Fingerstick Blood Samples Research Articles

A-194 Point of Care Glucose Test Time Interval Data Used as a Proxy Indicator for Glucose Meter Cleaning and Disinfection Adequacy Between Patient Testing Episodes

Abstract Background At a community hospital within our health system (269 inpatient beds and 46 glucose meters), a condition level finding was cited for blood found on one meter during a routine regulatory survey. Point of Care (POC) test instrument portability is often an essential characteristic in choosing to perform a POC test at the bedside. Glucose meters are in close proximity to patients who are providing fingerstick blood samples for immediate testing. The process of obtaining the blood sample and applying it to the test strip may result in blood inadvertently getting on a caregiver’s gloves and the glucose meter itself. Per the testing protocol, when testing different patients consecutively, the caregiver safely discards the used test strip, changes gloves, and performs the cleaning and disinfecting (C&D) of the glucose meter to ensure the next patient is not exposed to blood from the previous test. The C&D procedure requires a minimum two minutes of drying time. We estimate that consecutive POC glucose tests should have about a three minute gap when the meter gets proper C&D between patients. We sought to determine whether the time interval between tests could be used an indicator of improved C&D compliance during a process improvement project. Methods As a patient safety concern, improved compliance with C&D steps was needed. Various stakeholder groups conducted a three month long campaign of education, training, and surveillance to improve C&D compliance. As a proxy for monitoring the C&D, data on test times from individual glucose meters was downloaded from the POC middleware system. Sample information, patient identifiers, and test results were not obtained. Time intervals between tests were calculated and the number of tests that occurred on the same instrument with short intervals (< 3minutes) were counted. Results Data from the POC middleware system was downloaded from the month prior to and immediately following the project (July and November). In July, there were 733 instances of glucose tests being carried out within three minutes of a previous test on the same instrument, from a total of 6622 tests (11.1%). In November, there were 565 occurrences (out of 6445 tests, or 8.8%), a decrease of 23% from the beginning count, and a drop of 2.3% among all tests. A follow up survey found no instances of blood on meters. Conclusions Using the time between tests interval as a proxy for monitoring glucose meter C&D is straightforward when the data is readily available. In our application of this process, an improvement in the number of short intervals was found, but the number of short intervals was not completely eliminated. This is likely due to occurrences when a test was repeated on the same patient or when training or competency was taking place, circumstances in which C&D not required. To observe patient privacy, our data collection approach could not eliminate these potential confounders of our data.

Pesticide exposure and blood cholinesterase levels among adolescents from farming families in Northern Thailand.

Adolescents living in agricultural communities may be at risk for the adverse effects of pesticide exposure because they are involved in agriculture either as a career or to support their families. The purpose of this study was to investigate the association of farm activities related to pesticide exposure on blood cholinesterase (ChE) levels among adolescents from farming families in the north of Thailand. This cross-sectional study included 336 adolescents aged 12-19 years from farming families in Chiang Dao District, Chiang Mai Province. Data on pesticide exposure was collected using a questionnaire, and blood ChE activity was assessed using a ChE reactive paper test kit via fingerstick blood sampling. Overall, 51.2% of participants had abnormal blood ChE levels. Univariable logistic regression analysis revealed that pesticide-related activities on farms associated with abnormal ChE levels were mixing/spraying (OR=10.54; 95%CI=4.63-23.99), assisting or working in areas with pesticide application (OR=5.54; 95%CI=3.45-8.89), and harvesting (OR=3.70; 95%CI=2.35-5.82). In a multivariable model (Nagelkerke R2=0.374), mixing/spraying (OR=4.90; 95%CI=2.03-11.83) and assisting or working in areas with pesticide application (OR=2.61; 95%CI=1.49-4.57) were significantly associated with abnormal ChE levels, but harvesting (OR=1.48; 95%CI=0.84-2.61) was not significant after adjusting for sex, age in years, and entering or walking through a farm. The findings indicated that Thai adolescents living in farming families are at risk of pesticide exposure, particularly those involved in agricultural activities such as pesticide applicators. An intervention and measure to raise awareness and reduce the risk of pesticide exposure in adolescents is required.

SARS-CoV-2 Seroprevalence Trends in the Netherlands in the Variant of Concern Era: Input for Future Response.

To inform future response planning we aimed to assess SARS-CoV-2 trends in infection- and/or vaccine-induced immunity, including breakthrough infections, among (sub)groups, professions and regions in the Dutch population during the Variant of Concern (VOC)-era. In this prospective population-based cohort, randomly selected participants (n = 9985) aged 1-92 years (recruited early-2020) donated home-collected fingerstick-blood samples at six timepoints in 2021/2022, covering waves dominated by Alpha, Delta, and multiple Omicron (sub-)variants. IgG antibody assessment against Spike-S1 and Nucleoprotein was combined with vaccination- and testing data to estimate infection-induced (inf) and total (infection- and vaccination-induced) seroprevalence. Nationwide inf-seroprevalence rose modestly from 12% (95% CI 11-13) since Alpha to 26% (95% CI 24-28) amidst Delta, while total seroprevalence increased rapidly to 87% (95% CI 85-88), particularly in elderly and those with comorbidities (i.e., vulnerable groups). Interestingly, highest infection rates were noticeable among low/middle educated elderly, non-Western, those in contact professions, adolescents and young adults, and in low-vaccination coverage regions. Following Omicron emergence, inf-seroprevalence elevated sharply to 62% (95% CI 59-65) and further to 86% (95% CI 83-90) in late-2022, with frequent breakthrough infections and decreasing seroprevalence dissimilarities between most groups. Whereas > 90% of < 60-year-olds had been infected at least once, 30% of vaccinated vulnerable individuals had still not acquired hybrid immunity. Groups identified to have been infected disproportionally during the acute phase of the pandemic require specific attention in evaluation of control measures and future response planning worldwide. Furthermore, ongoing tailored vaccination efforts and (sero-)monitoring of vulnerable groups may remain important.

