Test For Detection Of Antibodies Research Articles

Evaluation of Two Serologic Tests for Rapid Detection of Anti-Leptospira Antibodies in California Sea Lions (Zalophus californianus).

Leptospirosis is a bacterial zoonosis impacting wild and domestic animals globally. Leptospira interrogans serovar Pomona is endemic in free-ranging California sea lions (CSLs; Zalophus californianus), and leptospirosis is frequently diagnosed in stranded CSLs. Serum microscopic agglutination test (MAT) is a commonly performed diagnostic assay, and CSLs with clinical disease have reliably elevated MAT titers. However, MAT results may not be available for several days after sampling. Given the zoonotic and high transmission potential of Leptospira spp., a point-of-care diagnostic test would be valuable in rehabilitation and managed care settings and during outbreak response efforts. The ID SNAP and Zoetis WITNESS anti-Leptospira antibody tests are rapid diagnostic tools that have been validated in dogs and give a qualitative (positive or negative), not quantitative (exact titer), result. The SNAP test uses ELISA to detect both immunoglobulin (Ig)M and IgG antibodies, whereas the WITNESS test is a lateral flow assay that only detects IgM. We compared SNAP and WITNESS results with MAT results by using serum collected from stranded and free-ranging CSL with negative, low, medium, and high anti-Leptospira antibody titers as previously determined by MAT. Percent agreement between SNAP and MAT results was high, with a Cohen's kappa statistic of 0.957. No WITNESS tests were positive. These findings suggest that the SNAP test may be useful for detecting anti-Leptospira antibodies and ruling out leptospirosis in CSL.

Use of an anti-D-alloimmunization kinetics model to correct the interval censored D-alloimmunization rate following red blood cell transfusions.

The rate of D-alloimmunization amongst RhD-negative recipients of RhD-positive red blood cell (RBC) transfusions is not certain. Recipients with a short duration between the index RhD-positive transfusion and the last antibody detection test that did not show anti-D might become D-alloimmunized in the future. A regression model was developed to predict how often such patients might develop D-alloimmunization in the future to help account for the immunohematological uncertainty that accompanies having short serological follow up periods. Using the published literature on recipients who were intentionally transfused with RhD-positive RBCs and serially followed with antibody screens, as well as unpublished datasets, a regression model was constructed to demonstrate the timing of D-alloimmunization for recipients who became D-alloimmunized within 6 months following the index transfusion. The model was then applied to a series of RhD-negative hospitalized recipients of at least one unit of RhD-positive RBCs who did not become D-alloimmunized but who had fewer than 6 months of serological follow up to weight their contribution to the D-alloimmunization rate. Overall, the rate of D-alloimmunization was 21/105 (20.0%). There were 39 patients whose last documented antibody screen was performed between 14 days and 6 months after the index RhD-positive transfusion, and these patients were entered into the weighted model. After applying the model, the D-alloimmunization rate rose to 26.3%. Using a weighted model can help reduce the immunohematological uncertainty that accompanies the inclusion of patients with relatively short serological follow up in studies of RBC alloimmunization.

Comparative Analysis of Hemagglutination Inhibition and Plaque Reduction Neutralization Tests for Japanese Encephalitis Virus Antibody Detection.

Japanese encephalitis (JE) is a zoonotic disease caused by the Japanese encephalitis virus (JEV), belonging to the Flaviviridae family. Diagnosis of Japanese encephalitis (JE) based on clinical signs alone is challenging due to the high proportion of subclinical cases. The Plaque Reduction Neutralization Test (PRNT) is considered the gold standard for detecting JE-specific antibodies because of its high specificity. However, PRNT is complex, time-consuming, and requires live viruses, limiting its applicability in routine diagnostics. In this study, we compared the sensitivity and correlation of the Hemagglutination Inhibition (HI) assay and PRNT for detecting JE antibodies in avian serum samples. We conducted a comparative analysis of the outcomes obtained from the PRNT and HI using 240 serum samples collected from 30 JEV-immunized avian subjects at various time points. Comparative analysis revealed a significant correlation between the HI and PRNT (R2 = 0.9321, p ≤ 0.0001). The Bland-Altman analysis also exhibited favorable concordance between the two assays. Consequently, HI may function as a viable substitute for PRNT in the screening of a substantial number of serum samples.

