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Advanced Drug Delivery Reviews Dec 2020Antibodies possess multiple biologically relevant features that have been engineered into new therapeutic formats. Two examples include the adaptable specificity of...
Antibodies possess multiple biologically relevant features that have been engineered into new therapeutic formats. Two examples include the adaptable specificity of their variable (Fv) region and the extension of plasma circulation times through their crystallizable (Fc) region. Since the invention of the single chain variable fragment (scFv) in 1988, antibody variable regions have been re-engineered into a wide variety of multifunctional nanostructures. Among these strategies, peptide-mediated self-assembly of variable regions through heterologous expression has become a powerful method to produce homogenous, functional biomaterials. This manuscript reviews recent reports of antibody fragments assembled through fusion with peptides and proteins, including elastin-like polypeptides (ELPs), collagen-like polypeptides (CLPs), albumin, transmembrane proteins, leucine zippers, silk protein, and viruses. This review further discusses the current clinical status of engineered antibody fragments and challenges to overcome.
Topics: Albumins; Antibodies; Biomedical Engineering; Collagen; Drug Delivery Systems; Humans; Nanostructures; Peptides; Proteins; Single-Chain Antibodies; Viral Proteins
PubMed: 33129938
DOI: 10.1016/j.addr.2020.10.017 -
PloS One 2023Traditional diagnostic tests for schistosome infections are suboptimal, particularly when the parasite burden is low. In the present review we sought to identify...
Diagnostic performances of Schistosoma haematobium and Schistosoma mansoni recombinant proteins, peptides and chimeric proteins antibody based tests. Systematic scoping review.
BACKGROUND
Traditional diagnostic tests for schistosome infections are suboptimal, particularly when the parasite burden is low. In the present review we sought to identify recombinant proteins, peptides, and chimeric proteins with potential to be used as sensitive and specific diagnostic tools for schistosomiasis.
METHODS
The review was guided by PRISMA-ScR guidelines, Arksey and O'Malley's framework, and guidelines from the Joanna Briggs Institute. Five databases were searched: Cochrane library, PubMed, EMBASE, PsycInfo and CINAHL, alongside preprints. Identified literature were assessed by two reviewers for inclusion. A narrative summary was used to interpret the tabulated results.
RESULTS
Diagnostic performances were reported as specificities, sensitivities, and AUC. The AUC for S. haematobium recombinant antigens ranged from 0.65 to 0.98, and 0.69 to 0.96 for urine IgG ELISA. S. mansoni recombinant antigens had sensitivities ranging from 65.3% to 100% and specificities ranging from 57.4% to 100%. Except for 4 peptides which had poor diagnostic performances, most peptides had sensitivities ranging from 67.71% to 96.15% and specificities ranging from 69.23% to 100%. S. mansoni chimeric protein was reported to have a sensitivity of 86.8% and a specificity of 94.2%.
CONCLUSION
The tetraspanin CD63 antigen had the best diagnostic performance for S. haematobium. The tetraspanin CD63 antigen Serum IgG POC-ICTs had a sensitivity of 89% and a specificity of 100%. Peptide Smp_150390.1 (216-230) serum based IgG ELISA had the best diagnostic performance for S. mansoni with a sensitivity of 96.15% and a specificity of 100%. Peptides were reported to demonstrate good to excellent diagnostic performances. S. mansoni multi-peptide chimeric protein further improved the diagnostic accuracy of synthetic peptides. Together with the advantages associated with urine sampling technique, we recommend development of multi-peptide chimeric proteins urine based point of care tools.
Topics: Animals; Schistosoma haematobium; Schistosoma mansoni; Tetraspanin 30; Peptides; Blood Group Antigens; Recombinant Proteins; Recombinant Fusion Proteins; Immunoglobulin G
PubMed: 36862712
DOI: 10.1371/journal.pone.0282233 -
The Journal of Infectious Diseases Jul 2023Most observational population-based studies identify respiratory syncytial virus (RSV) by nasal/nasopharyngeal swab reverse transcriptase real-time PCR (RT-PCR) only. We... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Most observational population-based studies identify respiratory syncytial virus (RSV) by nasal/nasopharyngeal swab reverse transcriptase real-time PCR (RT-PCR) only. We conducted a systematic review and meta-analyses to quantify specimen and diagnostic testing-based underascertainment of adult RSV infection.
