Serological Measurements Research Articles

Application of machine learning algorithms to identify serological predictors of COVID-19 severity and outcomes

BackgroundCritically ill hospitalized patients with COVID-19 have greater antibody titers than those with mild to moderate illness, but their association with recovery or death from COVID-19 has not been characterized.MethodsIn a cohort study of 178 COVID-19 patients, 73 non-hospitalized and 105 hospitalized patients, mucosal swabs and plasma samples were collected at hospital enrollment and up to 3 months post-enrollment (MPE) to measure virus RNA, cytokines/chemokines, binding antibodies, ACE2 binding inhibition, and Fc effector antibody responses against SARS-CoV-2. The association of demographic variables and more than 20 serological antibody measures with intubation or death due to COVID-19 was determined using machine learning algorithms.ResultsPredictive models reveal that IgG binding and ACE2 binding inhibition responses at 1 MPE are positively and anti-Spike antibody-mediated complement activation at enrollment is negatively associated with an increased probability of intubation or death from COVID-19 within 3 MPE.ConclusionsAt enrollment, serological antibody measures are more predictive than demographic variables of subsequent intubation or death among hospitalized COVID-19 patients.

B-043 Q-nab™ Igg kit: verification and validation of a novel cell-free quantitative neutralizing antibody assay

Abstract Background As the world exits the COVID-19 pandemic era, it is very important to assess population-level and individual seroprotectivity against multiple circulating and emerging SARS-CoV-2 strains, especially in vulnerable populations. Current serological measurements for neutralizing antibodies (NAbs) are either done using complex and time-intensive pseudovirus- or micro-neutralization assays or as a high throughput competitive ELISA assay. These assays, by design, cannot be multiplexed to measure NAb titers against multiple strains and suffer from a limited dynamic range. The Q-NAb IgG Tests, which rely on blocking the non-neutralizing antibodies (NNAbs) using a novel fusion protein, were developed and validated to quantitatively measure NAb titer against the SARS-CoV-2 strains used to develop the first two mRNA vaccines viz. ancestral and BA.4/5 strains. Methods The Q-NAb assay measures the NAb titer in a sample by first sequestering the NNAbs using the fusion protein (made by covalently coupling SARS-CoV-2 BA.4/5 RBD and h-ACE2 protein) thereby enriching the NAbs in the sample. Variant-specific NAbs are then detected using an indirect ELISA where the wells are coated with the variant RBD and yield a signal that is directly proportional to the concentration of NAb. Clinical samples from subjects that have either had a SARS-CoV-2 infection (N=27), taken the initial vaccine series (N=123) and/or the bivalent booster (N=151) and pre-pandemic samples (N=29) were commercially sourced. Q-NAb NAb titers were measured using the ancestral and BA.4/5 kits and were compared against corresponding MN50 values using both parametric and non-parametric models. Single-site precision, low-end sensitivity, dilutional linearity, and interference screening of Q-NAb IgG Kits were evaluated in accordance with appropriate CLSI guidelines. Traceability and total uncertainty of the Q-NAb IgG Kits (Ancestral and BA.4/5) to WHO International Standard 21/340 and 21/338 respectively was established using a calibration hierarchy adapted from ISO 17511:2020. Results Both the ancestral and BA.4/5 Q-NAb IgG Test Kits correlated with MN50 titers with a Spearman correlation coefficient of 0.90 and 0.89 respectively. The total uncertainty in traceability of calibration to WHO International standards 21/340 and 21/338 was found to be less than 10% for both tests. Single site precision across the assay range for BA.4/5 kit was found to be 6-10% with a limit of quantitation of 312 IU/mL. Assays exhibited dilutional linearity across their respective dynamic range and had no significant interference from common endogenous and exogenous substances. Conclusions We have successfully validated the novel Q-NAb IgG neutralization assay platform as individual assays for measuring neutralizing titers against ancestral and BA.4/5 SARS-CoV-2 strains. The assays have expanded dynamic range, excellent analytical performance and correlation to accepted gold-standard microneutralization assays. Both assays are calibrated and traceable to WHO international standards, thereby enabling the compilation and comparison of data from multiple clinical cohorts run across multiple laboratories. The design of the Q-NAb IgG Test kit makes it amenable to multiplexing (for example, on an MSD platform) to assess neutralization titers against multiple variants at the same time. Such a multiplexed platform can be used to assess vaccine efficacy and seroprotection against multiple variants including emerging variants.