Molecular Gene Expression Testing to Identify Alzheimer's Disease with High Accuracy from Fingerstick Blood.

There is no molecular test for Alzheimer's disease (AD) using self-collected samples, nor is there a definitive molecular test for AD. We demonstrate an accurate and potentially definitive TempO-Seq® gene expression test for AD using fingerstick blood spotted and dried on filter paper, a sample that can be collected in any doctor's office or can be self-collected. Demonstrate the feasibility of developing an accurate test for the classification of persons with AD from a minimally invasive sample of fingerstick blood spotted on filter paper which can be obtained in any doctor's office or self-collected to address health disparities. Fingerstick blood samples from patients clinically diagnosed with AD, Parkinson's disease (PD), or asymptomatic controls were spotted onto filter paper in the doctor's office, dried, and shipped to BioSpyder for testing. Three independent patient cohorts were used for training/retraining and testing/retesting AD and PD classification algorithms. After initially identifying a 770 gene classification signature, a minimum set of 68 genes was identified providing classification test areas under the ROC curve of 0.9 for classifying patients as having AD, and 0.94 for classifying patients as having PD. These data demonstrate the potential to develop a screening and/or definitive, minimally invasive, molecular diagnostic test for AD and PD using dried fingerstick blood spot samples that are collected in a doctor's office or clinic, or self-collected, and thus, can address health disparities. Whether the test can classify patients with AD earlier then possible with cognitive testing remains to be determined.

Diagnostic Efficiency of the Blood-Based Cepheid 3-Gene Host Response Test and Urine-Based Lipoarabinomannan for Active Tuberculosis Case Detection at a General Hospital in China.

To assess the diagnostic performance of the blood-based Cepheid 3-gene Host Response test (MTB-HR), urine-based Lipoarabinomannan (LAM), and a combination of MTB-HR and LAM (MTB-HR & LAM) for detecting active tuberculosis (ATB). All participants were recruited from the First Affiliated Hospital, Zhejiang University School of Medicine, between June 8, 2023 and September 13, 2023. Subsequently, the participants were classified into the ATB group or non-active tuberculosis (non-ATB) group based on microbiological evidence. MTB-HR and LAM tests were performed using fingerstick blood and urine samples from each participant, respectively. The diagnostic performance of the tests was evaluated based on the sensitivity, specificity, Youden index, and Kappa value. Pairwise comparisons of the areas under the receiver operating characteristic curves (AUROCs) between different tests were conducted using nonparametric methods. A total of 297 participants were included. The MTB-HR test demonstrated diagnostic efficacy with a sensitivity of 77.37% (95% CI: 70.37-84.38) and a specificity of 85.63% (95% CI: 80.19-91.06). The LAM test demonstrated a high specificity of 97.50% (95% CI: 95.08-99.92), albeit with a lower sensitivity of 54.74% (95% CI: 46.41-63.082). The sensitivity and specificity of the MTB-HR & LAM were 83.21% (95% CI: 76.95-89.47) and 83.13% (95% CI: 77.32-88.93), respectively. Only MTB-HR & LAM exhibited higher values of area under the receiver operating characteristic curve than the LAM test (MTB-HR & LAM vs LAM: 0.83 vs 0.76, P=0.0031). In this study, although both non-sputum-based triage MTB-HR and LAM do not meet the WHO diagnostic target currently, they show possible values for triage and diagnosis in ATB. Compared to single MTB-HR or LAM test, the combined MTB-HR & LAM does not demonstrate advantages.