Solid-phase red cell adherence versus gel column agglutination: Is there any difference for the detection of alloantibodies associated with the JK system?

Detection of alloantibodies associated with the JK system may be tricky. They are nevertheless associated with transfusion reactions and their detection is crucial. Retrospectively and over a period of 7 years, we compared the results obtained using two different assays for antibody detection. We performed antibody detection testing with solid-phase red cell adherence (SPRCA). If positive, the antibody identification was carried out with the SPRCA and confirmed with the gel method in Coombs medium. In case of discrepant results occurring in recently transfused patients, we investigated these patients during the post-transfusion period. Fifty-five patients with anti-JK1 or anti-JK2 were identified out of which 41 were further analyzed. Both techniques clearly identified 10 alloantibodies. In 22 cases, the alloantibody identified by SPRCA was not observed with the gel method because of negative detection tests. In one case, none of the techniques identified the alloantibody and in 8 cases, the final result was inconclusive (1/41 with the SPRCA and 8/41 with the gel method). Two patients having a highly probable delayed hemolytic transfusion reaction (DHTR) were identified among the discrepant results. For both cases, anti-JK2 was clearly identified by the SPRCA but showed inconclusive reactions with the gel method. This study shows that in 29 out of 41 cases, the anti-JK1 or anti-JK2 identified with the SPRCA method were not with the gel method in Coombs medium. Eleven cases (11/29) were clinically significant and among them, 4 likely DHTRs and 2 highly probable DHTRs occurred.

Using Soluble CD38 to Overcome Daratumumab Interference in Pretransfusion Compatibility Testing

Background: CD38 is a protein highly expressed on myeloma (MM) cells that has been shown to be an effective target antigen for monoclonal antibody therapies, so treatment with anti-CD38 monoclonal antibodies is a first line therapy for patients with MM. Although CD38 is weaker expressed on erythocytes anti-CD38 binds to CD38 on reagent RBCs and cause panreactivity in vitro and subsequent false positive reactions in indirect antiglobulin tests (IAT), antibody detection (screening) tests, antibody identification panels, and anti-human globulin (AHG) crossmatches. These findings suggest that the soluble CD38 method could improve transfusion safety for patients receiving anti-CD38 therapy, particularly in urgent clinical settings This study aims to evaluate the effectiveness of a new soluble CD38-based method in mitigating Daratumumab interference during pretransfusion compatibility testing." Methods: We evaluated the Grifols sCD38 method in 20 patients and compared it with the DTT method Results: In our experience the sCD38 method reduced testing time from 150 to 50 minutes and demonstrated 100% efficacy, compared to 90% with DTT. The sCD38 effectively mitigated the interference caused by anti-CD38 antibodies in 10 (100% efficacy) of patient samples tested while DTT was successful in only 9/10 (90% efficacy); no interference was observed in patients presenting anti erythrocyte antibodies. Moreover, there was no negative influence on DTT sensitive blood group systems such as KEL upon sCD38 treatment. Conclusions: In our Laboratory, in the year 2023, we processed 129 patients treated with anti-CD38. Therefore the reduction from 150 to 50 minutes in the time needed to perform tests for mitigation of anti-CD38 interference appears to be relevant with a recovery of approximately 210 technical-hours per year. Another highly appreciated operational aspect was the possibility of treating the patient's plasma and perform tests using automatic instruments (Erytra Grifols) available in our laboratory. In the evaluation of this new method, we did not observe failures in the mitigation of anti-CD38 interference. Furthermore, the results obtained in the samples that presented allo or auto antibodies were not affected by the treatment with sCD38. In our experience Grifols sCD38 assay is straightforward and quick to perform ant it is superior to DTT treatment in the mitigation of anti-CD38 antibody interference in MM patients treated with Daratumumab.

