Validation of commercial assays for measurements of trefoil factor family peptides in serum

2011 ◽  
Vol 49 (12) ◽  
Author(s):  
Mie H. Samson ◽  
Ebba Nexo
Keyword(s):  
Blood Donors ◽  
Reference Intervals ◽  
Cross Reactivity ◽  
Serum Concentrations ◽  
Trefoil Factor ◽  
Serum Samples ◽  
Measuring Range ◽  
Trefoil Peptides ◽  
Pathological Conditions ◽  
Trefoil Factor Family

AbstractTrefoil peptides (TFF1, TFF2 and TFF3) are 7–12 kDa molecules, secreted by mucin-producing epithelial cells. Increased serum concentrations have been reported in a number of pathological conditions, which warrants the need for validated commercially available assays.We validated commercial assays for TFF1-3 and compared results obtained with our in-house assays, using serum from blood donors.Level of detection was: ≤0.008 nmol/L. Measuring ranges were: 0.032–0.51 (TFF1), 0.038–0.76 (TFF2) and 0.019–0.15 (TFF3) nmol/L. Imprecision (CV), judged from the measurement of serum pools in two levels, was below 9% (TFF2 and TFF3) but up to 18% (mean 0.41 nmol/L) for TFF1. No cross reactivity between the TFFs (concentrations >100 nmol/L) was observed. The 95% non-parametric reference intervals were: <0.0032–0.53 (TFF1), 0.099–1.4 (TFF2) and 0.086–0.87 (TFF3) nmol/L. Comparing commercial to in-house assays (n=132), showed biases explained by differences in the calibrators (TFF1 and TFF2). A number of samples showed markedly different results.The commercial assays for TFF2 and TFF3 are acceptable for use on serum samples, while the TFF1 assay revealed a poor imprecision and a too narrow measuring range. Results obtained with the commercial and the in-house assays differed, partly because of differences in the calibrators employed.

scholarly journals Quantification and Characterization of Pregnancy-associated Complexes of Angiotensinogen and the Proform of Eosinophil Major Basic Protein in Serum and Amniotic Fluid

2000 ◽  
Vol 46 (8) ◽  
pp. 1099-1105 ◽  
Author(s):  
Michael Christiansen ◽  
Irakli Jaliashvili ◽  
Michael T Overgaard ◽  
Christian Ensinger ◽  
Peter Obrist ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Blood Donors ◽  
Basic Protein ◽  
Gel Filtration ◽  
Clinical Importance ◽  
Serum Concentrations ◽  
Major Basic Protein ◽  
Pathological Conditions ◽  
Eosinophil Major Basic Protein

Abstract Background: The proform of eosinophil major basic protein (ProMBP) exists in serum from pregnant women complexed with a variable fraction of angiotensinogen (Ang). A subfraction further binds complement C3dg in a 2:2:2 complex. The function, physiology, and clinical importance of ProMBP complexes are unknown, and the specific quantification of these complexes has not been possible. Methods: We developed an ELISA for the ProMBP/Ang complexes, using a monoclonal antibody against ProMBP for capture and a chicken anti-human Ang antiserum for detection. Calibrators were standardized with WHO IRP 78/610 for pregnancy proteins in the assay range 0.95–15.6 mIU/L. Results: The concentrations of ProMBP/Ang complexes in serum of nonpregnant blood donors (n = 79) were log-normally distributed with a central 95th interval of 985-3655 mIU/L. In pregnancy, mean serum concentrations were increased from week 7, and the concentrations reached term concentrations in week 18. ProMBP/Ang complexes eluted in gel filtration as a broad peak with a molecular mass of ∼230 kDa. The concentration of ProMBP/Ang/C3dg increased during blood coagulation, suggesting that the ProMBP/Ang/C3dg complex may be a marker of complement activation. Conclusions: ProMBP/Ang complexes are present in serum from nonpregnant persons as well as pregnant women, and the direct assays described here will make it possible to study the biochemistry and the clinical significance of different ProMBP complexes in pathological conditions and pregnancy.

scholarly journals Development of a Rapid and Sensitive Immunofluorometric Assay for Glutathione S-Transferase A

2001 ◽  
Vol 47 (5) ◽  
pp. 867-873 ◽  
Author(s):  
Laila K Dajani ◽  
Elisabeth Paus ◽  
David J Warren
Keyword(s):  
Blood Donors ◽  
Dynamic Range ◽  
Biological Fluids ◽  
Reference Interval ◽  
Reference Intervals ◽  
Serum Samples ◽  
Time Resolved ◽  
Prolonged Incubation ◽  
Routine Clinical Setting ◽  
Liver Markers

