Serum Samples Research Articles

Serologically Confirmed Human Leptospirosis in Colombia, 2015-2020.

Leptospirosis, a bacterial infection transmitted through contact with infected animals or contaminated water sources, imposes a substantial health burden in Colombia. Since 2007, the National Institute of Health (INS) has mandated the notification and confirmation of all suspected leptospirosis cases. This passive surveillance program employs the microscopic agglutination test (MAT) on serum samples to ascertain confirmed cases of leptospirosis infection. However, the absence of a robust surveillance system has hindered our comprehensive understanding of the morbidity, mortality, geographical distribution, species/serovars, and strains responsible for severe disease. Our study aimed to provide an epidemiological overview of MAT-confirmed human leptospirosis cases reported over 6 years (2015-2020) in Colombia. In addition, we offer insights into the status of leptospirosis in the country, focusing on risk factors and proposing potential improvements for diagnosis and disease management. During the 6-year surveillance period, the laboratory at the INS received 3,535 serum samples from suspected human leptospirosis cases, with 880 (25%) confirmed through MAT. The incidence of leptospirosis was calculated at 1.9 cases per 100,000 people, with a higher prevalence among men (82.1%). Furthermore, 54 (6.1%) deaths were confirmed as leptospirosis, and cases were documented across nearly all regions of Colombia. Our findings emphasize the urgent need to strengthen leptospirosis laboratory surveillance, implement effective prevention measures, and enhance diagnostic capabilities in Colombia. The analysis conducted in this study provides the groundwork for estimating the impact of leptospirosis and raises awareness of its significance in public health.

Determination of Gb3 and Lyso-Gb3 in Fabry Disease-Affected Patients by LC-MRM/MS

Limited or absent activity of the enzyme α-galactosidase A (α-Gal A), due to mutation in the related gene on the X chromosome, leads to the development of a rare hereditary and genetic disease known as Fabry disease (FD). This pathology involves a progressive accumulation in various organs of the substrates of the enzyme e.g., globotriaosylceramide (Gb3) and its deacylated form, globotriaosylsphingosine (Lyso-Gb3), suggesting these molecules as biomarkers of Fabry disease. The present paper describes the development of an analytical strategy for the identification and quantification of Gb3 and Lyso-Gb3, in serum and blood samples by using liquid chromatography (LC) coupled to mass spectrometry in multiple reaction monitoring (MRM/MS) ion mode. The best experimental conditions were obtained by extracting the glycolipids with chloroform/methanol/H2O (2/1/0.3) and by separating them on a C4 column with a linear gradient (A: H2O with 2 mM ammonium formate. B: methanol with 1 mM ammonium formate, both acidified with 0.2% formic acid). The best transitions (a combination of precursor and fragment ions—m/z) were 786.8 m/z > 268.3 m/z for Lyso-GB3, 1137.3 m/z > 264.3 m/z for Gb3, 1039.3 m/z > 264.4 m/z for N-heptadecanoyl-ceramide trihexoside, and 843.5 m/z > 264.3 m/z for N-glycinated lyso-ceramide trihexoside, the latter being used as an internal standard. The developed method provided a reliable, fast, and effective procedure for direct measurements of GB3 and Lyso-GB3 in serum and blood for diagnosis of Fabry disease, suggesting this method as a complementary assay to the current enzymatic test. Therefore, this approach could open new insights into the clinical diagnostics of lysosomal storage disorders.

Inflammation-Derived and Clinical Indicator-Based Predictive Model for Ischemic Stroke Recovery.