Strengthening Fungal Infection Diagnosis and Treatment: An In-depth Analysis of Capabilities in Honduras.

Invasive fungal infections (IFIs) are a major public health concern in low- and middle-income countries (LMICs) due to limited diagnostic and treatment resources, leading to high morbidity and mortality. Despite their significant global burden, IFIs are underrecognized and underdiagnosed in LMICs. This study evaluates the diagnostic and therapeutic capacities for managing IFI in Honduras, a country with unique health care challenges. From March to December 2023, a comprehensive survey was conducted across multiple health care centers in Honduras. The survey, reviewed for content and clarity by local medical institutions, targeted medical microbiologists and clinicians to assess various aspects of fungal disease diagnosis and treatment. Data included the availability and use of diagnostic tools and antifungal therapies, identifying gaps and limitations in current practices. The survey revealed that Candida spp (97.4%) and Aspergillus spp (35.9%) were the most concerning pathogens. Although microscopy and culture methods were available in most institutions, their application in suspected IFI cases was inconsistent, and antifungal susceptibility testing was rarely performed. Advanced diagnostic techniques, such as antigen detection, were available in only a few institutions, while antibody detection and polymerase chain reaction testing were entirely absent. All hospitals had access to at least 1 triazole antifungal, typically fluconazole, but there was a notable scarcity of more potent antifungals, including amphotericin B formulations and echinocandins. The limited use of available diagnostic tools and the restricted availability of essential antifungals were identified as major barriers to effective IFI management. This study highlights significant gaps in the diagnostic and therapeutic capabilities for managing IFI in Honduras. The underutilization of basic diagnostic tools, the inaccessibility of advanced testing methods, and the limited availability of essential antifungal medications underscore the urgent need for capacity-building initiatives, infrastructure improvements, and policy reforms. Addressing these deficiencies is critical for enhancing the management of IFI in Honduras, with broader implications for similar LMIC settings. These findings can inform targeted interventions and resource allocation to improve outcomes for patients with IFI.

Diagnostic performance of a rapid immunochromatographic test for the simultaneous detection of antibodies to Theileria equi and Babesia caballi in horses and donkeys

Diagnostic performance of a rapid immunochromatographic test for the simultaneous detection of antibodies to <i>Theileria equi</i> and <i>Babesia caballi</i> in horses and donkeys

A method for characterizing disease emergence curves from paired pathogen detection and serology data

Abstract Wildlife disease surveillance programs and research studies track infection and identify risk factors for wild populations, humans and agriculture. Often, several types of samples are collected from individuals to provide more complete information about an animal's infection history. Methods that jointly analyse multiple data streams to study disease emergence and drivers of infection via epidemiological process models remain underdeveloped. Joint‐analysis methods can more thoroughly analyse all available data, more precisely quantifying epidemic processes, outbreak status, and risks. We contribute a paired data modelling approach that analyses multiple samples from individuals. We use ‘characterization maps’ to link paired data to epidemiological processes through a hierarchical statistical observation model. Our approach can provide both Bayesian and frequentist estimates of epidemiological parameters and state. Our approach can also incorporate test sensitivity and specificity, and we propose model fit diagnostics. We motivate our approach through the need to use paired pathogen and antibody detection tests to estimate parameters and infection trajectories for the widely applicable susceptible, infectious, recovered (SIR) model. We contribute general formulas to link characterization maps to arbitrary process models and datasets and an extended SIR model that better accommodates paired data. We find via simulation that paired data can more efficiently estimate SIR parameters than unpaired data, requiring samples from 5 to 10 times fewer individuals. We use our method to study SARS‐CoV‐2 in wild white‐tailed deer (Odocoileus virginianus) from three counties in the United States. Estimates for average infectious times corroborate captive animal studies. The estimated average cumulative proportion of infected deer across the three counties is 73%, and the basic reproductive number (R0) is 1.88. Wildlife disease surveillance programs and research studies can use our methods to jointly analyse paired data to estimate epidemiological process parameters and track outbreaks. Paired data analyses can improve precision and accuracy when sampling is limited. Our methods use general statistical theory to let applications extend beyond the SIR model we consider and to more complicated examples of paired data. The methods can also be embedded in larger hierarchical models to provide landscape‐scale risk assessment and identify drivers of infection.