Abstract Background: The short half-life of the α-class glutathione S-transferases (GSTAs) in plasma combined with their even distribution throughout the liver lobule suggests that they may be useful complements to the more traditionally used liver markers. However, the currently available assays for measuring GSTAs in biological fluids have a poor dynamic range and are cumbersome, requiring multiple steps and prolonged incubation times. Methods: Hybridomas that secrete monoclonal antibodies to human GSTAs were produced and used to develop a rapid one-step immunometric assay for the determination of GSTA in serum. The assay uses a time-resolved immunofluorometric assay (TR-IFMA) format and requires 35 min of incubation. The reference interval was determined using 208 serum samples from healthy blood donors. We also compared our TR-IFMA with a commercially available enzyme immunoassay (EIA) for GSTAs. Results: The assay had a detection limit of 0.07 μg/L with a measuring range up to 625 μg/L. Within-run imprecision (CV) was 1.8–2.6% over the concentrations of GSTA tested (2.5–311 μg/L), with a between-run CV of &lt;5%. In healthy blood donors, the median values and reference intervals were 2.0 μg/L and 0.6–7.2 μg/L for females and 2.6 μg/L and 0.7–9.8 μg/L for males, respectively. GSTA concentrations determined with the TR-IFMA correlated well with those obtained using a commercially available EIA. Conclusions: This report describes a new assay for monitoring the concentrations of GSTAs in human serum. The method may be useful in further evaluating the potential of monitoring serum GSTAs in the routine clinical setting.

scholarly journals Comparison of sixteen serological SARS-CoV-2 immunoassays in sixteen clinical laboratories

2020 ◽  
Author(s):  
Lene Holm Harritshoej ◽  
Mikkel Gybel-Brask ◽  
Shoaib Afzal ◽  
Pia R. Kamstrup ◽  
Charlotte Svaerke Joergensen ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Blood Donors ◽  
High Sensitivity ◽  
Cross Reactivity ◽  
Nucleic Acid Amplification ◽  
Limited Data ◽  
Serum Samples ◽  
Diagnostic Use ◽  
Ig G ◽  
Abbott Architect

Serological SARS-CoV-2 assays are needed to support clinical diagnosis and epidemiological investigations. Recently, assays for the large-volume detection of total antibodies (Ab) and immunoglobulin (Ig) G and M against SARS-CoV-2 antigens have been developed, but there are limited data on the diagnostic accuracy of these assays. This study was organized as a Danish national collaboration and included fifteen commercial and one in-house anti-SARS-CoV-2 assays in sixteen laboratories. Sensitivity was evaluated using 150 serum samples from individuals diagnosed with asymptomatic, mild or moderate nonhospitalized (n=129) or hospitalized (n=31) COVID-19, confirmed by nucleic acid amplification tests, collected 13-73 days from symptom onset. Specificity and cross-reactivity were evaluated in samples collected prior to the SARS-CoV-2 epidemic from > 586 blood donors and patients with autoimmune diseases or CMV or EBV infections. Predefined specificity criteria of ≥99% were met by all total-Ab and IgG assays except one (Diasorin/LiaisonXL-IgG 97.2%). The sensitivities in descending order were: Wantai/ELISA total-Ab (96.7%), CUH/NOVO in-house ELISA total-Ab (96.0%), Ortho/Vitros total-Ab (95.3%), YHLO/iFlash-IgG (94.0%), Ortho/Vitros-IgG (93.3%), Siemens/Atellica total-Ab (93.2%), Roche-Elecsys total-Ab (92.7%), Abbott-Architect-IgG (90.0%), Abbott/Alinity-IgG (median 88.0%), Diasorin/LiaisonXL-IgG (84.6%), Siemens/Vista total-Ab (81.0%), Euroimmun/ELISA-IgG (78.0%), and Snibe/Maglumi-IgG (median 78.0%). The IgM results were variable, but one assay (Wantai/ELISA-IgM) had both high sensitivity (82.7%) and specificity (99%). The rate of seropositivity increased with time from symptom onset and symptom severity. In conclusion, predefined sensitivity and specificity acceptance criteria of 90%/99%, respectively, for diagnostic use were met in five of six total-Ab and three of seven IgG assays.

