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Background: High-titer neutralizing anti-cytokine autoantibodies have been shown to be involved in several acquired diseases, including pulmonary alveolar proteinosis, cryptococcal meningitis, and disseminated/extrapulmonary Nocardia infections (anti-GM-CSF autoantibodies), disseminated mycobacterial disease (anti-IFN-gamma autoantibodies), and some cases of severe COVID-19 infection (anti-type 1 interferons). Currently, patient blood samples are shipped via courier and require temperaturecontrolled conditions for transfer. This method is expensive and requires patients to have access to medical personnel to draw the blood. However, the well-established technique of collecting blood on a paper card as a dried blood spot (DBS) for diagnosis offers a point of care alternative which can be performed with a simple finger prick. This method is less invasive, cheaper, and allows for easy transport of patient samples. Method(s): 30 uL of whole blood from patients was blotted on filter paper and stored at 4C until use. The filter paper was hole punched and each punched spot was eluted with 150 uL of a 0.05% Tween PBS solution at room temperature overnight. The eluate was screened for anti-cytokine autoantibodies using a particle-based approach. Patient plasma was also screened in conjunction for comparison. Result(s): We confirmed the presence of autoantibodies in the DBS eluate from 4 previously diagnosed patients with anti-GM-CSF autoantibodies and 2 patients with anti-IFN-gamma autoantibodies. Functional studies showed the DBS eluate from a patient with anti-GM-CSF autoantibodies was able to block GM-CSF-induced STAT-5 phosphorylation in normal PBMC. As a proof of concept and to increase the number of patients evaluated, we also confirmed the presence of anti-cytokine autoantibodies using dried plasma eluate from 9 patients with known anti-GM-CSF autoantibodies and 9 patients with anti-IFN-gamma autoantibodies. Levels detected in DBS analyses were comparable to the levels found in plasma from the same patients not subjected to blotting and elution. Temperature studies showed that the autoantibodies were detected at similar levels when stored at 4C, 25C, and 40C for a week. Conclusion(s): The diagnosis of pathogenic anti-cytokine autoantibodies should be considered in the context of unusual or adult-onset infections, and screening for this diagnosis can be performed with dried blood spot testing.Copyright © 2023 Elsevier Inc.
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The COVID19 pandemic accelerated opportunities for innovation within the decentralization process of clinical trials with opportunities for implementation of patient-centric workflows for efficiency and cost-reduction. Decentralized sample collection, particularly whole blood using dried blood spots (DBS) provides the ideal mechanism for patient driven sample collection with ease of access to sample generation, drug level assessments and metabolomic prMegofiling, providing longitudinal real-time measure of drug specific pharmacodynamic readout for safety and efficacy. In this study, we report the development of a protocol for the capture and comprehensive profiling of metabolomics using dried blood spots from a cohort of 49 healthy volunteer donors. Using liquid chromatography combined with mass spectrometric (UPLC-MS/MS) methods an untargeted metabolomic approach resulted in the identification of >800 biochemicals of which a significant subset was found to be presented in corresponding matched plasma (from whole blood) samples. The biochemicals identified from the DBS samples included metabolites that were part of the lipid, amino acid, nucleotide, peptide, cofactors, carbohydrate and energy super pathways. A significant number of metabolites identified in the DBS samples were xenobiotics including those representing the biotransformation products of drugs. The overall metabolite profiles were analyzed for precision and accuracy of measure, variability in performance and dynamic range to establish benchmarks for evaluation. An additional cohort with a longitudinal sampling as part of the protocol provided the reproducibility of the analytic method for inter-day variability of metabolite performance over time. Although metabolomic profiles varied between individuals from a population perspective, there was minimal variation observed within individuals when samples were profiled longitudinally over several weeks. Thus, the protocols for DBS collection and the corresponding capture of a large set of metabolites with reproducible performance provides an opportunity for its implementation in oncological clinical trials as part of a de-centralized clinical trial solution.