RT-PCR Testi ile doğrulanmış COVID-19 olgularında hızlı antikor testi uyumluluğunun değerlendirilmesi

INTRODUCTION: It was aimed to determine the reliability of rapid antibody detection test (RADT) results and compatibility with RT-PCR assay in the screening and control of COVID-19 infection. METHODS: The retrospective study was performed with the permission of the Ministry of Health and the local ethics committee of our hospital. Between May 2020 and August 2021, 624 health staffs laboratory results were recorded. Data processing hospital (HIS) and laboratory information system (LIS) records of our hospital were used as data collection method. The level of agreement between tests was estimated using Cohen's κ index. Statistical analyzes were performed using SPSS open source software. RESULTS: The mean age of the participants in the study was 28,46 ± 2,35. 54% were female (337), 46% (n=287) were male, and they had no additional disease. Both rapid antibody testing and RT-PCR tests were negative in 86% (n=540) of all tests. Two nasopharyngeal specimens were collected from each case to perform the RADT and RT-PCR. 13,6% (n=102) of the included patients had positive RT-PCR results. The RADT detected 84 of the 102 RT-PCR-positive cases and there were no false positive results. Overall sensitivity and specificity were 84,7% and 100%, respectively. Sensitivity was found &gt;95% in symptomatic cases. DISCUSSION AND CONCLUSION: The Weimi Bio-Tech COVID-19 Ag RADT can be useful in screening for COVID-19, especially in cases in the first or second weeks of symptomatic infection.

Profile of gastroduodenal perforation patients admitted in a rural tertiary care hospital: An observational cross-sectional study.

Gastro-duodenal perforation is a common surgical emergency that remains a formidable health burden worldwide with significant morbidity and mortality. Ulcer disease remains the most common cause of gastro-duodenal perforation. Diagnosing the presence of H. pylori can help eradicate the infection from the community at large and thereby reduce the chances of gastro-duodenal perforation. To assess the clinical presentation of gastro-duodenal perforation patients and to evaluate the detection of Helicobacter pylori infection by available investigations. A descriptive observational study was conducted among 80 patients presenting with clinical features suggestive of gastro-duodenal perforation and confirmed by clinical, radiological basis and operative findings admitted at a rural tertiary care hospital during 2019-2020. Detailed history was taken from the patient/party, clinically examined, and blood/tissue samples were investigated. The patients were managed with standard treatment modality in the studied institute. Data were collected, compiled, and entered MS Excel and analyzed using appropriate software. Descriptive analysis was done in the form of proportion for categorical variables, mean or median for continuous variables. Cases of gastro-duodenal perforations were more among middle to later age of life, mostly affecting married male patients hailed from rural area and unskilled workers. History of intake of spicy food, prolonged starvation, history of NSAID use were common among them. Majority of the patients had history of pain abdomen in the past suggesting of PUD and history of taking variety group of acid reducing agents. Most of them presented with epigastric pain, vomiting, abdominal distension along with other signs of peritonitis. Obliteration of liver dullness and free gas under right dome of diaphragm was also noted in large proportion among them. Majority of cases were found positive for H. pylori on Histology (85%), followed by rapid urease test (RUT) (80%) and a positivity of 72.5% and 68.8% on serum IgG and IgA antibody respectively. Rapid Urease Test was more sensitive as well as specific in diagnosing of H. pylori than antibody detection test. Early detection of H. pylori infection and treatment with potent anti H. pylori therapy postoperatively has been found to be adequate.