METHODS
EMBASE, PubMed, and Web of Science were searched (January 2000-December 2021) for studies including adults using/comparing >1 RSV testing approach. We quantified test performance and RSV detection increase associated with using multiple specimen types.
RESULTS
Among 8066 references identified, 154 met inclusion. Compared to RT-PCR, other methods were less sensitive: rapid antigen detection test (RADT; pooled sensitivity, 64%), direct fluorescent antibody (DFA; 83%), and viral culture (86%). Compared to singleplex PCR, multiplex PCR's sensitivity was lower (93%). Compared to nasal/nasopharyngeal swab RT-PCR alone, adding another specimen type increased detection: sputum RT-PCR, 52%; 4-fold rise in paired serology, 44%; and oropharyngeal swab RT-PCR, 28%. Sensitivity was lower in estimates limited to only adults (for RADT, DFA, and viral culture), and detection rate increases were largely comparable.
CONCLUSIONS
RT-PCR, particularly singleplex testing, is the most sensitive RSV diagnostic test in adults. Adding additional specimen types to nasopharyngeal swab RT-PCR testing increased RSV detection. Synergistic effects of using ≥3 specimen types should be assessed, as this approach may improve the accuracy of adult RSV burden estimates.
Topics: Adult; Humans; Respiratory Syncytial Virus Infections; Sensitivity and Specificity; Respiratory Syncytial Virus, Human; Nasopharynx; Diagnostic Techniques and Procedures; Reverse Transcriptase Polymerase Chain Reaction
PubMed: 36661222
DOI: 10.1093/infdis/jiad012 -
International Journal of Rheumatic... May 2021To evaluate the diagnostic value of anti-citrullinated α-enolase peptide 1 (anti-CEP 1) antibody in patients with rheumatoid arthritis (RA) by conducting a systematic... (Meta-Analysis)
Meta-Analysis
AIM
To evaluate the diagnostic value of anti-citrullinated α-enolase peptide 1 (anti-CEP 1) antibody in patients with rheumatoid arthritis (RA) by conducting a systematic review and meta-analysis.
METHODS
The PubMed, Web of Science, Embase, Scopus, and Cochrane Library databases were searched for relevant studies published until September 23, 2020. A bivariate mixed-effects model was used to calculate the diagnostic indices from primary data of eligible studies. We performed meta-regression and subgroup analysis to explore the sources of heterogeneity.
RESULTS
Twenty-four articles, with a total of 17 380 patients with RA and 7505 control participants, met the criteria for inclusion in the meta-analysis. The pooled sensitivity, specificity, and positive and negative likelihood ratios for the anti-CEP 1 antibody were 44% (95% CI: 38%-51%), 97% (95% CI: 96%-98%), and 14.81 (95% CI: 10.66-20.57) and 0.57 (95% CI: 0.52-0.64), respectively. The pooled positive and negative predictive values were 0.96 (95% CI: 0.95-0.97) and 0.53 (95% CI: 0.43-0.63), respectively. The area under the summary receiver operating characteristic curve was 0.86. Meta-regression indicated that the anti-CEP 1 antibody detection method may be a source of heterogeneity. The subgroup analysis of the group in which the anti-CEP 1 antibody was detected by using a commercial enzyme-linked immunosorbent assay (ELISA) kit had a sensitivity of 59% (95% CI: 50%-68%) and a specificity of 93% (95% CI: 85%-97%).
CONCLUSIONS
The anti-CEP 1 antibody had moderate RA diagnostic value with relatively low sensitivity and high specificity. An ELISA may increase the RA diagnostic sensitivity.
Topics: Anti-Citrullinated Protein Antibodies; Antibodies; Arthritis, Rheumatoid; Biomarkers, Tumor; DNA-Binding Proteins; Enzyme-Linked Immunosorbent Assay; Genetic Predisposition to Disease; Humans; Peptides, Cyclic; Phosphopyruvate Hydratase; Sensitivity and Specificity; Tumor Suppressor Proteins
PubMed: 33713557
DOI: 10.1111/1756-185X.14093 -
Medicine Aug 2020The incidence of hepatocellular carcinoma (HCC) ranks sixth in the world, but its mortality is the third highest due to the lack of early diagnostic markers. Nowadays,... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
The incidence of hepatocellular carcinoma (HCC) ranks sixth in the world, but its mortality is the third highest due to the lack of early diagnostic markers. Nowadays, the increase of autoantibody levels has been found in many cancers, and many studies have begun to pay attention to the detection of anti-p53 antibodies in HCC. The purpose of this study is to quantitatively and comprehensively analyze the potential diagnostic value of anti-p53 autoantibodies in HCC METHODS:: English articles up to November 2019 were collected. The overall sensitivity and specificity were calculated. Besides, the positive likelihood ratio, negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and summary receiver operating characteristic curves of the overall diagnostic accuracy of anti-p53 antibody were calculated by STATA software. Finally, according to the heterogeneity of the results, the subgroup analysis, and the publication bias were performed.