Insights for possible association and impact of thyroidectomy to osteoarthritis

Background and aim of studyThyroidectomy and osteoarthritis have drawn more attention in last decades due to increase various local and systemic risk factors. This study is aimed to determine the association and impact between thyroidectomy and osteoarthritis by serological measurement of most specific related markers.ResultsMeasurement of thyroid markers showed the level of thyroid-stimulating hormone (TSH) was significantly increased, while parathyroid hormone (PTH), triiodothyronine (T3), and thyroxine (T4) levels were decreased in osteoarthritis subjected to thyroidectomy group (OTG) when compared to hyperthyroidism subjected to thyroidectomy group (TG), osteoarthritis group (OG), and healthy control group (CG). Detection the activity of bone markers showed the level of R-factor was significantly elevated concomitant with significant reduction in Dickkopf related protein 1 (DKK1), human hyaluronan-binding protein 2 (HABP2), osteocalcin (OC) in OG and OTG groups, while osteopontin (OPN) and procollagen I C-terminal propeptide (PICP) were significantly increased and decreased in TG and OTG. Furthermore, the level of S100 Calcium binding protein (S100CBP) showed significant decreased in patient’s groups, while TG with OTG groups exhibited significant reduction in sclerostin (SOST) concentration. Regarding the inflammatory markers, the levels of interleukin-1 (IL-1) was increased in the OTG, while the level of interleukin-10 (IL-10) was increased in OG and TG groups, and reduced in OTG. While, the level of transforming growth factor-beta (TGF-β) was decreased in OG and TG associated with significant increases in tumor necrosis factor-alpha level (TNF-α) in OTG. Measurement of oxidant and antioxidant activity markers showed the levels of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were significantly reduced in all patient’s groups compared to control, except the level of CAT in TG, whereas, malondialdehyde (MDA) level was increased in OG and OTG patients. Furthermore, the levels of Alkaline phosphatase (ALP), C-Reactive protein (CRP), and erythrocyte sedimentation rate (ESR) were increased in all patient groups compared to control, while fatty acid-binding protein (FABP) level was increased in OTG only.ConclusionThis unique study in Iraq is identified the interaction effect and impact of thyroidectomy to osteoarthritis according to the results that showed various changes and degree of correlation of study biomarkers in all patient groups, however more depth of specific quantitative and qualitative studies are required to support this association and the impact claim at molecular level.

Association between humoral serological markers levels and risk of SARS-CoV-2 infection after the primary COVID-19 vaccine course among ANRS0001S COV-POPART cohort participants

BackgroundWe assessed the prognostic value of serological humoral markers measured one month after the last dose of the primary COVID-19 vaccine course for predicting the risk of severe acute respiratory syndrome coronavirus 2 SARS-CoV-2 infection over the following six months in specific populations.MethodsANRS0001SCOV-POPART is a French nationwide multicenter prospective observational cohort study assessing the immune response to Covid-19 vaccines routinely administered to 11 subgroups of patients with chronic disease and a control group. Participants from the ANRS0001S COV-POPART were included if they received at least two doses of Covid-19 vaccine for the primary vaccine course, had measurements of anti-Spike, anti-receptor binding domain (RBD) IgG-specific or neutralizing antibodies one month after the end of the primary vaccine course, without being infected by SARS-CoV-2 before the measurement. SARS-CoV-2 infections defined by a positive PCR/antigenic test or seroconversion to detectable anti nucleocapsid antibodies were evaluated until the first COVID-19 booster injection. Cox proportional hazards models taking into account interval-censored data were implemented to estimate the association between each antibody level and the risk of SARS-CoV-2 infection. Predictive performances were evaluated by the area under the receiving operating characteristic curve (AUROC).ResultsTwo thousand five hundred seventy adults from a specific population and 1,123 from the control group were included. The cumulative probabilities of SARS-CoV-2 infections at five months after serological measurement were 6.0% 95% confidence interval: [5.0; 7.9] and 10.1% 95% confidence interval: [8.3; 11.9], respectively. Higher levels of anti-Spike IgG antibody were associated with a lower risk of SARS-CoV-2 infections in the control group, but not in the specific populations. Among the specific populations, AUROC were 74.5%, 74.9%, and 72.4% for anti-Spike IgG, anti-RBD IgG, and neutralizing antibodies, respectively. AUROC were superior in the specific populations, 82.0%, 81.2%, and 81.4% for anti-Spike IgG, anti-RBD IgG, and neutralizing antibodies, respectively.ConclusionsVaccine-induced antibody response after the primary course of Covid-19 infection only moderately discriminated between participants developing a SARS-CoV-2 infection during the Omicron wave.Trial registrationNCT04824651 (first posted: 2021-04-01).

Exercise as part of survivorship care in metastatic breast cancer: protocol for the randomized EMBody trial