Neuroinflammatory responses are closely associated with poststroke prognosis severity. This study aimed to develop a predictive model, combining inflammation-derived markers and clinical indicators, for distinguishing functional outcomes in patients with subacute ischemic stroke. Based on activities of daily living assessments, ischemic stroke participants were categorized into groups with little effective (LE) recovery and obvious effective (OE) recovery. Initial biocandidates were identified by overlapping differentially expressed proteins from proteomics of clinical serum samples (5 LE, 5 OE, and 6 healthy controls) and differentially expressed genes from an RNA sequence of the ischemic cortex in middle cerebral artery occlusion mice (n=3). Multidimensional validations were conducted in ischemia-reperfusion models and a clinical cohort (15 LE, 11 OE, and 18 healthy controls). Models of robust biocandidates combined with clinical indicators were developed with machine learning in the training data set and prediction in another test data set (15 LE and 11 OE). We identified 194 differentially expressed proteins (LE versus healthy controls) and 174 differentially expressed proteins (OE versus healthy controls) in human serum, and 5121 differentially expressed genes (day 3) and 5906 differentially expressed genes (day 7) in middle cerebral artery occlusion mice cortex. Inflammation-derived biomarkers TIMP1 (tissue inhibitor metalloproteinase-1) and galactosidase-binding protein LGLAS3 (galectin-3) exhibited robust increases under ischemic injury in mice and humans. TIMP1 and LGALS3 coupled with clinical indicators (hemoglobin, low-density lipoprotein cholesterol, and uric acid) were developed into a combined model for differentiating functional outcome with high accuracy (area under the curve, 0.8). The combined model is a valuable tool for evaluating prognostic outcomes, and the predictive factors can facilitate development of better treatment strategies.

Performance evaluation of microfluidic microplate-based fluorescent ELISA for qualitative detection of SARS-CoV-2–specific IgG and IgM

We evaluated the diagnostic performance of newly developed microfluidic microplate-based fluorescent ELISA for anti-SARS-CoV-2 antibody detection: the Veri-Q opti COVID-19 IgG and IgM ELISAs (hereafter, “Opti IgG/M”; MiCo BioMed, Gyeonggi-do, Republic of Korea), in comparison with conventional ELISAs. A total of 270 serum samples were analyzed, among which 90 samples were serially obtained from 25 COVID-19 patients. Another 180 samples were collected from 180 SARS-CoV-2–negative individuals. As comparative assays, we used SCoV-2 Detect IgG/M ELISA (hereafter, “InBios IgG/M”; InBios, Seattle, WA, USA) and Veri-Q COVID-19 IgG/IgM ELISA (hereafter, “Veri-Q IgG/M”; MiCo BioMed). Compared with conventional ELISAs, the Opti IgG yielded 97.1–100.0% positive percent agreement, 95.2–98.0% negative percent agreement, 96.3–97.8% total percent agreement, and kappa values of 0.90–0.94. Between the Opti IgM and the InBios IgM, the values were 93.7%, 96.6%, 95.9%, and 0.89, respectively. For the Opti IgG, sensitivities for the samples collected from 0–7, 8–14, 15–21, and ≥ 22 days after symptom onset were 40.0, 58.3, 94.1, and 100.0%, respectively. The values for the Opti IgM were 30.0, 54.2, 88.2, and 80%, respectively. The diagnostic specificities of the Opti IgG and IgM were 99.4 and 97.2%, respectively. The microfluidic microplate-based fluorescent ELISAs showed comparable diagnostic performance to conventional ELISAs for detecting anti-SARS-CoV-2 antibodies. With the combination of high throughput, a simplified workflow, and the ability to analyze reduced volumes, this new technology has great potential for improving SARS-CoV-2 serologic testing.

Graphene-based field-effect transistor biosensor for prostate-specific antigen detection

The development of a graphene-based field-effect transistor (GFET) aptasensor for prostate-specific antigen (PSA) detection. We present the novel use of 1-pyrenebutyric acid N-hydroxysuccinimide ester (PBASE) to functionalize the graphene surface, enabling covalent bonding of amine-functionalized PSA-binding aptamers. Under optimized conditions, the shift of the GFET aptasensor’s Dirac point voltage exhibited a systematic variation with PSA concentrations. The sensor demonstrated a relatively wide linear dynamic range spanning from 100 fM to 100 nM, with a detection limit of 3.5 pM. Importantly, it displayed satisfactory specificity against potential interfering proteins and demonstrated good reproducibility and stability. Furthermore, we successfully applied the proposed method for the quantification of PSA in human serum samples, indicating its potential for bioanalysis and clinical diagnostics. The GFET aptasensor’s potential in medical diagnostics and personalized healthcare, positioning it as a promising tool for rapid and accurate biomarker detection.