(Invited) Lab-in-a-Tube Design Enables a Rapid Diagnosis of Infectious Disease

Disease diagnosis increasingly relies on molecular tests that are often limited by infrastructure constraints. For example, tuberculosis (TB) remains a leading cause of death from infectious disease, but an estimated 4.2 million (39.6%) new TB cases were not diagnosed in 2021 and only 57% were confirmed by gold-standard sputum culture or PCR-based tests, partially due to limited accessibility. New point-of-care tests are thus urgently needed to address coverage disparities for chronic, malignant, and infectious diseases.We have developed two smartphone-based assays that can address two diagnostic shortfalls: an on-chip interferon-gamma release assay (IGRA) that detects a T-cell activation response induced by pathogen antigens in fingerstick blood samples, and a lab-in-tube assay that employs CRISPR to sensitively detect pathogen DNA in sputum. Both approaches translate current diagnostic approaches to point-of-care devices that require minimal equipment, user expertise, and time.Results from our on-chip IGRA also correlated with clinical IGRA results when we employed two proteins associated with TNF-alpha receptor signaling (4-1BB and OX-40) to analyze T-cell activation, indicating this approach could detect infections in individuals with compromised interferon-gamma responses; as observed in HIV patients, who are at increased risk for TB. On-chip IGRA results from a SARS-CoV-2-specific assay also corresponded with both infection and vaccination history, suggesting this data could be employed as a high-throughput, high-capacity test to evaluate the effect of vaccination or previous infection to confer a protective immune response, evaluate its change over time, and predict the response to new variant strains to guide healthcare decisions. Mitogen-induced results could also guide immunotherapy decisions, as reduced IGRA values in patients receiving immune checkpoint inhibitors predict poor treatment response, reduced progression-free survival, and increased risk for interstitial pneumonia, while their change after adoptive T-cell therapy can be an independent predictor for overall survival. Results from our lab-in-tube TB DNA assay also had robust diagnostic performance when compared to gold-standard clinical assays but lacked their more extensive personnel, workflow, and infrastructure requirements and were performed in a closed-tube system that protected user from exposure to infectious material. This lab-in-tube approach also permits parallel multiplex analyses to be performed in a single tube, and thus can be employed to detect mutations associated with drug-resistance to guide treatment decisions. For example, we found that an assay with an optimized guide RNA accurately detected a single-nucleotide polymorphism (rpoB S450L) responsible for the majority of rifampin-resistant TB cases.Both these self-contained handheld devices can employ lyophilized reagents to limit cold-chain concerns, can be readily adapted to diagnose other disease conditions by substituting other disease-specific antibodies or guide RNAs, use rechargeable batteries to avoid infrastructure limitations, and can directly transmit results to central sites to improve disease control efforts.

Methods of the PivotaL triAl of the Atellica VTLi point of care emergencY dePartment high sensitivity troponin evalUationS

BackgroundThe Atellica® VTLi point-of-care (POC) High Sensitivity Cardiac Troponin-I (hs-cTnI) assay is intended for use as an aid in the diagnosis of myocardial infarction (MI). Our primary objective is to assess its diagnostic performance in patients presenting with suspected acute coronary syndrome (ACS). MethodsThis prospective observational study will enrol ∼1500 patients at ∼20 U.S. Emergency Departments. After informed consent, adults (>21 years of age) with suspected ACS, and no prior enrollment in this study, will provide a fingerstick and venous blood sample within 2 h of ED presentation, >2 to ≤4 h, and >4 to ≤9 h (max. blood draw = 60 mL). HEART and EDACS scores will be prospectively documented. Patients without the first blood draw may be enrolled if the second draw was obtained. Capillary and venous whole blood will undergo Atellica VTLi assay testing, with remaining venous sample processed to plasma and run. All results will be blinded to the clinical care team. Site operators will undergo a 3-day familiarization period. Quality control testing will be performed daily. At 30 ± 3 days, patient mortality status, major adverse cardiac events, and rehospitalizations will be determined. A clinical endpoint adjudication committee, blinded to hs-cTnI VTLi result, will define the final diagnosis. Sensitivity, specificity, and predictive values will describe the assay performance. ResultsWe expect study completion within 114 weeks of enrollment of the first patient. ConclusionsIt is anticipated that the Atellica VTLi hs-cTnI assay validation study will define a performance equivalent to lab-based hs-cTnI, with results within ∼8 min at the point of care.

A-383 A Novel Lateral Flow Immunoassay for Health Biomarker and Immunosuppressive Drug Monitoring in Fingerstick Blood in a Point-of-Care Setting

Abstract Background Rapid, CLIA-waived quantitative testing can help eliminate delays in receiving care, improve telemedicine, enhance the management of chronic diseases and clinical trials, and reduce healthcare costs. Intelligent Optical Systems has developed an innovative Enhanced Lateral Flow Assay (ELFA) platform and partnered with the University of California, Irvine Nephrology Division and Wake Forest Institute for Regenerative Medicine for the clinical validation of the assay. The ELFA platform quantitatively measures the immunosuppressive drug tacrolimus (TAC), and health biomarkers such as proinflammatory cytokines IL6, IL8, matrix metalloproteinase-3 (MMP3), glial fibrillary acidic protein (GFAP, an indicator of traumatic brain injury), and cystatin C (CysC, an indicator of kidney function) from fingerstick blood at the point of care. The testing panel is continuously expanding. Methods The ELFA platform is an in vitro, quantitative, single plex or multiplexed lateral flow immunoassay that consists of three main components: (i) simple fingerstick whole blood sampling kit; (ii) lateral flow test strip with running buffer and dried fluorescent labeled affinity reagents; and (iii) miniaturized readout device that can be further developed with a controlled user interface, enabling untrained users to easily record results and instantly transmit them to the physician. Depending on the analytes, the ELFA point-of-care platform has undergone bench testing or clinical validation studies, including: (1) Single plex for TAC: Clinical validation using 5 uL of capillary fingerstick whole blood from kidney transplant recipients (KTR, n = 50) compared to standard LC-MS/MS laboratory method. (2) Multiplexed ELFA for TAC, IL6, and MMP3: In vitro assessment of limit of detection (LoD), detection range, specificity, and repeatability (n = 5) with 10 uL spiked whole blood. (3) Single plex ELFA for GFAP, IL8, and CysC: In vitro determination of the LoD, detection range, CV%, and correlation of spiked and estimated analyte levels with 10 uL of spiked whole blood. For all analytes, a 4-parameter logistic calibration curve with n = 3 for each level of analyte was constructed to determine the LoD, detection range, and CV%. Pearson correlation and Bland-Altman analysis were applied to correlate and compare data between spiked and estimated levels, or between ELFA and standard lab test methods. Results Study (1) demonstrated excellent correlation between ELFA and LC-MS/MS, with a correlation coefficient r-value of 0.89, and at 95% limit of agreement, a mean difference of 0.7 ng/mL in the clinically compared samples from 50 KTRs. Study (2) showed an LoD and range of detection of 2 ng/mL to 20 ng/mL, 1 ng/mL to 5 ng/mL, and 10 ng/mL to 200 ng/mL for the multiplexed detection of TAC, IL6, and MMP3, respectively. The repeatability assessment showed a &amp;lt;10%CV for all analytes. Study (3) showed an LoD and range of detection of 1 ng/mL to 10 ng/mL, 0.5 ng/mL to 5 ng/mL, and 0 to 5 mg/L for GFAP, IL8, and CysC, respectively. Conclusion The ELFA platform delivers minimally invasive, convenient sampling in a POC device using capillary fingerstick blood, and provides accurate, rapid measurements of TAC, which demonstrate good repeatability and strong correlation against LC-MS standard reference measurements.

