound (33.3 (deficient) vs 14.6 (suboptimal) vs 17.3 (optimal) %, P = 0.042), independently of gestational age. The incidence of severe preeclampsia was higher in the group not taking selenium supplements, particularly among those with twin pregnancies, compared to the group taking selenium supplements (0 (selenium supplement) vs 9.0 (no supplement) %, P = 0.015). Pregnant women experience mild selenium deficiency, which can lead to significant health issues including maternal thyroid autoimmunity and obstetrical complications during pregnancy. Guidelines for appropriate selenium intake according to the stage of pregnancy and the number of fetuses are needed.

Platelet Indices as Novel Surrogate Markers for the Prognosis of COVID-19 Infection: An Observational Study.

Background The new severe acute respiratory syndromecoronavirus 2 (SARS-CoV-2) causes severe acute respiratory illness accountable for causing the coronavirus disease 2019 (COVID-19) illness. Thrombotic issues, acute respiratory distress syndrome (ARDS), and cytokine storm are significant contributors to morbidity and mortality in patients with COVID-19. Elevated D-dimer levels and prothrombin times are further indicators of abnormal coagulation parameters in COVID-19 patients. This study aimed to study the platelet indices as prognostic markers in COVID-19 infection. Methods In this prospective observational study, 150 real-time reverse transcription-polymerase chain reaction (RT-PCR)-positive COVID-19 patients were enrolled between October 2020 and September 2021. All the subjects were screened and explained the study procedure in their native language. Following enrolment, a detailed history and physical examination were performed. Subsequently, laboratory investigations were performed, and patients were subjected to high-resolution computed tomography (HRCT) examination to classify patients into mild, moderate, and severe according to the severity of the illness. The platelet indices taken into account were plateletcrit (PCT) in percentage, platelet count (PLT) in lakh per microlitre, mean platelet volume (MPV) in femtolitres, and platelet distribution width (PDW) in femtolitres. Results The mean PLT was significantly greater among survivors than non-survivors (2.03 ± 0.72 versus 1.76 ± 0.47; p-value = 0.018). The mean MPV (10.42 ± 0.53 versus 9.22 ± 0.64; p-value <0.0001) and PDW (17.99 ± 1.53 versus 16.54 ± 0.91 fl; p-value <0.0001) were significantly greater among non-survivors than survivors. However, the mean PCT was significantly greater among survivors than non-survivors (0.22 ± 0.03% versus 0.18 ± 0.33%; p-value <0.0001).At a cut-off of 0.213, the sensitivity and specificity of PCT in predicting death were found to be 79.2% and 74.5%, respectively. At a cut-off of 16.75, the sensitivity and specificity of PDW in predicting death were found to be 68.8% and 59.8%, respectively. The findings demonstrated a relationship between elevated MPV and PDW and mortality and severe COVID-19 infection. Increased PCT was connected to higher survival, with a specificity and sensitivity of 87.5% and 75.5%, respectively, and MPV >9.75 may predict death. PDW >16.75 exhibited a specificity and sensitivity of 68.8% and 59.8%, respectively, in predicting death. With comparable sensitivity and specificity of 79.2% and 74.5%, PCT >0.213 may predict death. Conclusion In severely sick COVID-19 patients, platelet indices should be routinely calculated and can be utilized as simple, low-cost prognostic indicators.

Predicting Efficacy of a Purified Inactivated Zika Virus Vaccine in Flavivirus-Naïve Humans Using an Immunological Correlate of Protection in Non-Human Primates.