Comparison of in-house enzyme-linked immunosorbent assay (ELISA) and six commercial ELISAs for Detection of antibodies to Bordetella pertussis

Enzyme-linked immunosorbent assays (ELISA) are currently the method of choice for the serodiagnosis of pertussis and play a key role in the diagnosis of pertussis in adolescents and adults, as well as in epidemiological studies. In the present study, the in-house developed indirect ELISA was comparatively evaluated with six commercial kits from various manufacturers. Antipertussis antibodies were measured in 40 serum samples from patients with clinical symptoms of respiratory tract infection, in two WHO standards, and in seven human ECDC control sera. IgA and IgG antibodies were detected at a diagnostically significant level by different ELISA kits of 5.0% to 27.0% and 12.0% to 70.0% of patients' sera, appropriately. The analysis of results carried out with six commercial kits showed only 17.5% consistent results in class IgG (either clearly positive or negative). The average percentage of errors in the level of antibodies determined in the control samples, reference serum samples, differed quite significantly and ranged from 9.5% to 35.4% depending on the kit. This poor correlation of the results obtained on various serological tests intended for the serodiagnosis of pertussis may cause very serious diagnostic problems, especially when examining a serum sample obtained once during the course of the disease.

Animal and organoid models to elucidate the anti-fibrotic effect of steroid on biliary atresia

PurposeWe performed animal and organoid study to evaluate the anti-fibrotic effect of steroid on biliary atresia (BA) and the underlying patho-mechanism.MethodsBA animal models were created by inoculation of mice on post-natal day 1 with rhesus rotavirus (RRV). They received either 20 µl phosphate-buffered saline (PBS) or steroid from day 21 to day 34. On day 34, their serum samples were collected for hormonal markers. Necrosis, fibrosis and CK 19 expression in the liver were evaluated. Liver organoids were developed and their morphology as well as bulk RNA sequencing data were analyzed.ResultsTwenty-four mice developed BA features after RRV injection and were equally divided into steroid and PBS groups. On day 34, the weight gain of steroid group increased significantly than PBS group (p < 0.0001). All mice in the PBS group developed liver fibrosis but only one mouse in the steroid group did. Serum bilirubin and liver parenchymal enzymes were significantly lower in steroid group. The morphology of liver organoids were different between the two groups. A total of 6359 differentially expressed genes were found between steroid group and PBS group.ConclusionBased on our findings obtained from RRV-induced BA animal and organoid models, steroid has the potential to mitigate liver fibrosis in BA.

A hydrogen sulfide photoelectrochemical sensor based on BiVO4/Fe2O3 heterojunction.

A BiVO4/Fe2O3 heterojunction for non-enzymatic photoelectrochemical (PEC) determination of hydrogen sulfide (H2S) is reported. The BiVO4/Fe2O3 heterojunction promoted the separation of photo-generated carriers, reduced electron-hole recombination, and thus improved electron collection and photocurrent. The proposed BiVO4/Fe2O3/FTO sensor exhibited a linear range of 1-500μM and a detection limit of 0.51 nMH2S. In addition, high selectivity, good reproducibility, and stability were obtained for H2S sensing. Thedetection of H2S in water and serum samples demonstrated its feasibility. This work provides a new strategy to detect and understand the bio-function of H2S in the biological environment.

Molecular genetic characterization of hepatitis B virus in blood donors from South Vietnam

The problem of transfusion safety preventing parenteral viral hepatitis transmission remains relevant. Viral hepatitis B (HB) is the most common viral infection transmitted through transfusion procedures. One of the natural phases of a chronic viral hepatitis B (CHB) course is occult hepatitis B infection (OBI) characterized by undetectable HBsAg level (regardless of other serological marker levels) along with detected hepatic HBV DNA as well as blood viral load ranging from extremely low to undetectable. In Vietnam, prevention of transfusion-based HBV transmission is focused on donor screening; it is still based solely on HBsAg serology. As such, OBI remains a potential threat to blood transfusion safety. Assessing hepatitis B virus (HBV) DNA is a reliable preventive measure against HBV transmission from HBsAg– donors, especially in highly endemic regions. The aim of our work was HBV identification and molecular genetic characterization in blood donors from South Vietnam. The study material was presented by 500 donor serum samples. Subjects were examined for HBV markers with qualitative detection of HBsAg, HBs IgG, and HBcore IgG. Amplification and subsequent HBV sequencing were performed using nested PCR with overlapping primer pairs jointly flanking the complete HBV genome (S, P, C, X genes). Full-size HBV genome nucleotide sequences were obtained for 58 samples. Among blood donors, taking into account HBsAg+ and HBsAg– samples, HBV DNA was detected in 11.6%, including 8.6% OBI. HBV phylogenetic analysis showed genotypes B and C. Vaccine escape mutations and mutations that contribute to disease progression were identified. Current screening in Vietnam is insufficient for eliminating the risk of transfusion-transmitted HBV infection. The major risk factor is OBI. PCR testing for HBV should be considered for blood donor screening.