Palmer Station, Antarctica: A ground-based spaceflight analog suitable for validation of biomedical countermeasures for deep space missions

Astronauts are known to exhibit a variety of immunological alterations during spaceflight including changes in leukocyte distribution and plasma cytokine concentrations, a reduction in T-cell function, and subclinical reactivation of latent herpesviruses. These alterations are most likely due to mission-associated stressors including circadian misalignment, microgravity, isolation, altered nutrition, and increased exposure to cosmic radiation. Some of these stressors may also occur in terrestrial situations. This study sought to determine if crewmembers performing winterover deployment at Palmer Station, Antarctica, displayed similar immune alterations. The larger goal was to validate a ground analog suitable for the evaluation of countermeasures designed to protect astronauts during future deep space missions. For this pilot study, plasma, saliva, hair, and health surveys were collected from Palmer Station, Antarctica, winterover participants at baseline, and at five winterover timepoints. Twenty-six subjects consented to participate over the course of two seasons. Initial sample processing was performed at Palmer, and eventually stabilized samples were returned to the Johnson Space Center for analysis. A white blood cell differential was performed (real time) using a fingerstick blood sample to determine alterations in basic leukocyte subsets throughout the winterover. Plasma and saliva samples were analyzed for 30 and 13 cytokines, respectively. Saliva was analyzed for cortisol concentration and three latent herpesviruses (DNA by qPCR), EBV, HSV1, and VZV. Voluntary surveys related to general health and adverse clinical events were distributed to participants. It is noteworthy that due to logistical constraints caused by COVID-19, the baseline samples for each season were collected in Punta Arenas, Chile, after long international travel and during isolation. Therefore, the Palmer pre-mission samples may not reflect a true normal ‘baseline’. Minimal alterations were observed in leukocyte distribution during winterover. The mean percentage of monocyte concentration elevated at one timepoint. Plasma G-CSF, IL1RA, MCP-1, MIP-1β, TNFα, and VEGF were decreased during at least one winterover timepoint, whereas RANTES was significantly increased. No statistically significant changes were observed in mean saliva cytokine concentrations. Salivary cortisol was substantially elevated throughout the entire winterover compared to baseline. Compared to shedding levels observed in healthy controls (23%), the percentage of participants who shed EBV was higher throughout all winterover timepoints (52–60%). Five subjects shed HSV1 during at least one timepoint throughout the season compared to no subjects shedding during pre-deployment. Finally, VZV reactivation, common in astronauts but exceptionally rare in ground-based stress analogs, was observed in one subject during pre-deployment and a different subject at WO2 and WO3. These pilot data, somewhat influenced by the COVID-19 pandemic, do suggest that participants at Palmer Station undergo immunological alterations similar to, but likely in reduced magnitude, as those observed in astronauts. We suggest that winterover at Palmer Station may be a suitable test analog for spaceflight biomedical countermeasures designed to mitigate clinical risks for deep space missions.

Association between hemoglobin level and food consumption among female nursing students at King Faisal University, Saudi Arabia

Anemia exerts significant adverse impacts on health and the economy, both in developing and developed nations across the globe. The physiological and physical changes that transpire during adolescence and early adulthood necessitate heightened nutritional requirements. Among teenagers and young adults, anemia manifests as a frequent condition. The objective of our study was to determine the prevalence of anemia and its contributing factors among female nursing students enrolled at King Faisal University in Al Hasa, located in the Eastern Region of Saudi Arabia. Employing a cross-sectional design, we conducted an investigation involving a cohort of 83 nursing students who were in good health. To ensure adherence to COVID-19 safety protocols, we employed a practical sampling method to collect the samples. Hemoglobin (Hb) levels were assessed using a finger-stick capillary blood sample. According to the World Health Organization (WHO) criteria for diagnosing anemia, hemoglobin levels exceeding 12.0 g/dL indicate the absence of anemia. The study findings revealed that 59% of the participants were diagnosed with anemia due to their low hemoglobin levels. Substantial associations were observed between hemoglobin levels, anemia, and clinical factors such as chronic illnesses, heavy menstrual cycles, and dietary supplements. Based on these outcomes, anemia is highly prevalent among female university students. Furthermore, the research population may be susceptible to anemia if they engage in practices such as tea or coffee consumption, irregular meal patterns, or the intake of foods that impede iron absorption.