BackgroundExercise is associated with improved survival, physical functioning, treatment tolerability, and quality of life in early-stage breast cancer. These same endpoints matter in metastatic breast cancer (MBC). Prior trials in MBC have found exercise to be not feasible or of limited benefit, possibly due to inclusion of patients with heterogeneous disease trajectories. Patients with MBC have variable disease trajectories and supportive care needs; those with indolent MBC have longer life expectancy, lower symptom burden and distinct priorities, and are well-positioned to participate in and benefit from an exercise program. The EMBody trial aims to determine the impact of a multimodal exercise intervention on cardiorespiratory fitness, physical function, body composition, and patient-reported outcomes, specifically in patients with stable, indolent MBC.MethodsEligible patients have MBC with no evidence of disease progression on current therapy in the prior 12 months and cannot be receiving cytotoxic chemotherapy. The trial aims to enroll 100 patients, randomized 1:1 to the exercise intervention versus usual care, stratified by baseline function. The virtually-delivered exercise intervention arm achieves moderate intensity exercise with exercise physiologists 3 days/week for 16 weeks. The 60-minute sessions include aerobic, resistance, balance and stretching exercises. The exercise arm receives informational sessions on the role of exercise in cancer and principles of habit and self-efficacy. The primary endpoint is 16 week change in fitness on a ramp treadmill test between the exercise and control arms. Secondary endpoints include change in a physical function, muscle mass assessed by CT scans, and PROs of fatigue and quality of life. Exploratory analysis includes behavioral modifiers of exercise adherence and effectiveness and serologic measures of inflammatory, metabolic, and immune pathway biomarkers.DiscussionThe EMBody trial evaluates exercise in a unique patient population with indolent, non-progressive MBC. Patients living with MBC experience similar symptom burden to those undergoing therapy for early-stage disease and the benefits achieved with exercise could be similarly impactful. This trial will contribute evidence to support expansion of exercise recommendations, among other survivorship care efforts, to those living with metastatic disease. Clinical trial information: NCT05468034.Trial registrationNCT05468034. Date of registration: 7/12/2022.

Effectiveness after immunization with BNT162b2 and Gam-COVID-Vac for SARS-CoV-2 and neutralizing antibody titers in health care workers

Abstract Objectives The aim of this study was to describe the effectiveness of the vaccines (Tozinameran and Sputnik V), administered on a convenience sample of healthcare workers, and also to describe the relationship between the levels of neutralizing antibodies (NAbs) and the type of vaccine used, as well as their association with incident cases during follow-up. Methods The study included 262 participants, who underwent vaccination during the period from September 2021 until August 2022. For determining the levels of NAbs we used the CLIA based method, and all the samples were processed with the SNIBE Maglumi 800 analyzer. The patients were observed for one year for occurrence of incident infection. Results The participants with prior SARS-CoV-2 positivity showed substantially higher titer of NAbs (8.86 vs. 0.94, p<0.001). The participants in the Gam-COVID-Vac group had median levels of NAbs of 1.57 (IQR 0.42–5.73), while they in the Tozinameran group showed substantially higher levels of 2.37 (IQR 0.9–6.27). The incident cases after immunization had substantially lower median values of NAbs when compared to the rest (0.48 vs. 3.97, p<0.001), and the interval between the second dose and the serological measurements were similar. Conclusions The current study showed that the tested vaccines demonstrated vaccine effectiveness of over 50 % during the first year after the vaccination in a sample of health care workers. Although health care workers remain separate population group, when compared to the rest, the results could be extrapolated to populations with similar age and immune experience.

Abstract PO5-26-03: Evaluation of cardiotoxicity in Mexican patients with Breast Cancer under neoadjuvant treatment by two-dimension speckle echocardiography

Abstract Background Cardiotoxicity is a major concern in breast cancer patients treated with anthracyclines or anti-HER-2 therapy. The assessment of left ventricular ejection fraction (LVEF) by transthoracic echocardiogram (TTE) has been the most common method to evaluate cardiotoxicity. Different TTE parameters have been studied to assess cardiotoxicity, we aimed to evaluate left atrial strain (LAS) as a parameter of diastolic cardiotoxicity in Mexican patients under neoadjuvant treatment. Methods We prospectively recruited patients with breast cancer under neoadjuvant treatment with anthracyclines and/or anti-HER-2 from March 2022 to present. The evaluation includes TTE, and troponin measurements before chemotherapy, and respective follow-ups at 3 and 6 months from the baseline. We enrolled 187 patients, 172 and 131 had completed the three and six-month follow-ups, respectively. We limited the analysis to patients we could assess cardiotoxicity status, defined according to the ESC 2022 guidelines. Clinical and echocardiographic parameters were compared according to cardiotoxicity status using Chi-squared, two-tailed t-tests or Wilcoxon tests, as appropriate. Results The mean time of follow-up at second assessment was 213 days. The patients are divided into cardiotoxicity and no cardiotoxicity group. We reported 81 events of cardiotoxicity if we include troponin measurement or 36 events if we only evaluate TTE measurements. The incidence of cardiotoxicity in this study was not related with common risk factors as high BMI, presence of hypertension/diabetes or smoking status, but it was statistically associated with the presence of elevated LDL cholesterol (p 0.026). Fourteen percent (14%) were HR-/HER-2 (+), 44% HR+/HER-2 (-), 25% HR+/HER-2 (+), and 17% triple negative subtype. Eightyfive percent (85%) of patients received anthracyclines, 28% in combination with anti-HER-2 treatment, 12% received double anti-HER-2 blockade anthracycline free. The accumulated dose of anthracycline didn’t differ between groups. The use of anthracyclines and double anti/HER blockade was statically associated with development of CTRCD (p < 0.01 and p < 0.01), respectively, but not with a single anti-HER-2 treatment. In troponin-based cardiotoxicity definition, at the three-month follow-up, those who developed cancer therapy-related cardiac dysfunction (CTRCD) had only statically significant lower LVEF (Table 1) with respect to basal assessment. LASr baseline, three months and six months was similar between groups. In the cardiotoxicity group without troponin measurement, we observed statically significant decreased LVEF and LV GLS at 3 months and six months, and tendency to decreased LASr with respect to basal evaluation. Conclusions In our cohort the only modifiable risk factor with impact in the development of CTRCD was dyslipidemia, specifically high LDL. The traditional chemotherapy schemas as anthracyclines and doble anti HER-2 blockade correlate with the development of cardiotoxicity, but not the use of anti-HER-2 as single agent. The addition of troponin measurement to cardiotoxicity definition detected a greater number of events in this study, but doesn’t reflect changes in ETT parameters as LV- GLS and LVEF at this time of follow up, which means structural changes induced by treatment take time and serological measurement of troponin can enhance sensitivity and allows early detection. Further follow up and ETT assessment are needed. Table 1. Cardiotoxicity events including or not troponin levels and TTE parameters. Citation Format: Haydee Williams-Sanchez, Jose Rodrigo Espinosa-Fernandez, Sandy Ruiz-Cruz, Areli Velazquez-Martinez, Nilda Espinola-Zavaleta, Enrique C. Guerra, Alexis D Aparicio-Ortiz, Aldo Cabello-Ganem, Santiago Luna-Alcalá, Leonardo Proaño-Bernal, Neftali Eduardo Antonio-Villa. Evaluation of cardiotoxicity in Mexican patients with Breast Cancer under neoadjuvant treatment by two-dimension speckle echocardiography [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-26-03.