Copper(II)-Tannic Acid@Cu with In Situ Grown Gold Nanoparticles as a Bifunctional Matrix for Facile Construction of Label-Free and Ultrasensitive Electrochemical cTnI Immunosensor.

Sensitive detection of cardiac troponin I (cTnI) is of great significance in the diagnosis of a fatal acute myocardial infarction. A redox-active nanocomposite of copper(II)-tannic acid@Cu (CuTA@Cu) was herein prepared on the surface of a glassy carbon electrode by electrochemical deposition of metallic copper combined with a metal stripping strategy. Then, HAuCl4 was in situ reduced to gold nanoparticles (AuNPs) by strong reductive catechol groups in the TA ligand. The AuNPs/CuTA@Cu composite was further utilized as a bifunctional matrix for the immobilization of the cTnI antibody (anti-cTnI), producing an electrochemical immunosensor. Electrochemical tests show that the immunoreaction between anti-cTnI and target cTnI can cause a significant reduction of the electrochemical signal of CuTA@Cu. It can be attributed to the insulating characteristic of the immunocomplex and its barrier effect to the electrolyte ion diffusion. From the signal changes of CuTA@Cu, cTnI can be analyzed in a wide range from 10 fg mL-1 to 10 ng mL-1, with an ultralow detection limit of 0.65 fg mL-1. The spiked recovery assays show that the immunosensor is reliable for cTnI determination in human serum samples, demonstrating its promising application in the early clinical diagnosis of myocardial infarction.

Acute Q fever in patients with an influenza-like illness in regional New South Wales, Australia.

Query (Q) fever is a zoonosis caused by the bacterium Coxiella burnetii typically presenting as an influenza-like illness (ILI) with or without hepatitis. The infection may be missed by clinicians in settings of low endemicity, as the presentation is clinically not specific, and there are many more common differential diagnoses for ILI including SARS-CoV-2 infection. Residual serum samples were retrospectively tested for Phase 1 and 2 Q fever-specific IgM, IgG, IgA antibodies by indirect immunofluorescence and C. burnetii DNA by polymerase chain reaction. They had not been previously tested for Q fever, originating from undiagnosed patients with probable ILI, aged 10-70 years and living in regional New South Wales, Australia. The results were compared with contemperaneous data on acute Q fever diagnostic tests which had been performed based on clinicians requests from a geographically similar population. Only one (0.2%) instance of missed acute Q fever was identified after testing samples from 542 eligible patients who had probable ILI between 2016-2023. Laboratory data showed that during the same period, 731 samples were tested for acute Q fever for clinician-initiated requests and of those 70 (9.6%) were positive. Probability of being diagnosed with Q fever after a clinician initiated request was similar regardless of the patients sex, age and the calendar year of sampling. In this sample, Q fever was most likely to be diagnosed via clinician requested testing rather than by testing of undiagnosed patients with an influenza like illness.

Serum biomarkers at disease onset for personalized therapy in multiple sclerosis.