Lessons Learned From the Implementation of a Pilot Study on Self-collected Specimen Return by Sexual Minority Men (Project Caboodle!): Qualitative Exploration.

Self-collection of specimens at home and their return by mail might help reduce some of the barriers to HIV and bacterial sexually transmitted infection (STI) screening encountered by gay, bisexual, and other men who have sex with men (GBMSM). To evaluate the benefits and challenges of bringing this approach to scale, researchers are increasingly requesting GBMSM to return self-collected specimens as part of web-based sexual health studies. Testing self-collected hair samples for preexposure prophylaxis drug levels may also be a viable option to identify GBMSM who face adherence difficulties and offer them support. Project Caboodle! sought to evaluate the acceptability and feasibility of self-collecting at home and returning by mail 5 specimens (a finger-stick blood sample, a pharyngeal swab, a rectal swab, a urine specimen, and a hair sample) among 100 sexually active GBMSM in the United States aged between 18 and 34 years. In this manuscript, we aimed to describe the key lessons learned from our study's implementation and to present recommendations offered by participants to maximize the rates of self-collected specimen return. Following the specimen self-collection phase, a subset of 25 participants (11 who returned all 5 specimens, 4 who returned between 1 and 4 specimens, and 10 who did not return any specimens) was selected for in-depth interviews conducted via a videoconferencing platform. During the session, a semistructured interview guide was used to discuss the factors influencing decisions regarding returning self-collected specimens for laboratory processing. The transcripts were analyzed using template analysis. University branding of web-based and physical materials instilled a sense of trust in participants and increased their confidence in the test results. Shipping the specimen self-collection box in plain unmarked packaging promoted discretion during transit and on its receipt. Using different colored bags with matching color-coded instructions to self-collect each type of specimen minimized the potential for confusion. Participants recommended including prerecorded instructional videos to supplement the written instructions, providing information on the importance of triple-site bacterial STI testing, and adding a reminder of the types of testing that would and would not be conducted on hair samples. Participants also suggested tailoring the specimen self-collection box to include only the tests that they might be interested in completing at that time, adding real-time videoconferencing to the beginning of the study to introduce the research team, and sending personalized reminders following the delivery of the specimen self-collection box. Our results offer valuable insights into aspects that facilitated participant engagement in self-collected specimen return, as well as areas for potential improvement to maximize return rates. Our findings can help guide the design of future large-scale studies and public health programs for home-based HIV, bacterial STI, and preexposure prophylaxis adherence testing. RR2-10.2196/13647.

Leukocyte Telomere Length in Children Born Following Blastocyst-Stage Embryo Transfer

ABSTRACT Several recent studies have suggested an association between children conceived by assisted reproductive technology (ART) and a distinct growth pattern in early life, which has been linked to diseases of older age. Telomere shortening, specifically a shorter leukocyte telomere length (LTL), has also been linked to age-related diseases including cardiometabolic diseases and cancer. Initial telomere length is shaped by a telomere reset process during gamete fertilization and the early stages of preimplantation development. Given that ART involves the in vitro manipulation of oocytes and embryos, this study aimed to evaluate the association between ART-related factors and LTL in children. Whole genome-sequencing (WGS) data from the Nanjing and Suzhou centers of the China National Birth Cohort (CNBC) were obtained from 1137 individuals from 365 parent-children families, including 202 children conceived using ART and 205 conceived spontaneously. The association was determined between blastocyst-stage transfer and shorter telomere length in 180 children conceived by ART in the same centers. In addition, qPCR was used to perform validation on fingerstick blood samples from 406 children conceived using ART at 3 different centers in China. Data from qPCR were then compared with data obtained from WGS in 70 children in the discovery cohort with sufficient DNA samples. Associations between parental factors and demographics with LTL were examined in the discovery cohort. LTL attribution with aging was calculated using data from the discovery cohort, 1185 individuals aged 40–69 years from healthy controls in the Nanjing Lung Cancer Cohort with LTL measured using WGS, and 1452 East Asian adults aged 40–69 years in the UK biobank with LTL measured using qPCR. Results of association analyses found paternal LTL (β = 0.27, P = 3.26 × 10−8), maternal LTL (β = 0.26, P = 2.41 × 10−7), plurality (twins vs singletons; β = −0.34, P = 0.010), sex of children (male vs female; β = −0.22, P = 0.032), gestational age (β = 0.05, P = 0.026), and conception type (ART-conceived pregnancy vs spontaneously conceived, β = −0.35, P = 5.98 × 10−4) were all significantly associated with LTL in children. Multivariate regression analysis revealed that children conceived by ART had a significantly shorter LTL than those conceived spontaneously, even when adjusting for parental age at conception (adjusted β = −0.41, P = 3.33 × 10−4). Transfer of blastocyst-stage embryos was found to be significantly associated with shorter LTL (β = −0.54, P = 2.69 × 10−3). In addition, when LTL in children from spontaneous pregnancies was compared with LTL in children from ART pregnancies through cleavage-stage versus blastocyst-stage transfer, the LTL of the cleavage-stage group was comparable to the spontaneous pregnancy group, whereas the LTL of the blastocyst-stage group was shorter (β = −0.67, P = 7.81 × 10−8). This result suggests that the difference in LTL between transfer stages might explain the difference between the ART-conceived and spontaneous pregnancy groups. No associations between COS protocols, fertilization methods, or embryo transfer cycles on shorter LTL in children were observed. The multicenter validation cohort had similar associations between blastocyst-stage transfer and shorter LTL. Shortened LTL associated with blastocyst transfer was equivalent to 13.93 years (95% CI, 4.64–23.22 years), 13.42 years (95% CI, 4.52–22.21 years), and 10.85 years (95% CI, 1.03–20.67 years) of aging between 40–69 years in the discovery and 2 validation cohorts, respectively. The results of this study demonstrate that children conceived by ART are associated with a shorter LTL compared with those conceived spontaneously, and transfer of blastocyst-stage embryos was associated with shorter LTL in children than is the transfer of cleavage-stage embryos.