Serological Surveillance and Risk Factor Analysis for Parrot Bornavirus in Taiwan

Parrots are traded globally and pose a substantial risk for disease transmission involving parrot-specific pathogens. Parrot bornavirus (PaBV) belongs to the Bornaviridae family and encompasses two clades: alphapsittaciforme (PaBV-1 to -4, PaBV-7, and -8) and betapsittaciforme (PaBV-5 and PaBV-6). These clades cause proventricular dilatation disease, a chronic disease affecting all parrot species. PaBV infections can persist for varying durations in parrots, but the transmission routes are still not well understood. Therefore, surveillance of PaBV-infected parrots is necessary for disease control and improving psittacine aviculture. This study used isolated PaBV-4 NTUCL7 and PaBV-5 NTUCL54 strains to establish and validate two serological diagnostic methods: immunoblotting (IB) and immunocytochemical staining (ICC). To determine the prevalence of PaBV in parrots in Taiwan, 370 clinical serum samples were collected from 13 collaborative veterinary hospitals during a 1-year surveillance period. Serological surveillance revealed a seropositivity rate of 25.68%. Among the seropositive samples, 91.58% were infected with alphapsittaciforme PaBV, demonstrating the predominance of this viral clade in parrots. An analysis of risk factors also demonstrated an association between seropositivity and parrot genera, age, and clinical signs. Cohen’s kappa coefficient analysis showed a high degree of similarity (kappa value = 0.975) between the IB and ICC results, which shows that these serological diagnostic measures are robust. This study established two reliable serological diagnostic measures that are instrumental in serological surveillance, particularly in one of the major parrot-exporting regions. The surveillance results increase the understanding of PaBV infection and associated risk factors and allow methods to be devised for the conservation and protection of parrot populations.

A Global Perspective on Oral Vaccination of Wildlife against Rabies.

The long-term mitigation of human-domestic animal-wildlife conflicts is complex and difficult. Over the last 50 yr, the primary biomedical concepts and actualized collaborative global field applications of oral rabies vaccination to wildlife serve as one dramatic example that revolutionized the field of infectious disease management of free-ranging animals. Oral vaccination of wildlife occurred in diverse locales within Africa, Eurasia, the Middle East, and North America. Although rabies is not a candidate for eradication, over a billion doses of vaccine-laden baits distributed strategically by hand, at baiting stations, or via aircraft, resulted in widespread disease prevention, control, or local disease elimination among mesocarnivores. Pure, potent, safe, and efficacious vaccines consisted of either modified-live, highly attenuated, or recombinant viruses contained within attractive, edible baits. Since the late 1970s, major free-ranging target species have included coyotes (Canis latrans), foxes (Urocyon cinereoargenteus; Vulpes vulpes), jackals (Canis aureus; Lupulella mesomelas), raccoons (Procyon lotor), raccoon dogs (Nyctereutes procyonoides), and skunks (Mephitis mephitis). Operational progress has occurred in all but the latter species. Programmatic evaluations of oral rabies vaccination success have included: demonstration of biomarkers incorporated within vaccine-laden baits in target species as representative of bait contact; serological measurement of the induction of specific rabies virus neutralizing antibodies, indicative of an immune response to vaccine; and most importantly, the decreasing detection of rabies virus antigens in the brains of collected animals via enhanced laboratory-based surveillance, as evidence of management impact. Although often conceived mistakenly as a panacea, such cost-effective technology applied to free-ranging wildlife represents a real-world, One Health application benefiting agriculture, conservation biology, and public health. Based upon lessons learned with oral rabies vaccination of mesocarnivores, opportunities for future extension to other taxa and additional diseases will have far-reaching, transdisciplinary benefits.