The potential of combining serum neurofilament light chain (sNfL) and glial fibrillary acidic protein (sGFAP) levels to predict disability worsening in multiple sclerosis (MS) remains underexplored. We aimed to investigate whether sNfL and sGFAP values identify distinct subgroups of patients according to the risk of disability worsening and their response to disease-modifying treatments (DMTs). This multicentre study, conducted across thirteen European hospitals, spanned from July 15, 1994, to August 18, 2022, with follow-up until September 26, 2023. We enrolled MS patients who had serum samples collected within 12 months from disease onset and before initiating DMTs. Multivariable regression models were used to estimate the risk of relapse-associated worsening (RAW), progression independent of relapse activity (PIRA), and Expanded Disability Status Scale (EDSS) score of 3. Of the 725 patients included, median age was 34.2 years (IQR, 27.6-42.4), and 509 patients (70.2%) were female. Median follow-up duration was 6.43 years (IQR, 4.65-9.81). Higher sNfL values associated with an elevated risk of RAW (HR of 1.45; 95% CI 1.19-1.76; P < 0.001), PIRA (HR of 1.43; 95% CI 1.13-1.81; P = 0.003), and reaching an EDSS of 3 (HR of 1.55; 95% CI 1.29-1.85; P < 0.001). Moreover, higher sGFAP levels were linked to a higher risk of achieving an EDSS score of 3 (HR of 1.36; 95% CI 1.06-1.74; P = 0.02) and, in patients with low sNfL values, to PIRA (HR of 1.86; 95% CI 1.01-3.45; P = 0.04). We further examined the combined effect of sNfL and sGFAP levels. Patients with low sNfL and sGFAP values (NLGL) exhibited a low risk of all outcomes and served as reference. Untreated patients with high sNfL levels showed a higher risk of RAW, PIRA, and reaching an EDSS of 3. Injectable or oral DMTs reduced the risk of RAW in these patients but failed to mitigate the risk of PIRA and reaching an EDSS of 3. Conversely, high-efficacy DMTs counteracted the heightened risk of these outcomes, except for the risk of PIRA in patients with high sNfL and sGFAP levels. Patients with low sNfL and high sGFAP values (NLGH) showed an increased risk of PIRA and achieving an EDSS of 3, which remained unchanged with either high-efficacy or other DMTs. In conclusion, evaluating sNfL and sGFAP levels at disease onset in MS may identify distinct phenotypes associated with diverse immunological pathways of disability acquisition and therapeutic response.

Association of miR-338-3p with survival outcomes in gastric cancer patients who received peri-operative blood transfusion.

Perioperative blood transfusion (BT) is frequent in the treatment of gastric cancer (GC), but its effects on the prognosis of GC remains controversial. In this study, we aimed to further confirm the relationship of perioperative BT with GC overall survival and to evaluate the predictive value of microRNA-338-3p (miR-338-3p) for the prognosis of GC patients who received perioperative BT. Clinical data and serum samples were collected and analyzed from 246 patients with GC. Five-year follow-up survival information was assessed by Kaplan-Meier survival analysis. miR-338-3p relative expression was assessed by RT-qPCR, and its relationship with the prognosis of GC patients, who received perioperative BT, was evaluated using Kaplan-Meier curves and Cox regression analysis. GC patients received perioperative BT had poor 5year survival than those without BT. In patients received BT, miR-338-3p expression was higher in survival cases than died population and high miR-338-3p was independently associated with better overall survival prognosis. Perioperative BT is related with poor prognosis in GC patients and miR-338-3p may be a prognostic biomarker for GC patients received perioperative BT. BT in perioperative GC patients should be cautious, especially for those with low levels of miR-338-3p.

Development of a Lateral Flow Assay for the Detection of the Hepatitis C Virus Core Antigen.

Hepatitis C virus (HCV) infection remains a global health challenge, with millions of people affected annually. Current diagnostic methods, reliant on antibody screening and viral RNA detection, are complex, costly, and often inaccessible, particularly in resource-limited settings. Development of a lateral flow immunochromatography-based assay for detecting the highly conserved hepatitis C core antigen (HCVcAg). The assay relies on the interaction of four highly specific and cross-reactive monoclonal antibodies with recombinant HCVcAg from five different genotypes in a double antibody sandwich format. Latex and colloidal gold were evaluated as detector nanoparticles. Extensive evaluation of 32 antibody combinations led to identifying the most sensitive antibody pairs. The chosen assay, named LN17, demonstrated a target sensitivity of 10 ng/strip, with potential clinical implications for detecting HCV. Furthermore, the study examined matrix effects in serum samples, providing valuable insights for future clinical application. The developed assay holds promise as a rapid, cost-effective, and user-friendly tool to enhance accessibility to hepatitis C screening, especially in high-risk populations and resource-limited environments.