Performance Evaluation of a New Fluorescent-Based Lateral Flow Immunoassay for Quantification of Hemoglobin A1c (HBA1c) in Diabetic Patients

Rapid hemoglobin A1C (HbA1c) level monitoring is essential in slowing the progression of diabetes. This need becomes challenging in low resources countries where the social burden of the disease is overwhelming. Recently, fluorescent-based lateral flow immunoassays (LFIAs) gained wide attention for small laboratories and population surveillance. We aim to evaluate the performance of Finecare™ HbA1c Rapid Test, certified by CE, NGSP, and IFCC, for the quantitative measurement of hemoglobin A1C (HbA1c) along with its reader. A total of 100 (fingerstick and venepuncture whole blood) samples were analyzed by Wondfo Finecare™ HbA1c Rapid Quantitative Test and the results were compared with the reference assay Cobas Pro c503. A strong correlation was observed between Finecare™/Cobas Pro c503 with fingerstick (r > 0.93, p < 0.0001) and venous (r > 0.97, p < 0.0001) blood samples. Finecare™ measurements showed excellent agreement and compliance with Roche Cobas Pro c503 as the mean bias was negligible; 0.05 (Limits-of-agreement: -0.58-0.68) with fingerstick and 0.003 (Limits-of-agreement: -0.49-0.50) with venous blood. Interestingly, a very small mean bias (0.047) was also shown between the fingerstick and the venepuncture data, indicating that the type of sample used does not affect the results and the high reproducibility of the assay. Finecare™ showed 92.0% (95% CI: 74.0-99.0) sensitivity and 94.7% (95% CI: 86.9-98.5) specificity compared to the Roche Cobas Pro c503 using fingerstick whole blood samples. Finecare™ showed 100% (95% CI: 86.3-100) sensitivity and 98.7% (95% CI: 92.8-100) specificity compared to the Cobas Pro c503 using venepuncture samples. Cohen's Kappa denoted excellent agreement with Cobas Pro c503; 0.84 (95% CI: 0.72-0.97) and 0.97 (95% CI: 0.92-1.00) using fingerstick and venous blood samples, respectively. Most importantly, Finecare™ showed a significant difference between normal, pre-diabetic, and diabetic samples (p < 0.0001). Similar results were obtained when an additional 47 samples (from different participants; mainly diabetic) were analyzed in a different lab using different Finecare™ analyzer and different kit lot number. Finecare™ is a reliable and rapid assay (5 min) which can be easily implemented for long-term monitoring of HbA1c in diabetic patients, particularly in small laboratory settings.

Sensitivity and specificity of two investigational Point of care tests for Syphilis and HIV (PoSH Study) for the diagnosis and treatment of infectious syphilis in Canada: a cross-sectional study