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Background: Monitoring of HIV-infected individuals on antiretroviral treatment requires periodic viral load(VL) measurements to ascertain adequate response to treatment. While plasmaVL is widely available in health facilities, it is difficult for use among key populations(KPs) due to their high mobility and sophisticated sample storage and transport requirements, which are not available for community VL sample collection. Use of Dried Blood Spot(DBS) VL measurement has shown promise as an alternative to plasma specimens for KPs. Studies to investigate the performance of DBSVL quantification against the standard plasma VL assay has proven to be within acceptable range. DBSVL was introduced for sample collection among KPs when it became difficult to safely and appropriately collect, store and transport samples during COVID-19 lockdown. This study assessed the usefulness of the use of DBSVL deployed by USAID to ensure access to HIV VL services among KPs in 7 states of Nigeria during COVID-19 lockdown Methods: To mitigate the impact of COVID-19 lockdown, virtual trainings were conducted for one-stop-shops and community VL champions of USAID partners providing KPs services in seven states of Nigeria on DBS sample collection, storage and transportation and remote test ordering was activated for service providers. Standard operating procedures and job aids were deployed to points of service and laboratory equipment were verified for DBSVL testing. VL sample collection rate(SCR), VL coverage(VLC), VL suppression(VLS), turnaround time (TAT) and cost savings for the program between March2019 and February2021 were compared using the two-sample independent t test pre-COVID (March2019- February2020) and during-COVID lockdown (March2020 -February2021) at 95 confidence interval and < 0.05 level of significance. Result(s): There was a significant increase (p< 0.05) in SCR from 73% to 94%, VLC 44% to 85%, and VLS 78% to 95% pre-COVID to during-COVID respectively despite increase in number of clients eligible for VL. However, the median TAT remained unchanged at 29 days. There was a 60% cost savings for the program due to reduction in consumables needed for sample collection and processing and convenience in sampling among KP clients. Conclusion(s): Implementation of DBSVL resulted in increases in both VLC and VLS with an improved TAT for KPs clients in seven states of Nigeria. KPs Program implementers should consider introduction of DBSVL sampling among KPs for a better VL access and clinical outcome.
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Background: Confirmed COVID-19 case counts underestimate SARS-CoV-2 infections, particularly in countries with limited testing capacity. Pregnant women attending antenatal care (ANC) clinics have served as healthy population surrogates to monitor diseases like HIV and malaria. We measured SARS-CoV-2 seroprevalence among women attending ANC clinics to assess infection trends over time in Zambia. Method(s): We conducted repeated cross-sectional surveys among pregnant women aged 15-49 years attending their first ANC visits in 3 districts of Zambia during September 2021-September 2022. Up to 200 women per district were enrolled each month, completing a standardized questionnaire. Dried blood spot samples were collected for serologic testing for prior infection using the Tetracore FlexImmArrayTM SARS-CoV-2 Human IgG Antibody Test and HIV testing according to national guidelines. We calculated odds ratios (ORs) for SARS-CoV-2 seroprevalence by demographic characteristics, adjusting for the district. Result(s): A total of 5,351 women were enrolled at 29 study sites between September 2021 and September 2022. Participants' median age was 25 years (interquartile range: 21-30), 530 (9.9%) tested positive for HIV, and 101 (1.9%) reported a prior positive COVID-19 test. Overall, SARS-CoV-2 seroprevalence was 67%, and rose from 49% in September 2021 to 85% in September 2022 (Figure 1). The greatest increase in seroprevalence occurred during the 4th wave caused by the Omicron variant (48% in December 2021 to 63% in January 2022). Seroprevalence was significantly higher among women living in urban districts (Chipata and Lusaka) compared to rural Chongwe District (Chipata OR: 1.2, 95% confidence interval [CI]: 1.1-1.4;Lusaka OR: 1.7, 95% CI: 1.5-2.0). The age group was not significantly associated with seroprevalence after adjusting for the district (aOR: 1.1, 95% CI: 1.0-1.2). Seroprevalence was significantly lower among women living with HIV than women living without HIV (aOR: 0.8, 95% CI: 0.6-0.9). Conclusion(s): Overall, two-thirds of women in the three surveyed districts in Zambia had evidence of SARS-CoV-2 exposure, rising to 85% after the Omicron variant spread throughout the country. ANC clinics have a potential role in ongoing SARS-CoV-2 serosurveillance and can continue to provide insights into SARS-CoV-2 infection dynamics. Furthermore, they provide a platform for focused SARS-CoV-2 prevention messaging and COVID-19 management in pregnant women at higher risk of severe disease. (Figure Presented).