Ultrasensitive Method Enables Liquid Biopsy for the Precise Detection of Circulating MicroRNAs.

Due to invasive and serial examinations of bioactive molecules, liquid biopsy (LB) has emerged as a rapid and reliable solution for early disease detection and monitoring. Developing portable devices with high specificity and sensitivity for LB is highly valuable. To realize a generalized approach to increase the sensitivity of LB, we developed an ultrasensitive diagnostic biochip based on the amplification of miRNA by recombinase polymerase amplification and the significant enhancement of fluorescence signals by photonic crystal (PC) materials. The PCs-RPA biochip has a detection limit as low as 0.24 aM, a wide linear range of 8 orders of magnitude, and excellent specificity. Such advantages realize the accurate detection of circulating miRNAs with very low content in clinical serum samples for the precise diagnosis of nonsmall cell lung cancer.

Label free and ultrasensitive electrochemical detection of carcinoembryonic antigen using a disposable aptasensor based on Pd and graphene

We prepared an electrochemical aptasensor for label-free analysis of carcinoembryonic antigen (CEA). Herein, PdNPs were synthesized on the surface of graphene-modified screen-printed carbon electrodes (Pd-GN/SPCE) via electrochemical method for immobilisation of CEA aptamer as a bio-recognition element. The morphological characterizations of the fabricated Pd-GN/SPCE were performed using SEM, EDX, and elemental mapping that confirmed the successful electrochemical deposition of PdNPs. A disposable aptasensor for ultrasensitive electrochemical measurement of CEA was proposed by immobilising CEA aptamer on Pd-GN/SPCE. The electrochemical measurements were performed using 5 mM [Fe(CN)6]3-/4- as a redox probe. The electrochemical deposition of PdNPs improved the electrical conductivity resulting in enhanced current response for the redox probe. When CEA antigen interacts with CEA aptamer, it reduces the oxidation and reduction current of [Fe(CN)6]3-/4- due to the attachment of biomolecules to the electrode surfaces that hinders the electron transfer. The current changes of the redox species before and after CEA binding were measured using DPV. The developed aptasensor possessed a wide calibration range of 0.002–200 ng/mL and detection limit of 1.0 pg/mL. The aptamer-immobilised electrode provides an exceptional selectivity, reproducibility, and sensitive measurement of CEA. Moreover, the effective sensing of CEA in human serum samples with great recoveries (99.4––106 %) demonstrated its capability for clinical analysis.

Design and application of an ultrasensitive and selective tobromycin electrochemiluminescence aptasensor using MXene /Ni/Sm-LDH-based nanocomposite.

Using a chemiluminescence reaction between luminol and H2O2 in basic solution, an ultrasensitive electrochemiluminescence (ECL) aptasensor was developed for the determination oftobramycin (TOB), as an aminoglycoside antibiotic. Ti3C2/Ni/Sm-LDH-based nanocomposite effectively catalyzes the oxidation of luminol and decomposition of H2O2, leading to the formation of different reactive oxygen species (ROSs), thus amplifying the ECL signal intensity of luminol, which can be used for the determination of TOB concentration. To evaluate the performance of the electrochemiluminescence aptasensor and synthesized nanocomposite, different methods such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analyses were performed. The considerable specific area, large number of active sites, and enhanced electron transfer reaction on this nanocomposite led to the development of an ECL aptasensor with high sensitivity and electrocatalytic activity. After optimizing the preparation method and analysis conditions, the aptasensor revealed a wide linear response ranging from 1.0 pM to 1.0 μM with a detection limit of 18 pM, displaying outstanding accuracy, specificity, and response stability. The developed ECL sensor was found to be applicable to the determination of TOB in human serum samples and is anticipated to possess excellent clinical potentials for detecting other antibiotics, as well.

Causal mediation analyses for the natural course of hepatitis C: a prospective cohort study.