Development and evaluation of time-resolved rapid immunofluorescence test for detection of TSOL18 specific antibody in porcine cysticercosis infections

BackgroundPorcine cysticercosis, a serious zoonotic parasitic disease, is caused by the larvae of Taenia solium and has been acknowledged by the World Organization for Animal Health. The current detection methods of Cysticercus cellulosae cannot meet the needs of large-scale and rapid detection in the field. We hypothesized that the immunofluorescence chromatography test strip (ICS) for detecting Cysticercus cellulosae, according to optimization of a series of reaction systems was conducted, and sensitivity, specificity, and stability testing, and was finally compared with ELISA. This method utilizes Eu3+-labeled time-resolved fluorescent microspheres (TRFM) coupled with TSOL18 antigen to detect TSOL18 antibodies in infected pig sera.ResultsICS and autopsy have highly consistent diagnostic results (n = 133), as determined by Cohen’s κ analysis (κ = 0.925). And the results showed that the proposed ICS are high sensitivity (0.9459) with specificity (0.9792). The ICS was unable to detect positive samples of other parasites. It can be stored for at least six months at 4℃.ConclusionsIn summary, we established a TRFM-ICS method with higher sensitivity and specificity than indirect ELISA. Results obtained from serum samples can be read within 10 min, indicating a rapid, user-friendly test suitable for large-scale field detection.

Overview on utility of in-house tests for detection of systemic infectious diseases in dogs

For detection of infectious diseases, several point-of-care (POC) tests are on the market in addition to methods performed in commercial laboratories. These POC tests are based on enzyme-linked immunosorbent assay (ELISA) or other immunochromatographic technologies and present results within few minutes in veterinary practice. This article gives an overview of the utility of numerous POC tests of different manufacturers for detection of parvovirus antigen in feces, Dirofilaria (D.) immitis antigen in blood as well as antibodies against Borrelia (B.) burgdorferi, Anaplasma (A.) spp., Ehrlichia (E.) spp., Leptospira (L.) spp. and Leishmania (L.) infantum in blood (single or in different combinations). Sensitivity and specificity of these tests are important for their usefulness in veterinary practice. Furthermore, presence of antibodies or detection of antigen has to correlate with the presence of clinical signs. POC tests for detection of canine parvovirus antigen have a very high specificity, the sensitivity of all evaluated POC tests, however, is very low. POC tests for detection of D. immitis antigen have a very high sensitivity and specificity. As they detect antigen from the uterus of female adult parasites, test results are negative when only very few female or only male adults are present. POC tests for detection of antibodies against B. burgdorferi only indicate contact with Borrelia spp. and do not prove clinical Lyme disease, as the infection only extremely rarely causes clinical signs. POC tests for detection of antibodies against A. phagocytophilum are also not suitable for diagnosis of clinical anaplasmosis. Infections with A. phagocytophilum only lead to clinical disease in very rare cases and in these, clinical signs occur before the development of antibodies. POC tests for detection of antibodies against E. canis have a very high sensitivity as well as specificity. POC tests for detection of antibodies against L. infantum and Leptospira species (spp.) show a very high specificity and a high sensitivity. However, Leptospira spp. antibody-positive results may occur following vaccination, as the POC tests cannot distinguish between field and vaccination strains.

Diagnostic performance of a rapid immunochromatographic test for the simultaneous detection of antibodies to Theileria equi and Babesia caballi in horses and donkeys

