scholarly journals SAT0253 ANTI-NEUTROPHIL CYTOPLASMATIC ANTIBODIES PREDATE SYMPTOM ONSET OF ANCA-ASSOCIATED VASCULITIS. A CASE-CONTROL STUDY

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1069.2-1070
Author(s):  
E. Berglin ◽  
A. J. Mohammad ◽  
J. Dahlqvist ◽  
C. Eriksson ◽  
J. Sjöwall ◽  
...  
Keyword(s):  
Cause Of Death ◽  
Symptom Onset ◽  
Severe Disease ◽  
Disease Onset ◽  
Control Sample ◽  
Discharge Summary ◽  
Serum Samples ◽  
Blood Samples ◽  
Anca Associated Vasculitis ◽  
Time Point

Background:Presence of anti-neutrophil cytoplasmatic autoantibodies (ANCA) is important for the diagnosis of ANCA-associated vasculitis (AAV) and reflects on-going immune processes. The timing of the antibody development and its contribution to disease is not well established.Objectives:To investigate the presence of proteinase 3 (PR3)- and myeloperoxidase (MPO)-ANCA in blood samples collected from healthy individuals who subsequently developed AAV.Methods:The Swedish National Patient Register of inpatient care and the Swedish Cause of Death Register were used to identify individuals assigned ICD codes for AAV (1) in the discharge summary or cause of death, respectively. The resulted cohort was then linked to the registers of 4 different biobanks to identify those with available predating blood samples. Diagnoses of AAV were confirmed and time point for onset of symptoms was identified by reviewing all available case records (1); 68 were classified as granulomatosis with polyangiitis (GPA), 14 as microscopic polyangiitis (MPA), and 4 as eosinophilic GPA (EGPA). The 86 cases (36 males, 50 females) had a mean (SD) age of 51.9 (16.9) years at sampling, with ≥1 sample (26% plasma, 74% serum samples). The sampling time point before onset of symptoms was mean (SD); 4.4 (3.1) years. Serum and plasma control samples (n=198; 82 males, 116 females; mean age (SD); 52.0 (16.5) years) were identified and matched for sex, age and date of sampling. The samples were first screened for ANCA using high sensitive ELISA (ORGANTEC diagnostika, Germany) and samples close to or above cut-off level were further analysed for capture PR3- and capture MPO-ANCA (ELISA; SVAR Life Science, Sweden). For each case one control sample was included for the ANCA specificity tests. Statistical calculations were performed using SPSS software.Results:In ANCA-screen 36.0% of the cases and 2.6 % of controls tested positive (p<0.001). 23/52 (44.2%) of the cases were PR3-ANCA positive (OR 56.3; 95% CI 7.26-436.62) and 8/52 (15.4%) were MPO-ANCA positive (OR 4.18; 95% CI 1.05-16.62). The mean (SD) predating time for PR3-ANCA positivity was 3.73 (3.49) years and for MPO-ANCA positivity 2.11 (1.46) years. Cases with positive predating PR3-ANCA were younger (46.0±19.4 vs 65.6±12.0 years; P<0.001) than cases with a negative predating PR3-ANCA. MPO-ANCA positive vs. MPO-ANCA negative pre-dating cases had more often severe disease (kidney/lung/peripheral nervous system) (OR 15.08; 95% CI 1.68—135.54) at disease onset. Furthermore, predating MPO-ANCA positive vs predating PR3-ANCA positive cases had significantly more often severe manifestations at disease onset (87.5% vs 28.6%; p<0.05). Cases positive vs. negative for MPO-ANCA in predating samples were less often classified as GPA (37.5% vs 86.4%; p<0.01) and more often as MPA (62.5% vs 13.6%; p<0.05).Conclusion:The production of both PR3 and MPO-ANCA starts already years before onset of symptoms of AAV. Presence of MPO-ANCA appeared closer to symptom onset and with more severe disease presentation. Differences in the disease phenotype and disease severity were evident between the two ANCA serotypes.References:[1]Watts et al. Ann Rheum Dis 2007;66:222-22Acknowledgments: :Vasculitis Foundation, USADisclosure of Interests:Ewa Berglin: None declared, Aladdin J Mohammad Speakers bureau: lecture fees from Roche and Elli Lilly Sweden, PI (GiACTA study), Johanna Dahlqvist: None declared, Catharina Eriksson: None declared, Johanna Sjöwall: None declared, Solbritt Rantapää Dahlqvist: None declared

scholarly journals SARS-CoV-2 RNA detected in blood products from patients with COVID-19 is not associated with infectious virus