Extraction of the CDRH3 sequence of the mouse antibody repertoire selected upon influenza virus infection by subtraction of the background antibody repertoire.

As specific interactions between antigens and cell-surface antibodies trigger the proliferation of B-cell clones, the frequency of each antibody sequence in the samples reflects the size of each clonal population. Nevertheless, it is extremely difficult to extract antigen-specific antibody sequences from the comprehensive bulk antibody sequences obtained from blood samples due to repertoire bias influenced by exposure to dietary antigens and other infectious agents. This issue can be addressed by subtracting the background noise from the post-immunization or post-infection repertoire data. In the present study, we propose a method to quantify repertoire data from comprehensive repertoire data. This method allowed subtraction of the background repertoire, resulting in more accurate extraction of expanded antibody repertoires upon influenza virus infection. This accurate extraction of antigen- or infection-specific repertoire information is a useful tool for vaccine evaluation.

Immunogenicity of 2-Dose HPV Vaccine Series for Postpartum Women

Postpartum human papillomavirus (HPV) vaccination is a promising strategy to increase HPV vaccination uptake in the US, particularly for reaching vaccine-naive women and those who lack health insurance beyond the pregnancy period. However, completion of the 3-dose vaccine regimen is challenging. To evaluate the immunogenicity of a 2-dose postpartum HPV vaccination regimen (0 and 6 months) and assess whether it is noninferior to a 3-dose postpartum HPV vaccination regimen (0, 1-2, and 6 months) administered to historical controls. A noninferiority, open-label, nonrandomized immunogenicity trial was conducted from August 4, 2020, to June 23, 2022, of postpartum patients aged 15 to 45 years who delivered at 2 hospitals in Baltimore, Maryland. Historical controls were adolescents and young women aged 16 to 26 years. Two doses of the nonavalent HPV vaccine administered 6 months apart. The primary outcome was noninferiority (90% CI, lower bound >0.67) of the geometric mean titer (GMT) ratio for HPV-16 among postpartum women compared with historical controls. Secondary outcomes were noninferiority of GMT ratios for the other 8 HPV types and percentage seroconversion for each HPV type. As a noninferiority trial, the primary analysis used the per-protocol analysis. Of 225 enrolled participants, the mean (SD) age at baseline was 29.9 (6.8) years, and 171 (76.0%) were HPV-16 seronegative at baseline. Of these 171 participants, 129 (75.4%) received a second vaccine dose and completed the subsequent 4-week serologic measurements. Relative to historical controls, the HPV-16 GMT ratio was 2.29 (90% CI, 2.03-2.58). At month 7, HPV-16 GMT was higher after the 2-dose regimen (7213.1 mMU/mL [90% CI, 6245.0-8331.4 mMU/mL]) than among historic controls after the 3-dose regimen (3154.0 mMU/mL [90% CI, 2860.2-3478.0 mMU/mL]). Similarly, the lower bound of the 90% CI of the GMT ratio was above 1 for the 8 HPV types 6, 11, 18, 31, 33, 45, 52, and 58. A total of 118 of 134 women (88.1%) seroconverted for HPV-16 after the first dose; 4 weeks after the second dose, the seroconversion rate was 99% or greater for all HPV types. This study suggests that immunogenicity of a 2-dose HPV vaccination regimen given 6 months apart among postpartum women was noninferior to a 3-dose regimen among young historical controls. Most women seroconverted after the first dose of the 2-dose regimen. These results demonstrate that postpartum vaccination using a reduced schedule may be a promising strategy to increase HPV vaccine series completion. ClinicalTrials.gov Identifier: NCT04274153.

Molecular and clinical effects of aromatase inhibitor therapy on skeletal muscle function in early-stage breast cancer