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BACKGROUND: Worldwide there are an estimated 463 million people with diabetes. In the UK people with diabetes are offered annual review which includes monitoring of Haemoglobin A1c (HbA1c). This can identify people with diabetes who are not meeting their glycaemic targets, enabling early intervention. Those who do not attend these reviews often have poorer health outcomes. During the Coronavirus disease 2019 (COVID-19) pandemic, there was a 77% reduction in monitoring of HbA1c in the UK. AIM: We hypothesise that people with diabetes could take finger-prick samples at home for measurement of HbA1c. We will examine the agreement and correlation of capillary HbA1c values compared to a venous reference standard. We will explore reliability and repeatability of capillary HbA1c testing methods. We will explore the direction of effect of storage variables. We will also explore patient acceptability and safety. We will look at capillary blood methods which would be suitable for posting. METHOD: Using core terms of 'Diabetes', 'HbA1c' and 'Capillary sampling' we will search MEDLINE, Embase, CINAHL, Web of Science Core Collection, Google Scholar, Open Grey, and other grey literature from database inception until 2021. Risk of bias will be assessed using the 'COSMIN risk of bias tool to assess the quality of studies on reliability and measurement error'. CONCLUSION: We will produce a narrative synthesis to explore whether there are viable postal alternatives to venous sampling as well as exploring acceptability and safety of patient self-collection. PROSPERO REGISTRATION NUMBER: CRD42021225606.
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Introduction Self-sampled specimens to test for blood borne viruses can involve either mini tube testing (MTT) or dried blood spot testing (DBST).[1] In the UK, remote testing for STIs has increased in recent years, a trend enhanced by the COVID-19 pandemic. Whilst information is already available on these different testing technologies, little is known about the patient experience of home blood-sampling. We present a pilot service evaluation to explore the patient experience of DBST and MTT. Methods DBST kits (including tests for HIV, syphilis, Hepatitis B and C) were sent to 30 patients. People were included in this service evaluation if they were MSM who had a) requested an online MTT kit from our clinic website within the preceding 6 months, b) subsequently returned a blood sample which was inadequate for analysis and c) not yet attended the department for a venous sample. Sample return rates and results were analysed, and patients were also invited to complete a short telephone survey. Discussion Our sample return rate was 67%. This is higher than the reported average from UKHSA for MTT (57%).[2] Nineteen patients completed the survey discussing their experience of both MTT and DBST. We identified significant issues faced by patients when carrying out remote MTT which included logistical difficulties when collecting blood samples, pain and distress. Comparatively, our evaluation demonstrated that DBST was less labour-intensive and therefore the preferred test for 100% of our respondents. Conclusion DBST proves to be a promising and acceptable candidate for future delivery of blood borne virus home sampling.
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Serological testing of large representative populations for antibodies to SARS-CoV-2 is needed to estimate seroprevalence, transmission dynamics, and the duration of antibody responses from natural infection and vaccination. In this study, a high-throughput SARS-CoV-2 multiplex microsphere immunoassay (MMIA) was developed for the receptor binding domain (RBD) and nucleocapsid (N) that was more sensitive than enzyme-linked immunosorbent assay (ELISA) (98% versus 87%). The MMIA was then applied and validated in 264 first responders in Colorado using serum and dried blood spot (DBS) eluates, compared to ELISA, and evaluated for neutralizing antibodies. Four percent (11/264) of first responders were seropositive in July to August 2020. Serum and DBS were highly correlated for anti-RBD and anti-N antibodies (R = 0.83, P < 0.0001 and R = 0.87, P < 0.0001, respectively) by MMIA. The MMIA accurately predicted SARS-CoV-2 neutralizing antibodies using DBS (R = 0.76, P = 0.037). On repeat antibody testing 3 months later, anti-RBD IgG decreased less rapidly than anti-N IgG measured by MMIA, with a median change in geometric median fluorescence intensity of 62% versus 79% (P < 0.01) for anti-RBD and anti-N IgG, respectively. This novel MMIA using DBS could be scalable for rapid and affordable SARS-CoV-2 serosurveillance in the United States and globally.