2020 ◽  
Vol 5 ◽  
pp. 181
Author(s):  
Monique I. Andersson ◽  
Carolina V. Arancibia-Carcamo ◽  
Kathryn Auckland ◽  
J. Kenneth Baillie ◽  
Eleanor Barnes ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Severe Disease ◽  
Acute Infection ◽  
Laboratory Diagnosis ◽  
Blood Products ◽  
Rt Pcr ◽  
Serum Samples ◽  
Blood Samples ◽  
Viral Loads ◽  
Clinical Cohort

Background: Laboratory diagnosis of SARS-CoV-2 infection (the cause of COVID-19) uses PCR to detect viral RNA (vRNA) in respiratory samples. SARS-CoV-2 RNA has also been detected in other sample types, but there is limited understanding of the clinical or laboratory significance of its detection in blood. Methods: We undertook a systematic literature review to assimilate the evidence for the frequency of vRNA in blood, and to identify associated clinical characteristics. We performed RT-PCR in serum samples from a UK clinical cohort of acute and convalescent COVID-19 cases (n=212), together with convalescent plasma samples collected by NHS Blood and Transplant (NHSBT) (n=462 additional samples). To determine whether PCR-positive blood samples could pose an infection risk, we attempted virus isolation from a subset of RNA-positive samples. Results: We identified 28 relevant studies, reporting SARS-CoV-2 RNA in 0-76% of blood samples; pooled estimate 10% (95%CI 5-18%). Among serum samples from our clinical cohort, 27/212 (12.7%) had SARS-CoV-2 RNA detected by RT-PCR. RNA detection occurred in samples up to day 20 post symptom onset, and was associated with more severe disease (multivariable odds ratio 7.5). Across all samples collected ≥28 days post symptom onset, 0/494 (0%, 95%CI 0-0.7%) had vRNA detected. Among our PCR-positive samples, cycle threshold (ct) values were high (range 33.5-44.8), suggesting low vRNA copy numbers. PCR-positive sera inoculated into cell culture did not produce any cytopathic effect or yield an increase in detectable SARS-CoV-2 RNA. There was a relationship between RT-PCR negativity and the presence of total SARS-CoV-2 antibody (p=0.02). Conclusions: vRNA was detectable at low viral loads in a minority of serum samples collected in acute infection, but was not associated with infectious SARS-CoV-2 (within the limitations of the assays used). This work helps to inform biosafety precautions for handling blood products from patients with current or previous COVID-19.

scholarly journals SARS-CoV-2 RNA detected in blood samples from patients with COVID-19 is not associated with infectious virus

2020 ◽  
Author(s):  
Monique I Andersson ◽  
Carolina V Arancibia-Cárcamo ◽  
Kathryn Auckland ◽  
J Kenneth Baillie ◽  
Eleanor Barnes ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Severe Disease ◽  
Acute Infection ◽  
Laboratory Diagnosis ◽  
Rt Pcr ◽  
Serum Samples ◽  
Blood Samples ◽  
Viral Loads ◽  
Clinical Cohort ◽  
Copy Numbers