ObjectivesSingle-visit testing and treatment for syphilis can reduce follow-up visits. The objectives of this study were to evaluate the performance and treatment outcomes of two dual syphilis/HIV point-of-care tests (POCTs). MethodsParticipants aged 16 years and older were offered concurrent syphilis/HIV POCTs with fingerstick blood sampling using two extremely rapid (<5 minutes) devices (MedMira Multiplo Rapid TP/HIV test and INSTI Multiplex HIV-1/HIV-2/Syphilis Antibody Test). Those with positive POCT results were offered same-day syphilis treatment and linkage to HIV care. Nurses performed testing at two emergency departments, a First Nations community, a correctional facility, and a sexually transmitted infection clinic. POCT results were compared with those of standard serological testing. Sensitivity and specificity were calculated. ResultsBetween August 2020 and February 2022, 1526 visits were completed. Both POCTs accurately identified participants with HIV (sensitivity, 100% [24 of 24]; 95% CI, 86.2–100%; specificity, 99.6% [1319 of 1324]; 95% CI, 99.1–99.8%), linking 24 HIV cases to care. Both tests were most sensitive with a rapid plasma reagin (RPR) of ≥1:8 dilutions (Multiplo: sensitivity, 98.3% [231 of 235]; 95% CI, 95.7–99.3%; specificity, 99.5% [871 of 875]; 95% CI, 98.8–99.8%; INSTI Multiplex: sensitivity, 97.9% [230 of 235]; 95% CI, 95.1–99.1%; specificity, 99.8% [873 of 875]; 95% CI, 99.2–99.9%) and least sensitive with non-reactive RPR (Multiplo: sensitivity, 54.1% [59 of 109]; 95% CI, 44.8–63.2%; specificity, 99.5% [871 of 875]; 95% CI, 98.8–99.8%; INSTI Multiplex: sensitivity, 28.4% [31 of 109]; 95% CI, 20.8–37.5%; specificity, 99.8% [873 of 875]; 95% CI, 99.2–99.9%). Eighty-five percent of participants with infectious syphilis were treated on the same day as the positive POCT result. DiscussionTwo extremely rapid (<5 minutes) dual syphilis/HIV POCTs showed excellent sensitivity and specificity for the diagnosis of active syphilis (RPR, ≥1:8 dilutions) and HIV and confirmed the ability to offer single-visit testing and treatment for syphilis and linkage to HIV care in diverse clinical settings.

Evaluation of SARS-CoV-2-Specific T-Cell Activation with a Rapid On-Chip IGRA.

Interferon-gamma release assays (IGRAs) that measure pathogen-specific T-cell response rates can provide a more reliable estimate of protection than specific antibody levels but have limited potential for widespread use due to their workflow, personnel, and instrumentation demands. The major vaccines for SARS-CoV-2 have demonstrated substantial efficacy against all of its current variants, but approaches are needed to determine how these vaccines will perform against future variants, as they arise, to inform vaccine and public health policies. Here we describe a rapid, sensitive, nanolayer polylysine-integrated microfluidic chip IGRA read by a fluorescent microscope that has a 5 h sample-to-answer time and uses ∼25 μL of a fingerstick whole blood sample. Results from this assay correlated with those of a comparable clinical IGRA when used to evaluate the T-cell response to SARS-CoV-2 peptides in a population of vaccinated and/or infected individuals. Notably, this streamlined and inexpensive assay is suitable for high-throughput analyses in resource-limited settings for other infectious diseases.

1931. Antibodies to SARS-CoV-2 in a Medical School Department of Pediatrics

Abstract Background Healthcare workers are at high risk of Covid-19 (C19) infection and received priority for C19 vaccinations. Therefore, we conducted a serosurvey to determine anti-C19 antibodies and evidence of C19 infection in health care employees who did or did not have direct contact with patients. Methods 49 participants provided finger stick blood samples collected onto filter papers and tested for antibodies to C19 using Bio-Plex Pro Human SARS-CoV-2 IgG reagents. Antibodies to C19 nucleocapsid (N), receptor-binding domain (RBD), spike 1 (S1), and spike 2 (S2) were measured. Samples were collected 8 to 11 months after C19 vaccines were made available. Results All participants received two doses of Pfizer BioNTech or Moderna RNA-based C19 vaccines, and all showed serological evidence of antibodies to C19 RBD, S1, and S2. Antibodies to N, considered a marker of C19 infection, were detected in 16 individuals, of whom 10 reported having a PCR documented C19 infections. 6 individuals had evidence of C19 infection of which they were not aware. Antibody levels were notably higher following infection and for not infected participants following Pfizer-BioNTech vaccination. There was a 20% higher infection rate in participants with direct patient contact. Conclusion This vaccinated population had significant rates of strong antibody responses to C19 infection and a notable rate of C19 infections, most notable in those providing direct patient care. Disclosures All Authors: No reported disclosures.

A Highly Sensitive Immunoassay for Determination of Immune Response to SARS-CoV-2 in Capillary Blood Samples.

Throughout the pandemic, serological assays have been revealed as crucial for detecting previous exposures to the virus and determining the timing of antibody maintenance after vaccination or natural infection. This study aimed to develop an optimized enzyme-linked immunosorbent assay (ELISA)-based serology, which could be used in case of reagent shortages, such as that occurred in the beginning of this health emergency. As a result, we present a high-sensitive immunoassay for the determination of IgG levels in venous serum samples, using 2 μg/mL antigen (receptor-binding domain of the spike protein S1) for coating the plate and utilizing human samples at a dilution 1:1000. This method showed non-inferiority features versus a commercial kit, is less expensive, and has a higher spectrophotometric range that allows for a better quantification of the antibody titers. The optical density values before and after heating venous serum samples at 56 °C during 30 min was quite similar, showing that heat inactivation can be used to reduce the biohazardous risks while handling samples. Furthermore, we show that finger-stick capillary blood samples can also serve as a suitable source for IgG detection, bypassing the need for serum isolation and being suitable for point-of-care application (Pearson's coefficient correlation with capillary serum was 0.95, being statistically significant).