A traditional phase 3 clinical efficacy study for a Zika vaccine may be unfeasible because of the current low transmission of Zika virus (ZIKV). An alternative clinical development approach to evaluate Zika vaccine efficacy (VE) is therefore required, delineated in the US FDA's Accelerated Approval Program for licensure, which utilizes an anti-Zika neutralizing antibody (Zika NAb) titer correlated with non-human primate (NHP) protection as a surrogate endpoint. In this accelerated approval approach, the estimation of VE would be inferred from the percentage of phase 3 trial participants achieving the established surrogate endpoint. We provide a statistical framework to predict the probability of protection for human participants vaccinated with a purified inactivated ZIKV vaccine (TAK-426), in the absence of VE measurements, using NHP data under a single-correlate model. Based on a logistic regression (LR) with bias-reduction model, a probability of 90% protection in humans is expected with a ZIKV NAb geometric mean titer (GMT) ≥ 3.38 log10 half-maximal effective concentration (EC50). The predicted probability of protection of TAK-426 against ZIKV infection was determined using the two-parameter LR model that fit the calculated VE in rhesus macaques and the flavivirus-naïve phase 1 trial participants' ZIKV NAb GMTs log10 EC50, measured by a ZIKV reporter virus particle assay, at 1 month post dose 2. The TAK-426 10 µg dose predicted a probability of protection from infection of 98% among flavivirus-naïve phase 1 trial participants.

Reduced olfactory bulb volume accompanies olfactory dysfunction after mild SARS-CoV-2 infection

Despite its high prevalence, the determinants of smelling impairment in COVID-19 remain not fully understood. In this work, we aimed to examine the association between olfactory bulb volume and the clinical trajectory of COVID-19-related smelling impairment in a large-scale magnetic resonance imaging (MRI) analysis. Data of non-vaccinated COVID-19 convalescents recruited within the framework of the prospective Hamburg City Health Study COVID Program between March and December 2020 were analyzed. At baseline, 233 participants underwent MRI and neuropsychological testing as well as a structured questionnaire for olfactory function. Between March and April 2022, olfactory function was assessed at follow-up including quantitative olfactometric testing with Sniffin’ Sticks. This study included 233 individuals recovered from mainly mild to moderate SARS-CoV-2 infections. Longitudinal assessment demonstrated a declining prevalence of self-reported olfactory dysfunction from 67.1% at acute infection, 21.0% at baseline examination and 17.5% at follow-up. Participants with post-acute self-reported olfactory dysfunction had a significantly lower olfactory bulb volume at baseline than normally smelling individuals. Olfactory bulb volume at baseline predicted olfactometric scores at follow-up. Performance in neuropsychological testing was not significantly associated with the olfactory bulb volume. Our work demonstrates an association of long-term self-reported smelling dysfunction and olfactory bulb integrity in a sample of individuals recovered from mainly mild to moderate COVID-19. Collectively, our results highlight olfactory bulb volume as a surrogate marker that may inform diagnosis and guide rehabilitation strategies in COVID-19.

Kisspeptin signaling in astrocytes modulates the reproductive axis.

Reproduction is safeguarded by multiple, often cooperative regulatory networks. Kisspeptin signaling, via KISS1R, plays a fundamental role in reproductive control, primarily by regulation of hypothalamic GnRH neurons. We disclose herein a pathway for direct kisspeptin actions in astrocytes that contributes to central reproductive modulation. Protein-protein-interaction and ontology analyses of hypothalamic proteomic profiles after kisspeptin stimulation revealed that glial/astrocyte markers are regulated by kisspeptin in mice. This glial-kisspeptin pathway was validated by the demonstrated expression of Kiss1r in mouse astrocytes in vivo and astrocyte cultures from humans, rats and mice, where kisspeptin activated canonical intracellular signaling-pathways. Cellular co-expression of Kiss1r with the astrocyte markers, GFAP and S100-β, occurred in different brain regions, with higher percentage in Kiss1- and GnRH-enriched areas. Conditional ablation of Kiss1r in GFAP-positive cells, in the G-KiRKO mouse, altered gene expression of key factors in PGE2 synthesis in astrocytes, and perturbed astrocyte-GnRH neuronal appositions, as well as LH responses to kisspeptin and LH pulsatility, as surrogate marker of GnRH secretion. G-KiRKO mice also displayed changes in reproductive responses to metabolic stress induced by high-fat diet, affecting female pubertal onset, estrous cyclicity and LH-secretory profiles. Our data unveil a non-neuronal pathway for kisspeptin actions in astrocytes, which cooperates in fine-tuning the reproductive axis and its responses to metabolic stress.