ABSTRACTBackgroundLaboratory diagnosis of SARS-CoV-2 infection (the cause of COVID-19) uses PCR to detect viral RNA (vRNA) in respiratory samples. SARS-CoV-2 RNA has also been detected in other sample types, but there is limited understanding of the clinical or laboratory significance of its detection in blood.MethodsWe undertook a systematic literature review to assimilate the evidence for the frequency of vRNA in blood, and to identify associated clinical characteristics. We performed RT-PCR in serum samples from a UK clinical cohort of acute and convalescent COVID-19 cases (n=212), together with convalescent plasma samples collected by NHS Blood and Transplant (NHSBT) (n=111 additional samples). To determine whether PCR-positive blood samples could pose an infection risk, we attempted virus isolation from a subset of RNA-positive samples.ResultsWe identified 28 relevant studies, reporting SARS-CoV-2 RNA in 0-76% of blood samples; pooled estimate 10% (95%CI 5-18%). Among serum samples from our clinical cohort, 27/212 (12.7%) had SARS-CoV-2 RNA detected by RT-PCR. RNA detection occurred in samples up to day 20 post symptom onset, and was associated with more severe disease (multivariable odds ratio 7.5). Across all samples collected ≥28 days post symptom onset, 0/143 (0%, 95%CI 0.0-2.5%) had vRNA detected. Among our PCR-positive samples, cycle threshold (ct) values were high (range 33.5-44.8), suggesting low vRNA copy numbers. PCR-positive sera inoculated into cell culture did not produce any cytopathic effect or yield an increase in detectable SARS-CoV-2 RNA.ConclusionsvRNA was detectable at low viral loads in a minority of serum samples collected in acute infection, but was not associated with infectious SARS-CoV-2 (within the limitations of the assays used). This work helps to inform biosafety precautions for handling blood products from patients with current or previous COVID-19.

scholarly journals SARS-CoV-2 RNA detected in blood products from patients with COVID-19 is not associated with infectious virus

2020 ◽  
Vol 5 ◽  
pp. 181
Author(s):  
Monique I. Andersson ◽  
Carolina V. Arancibia-Carcamo ◽  
Kathryn Auckland ◽  
J. Kenneth Baillie ◽  
Eleanor Barnes ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Severe Disease ◽  
Acute Infection ◽  
Laboratory Diagnosis ◽  
Blood Products ◽  
Rt Pcr ◽  
Serum Samples ◽  
Blood Samples ◽  
Viral Loads ◽  
Clinical Cohort

Background: Laboratory diagnosis of SARS-CoV-2 infection (the cause of COVID-19) uses PCR to detect viral RNA (vRNA) in respiratory samples. SARS-CoV-2 RNA has also been detected in other sample types, but there is limited understanding of the clinical or laboratory significance of its detection in blood. Methods: We undertook a systematic literature review to assimilate the evidence for the frequency of vRNA in blood, and to identify associated clinical characteristics. We performed RT-PCR in serum samples from a UK clinical cohort of acute and convalescent COVID-19 cases (n=212), together with convalescent plasma samples collected by NHS Blood and Transplant (NHSBT) (n=462 additional samples). To determine whether PCR-positive blood samples could pose an infection risk, we attempted virus isolation from a subset of RNA-positive samples. Results: We identified 28 relevant studies, reporting SARS-CoV-2 RNA in 0-76% of blood samples; pooled estimate 10% (95%CI 5-18%). Among serum samples from our clinical cohort, 27/212 (12.7%) had SARS-CoV-2 RNA detected by RT-PCR. RNA detection occurred in samples up to day 20 post symptom onset, and was associated with more severe disease (multivariable odds ratio 7.5). Across all samples collected ≥28 days post symptom onset, 0/494 (0%, 95%CI 0-0.7%) had vRNA detected. Among our PCR-positive samples, cycle threshold (ct) values were high (range 33.5-44.8), suggesting low vRNA copy numbers. PCR-positive sera inoculated into cell culture did not produce any cytopathic effect or yield an increase in detectable SARS-CoV-2 RNA. Conclusions: vRNA was detectable at low viral loads in a minority of serum samples collected in acute infection, but was not associated with infectious SARS-CoV-2 (within the limitations of the assays used). This work helps to inform biosafety precautions for handling blood products from patients with current or previous COVID-19.

scholarly journals THU0296 PROTEIN PROFILING IN INDIVIDUALS BEFORE ONSET OF ANCA-ASSOCIATED VASCULITIS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 376.2-376
Author(s):  
E. Berglin ◽  
A. Esberg ◽  
J. Dahlqvist ◽  
J. Sjöwall ◽  
A. Lundquist ◽  
...  
Keyword(s):  
Immune System ◽  
Growth Factor ◽  
Random Forest ◽  
Symptom Onset ◽  
Partial Least Square ◽  
Protein Profiling ◽  
Serum Samples ◽  
Anca Associated Vasculitis ◽  
Significant Difference ◽  
Novel Biomarkers