Autoimmune gene expression profiling of fingerstick whole blood in Chronic Fatigue Syndrome

BackgroundMyalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating condition that can lead to severe impairment of physical, psychological, cognitive, social, and occupational functions. The cause of ME/CFS remains incompletely understood. There is no clinical diagnostic test for ME/CFS. Although many therapies have been used off-label to manage symptoms of ME/CFS, there are limited, if any, specific therapies or cure for ME/CFS. In this study, we investigated the expression of genes specific to key immune functions, and viral infection status in ME/CFS patients with an aim of identifying biomarkers for characterization and/or treatment of the disease.MethodsIn 2021, one-hundred and sixty-six (166) patients diagnosed with ME/CFS and 83 healthy controls in the US participated in this study via a social media-based application (app). The patients and heathy volunteers consented to the study and provided self-collected finger-stick blood and first morning void urine samples from home. RNA from the fingerstick blood was tested using DxTerity’s 51-gene autoimmune RNA expression panel (AIP). In addition, DNA from the same fingerstick blood sample was extracted to detect viral load of 4 known ME/CFS associated viruses (HHV6, HHV7, CMV and EBV) using a real-time PCR method.ResultsAmong the 166 ME/CFS participants in the study, approximately half (49%) of the ME/CFS patients reported being house-bound or bedridden due to severe symptoms of the disease. From the AIP testing, ME/CFS patients with severe, bedridden conditions displayed significant increases in gene expression of IKZF2, IKZF3, HSPA8, BACH2, ABCE1 and CD3D, as compared to patients with mild to moderate disease conditions. These six aforementioned genes were further upregulated in the 22 bedridden participants who suffer not only from ME/CFS but also from other autoimmune diseases. These genes are involved in T cell, B cell and autoimmunity functions. Furthermore, IKZF3 (Aiolos) and IKZF2 (Helios), and BACH2 have been implicated in other autoimmune diseases such as systemic lupus erythematosus (SLE) and Rheumatoid Arthritis (RA). Among the 240 participants tested with the viral assays, 9 samples showed positive results (including 1 EBV positive and 8 HHV6 positives).ConclusionsOur study indicates that gene expression biomarkers may be used in identifying or differentiating subsets of ME/CFS patients having different levels of disease severity. These gene targets may also represent opportunities for new therapeutic modalities for the treatment of ME/CFS. The use of social media engaged patient recruitment and at-home sample collection represents a novel approach for conducting clinical research which saves cost, time and eliminates travel for office visits.

Perceptions and Experiences of Returning Self-collected Specimens for HIV, Bacterial STI and Potential PrEP Adherence Testing among Sexual Minority Men in the United States.

Few studies among gay, bisexual and other men who have sex with men (GBMSM) have examined facilitators and barriers to self-collecting specimens for extragenital STI screening, and none have evaluated attitudes towards self-collecting hair samples that can be utilized for PrEP drug level testing to assess adherence. To address this gap, we interviewed 25 sexually active GBMSM who were offered a choice to self-collect and return finger-stick blood samples (for actual HIV testing), pharyngeal swabs, rectal swabs and urine specimens (for actual gonorrhea and chlamydia testing), and hair samples (to visually determine their adequacy for PrEP drug level testing): 11 who returned all, 4 who returned some, and 10 who did not return any. Participants found self-collecting finger-stick blood samples and rectal swabs more challenging than other specimens. Frequently discussed facilitators of return included an opportunity to confirm one’s HIV or STI status, limited access to a healthcare provider and a desire to advance research focusing on home-based testing. Commonly cited barriers to return included low self-efficacy pertaining to self-collection and apprehension around the possibility of delay or loss of specimens during transit. Offering additional support such as real-time video conferencing may prove helpful in future field-based research with GBMSM.

Chagas disease in northern Chile: Detection of Trypanosoma cruzi in children, dogs and triatomine bugs

Chagas disease is an anthropozoonotic disease caused by the protozoan Trypanosoma cruzi, transmitted by triatomine vectors. In Chile, there are four species of triatomine bugs that are potential vectors of T. cruzi, being Triatoma infestans the main vector in endemic areas of the country. The “Programa Nacional de Control Vectorial de la Enfermedad de Chagas de Chile” has significantly reduced the rates of home infestation to less than 1% and has interrupted vectorial transmission since 1999. The objective of this study was to evaluate the impact of vectorial control and the continuity of the interruption of vectorial transmission in northern Chile (provincia de El Loa, región de Antofagasta). The study comprised fingerstick blood samples of 2104 children, attending local school, venous blood samples of 65 dogs, associated to houses with T. infestans unique findings and vector infestation, and intestine samples of 284 T. infestans specimens, from the provincia de El Loa, during 2014–2016 period. The samples were analyzed by enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence and/or polymerase chain reaction (PCR) techniques. A total of 5 children (0.24%), 7 dogs (10.8%), and 6 specimens of T. infestans (2.1%) resulted positive to T. cruzi infection. This study showed that the risk of transmission of Chagas disease is low in the north of Chile (provincia de El Loa), detected a low positive rate of chagasic children and of infected triatomine bugs, and showed the existence of T. cruzi transmission in dogs, which are used as natural sentinels for the detection of T. cruzi infection, being especially useful during surveillance program in human population characterized by low seroprevalence.