Alterations in serum thyroid hormones in euthyroid children with circulating anti-thyroid antibodies

1982 ◽  
Vol 99 (4) ◽  
pp. 500-507 ◽  
Author(s):  
Salvador Villalpando ◽  
Ignacia Cisneros ◽  
Guadalupe García-Bulnes ◽  
Bárbara Urquieta ◽  
Lourdes Mondragón ◽  
...  
Keyword(s):  
Clinical Symptoms ◽  
Age Distribution ◽  
Serum Levels ◽  
Paper Electrophoresis ◽  
Cross Reactivity ◽  
High Serum ◽  
Thyroid Antibodies ◽  
Serum Concentrations ◽  
Serum Samples ◽  
Scanty Information

Abstract. Anti-thyroid antibodies are frequently found in otherwise normal populations (4.5–25.8%); however, there is scanty information about thyroid function status in affected individuals. In this report, the serum concentrations of TSH, T3, T4, rT3 and TBG and the titre of anti-thyroglobulin and anti-microsomal antibodies (haemagglutination technique) were studied in 520 healthy school children (260 boys and 260 girls) aged 6.0–17.9 years. Titres equal or greater than 1:16 of one or both antibodies were detected in 58 boys and in 77 girls (in 33 boys and in 24 girls with, and in 25 boys and 43 girls without, associated abnormalities in the serum concentrations of one or several hormones). The age distribution of thyroid antibodies followed a trimodal pattern with peaks at 7, 11 and 16–17 years in both sexes. The most striking finding was an abnormally elevated T3 concentration in 22 boys and 5 girls with positive antibodies, with no symptoms of thyroid dysfunction and with no clear relationship with simultaneous abnormalities in TSH, T4 or rT3; however, in 5 boys the TBG serum levels were increased. Serum from these patients was incubated with [125I]T3 before free radioactivity was precipitated with dextran-coated charcoal and the aliquots were analyzed by paper electrophoresis. Serum samples with high T3 levels bound significantly more radioactivity than normal or T3-free serum (P < 0.001) and an abnormal peak of radioactivity was present in the gamma globulin fraction, in the former but not in the latter two types of sera. The presence of high serum T3 levels in the absence of clinical symptoms of hyperthyroidism was probably due to sequestration of T3 by the anti-thyroglobulin antibody, which may have cross-reactivity with T3 and T4, as has previously been demonstrated both in animals and humans.

Trefoil factor family peptides are increased in the saliva of children with mucositis

2011 ◽  
Vol 49 (12) ◽  
Author(s):  
Fran Verey ◽  
Ebba Nexo ◽  
Rosemary Greenwood ◽  
Monica Berry ◽  
Anthony P. Corfield
Keyword(s):  
Rank Correlation ◽  
Oral Disease ◽  
Healthy Children ◽  
Trefoil Factor ◽  
Oncology Patients ◽  
Trefoil Peptides ◽  
Trefoil Peptide ◽  
Healing Phase ◽  
Trefoil Factor Family ◽  
Pre Treatment

AbstractMucositis is a painful ulcerative condition of the oral cavity and gastrointestinal tract, occurring in association with chemotherapy and radiotherapy regimes. Trefoil factor family peptides (TFF, trefoil peptides), present in saliva, contribute to epithelial restitution and repair and are therefore potentially important in the healing phase of mucositis. This study aimed to assess any changes in the levels of trefoil peptides in oncology patients with and without mucositis.Saliva was collected from healthy children, pre-treatment oncology patients, neutropenic patients on treatment with no oral disease and mucositic patients. TFF1, 2 and 3 were quantified using ELISA.In healthy children TFF2 and 3 were positively correlated with age (ρ=0.454, p=0.01 for TFF2; ρ=0.410, p=0.05 for TFF3 Spearman rank correlation). TFF3 was higher in mucositis compared to all other groups. A linear regression prediction model indicated that TFF3, but not TFF1 and TFF2, was significantly different in mucositic and healthy controls, suggesting an altered pattern of trefoil peptide secretion (p=0.021).This study is the first to focus on trefoil peptides in paediatric saliva. It shows the correlation between TFF2, TFF3 and age in healthy children. Paediatric mucositis disease occurs in the presence of increased concentrations and an altered pattern of trefoil peptides.

scholarly journals A Label and Probe-Free Zika Virus Immunosensor Prussian Blue@carbon Nanotube-Based for Amperometric Detection of the NS2B Protein

Biosensors ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 157
Author(s):  
Bárbara V. M. Silva ◽  
Marli T. Cordeiro ◽  
Marco A. B. Rodrigues ◽  
Ernesto T. A. Marques ◽  
Rosa F. Dutra
Keyword(s):  
Carbon Nanotube ◽  
Prussian Blue ◽  
Zika Virus ◽  
Point Of Care ◽  
Amperometric Detection ◽  
Cross Reactivity ◽  
Structural Protein ◽  
Serum Samples ◽  
Polypyrrole Composite ◽  
Congenital Disabilities