Background:Etiology and pathogenesis of ANCA-associated vasculitis (AAV) is multifactorial and understanding of the processes leading from a healthy immune system to autoimmunity and on to debut of symptoms in AAV is rudimentary.Objectives:To identify inflammatory proteins related to the early processes preceding AAV development, and potential novel biomarkers, using large-scale protein analysesMethods:The Swedish National Patient Register of in-patient carevand the Swedish Cause of Death Register with discharge diagnosis from ICD-9 and-10 for AAV were co-analysed with the registers of 4 different blood biobanks to identify AAV individuals with available samples predating onset of symptom. Of the pre-AAV cases 86 (36 male, 50 female; mean age (SD); 51.9 (16.9) years) were identified with at least one plasma or serum sample (28 plasma, and 100 serum) pre-dating symptom onset (mean (SD); -4.3 (3.1) years), and 14 had 2-3 samples. Serum and plasma control samples matched for sex, age and sampling date were identified (n=198; 82 male, 116 female; mean age (SD); 51.9±15.9 years). The samples were analysed for levels of 92 proteins using proximity extension assay (OLINK inflammation panel, SciLifeLab, Uppsala, Sweden). Data were analysed using routine statistical methods, random forest and Partial Least square-discriminant analysis (PLS-DA).Results:As previously described for the assay significant difference between plasma and serum samples were observed both in pre-AAV individuals and controls. In pre-AAV plasma samples significantly increased concentrations of interleukin (IL)-2, chemokine ligand (CCL)-4, fibroblast growth factor (FGF)21, IL-4 and CCL20 were found closer to symptom onset, (<5 years) than later (> 5 years) and compared with controls. In serum tumor necrosis factor receptor superfamily member (TNFRSF)9, CXCL9, osteoprotegerin and vascular endothelial growth factor-A were significantly increased <5 years before onset vs. later (>5 years) and compared with controls. PLS-DA score scattered plot separated the pre-AAV individuals from healthy controls (R2=0.26), with significantly increased levels of CCL23, CXCL5, and matrix metalloproteinases-1 (MMP-1),transforming growth factor-ß, orosomucoid, en-rage (S100A12) and IL-7 and decreased FGF-19 level in serum. Binary logistic regression analyses comparing tertiles for these proteins confirmed significantly increased odds ratios for disease development of CCL23, CXCL5 and MMP-1. The findings were confirmed in random forest analysis where these factors were among the 20 most discriminatory factors between pre-symptomatic AAV and controls.Conclusion:In serum samples collected years before symptom onset of AAV, proteins involved in immune system activation were increased, suggesting that the inflammatory process is initiated long before clinical manifestations of the disease appear. These findings propose the elevated proteins as novel biomarkers for disease progression.References:[1]Watts et al. Ann Rheum Dis 2007;66:222-22Acknowledgments:Vasculitis Foundation, USADisclosure of Interests:Ewa Berglin: None declared, Anders Esberg: None declared, Johanna Dahlqvist: None declared, Johanna Sjöwall: None declared, Anders Lundquist: None declared, Kristina Lejon: None declared, Ingegerd Johansson: None declared, Aladdin J Mohammad Speakers bureau: lecture fees from Roche and Elli Lilly Sweden, PI (GiACTA study), Solbritt Rantapää Dahlqvist: None declared

scholarly journals Analytical and diagnostic performances of a high-throughput immunoassay for SARS-CoV-2 IgM and IgG

2020 ◽  
Author(s):  
Andrea Padoan ◽  
Chiara Cosma ◽  
Paolo Zaupa ◽  
Mario Plebani
Keyword(s):  
Sensitivity And Specificity ◽  
Symptom Onset ◽  
Severe Disease ◽  
Onset Time ◽  
Time Frame ◽  
Serum Samples ◽  
Time Period ◽  
Analytical Imprecision ◽  
Range Of Values