We evaluated biochemical changes in skeletal muscle of women with breast cancer initiating aromatase inhibitors (AI), including oxidation of ryanodine receptor RyR1 and loss of stabilizing protein calstabin1, and detailed measures of muscle function. Fifteen postmenopausal women with stage I–III breast cancer planning to initiate AI enrolled. Quadriceps muscle biopsy, dual-energy x-ray absorptiometry, isokinetic dynamometry, Short Physical Performance Battery, grip strength, 6-min walk, patient-reported outcomes, and serologic measures of bone turnover were assessed before and after 6 months of AI. Post-AI exposure, oxidation of RyR1 significantly increased (0.23 ± 0.37 vs. 0.88 ± 0.80, p < 0.001) and RyR1-bound calstabin1 significantly decreased (1.69 ± 1.53 vs. 0.74 ± 0.85, p < 0.001), consistent with dysfunctional calcium channels in skeletal muscle. Grip strength significantly decreased at 6 months. No significant differences were seen in isokinetic dynamometry measures of muscle contractility, fatigue resistance, or muscle recovery post-AI exposure. However, there was significant correlation between oxidation of RyR1 with muscle power (r = 0.60, p = 0.02) and muscle fatigue (r = 0.57, p = 0.03). Estrogen deprivation therapy for breast cancer resulted in maladaptive changes in skeletal muscle, consistent with the biochemical signature of dysfunctional RyR1 calcium channels. Future studies will evaluate longer trajectories of muscle function change and include other high bone turnover states, such as bone metastases.

The use of recombinant K39, KMP11, and crude antigen-based indirect ELISA as a serological diagnostic tool and a measure of exposure for cutaneous leishmaniasis in Sri Lanka.

Cutaneous leishmaniasis (CL) in Sri Lanka is caused by Leishmania donovani, a parasite widely known to cause visceral leishmaniasis. Despite the fact that CL is not generally believed to elicit serological immune responses, recent studies show the presence of antibody responses against this atypical form of CL. This study assesses the potential of using recombinant K39 (rK39), KMP11, and crude parasite antigen-based indirect ELISAs as serological diagnostic tools and measures of exposure for CL in Sri Lanka. The study used serum samples from confirmed CL patients (n = 266) and apparently healthy individuals from endemic settings (n = 411). Serum samples from individuals residing in non-endemic areas were used as negative controls. In-house indirect ELISAs were optimized and validated for recombinant antigens. Previously validated crude parasite extract-based indirect ELISA was performed for comparison. The statistical analyses were performed using SPSS v26.0. The rK39 (sensitivity = 71.2%, specificity = 64%) and KMP11 (sensitivity = 79.2%, specificity = 71.4%) based indirect ELISA were shown to be less suitable for the diagnosis of CL, while crude parasite extract-based indirect ELISA (sensitivity = 82.4%, specificity = 85.7%) might be a better method of diagnosis. All 03 ELISAs seemed to be good methods as measures of exposure since correlations were observed between the seropositivity of all 03 ELISAs (rK39: p = 0.037, KMP11: p = 0.007, CrudeAg: p = 0.000) with provincial case incidences. The findings will be important in identifying the disease hotspots in order to design the control measures for CL induced by L. donovani in Sri Lanka.

An Alternative Serological Measure for Assessing Foot-and-Mouth Disease Vaccine Efficacy against Homologous and Heterologous Viral Challenges in Pigs.

To analyze the relationship between homologous and heterologous serological titers of immunized pigs and their protection statuses against FMD virus challenges, in the present study, the correlation between the virus neutralization titers at 21 and 28 dpv and the protection statuses at 28 dpv against challenge with FMD virus was analyzed using data sets comprising five different combinations of homologous or heterologous challenge experiments in pigs vaccinated with type O (n = 96), A (n = 69), and Asia 1 (n = 74). As a result, the experiments were divided into three groups (21D-1, 21D-2, and 21D-3) in the 21-dpv model and two groups (28D-1 and 28D-2) in the 28-dpv model. Each response curve of groups 21D-1 and 21D-2 in the 21-dpv model was very similar to each curve of groups 28D-1 and 28D-2 in the 28-dpv model, respectively, even though there was an exceptional extra group (21D-3) in the 21-dpv model. The average titers estimating 0.75 probability of protection ranged from 1.06 to 1.62 log10 in the 21-dpv model and from 1.26 to 1.64 log10 in the 28-dpv model. In summary, we demonstrated that the serological method is useful for predicting the homologous and heterologous protection statuses of vaccinated pigs.

Dynamics of Serologic Change to Gluten in Celiac Disease Patients.

Serologic measures of tissue transglutaminase (tTG) immunoglobulin A (IgA) and deamidated gliadin peptide (DGP) IgA and immunoglobulin G (IgG) are hallmark tests utilized when diagnosing individuals for celiac disease (CeD) and for monitoring adherence to a gluten-free diet (GFD), currently the only available treatment for CeD. We address two issues in this study: (i) the relapse to seropositivity for CeD patients who resume a gluten containing diet and (ii) the correlation between two different tTG-IgA assays near the upper limit of normal (ULN) designated thresholds. Regarding the first issue, often a suspected CeD individual is put back on a gluten diet to return to their serologic levels. However, we show it requires a substantial amount of gluten for serology to return to a positive level. For example, in one study of 22 patients treated with placebo and taking 84 g of gluten over 6 weeks, only two converted from seronegative to seropositive for tTG-IgA. Regarding the second topic, we compare the relationship for different serologic assays, namely tTG-IgA AB (recombinant, ULN = 4 units/mL) vs. tTG-IgA (non-recombinant, ULN = 20 units). There is a strong correlation between both measurements as evidenced by a Pearson coefficient of R = 0.8584; however, we observed that the cross-correlation in terms of sensitivity and specificity improved substantially by using an ULN value of three instead of four for the tTG-IgA AB (recombinant) assay. This result suggests that assay thresholds used for initial diagnosis in patients who have not yet started a GFD may need to be adjusted for monitoring and in the setting of a diagnostic gluten challenge.