RESULTS
A total of 16 eligible studies were incorporated into this meta-analysis, including 1323 patients with HCC and 1896 control. The pooled sensitivity was 0.28(0.17-0.41) and specificity was 0.98 (0.95-0.99). The pooled DOR was 10.44 (6.31-17.29) and the pooled NLR was 0.74 (0.63-0.86). The area under ROC curve of symmetrical ROC was 0.840.
CONCLUSIONS
The anti-p53 antibody has a high specificity for HCC, but the low sensitivity is not perfect and would limit the clinical application. The anti-p53 antibody would help rule out HCC but not help rule in HCC for early diagnosis. Whether combined as a diagnostic panel with other biomarkers or laboratory tests may prove useful requires further study.
Topics: Aged; Aged, 80 and over; Antibodies; Biomarkers, Tumor; Carcinoma, Hepatocellular; Case-Control Studies; Evaluation Studies as Topic; Female; Humans; Incidence; Liver Neoplasms; Male; Middle Aged; Sensitivity and Specificity; Tumor Suppressor Protein p53
PubMed: 32846849
DOI: 10.1097/MD.0000000000021887 -
Clinical Infectious Diseases : An... Jun 2020We reviewed relevant syphilis diagnostic literature and conducted a meta-analysis to address the question, "What is the sensitivity and specificity of the Syphilis... (Meta-Analysis)
Meta-Analysis
We reviewed relevant syphilis diagnostic literature and conducted a meta-analysis to address the question, "What is the sensitivity and specificity of the Syphilis Health Check, a rapid qualitative test for the detection of human antibodies to Treponema pallidum." The Syphilis Health Check is the only rapid syphilis test currently cleared by the Food and Drug Administration (FDA). We conducted a systematic review and a meta-analysis using Bayesian bivariate random-effects and fixed-effect models to create pooled estimates of sensitivity and specificity of the Syphilis Health Check. We identified 5 test evaluations published in the literature and 10 studies submitted to the FDA and for a Clinical Laboratory Improvement Amendments waiver application. The pooled sensitivity (95% CI) from the laboratory evaluations (n = 5) was 98.5% (92.1-100%), while pooled specificity was 95.9% (81.5-100.0%). The pooled sensitivity for prospective studies (n = 10) was 87.7% ( 71.8-97.2%), while pooled specificity was 96.7% (91.9-99.2%). Using nontreponemal supplemental testing, the sensitivity improved to a pooled sensitivity of 97.0% (94.8-98.6%). The Syphilis Health Check may provide accurate detection of treponemal antibody.
Topics: Antibodies, Bacterial; Bayes Theorem; Humans; Point-of-Care Systems; Prospective Studies; Sensitivity and Specificity; Syphilis; Syphilis Serodiagnosis; Treponema pallidum
PubMed: 32578863
DOI: 10.1093/cid/ciaa350 -
PloS One 2021Increasingly, vaccine efficacy studies are being recommended in low-and-middle-income countries (LMIC), yet often facilities are unavailable to take and store infant...
BACKGROUND
Increasingly, vaccine efficacy studies are being recommended in low-and-middle-income countries (LMIC), yet often facilities are unavailable to take and store infant blood samples correctly. Dried blood spots (DBS), are useful for collecting blood from infants for diagnostic purposes, especially in low-income settings, as the amount of blood required is miniscule and no refrigeration is required. Little is known about their utility for antibody studies in children. This systematic review aims to investigate the correlation of antibody concentrations against infectious diseases in DBS in comparison to serum or plasma samples that might inform their use in vaccine clinical trials.
METHODS AND FINDINGS
We searched MEDLINE, Embase and the Cochrane library for relevant studies between January 1990 to October 2020 with no language restriction, using PRISMA guidelines, investigating the correlation between antibody concentrations in DBS and serum or plasma samples, and the effect of storage temperature on DBS diagnostic performance. We included 40 studies in this systematic review. The antibody concentration in DBS and serum/plasma samples reported a good pooled correlation, (r2 = 0.86 (ranged 0.43 to 1.00)). Ten studies described a decline of antibody after 28 days at room temperature compared to optimal storage at -20°C, where antibodies were stable for up to 200 days. There were only five studies of anti-bacterial antibodies.