BackgroundAbstractReliable SARS-CoV-2 serological assays are required for diagnosing infections, for the serosurveillance of past exposures and for assessing the response to future vaccines. In this study, the analytical and clinical performances of a chemiluminescent immunoassays for SARS-CoV-2 IgM and IgG detection (Mindray CL-1200i), targeting Nucleocapsid (N) and receptor binding domain (RBD) portion of the Spike protein, were evaluated.MethodsPrecision and linearity were evaluated using standardized procedures. A total of 157 leftover serum samples from 81 hospitalized confirmed COVID-19 patients (38 with moderate and 43 with severe disease) and 76 SARS-CoV-2 negative subjects (44 healthcare workers, 20 individuals with rheumatic disorders, 12 pregnant women) were included in the study. In an additional series of 44 SARS-CoV-2 positive, IgM and IgG time kinetics were also evaluated in a time-period of 38 days.ResultsPrecision was below or equal to 4% for both IgM and IgG, in all the studied levels, whilst a slightly significant deviation from linearity was observed for both assays in the range of values covering the manufacturer’s cut-off. Considering a time frame ≥ 12 days post symptom onset, sensitivity and specificity for IgM were 92.3% (95%CI:79.1%-98.4%) and 92.1% (95%CI:83.6%-97.0%). In the same time frame, sensitivity and specificity for IgG were 100% (95%CI:91.0%-100%) and 93.4% (95%CI:85.3%-97.8%). The assays agreement was 73.9% (Cohen’s kappa of 0.373). Time kinetics showed a substantial overlapping of IgM and IgG response, the latter values being elevated up to 38 days from symptoms onset.ConclusionsAnalytical imprecision is satisfactory as well as the linearity, particularly when taking into account the fact that both assays are claimed to be qualitative. Diagnostic sensitivity of IgG was excellent, especially considering specimens collected ≥12 days post symptom onset. Time kinetics suggest that IgM and IgG are detectable early in the course of infection, but the role of SARS-CoV-2 antibodies in clinical practice still requires further evaluations.

scholarly journals Epidemiological parameters of coronavirus disease 2019: a pooled analysis of publicly reported individual data of 1155 cases from seven countries

2020 ◽  
Author(s):  
Shujuan Ma ◽  
Jiayue Zhang ◽  
Minyan Zeng ◽  
Qingping Yun ◽  
Wei Guo ◽  
...  
Keyword(s):  
Latent Period ◽  
Incubation Period ◽  
Symptom Onset ◽  
Severe Disease ◽  
Individual Data ◽  
Robust Estimates ◽  
Upper Limit ◽  
Serial Interval ◽  
Epidemiological Parameters ◽  
Time Point

SummaryBackgroundThe outbreak of coronavirus disease 2019 (COVID-19) has been declared a pandemic by the World Health Organization, while several key epidemiological parameters of the disease remain to be clarified. This study aimed to obtain robust estimates of the incubation period, upper limit of latent period (interval between infector’s exposure and infectee’s exposure), serial interval, time point of exposure (the day of infectee’s exposure to infector relative to the latter’s symptom onset date) and basic reproduction number (R0) of COVID-19.MethodsBetween late February and early March of 2020, the individual data of laboratory confirmed cases of COVID-19 were retrieved from 10728 publicly available reports released by the health authorities of and outside China and from 1790 publications identified in PubMed and CNKI. To be eligible, a report had to contain the data that allowed for estimation of at least one parameter. As relevant data mainly came from clustering cases, the clusters for which no evidence was available to establish transmission order were all excluded to ensure accuracy of estimates. Additionally, only the cases with an exposure period spanning 3 days or less were included in the estimation of parameters involving exposure date, and a simple method for determining exposure date was adopted to ensure the error of estimates be small (< 0.3 day). Depending on specific parameters, three or four of normal, lognormal, Weibull, and gamma distributions were fitted to the datasets and the results from appropriate models were presented.FindingsIn total, 1155 cases from China, Japan, Singapore, South Korea, Vietnam, Germany and Malaysia were included for the final analysis. The mean and standard deviation were 7.44 days and 4.39 days for incubation period, 2.52 days and 3.95 days for the upper limit of latent period, 6.70 days and 5.20 days for serial interval, and −0.19 day (i.e., 0.19 day before infector’s symptom onset) and 3.32 days for time point of exposure. R0 was estimated to be 1.70 and 1.78 based on two different formulas. For 39 (6.64%) cases, the incubation periods were longer than 14 days. In 102 (43.78%) infector-infectee pairs, transmission occurred before infectors’ symptom onsets. In 27 (3.92%) infector-infectee pairs, infectees’ symptom onsets occurred before those of infectors. Stratified analysis showed that incubation period and serial interval were consistently longer for those with less severe disease and for those whose primary cases had less severe disease. Asymptomatic transmission was also observed.InterpretationThis study obtained robust estimates of several key epidemiological parameters of COVID-19. The findings support current practice of 14-day quarantine of persons with potential exposure, but also suggest that longer monitoring periods might be needed for selected groups. The estimates of serial interval, time point of exposure and latent period provide consistent evidence on pre-symptomatic transmission. This together with asymptomatic transmission and the generally longer incubation and serial interval of less severe cases suggests a high risk of long-term epidemic in the absence of appropriate control measures.FundingThis work received no funding from any source.