BackgroundHepatitis C virus (HCV) infection is a systemic disease. However, the relative contribution of intrahepatic and extrahepatic diseases to mediating HCV-induced mortality is unclear, albeit critical in resource allocation for reducing preventable deaths. To this end, this study comprehensively quantified the extent to which intrahepatic and extrahepatic diseases mediate HCV-induced mortality.MethodsA community-based cohort study with >25 years of follow-up was conducted in Taiwan. HCV infection was profiled by antibodies against HCV and HCV RNA in participants' serum samples. The cohort data were linked to Taiwan's National Health Insurance Research Database to determine the incidences of potential mediating diseases and mortality. We employed causal mediation analyses to estimate the mediation effects of HCV on mortality in relation to the incidences of 34 candidate diseases.ResultsIn 18,972 participants with 934 HCV infection, we observed that 54.1% of HCV-induced mortality was mediated by intrahepatic diseases, such as liver cirrhosis and liver cancer, and 45.9% of mortality was mediated by extrahepatic diseases. The major extrahepatic mediating diseases included septicemia (estimated proportion of HCV-induced mortality mediated through the disease: 25.2%), renal disease (16.7%), blood/immune diseases (12.2%), gallbladder diseases (9.7%), and endocrine diseases (9.6%). In women, hypertension (20.0%), metabolic syndrome (18.9%), and type 2 diabetes (17.0%) also mediated HCV-induced mortality. A dose-response relationship of HCV viral load was further demonstrated for the mediation effect.ConclusionBoth intrahepatic and extrahepatic manifestations mediated approximately a half of HCV-induced mortality. The mediation mechanisms are supported by a dose-response relationship of HCV viral load.

Seroprevalence of canid alphaherpesvirus-1 and associated risk factors in domestic dogs in North Queensland, Australia

Canid alphaherpesvirus-1 (CaHV-1) may cause a highly fatal haemorrhagic disease in neonatal pups and is associated with reproductive, respiratory and ocular disease in older dogs. Although assumed to have a world-wide distribution, there have been few reports of CaHV-1 in Australia. The aim of this study was to investigate the seroprevalence of CaHV-1 in household dogs in a residential suburb in Townsville, as well as in dogs attending two dog shows in the region. Study participants were recruited through door-to-door non-probability sampling (Douglas dogs, n = 185) or invited to participate (Show dogs; n = 76). Dog owners completed a questionnaire that investigated possible risk factors for recent exposure to CaHV-1. A serum sample from each dog was assayed for anti-CaHV-1 antibodies using a commercially available ELISA. Associations between seropositive dogs and owner-reported risk factors were analysed using univariable analysis and multivariable logistic regression models. The seroprevalence of CaHV-1 was 11.4 % (95 % CI 6.8–15.9 %) and 17.1 % (95 % CI 5.5–28.8) for the Douglas and Show dogs, respectively, with a pooled seroprevalence of 13 % (95 % CI 8.3–17.7 %). Dogs that had suffered from conjunctivitis within the previous 3 months or were involved in breeding were more likely to be seropositive to CaHV-1. No other significant risk factors were identified. In conclusion, CaHV-1 is circulating in dogs in North Queensland and may be contributing to foetal and neonatal losses in this region.

Metabolic signatures of population exposure to metal mixtures: A metabolome-wide association study

Numerous studies have explored the health impacts of individual metal exposures, yet the effects of metal mixtures on human endogenous metabolism remain largely unexplored. We aimed to assess the serum metabolic signatures of people exposed to metal mixtures. Serum and urine samples were collected from 186 workers at a steel factory in Anhui, China, in September 2019. Inductively coupled plasma mass spectrometry was used to analyze the concentrations of 23 metal elements. The serum metabolome was determined by liquid chromatography-mass spectrometry (LC-MS). A metabolome-wide association study (MWAS) was performed across the metal exposures and metabolism using quantile g-computation modeling. Pathway enrichment analysis was performed using MetaboAnalyst. We identified 226 metabolites associated with metal mixtures, primarily involving lipid metabolism (glycerophospholipids, sphingolipids), amino acid metabolism (arginine and proline, alanine, aspartate and glutamate metabolism) and caffeine metabolic pathways. Exposure to metal mixtures is mainly associated with alterations in lipid metabolism and amino acid metabolism, particularly in the glycerophospholipid and arginine and proline metabolism pathways.