Zika virus (ZIKV) is a mosquito-borne infection, predominant in tropical and subtropical regions causing international concern due to the ZIKV disease having been associated with congenital disabilities, especially microcephaly and other congenital abnormalities in the fetus and newborns. Development of strategies that minimize the devastating impact by monitoring and preventing ZIKV transmission through sexual intercourse, especially in pregnant women, since no vaccine is yet available for the prevention or treatment, is critically important. ZIKV infection is generally asymptomatic and cross-reactivity with dengue virus (DENV) is a global concern. An innovative screen-printed electrode (SPE) was developed for amperometric detection of the non-structural protein (NS2B) of ZIKV by exploring the intrinsic redox catalytic activity of Prussian blue (PB), incorporated into a carbon nanotube–polypyrrole composite. Thus, this immunosensor has the advantage of electrochemical detection without adding any redox-probe solution (probe-less detection), allowing a point-of-care diagnosis. It was responsive to serum samples of only ZIKV positive patients and non-responsive to negative ZIKV patients, even if the sample was DENV positive, indicating a possible differential diagnosis between them by NS2B. All samples used here were confirmed by CDC protocols, and immunosensor responses were also checked in the supernatant of C6/36 and in Vero cell cultures infected with ZIKV.

scholarly journals MMP-7 Serum and Tissue Levels Are Associated with Poor Survival in Platinum-Treated Bladder Cancer Patients

Diagnostics ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 48
Author(s):  
Tibor Szarvas ◽  
Michèle J. Hoffmann ◽  
Csilla Olah ◽  
Eszter Szekely ◽  
Andras Kiss ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Cancer Patients ◽  
Cell Lines ◽  
Checkpoint Inhibitors ◽  
Serum Concentrations ◽  
Serum Samples ◽  
Poor Overall Survival ◽  
Platinum Sensitivity ◽  
Therapeutic Decisions ◽  
Platinum Based Chemotherapy

Chemotherapy resistance is a main cause of therapeutic failure and death in bladder cancer. With the approval of immune checkpoint inhibitors, prediction of platinum treatment became of great clinical importance. Matrix metalloproteinase-7 (MMP-7) was shown to be involved in cisplatin resistance. Therefore, tissue and circulating MMP-7 levels were evaluated in 124 bladder cancer patients who received postoperative platinum-based chemotherapy. Tissue MMP-7 levels were analyzed by immunohistochemistry in 72 formalin-fixed, paraffin-embedded chemo-naïve tumor samples, while MMP-7 serum concentrations were determined in 132 serum samples of an independent cohort of 52 patients. MMP-7 tissue and serum levels were correlated with clinicopathological and follow-up data. MMP-7 gene expression was determined by RT-qPCR in 20 urothelial cancer cell lines and two non-malignant urothelial cell lines. MMP-7 was overexpressed in RT-112 and T-24 cells by stable transfection, to assess its functional involvement in platinum sensitivity. High MMP-7 tissue expression and pretreatment serum concentrations were independently associated with poor overall survival (tissue HR = 2.296, 95%CI = 1.235–4.268 and p = 0.009; serum HR = 2.743, 95%CI = 1.258–5.984 and p = 0.011). Therefore, MMP-7 tissue and serum analysis may help to optimize therapeutic decisions. Stable overexpression in RT-112 and T-24 cells did not affect platinum sensitivity.

scholarly journals Dogs as Sentinels for Flavivirus Exposure in Urban, Peri-Urban and Rural Hanoi, Vietnam

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 507
Author(s):  
Long Pham-Thanh ◽  
Thang Nguyen-Tien ◽  
Ulf Magnusson ◽  
Vuong Bui-Nghia ◽  
Anh Bui-Ngoc ◽  
...  
Keyword(s):  
Mosquito Control ◽  
Risk Mitigation ◽  
Significant Risk ◽  
Cross Sectional Study ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Cross Sectional ◽  
Major Health ◽  
Household Level