scholarly journals PSII-28 Effect of route of administration of dinoprost tromethamine on serum profiles of PGFM and progesterone in lactating Holstein cows

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 377-377
Author(s):  
Megan A Mezera ◽  
Megan R Lauber ◽  
Adam D Beard ◽  
Elisa M Cabrera ◽  
Milo C Wiltbank ◽  
...  
Keyword(s):  
Route Of Administration ◽  
Holstein Cows ◽  
Serum Samples ◽  
Blood Samples ◽  
Prostaglandin F2 Alpha ◽  
To Receive ◽  
Time Point

Abstract Our objective was to compare serum profiles of 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) and circulating progesterone (P4) concentrations in lactating Holstein cows based on route of administration of dinoprost tromethamine administered 7 d after administration of GnRH. Multiparous lactating Holstein cows were fitted with indwelling jugular catheters 6 d after the last GnRH treatment of an Ovsynch protocol (d 0), and cows were randomized on d 7 to receive 25 mg dinoprost tromethamine (2 mL Lutalyse® HighCon; Zoetis, Parsippany-Troy Hills, NJ) either s.c. in the neck (SC; n = 6) or i.m. in the semitendenous muscle (IM; n = 6). Blood samples were collected via jugular catheters 24, 2, and 1 h before treatment to establish baseline P4 concentrations. Blood samples were collected every 15 min after treatment for 1.75 h, then every 30 min for 48 h, and at 60 and 72 h with the last time point corresponding to timed AI after an Ovsynch protocol. Serum samples were stored frozen and later assayed for PGFM and P4 concentrations via ELISA. Circulating PGFM concentrations were greater (P &lt; 0.05) for SC than for IM cows from 15 to 90 minutes after treatment which resulted in a greater (P = 0.02) area under the PGFM curve during the first 2 h after treatment (2,223 ± 160 pg•hr/mL vs. 1,586 ± 150 pg•hr/mL for SC vs. IM cows, respectively). By contrast, circulating P4 concentrations normalized to percent of baseline P4 concentrations did not differ between treatments at any time point after treatment during the experiment. In conclusion, although SC cows had greater circulating PGFM concentrations 15 to 90 min after treatment than IM cows, the decrease in circulating P4 concentrations during induced luteolysis did not differ based on route of dinoprost tromethamine administration. Supported by NIFA USDA Hatch project 1019532.

scholarly journals Toxemia in Human Naturally Acquired Botulism

Toxins ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 716
Author(s):  
Christine Rasetti-Escargueil ◽  
Emmanuel Lemichez ◽  
Michel R. Popoff
Keyword(s):  
Severe Disease ◽  
Disease Onset ◽  
High Specificity ◽  
Mouse Bioassay ◽  
Serum Samples ◽  
Wound Botulism ◽  
Food Borne ◽  
Autoimmune Neuropathy ◽  
Infant Botulism