Pathophysiology, Diagnosis, Prognosis, and Prevention of Poststroke Epilepsy: Clinical and Research Implications.

Poststroke epilepsy (PSE) is associated with higher mortality and poor functional and cognitive outcomes in patients with stroke. With the remarkable development of acute stroke treatment, there is a growing number of survivors with PSE. Although approximately 10% of patients with stroke develop PSE, given the significant burden of stroke worldwide, PSE is a significant problem in stroke survivors. Therefore, the attention of health policymakers and significant funding are required to promote PSE prevention research. The current PSE definition includes unprovoked seizures occurring more than 7 days after stroke onset, given the high recurrence risks of seizures. However, the pathologic cascade of stroke is not uniform, indicating the need for a tissue-based approach rather than a time-based one to distinguish early seizures from late seizures. EEG is a commonly used tool in the diagnostic work-up of PSE. EEG findings during the acute phase of stroke can potentially stratify the risk of subsequent seizures and predict the development of poststroke epileptogenesis. Recent reports suggest that cortical superficial siderosis, which may be involved in epileptogenesis, is a promising marker for PSE. By incorporating such markers, future risk-scoring models could guide treatment strategies, particularly for the primary prophylaxis of PSE. To date, drugs that prevent poststroke epileptogenesis are lacking. The primary challenge involves the substantial cost burden due to the difficulty of reliably enrolling patients who develop PSE. There is, therefore, a critical need to determine reliable biomarkers for PSE. The goal is to be able to use them for trial enrichment and as a surrogate outcome measure for epileptogenesis. Moreover, seizure prophylaxis is essential to prevent functional and cognitive decline in stroke survivors. Further elucidation of factors that contribute to poststroke epileptogenesis is eagerly awaited. Meanwhile, the regimen of antiseizure medications should be based on individual cardiovascular risk, psychosomatic comorbidities, and concomitant medications. This review summarizes the current understanding of poststroke epileptogenesis, its risks, prognostic models, prophylaxis, and strategies for secondary prevention of seizures and suggests strategies to advance research on PSE.

Development and Evaluation of Vegan Yogurts and Sour Milk Alternatives from White Lupin (Lupinus albus L.)

Cow milk allergy (CMA) triggers a clinically abnormal immunological response to cow milk proteins. To address this issue, extensive studies have explored milk alternatives from various animal and plant sources. This study introduces a method for producing white lupin milk, resulting in fermented dairy-like products (vegan yogurt and sour milk alternatives). Four commercial yogurt cultures, including two mesophilic (CHN-11, CHN-22) and two thermophilic (YC-380, YC-X11) mixed bacterial cultures, were tested, with thermophilic ones yielding superior sensory outcomes for lupin-based yogurt alternatives. Incorporating inulin (2%) enhanced sensory appeal, particularly evident in strawberry and peach-flavoured variants, which achieved sensory scores comparable to cow milk yogurts. Furthermore, white lupin-based yogurts demonstrated superior water-holding capacity (up to 47.11 g/100 g in comparison with 42.35 g/100 g measured for cow milk yogurt), influencing texture and mouthfeel. They also exhibited favourable fatty acid profiles, notably rich in beneficial unsaturated fatty acids such as linoleic and linolenic acid (up to 10.15% and 8.43%, respectively), indicating potential health benefits. Sensory evaluation underscored the impact of starter cultures on product attributes, with certain cultures yielding more favourable results. In conclusion, white lupin emerges as a promising alternative protein source with the potential to produce high-quality dairylike products. While white lupin-based products hold promise as functional foods for individuals with specific dietary needs, further research is necessary to address potential allergenic concerns associated with white lupin proteins.