Diseases caused by flaviviruses, including dengue fever and Japanese encephalitis, are major health problems in Vietnam. This cross-sectional study explored the feasibility of domestic dogs as sentinels to better understand risks of mosquito-borne diseases in Hanoi city. A total of 475 dogs serum samples from 221 households in six districts of Hanoi were analyzed by a competitive enzyme-linked immunosorbent assay (cELISA) for antibodies to the pr-E protein of West Nile virus and other flaviviruses due to cross-reactivity. The overall flavivirus seroprevalence in the dog population was 70.7% (95% CI = 66.4–74.8%). At the animal level, significant associations between seropositive dogs and district location, age, breed and keeping practice were determined. At the household level, the major risk factors were rural and peri-urban locations, presence of pigs, coil burning and households without mosquito-borne disease experience (p < 0.05). Mosquito control by using larvicides or electric traps could lower seropositivity, but other measures did not contribute to significant risk mitigation of flavivirus exposure in dogs. These results will support better control of mosquito-borne diseases in Hanoi, and they indicate that dogs can be used as sentinels for flavivirus exposure.

scholarly journals Vitamin D Metabolites and Clinical Outcome in Hospitalized COVID-19 Patients

Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2129
Author(s):  
Sieglinde Zelzer ◽  
Florian Prüller ◽  
Pero Curcic ◽  
Zdenka Sloup ◽  
Magdalena Holter ◽  
...  
Keyword(s):  
Vitamin D ◽  
Degradation Products ◽  
University Hospital ◽  
Vitamin D Metabolites ◽  
Serum Concentrations ◽  
Serum Samples ◽  
Liquid Chromatography Tandem Mass ◽  
Relevant Role ◽  
Metabolite Ratio ◽  
The University

(1) Background: Vitamin D, a well-established regulator of calcium and phosphate metabolism, also has immune-modulatory functions. An uncontrolled immune response and cytokine storm are tightly linked to fatal courses of COVID-19. The present retrospective study aimed to inves-tigate vitamin D status markers and vitamin D degradation products in a mixed cohort of 148 hospitalized COVID-19 patients with various clinical courses of COVID-19. (2) Methods: The serum concentrations of 25(OH)D3, 25(OH)D2, 24,25(OH)2D3, and 25,26(OH)2D3 were determined by a validated liquid-chromatography tandem mass-spectrometry method in leftover serum samples from 148 COVID-19 patients that were admitted to the University Hospital of the Medical Uni-versity of Graz between April and November 2020. Anthropometric and clinical data, as well as outcomes were obtained from the laboratory and hospital information systems. (3) Results: From the 148 patients, 34 (23%) died within 30 days after admission. The frequency of fatal outcomes did not differ between males and females. Non-survivors were significantly older than survivors, had higher peak concentrations of IL-6 and CRP, and required mechanical ventilation more frequently. The serum concentrations of all vitamin D metabolites and the vitamin D metabolite ratio (VMR) did not differ significantly between survivors and non-survivors. Additionally, the need for res-piratory support was unrelated to the serum concentrations of 25(OH)D vitamin D and the two vitamin D catabolites, as well as the VMR. (4) Conclusion: The present results do not support a relevant role of vitamin D for the course and outcome of COVID-19.

scholarly journals Biological variation and reference change value data for serum copper, zinc and selenium in Turkish adult population

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ceylan Bal ◽  
Serpil Erdogan ◽  
Gamze Gök ◽  
Cemil Nural ◽  
Betül Özbek ◽  
...  
Keyword(s):  
Adult Population ◽  
Reference Intervals ◽  
Serum Copper ◽  
Biological Variation ◽  
Serum Samples ◽  
Reference Change Value ◽  
Index Of Individuality ◽  
Copper Zinc ◽  
Clinically Significant ◽  
Analytical Variation

Abstract Objectives Calculation of biological variation (BV) components is very important in evaluating whether a test result is clinically significant. The aim of this study is to analyze BV components for copper, zinc and selenium in a cohort of healthy Turkish participants. Methods A total of 10 serum samples were collected from each of the 15 healthy individuals (nine female, six male), once a week, during 10 weeks. Copper, zinc and selenium levels were analyzed by atomic absorption spectrometer. BV parameters were calculated with the approach suggested by Fraser. Results Analytical variation (CVA), within-subject BV (CVI), between-subject BV (CVG) values were 8.4, 7.1 and 4.3 for copper; 4.2, 9.1 and 13.7 for zinc; 7.6, 2.5 and 6.9 for selenium, respectively. Reference change values (RCV) were 30.46, 27.56 and 22.16% for copper, zinc and selenium, respectively. The index of individuality (II) values were 1.65, 0.66 and 0.36 for copper, zinc and selenium, respectively. Conclusions According to the results of this study, traditional reference intervals can be used for copper but we do not recommend using it for zinc and selenium. We think that it would be more accurate to use RCV value for zinc and selenium in terms of following significant changes in recurrent results of a patient.

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