Human botulism is a severe disease characterized by flaccid paralysis and inhibition of certain gland secretions, notably salivary secretions, caused by inhibition of neurotransmitter release. Naturally acquired botulism occurs in three main forms: food-borne botulism by ingestion of preformed botulinum neurotoxin (BoNT) in food, botulism by intestinal colonization (infant botulism and intestinal toxemia botulism in infants above one year and adults), and wound botulism. A rapid laboratory confirmation of botulism is required for the appropriate management of patients. Detection of BoNT in the patient’s sera is the most direct way to address the diagnosis of botulism. Based on previous published reports, botulinum toxemia was identified in about 70% of food-borne and wound botulism cases, and only in about 28% of infant botulism cases, in which the diagnosis is mainly confirmed from stool sample investigation. The presence of BoNT in serum depends on the BoNT amount ingested with contaminated food or produced locally in the intestine or wound, and the timeframe between serum sampling and disease onset. BoNT levels in patient’s sera are most frequently low, requiring a highly sensitive method of detection. Mouse bioassay is still the most used method of botulism identification from serum samples. However, in vitro methods based on BoNT endopeptidase activity with detection by mass spectrometry or immunoassay have been developed and depending on BoNT type, are more sensitive than the mouse bioassay. These new assays show high specificity for individual BoNT types and allow more accurate differentiation between positive toxin sera from botulism and autoimmune neuropathy patients.

scholarly journals The dynamic antibody responses on COVID-19 patients with different severity: A retrospective research

2020 ◽  
Author(s):  
Wanrong Lu ◽  
Ping Wu ◽  
Liang He ◽  
Yifan Meng ◽  
Peng Wu ◽  
...  
Keyword(s):  
Regression Models ◽  
Severe Disease ◽  
Disease Onset ◽  
Antibody Responses ◽  
Clinical Severity ◽  
Serum Samples ◽  
Logistic Regression Models ◽  
The Difference ◽  
Igg Level

Abstract ObjectivesWe aimed to explore the association between dynamic antibody responses and the clinical severity of COVID-19. MethodsWe collected complete follow-up data of 777 pathogen-confirmed COVID-19 patients with corresponding IgG/IgM testing results. ResultsWe found the overall positive rates of IgG and IgM in severe patients were slightly higher than those in non-severe patients. In addition, higher IgG levels were detected in severe patients compared with non-severe patients (P=0.026). Through further analysis, our results showed that the statistical difference in the IgG only significant in serum samples taken ≤14 days from disease onset (P<0.001). In 74 patients who taken detection more than three times, by analyzing the antibody expression levels at different time points, we found that the difference between IgG was more obvious than that of IgM among severe/non-severe patients. In multivariate logistic regression models, after adjusting for cofactors, the higher anti-SARS-CoV-2 IgG level before 14 days from disease onset was independently associated with severe disease in COVID-19 (OR=1.310, 95%CI= 1.137-1.509).ConclusionWe observed differences in antibody responses among COVID-19 patients with different disease severity. A high IgG level in the first 14 days from disease onset might positively associate with severe disease.

scholarly journals PRRSV detection by qPCR in processing fluids and serum samples collected in a positive stable breeding herd following mass vaccination of sows with a modified live vaccine

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
A. Lebret ◽  
P. Berton ◽  
V. Normand ◽  
I. Messager ◽  
N. Robert ◽  
...  
Keyword(s):  
The United States ◽  
Live Vaccine ◽  
Mass Vaccination ◽  
Respiratory Syndrome Virus ◽  
Serum Samples ◽  
Blood Samples ◽  
Stability Monitoring ◽  
Breeding Herd ◽  
Modified Live Vaccine ◽  
Processing Fluid

AbstractIn the last two decades, in France, Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) stabilization protocols have been implemented using mass vaccination with a modified live vaccine (MLV), herd closure and biosecurity measures. Efficient surveillance for PRRSV is essential for generating evidence of absence of viral replication and transmission in pigs. The use of processing fluid (PF) was first described in 2018 in the United States and was demonstrated to provide a higher herd-level sensitivity compared with blood samples (BS) for PRRSV monitoring. In the meantime, data on vertical transmission of MLV viruses are rare even as it is a major concern. Therefore, veterinarians usually wait for several weeks after a sow mass vaccination before starting a stability monitoring. This clinical study was conducted in a PRRSV-stable commercial 1000-sow breed-to-wean farm. This farm suffered from a PRRS outbreak in January 2018. After implementing a stabilisation protocol, this farm was controlled as stable for more than 9 months before the beginning of the study. PF and BS at weaning were collected in four consecutive batches born after a booster sow mass MLV vaccination. We failed to detect PRRSV by qPCR on PF and BS collected in a positive-stable breeding herd after vaccination with ReproCyc® PRRS EU (Boehringer Ingelheim, Ingelheim, Germany).

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