Systemic lupus erythematosus patients have unique changes in serum metabolic profiles across age associated with cardiometabolic risk.

Cardiovascular disease through accelerated atherosclerosis is a leading cause of mortality for patients with systemic lupus erythematosus (SLE), likely due to increased chronic inflammation and cardiometabolic defects over age. We investigated age-associated changes in metabolomic profiles of SLE patients and healthy controls (HCs). Serum NMR metabolomic profiles from female SLE patients (n = 164, age = 14-76) and HCs (n = 123, age = 13-72) were assessed across age by linear regression and by age group between patients/HCs (Group 1, age ≤ 25, n = 62/46; Group 2, age = 26-49, n = 50/46; Group 3, age ≥ 50, n = 52/31) using multiple t tests. The impact of inflammation, disease activity and treatments were assessed, and UK Biobank disease-wide association analysis of metabolites was performed. Age-specific metabolomic profiles were identified in SLE patients vs HCs, including reduced amino acids (Group 1), increased very-low-density lipoproteins (Group 2), and increased low-density lipoproteins (Group 3). Twenty-five metabolites were significantly altered in all SLE age groups, dominated by decreased atheroprotective high-density lipoprotein (HDL) subsets, HDL-bound apolipoprotein (Apo)A1 and increased glycoprotein acetyls (GlycA). Furthermore, ApoA1 and GlycA were differentially associated with disease activity and serological measures, as well as atherosclerosis incidence and myocardial infarction mortality risk through disease-wide association. Separately, glycolysis pathway metabolites (acetone/citrate/creatinine/glycerol/lactate/pyruvate) uniquely increased with age in SLE, significantly influenced by prednisolone (increased pyruvate/lactate) and hydroxychloroquine (decreased citrate/creatinine) treatment and associated with type 1 and type 2 diabetes by disease-wide association. Increasing HDL (ApoA1) levels through therapeutic/nutritional intervention, whilst maintaining low disease activity, in SLE patients from a young age could improve cardiometabolic disease outcomes. Biomarkers from the glycolytic pathway could indicate adverse metabolic effects of current therapies.

Investigating associations of multiple common infections with brain structure and white matter lesions: findings from prospective neuroimaging studies

AbstractBackgroundEvidence for a role of common infections in neurodegenerative and cerebrovascular diseases is conflicting, and the extent to which pathogen exposure associates with subclinical imaging markers of these diseases is unclear. We aimed to investigate associations between a panel of serological measures characterising exposure to common pathogens – selected based on their relevance to public health – and brain volume, hippocampal volume, and white matter lesions in two population‐based cohorts in the UK.MethodSerology and imaging data were available for 1371 participants across two studies: the UK Biobank (N = 935, mean age(SD)[years] = 55.3(7.7) at serology; 63.8(7.7) at imaging) and the Medical Research Council National Survey of Health and Development [N = 436, mean age(SD) [years] = 63.3(1.1) years at serology; 70.7(0.7) years at imaging). Serology measures included a) serostatuses of 17 pathogens, b) total proportion of 17 pathogens exposed to, and c) total proportion of 11 neurotropic pathogens exposed to (Table 1). Associations between serology measures and outcomes (brain volume, hippocampal volume, and white matter lesion volume) were tested using linear regression. Regression models included adjustments for total intracranial volume and clinic information (basic models), and age, sex, ethnicity, education, socioeconomic position and lifestyle factors (Figure 1). Findings across cohorts were meta‐analysed using random‐effects models. The present study will be expanded to include an additional cohort (Southall and Brent Revisited,N≤1200) to add more precision for identifying associations.ResultSeropositivity to seven pathogens associated with an outcome in basic models, and four in fully‐adjusted models: seropositivity to JC virus was associated with smaller brain volumes, Epstein‐Barr virus with larger brain volumes, Merkel cell virus with larger hippocampal volumes and fewer white matter lesions, and C.trachomatis with fewer white matter lesions (Figure 2). Neurotropic pathogen burden scores associated with smaller hippocampal volumes in basic models, but no associations were seen for either pathogen burden score in fully‐adjusted models.ConclusionWe found some evidence of both positive and negative associations between common infections and imaging markers of subclinical cerebrovascular disease and neurodegeneration, with no evidence of relationships with pathogen burden. This work highlights key relationships for further investigation, which may reveal novel pathways associated with brain structure and cerebrovascular pathology.