CONCLUSIONS
There is a good correlation between antibody concentrations in DBS and serum/plasma samples, supporting the wider use of DBS in vaccine and sero-epidemiological studies, but there is limited data on anti-bacterial antibodies. The correct storage of DBS is critical and may be a consideration for longer term storage.
Topics: Antibodies; Antibodies, Bacterial; Communicable Diseases; Dried Blood Spot Testing; Humans; Protein Stability; Sensitivity and Specificity; Temperature
PubMed: 33720928
DOI: 10.1371/journal.pone.0248218 -
Frontiers in Medicine 2021To evaluate the diagnostic accuracy of antineutrophil cytoplasmic antibody (ANCA) renal risk score (ARRS) for prediction of renal outcome in patients with...
To evaluate the diagnostic accuracy of antineutrophil cytoplasmic antibody (ANCA) renal risk score (ARRS) for prediction of renal outcome in patients with ANCA-associated glomerulonephritis (ANCA-GN). We searched PubMed, EMBASE, Ovid, Web of Science, the Cochrane Library, and ClinicalTrials.gov for studies, which used ARRS to predict end-stage renal disease (ESRD) in patients with ANCA-GN. Two reviewers independently screened articles for inclusion, assessed the quality of studies with both an adapted Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. We calculated the combined patients with ESRD in the ARRS categories and presented the summary and individual estimates based on the ARRS categories. Then, the sensitivity, specificity, diagnostic odds ratio (DOR), positive/negative likelihood ratio, and the area under the receiver operating characteristic (AUROC) curves of the pooled data for ARRS were used to assess the accuracy of the "above the low-risk threshold" (ARRS ≥ 2) and "high-risk grade" (ARRS ≥ 8) for renal outcome of patients with ANCA-GN. The hierarchical summary ROC (HSROC) was used to verify the accuracy value. The clinical utility of ARRS was evaluated by the Fagan plot. Heterogeneity was explored using meta-regression and subgroup analysis. A total of 12 distinct cohorts from 11 articles involving 1,568 patients with ANCA-GN were analyzed. The cumulative patients with ESRD at the maximum follow-up of 60 months was 5% (95% CI: 0.02-0.07; < 0.001) for ANCA-GN with low ARRS (0-1 points) and significantly increased to 22% (95% CI: 0.15-0.29; < 0.001) medium ARRS (2-7 points). The combined cumulative patients with ESRD was 59% (95% CI: 0.49-0.69; < 0.001) high ARRS (8-11 points). The pooled sensitivity of ARRS ≥ 2 in predicting ESRD was 98% with a specificity of 30% and a DOR of 15.08 and the mean AUROC value was 0.82. The pooled sensitivity of ARRS ≥ 8 in predicting ESRD was 58% with a specificity of 86% and a DOR of 7.59. The meta-regression and subgroup analysis indicated that variation in the geographic regions, study design, index risk, follow-up time, age of patient, publication year, and number of patient could be the potential sources of heterogeneity in the diagnosis of ARRS ≥ 8. This meta-analysis emphasized the good performance of the ARRS score in predicting the renal outcome in patients with ANCA-GN. However, these findings should be verified by future large-scale prospective studies.
PubMed: 35071256
DOI: 10.3389/fmed.2021.736754 -
Euro Surveillance : Bulletin Europeen... May 2023BackgroundSerological surveys have been the gold standard to estimate numbers of SARS-CoV-2 infections, the dynamics of the epidemic, and disease severity. Serological... (Meta-Analysis)
Meta-Analysis
BackgroundSerological surveys have been the gold standard to estimate numbers of SARS-CoV-2 infections, the dynamics of the epidemic, and disease severity. Serological assays have decaying sensitivity with time that can bias their results, but there is a lack of guidelines to account for this phenomenon for SARS-CoV-2.AimOur goal was to assess the sensitivity decay of seroassays for detecting SARS-CoV-2 infections, the dependence of this decay on assay characteristics, and to provide a simple method to correct for this phenomenon.MethodsWe performed a systematic review and meta-analysis of SARS-CoV-2 serology studies. We included studies testing previously diagnosed, unvaccinated individuals, and excluded studies of cohorts highly unrepresentative of the general population (e.g. hospitalised patients).ResultsOf the 488 screened studies, 76 studies reporting on 50 different seroassays were included in the analysis. Sensitivity decay depended strongly on the antigen and the analytic technique used by the assay, with average sensitivities ranging between 26% and 98% at 6 months after infection, depending on assay characteristics. We found that a third of the included assays departed considerably from manufacturer specifications after 6 months.ConclusionsSeroassay sensitivity decay depends on assay characteristics, and for some types of assays, it can make manufacturer specifications highly unreliable. We provide a tool to correct for this phenomenon and to assess the risk of decay for a given assay. Our analysis can guide the design and interpretation of serosurveys for SARS-CoV-2 and other pathogens and quantify systematic biases in the existing serology literature.
Topics: Humans; SARS-CoV-2; COVID-19; Sensitivity and Specificity; COVID-19 Testing; Serologic Tests; Antibodies, Viral
PubMed: 37227301
DOI: 10.2807/1560-7917.ES.2023.28.21.2200809 -
The Lancet. Infectious Diseases May 2021Cryptosporidiosis is a common cause of diarrhoea in young children (aged younger than 24 months) in low-resource settings but is currently challenging to diagnose....
BACKGROUND
Cryptosporidiosis is a common cause of diarrhoea in young children (aged younger than 24 months) in low-resource settings but is currently challenging to diagnose. Light-emitting diode fluorescence microscopy with auramine-phenol staining (LED-AP), recommended for tuberculosis testing, can also detect Cryptosporidium species. A lateral-flow test not requiring refrigerator storage (by contrast with most immunochromatographic lateral-flow assays) has also recently been developed for Cryptosporidium spp detection. We aimed to evaluate the diagnostic accuracy and operational feasibility of LED-AP and the lateral-flow test strip for cryptosporidiosis in children.
METHODS
We did a prospective diagnostic accuracy study in two health-care facilities in Ethiopia, in a consecutive series of children younger than 5 years of age with diarrhoea (three or more loose stools within the previous 24 h) or dysentery (at least one loose stool with stains of blood within the previous 24 h). Stool samples were tested for Cryptosporidium spp by LED-AP and the lateral-flow test strip; accuracy of each test was estimated by independent and blind comparison with a composite reference standard comprising quantitative immunofluorescent antibody test (qIFAT), ELISA, and quantitative PCR (qPCR). Quantitative cutoff values for diarrhoea-associated infection were established in an embedded case-control substudy, with cases of cryptosporidiosis coming from the 15 districts in and around Jimma and the eight districts surrounding Serbo, and community controls without diarrhoea in the previous 48 h recruited by weekly frequency matching by geographical district of the household, age group, and enrolment week.
FINDINGS
Stool samples from 912 children with diarrhoea or dysentery and 706 controls from the case-control substudy were tested between Dec 22, 2016, and July 6, 2018. Estimated reference-standard cutoff values for cryptosporidiosis positivity were 2·3 × 10 DNA copies per g of wet stool for qPCR, and 725 oocysts per g for qIFAT. LED-AP had a sensitivity for cryptosporidiosis of 88% (95% CI 79-94; 66 of 75 samples) and a specificity of 99% (98-99; 717 of 726 samples); the lateral-flow test strip had a sensitivity of 89% (79-94; 63 of 71 samples) and a specificity of 99% (97-99; 626 of 635 samples).
INTERPRETATION
LED-AP has high sensitivity and specificity for cryptosporidiosis and should be considered as a dual-use technology that can be easily integrated with existing laboratory infrastructures in low-resource settings. The lateral-flow test strip has similar sensitivity and specificity and provides an alternative that does not require microscopy, although purchase cost of the test strip is unknown as it is not yet available on the market.
FUNDING
Norwegian Research Council GLOBVAC fund, The Bill & Melinda Gates Foundation, Norwegian Society for Medical Microbiology, University of Bergen, and Vestfold Hospital Trust.
Topics: Child; Cryptosporidiosis; Cryptosporidium; Databases, Factual; Diagnostic Tests, Routine; Diarrhea; Ethiopia; Feasibility Studies; Feces; Humans; Immunoassay; Prospective Studies; Real-Time Polymerase Chain Reaction; Sensitivity and Specificity
PubMed: 33278916
DOI: 10.1016/S1473-3099(20)30556-9