Performance evaluation of the EUROIMMUN anti‐acetylcholine receptor enzyme‐linked immunoassay

AbstractObjectivesAnti‐acetylcholine receptor antibodies (AChR Ab) are one of the pathogenic autoantibodies in myasthenia gravis (MG), and they are specifically mentioned in the Japanese clinical guidelines for MG. In the serological diagnosis and measurement of autoantibodies as an adjunct marker for MG, the radioimmunoassay (RIA) method has been conventionally used as the gold standard. However, there have been several worldwide concerns regarding the use of radioisotopes. In this study, we evaluated the performance of the EUROIMMUN AChR Ab enzyme‐linked immunosorbent assay (ELISA) in comparison with RIA.MethodsELISA reproducibility and dilution linearity were analyzed using AChR Ab‐positive samples. Sera from 50 patients with suspected MG and 50 healthy donors were used to assess the correlation and qualitative agreement between the two methods.ResultsThe ELISA showed good interassay precision and dilution linearity. The correlation coefficient, sensitivity, specificity and overall agreement of the ELISA in comparison with the conventional RIA amounted to 0.87, 98%, 92% and 95% (kappa = 0.895), respectively. Analysis of the discordant results suggested that the ELISA might be more capable of detecting low AChR Ab reactivity in patients with suspected MG.ConclusionsThe AchR Ab ELISA provides a reliable tool for the quantification of AchR Ab, supporting the diagnosis of MG. As a non‐isotopic assay with good precision, shorter handling time and high correlation with the conventional RIA, the AChR ELISA could be a useful alternative in the laboratory routine.

Polyphenol-rich diet mediates interplay between macrophage-neutrophil and gut microbiota to alleviate intestinal inflammation

Dietary phenolic acids alleviate intestinal inflammation through altering gut microbiota composition and regulating macrophage activation. However, it is unclear how individual phenolic acids affect the interactions between intestinal microbiota and macrophages in the context of inflammatory bowel disease (IBD). Here, we aim to elucidate the mechanism by which phenolic acids alleviate gut inflammation. Mice with or without depletion of macrophages were administered with four individual phenolic acids including chlorogenic, ferulic, caffeic, and ellagic acids, following dextran sulfate sodium (DSS) treatment. Gut microbiota depletion and fecal microbiota transplantation were further performed in mice to investigate the role of the gut microbiota in phenolic acid-mediated protective effect. Colitis severity was evaluated using histological, serological, and immunological measurements. Absence of intestinal microbiota and macrophage deteriorate the epithelial injury in DSS colitis. Chlorogenic acid mitigated colitis by reducing M1 macrophage polarization through suppression of pyruvate kinase M 2 (Pkm2)-dependent glycolysis and inhibition of NOD-like receptor protein 3 (Nlrp3) activation. However, ferulic acid-mediated reduction of colitis was neutrophil-dependent through diminishing the formation of neutrophil extracellular traps. On the other hand, the beneficial effects of caffeic acid and ellagic acid were dependent upon the gut microbiota. In fact, urolithin A (UroA), a metabolite transformed from ellagic acid by the gut microbiota, was found to alleviate colitis and enhance gut barrier function in an IL22-dependent manner. Overall, our findings demonstrated that the mechanisms by which phenolic acid protected against colitis were resulted from the interaction between gut microbiota and macrophage-neutrophil.

Brain-derived extracellular vesicles as serologic markers of brain injury following cardiac arrest: A pilot feasibility study

AimAssessment of neurologic injury within the immediate hours following out-of-hospital cardiac arrest (OHCA) resuscitation remains a major clinical challenge. Extracellular vesicles (EVs), small bodies derived from cytosolic contents during injury, may provide the opportunity for “liquid biopsy” within hours following resuscitation, as they contain proteins and RNA linked to cell type of origin. We evaluated whether micro-RNA (miRNA) from serologic EVs were associated with post-arrest neurologic outcome. MethodsWe obtained serial blood samples in an OHCA cohort. Using novel microfluidic techniques to isolate EVs based on EV surface marker GluR2 (present on excitatory neuronal dendrites enriched in hippocampal tissue), we employed reverse transcription quantitative polymerase chain reaction (RT-qPCR) methods to measure a panel of miRNAs and tested association with dichotomized modified Rankin Score (mRS) at discharge. ResultsEVs were assessed in 27 post-arrest patients between 7/3/2019 and 7/21/2022; 9 patients experienced good outcomes. Several miRNA species including miR-124 were statistically associated with mRS at discharge when measured within 6 hours of resuscitation (AUC = 0.84 for miR-124, p < 0.05). In a Kendall ranked correlation analysis, miRNA associations with outcome were not strongly correlated with standard serologic marker measurements, or amongst themselves, suggesting that miRNA provide distinct information from common protein biomarkers. ConclusionsThis study explores the associations between miRNAs from neuron-derived EVs (NDEs) and circulating protein biomarkers within 6 hours with neurologic outcome, suggesting a panel of very early biomarker may be useful during clinical care. Future work will be required to test larger cohorts with a broader panel of miRNA species.