BackgroundEquine piroplasmosis is caused by two tick-borne protozoan parasites, Theileria equi and Babesia caballi,, which are clinically relevant in susceptible horses, donkeys, and mules. Moreover, equine piroplasmosis significantly constrains international trading and equestrian events. Rapidly diagnosing both parasites in carrier animals is essential for implementing effective control measures. Here, a rapid immunochromatographic test for the simultaneous detection of antibodies to T. equi and B. caballi was evaluated using samples from horses and donkeys collected in Greece, Israel, and Italy. The results were compared with an improved competitive enzyme-linked immunosorbent assay (cELISA) for detecting antibodies to both parasites using the same panel of samples.MethodsBlood samples were collected from 255 horses and donkeys. The panel consisted of 129 horses sampled at four locations in northern Greece, 105 donkeys sampled at four locations in Sicily, and 21 horses sampled at two locations in Israel. The rapid test and the cELISA were performed according to the manufacturer’s instructions, and the results were subjected to a statistical analysis to determine the sensitivity and specificity of both tests and their association.ResultsThe immunochromatographic test provided a result within 15 min and can be performed in the field, detecting both pathogens simultaneously. The overall coincidence rate between the rapid test and the cELISA for detecting antibodies against T. equi was 93% and 92.9% for B. caballi. The rapid test’s sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for T. equi were above 91.5%. Sixteen samples were positive for both parasites in the rapid test and eight in the cELISA. Either test had no significant association between T. equi and B. caballi detection. The detection rates of both parasites were significantly higher in Italy than in Greece or Israel and in donkeys than in horses. The agreement for T. equi between the results of both tests was high in Greece (93.8%) and Italy (95.2%) and moderate in Israel (76.2%). For B. caballi, the specificity and NPV of the rapid test were high (94.2% and 98.3%, respectively), although the sensitivity and PPV were moderate (69.2% and 39.1%, respectively) due to the small sample size. However, for B. caballi, the sensitivity was higher with the rapid test.ConclusionsThe rapid test detected T. equi and B. caballi simultaneously in the field, potentially replacing laborious cELISA testing and is recommended for import/export purposes. The test can also be helpful for the differential diagnosis of clinical cases, since seropositivity may rule out equine piroplasmosis since it does not indicate current or active infection.Graphical

Establishing and verifying the threshold value of HLA mixed antigen reagent screening test results

Objective: To establish the threshold value of human leukocyte antigen (HLA) mixed antigen reagent screening test results, and to verify it by HLA single antigen reagent confirmation test results. Methods: The results of 2 255 serum samples tested for HLA antibodies by HLA mixed antigen reagent in the department of HLA Laboratory, the First Affiliated Hospital of Soochow University from October 2017 to December 2021 were retrospectively analyzed. Among them, 1 139 samples were also tested by single antigen HLA Class-Ⅰ reagent and 1 116 samples were also tested by single antigen HLA Class-Ⅱ reagent. Based on the same antigens coated with both reagents, the Mean Fluorescence Intensity (MFI) and Nomalized Background ratio (NBG ratio) of 12 HLA Class-Ⅰ beads and 5 HLA Class-Ⅱ beads in the HLA mixed antigen reagent and the MFI of 77 anti-HLA class-Ⅰ antibodies and 35 anti-HLA class-Ⅱ antibodies detected by HLA single antigen reagent were recorded. The MFI and NBG ratio of HLA mixed antigen reagent beads in 1 139 or 1 116 samples were segmented according to the positive rate of antibodyies detected by the single antigen reagent corresponding to the antigens coated with each HLA mixed antigen reagent bead, and the results of the HLA mixed antigen screening test were verified by the HLA single antigen reagent confirmation test. Results: The threshold values of MFI and NBG ratio of HLA mixed antigen reagent's 17 beads were established. The MFI of No. 1 to No. 17 beads of HLA mixed antigen reagent ranged from 26.86 to 21 925.58, and the NBG ratio ranged from 0 to 434.65. According to the positive detection rate of HLA single antigen reagent corresponding to the coated antigens, the MFI and NBG ratio of the beads of HLA mixed antigen reagent were divided into positive interval, suspicious positive interval, suspicious negative interval and negative interval. The positive rates of anti-HLA class-Ⅰ antibodies by HLA mixed antigen reagent and single antigen HLA Class-Ⅰ reagent were 87.5% (997/1 139) and 66.3% (755/1 139). The positive rates of anti-HLA class-Ⅱ antibodies were 63.4% (707/1 116) and 44.9% (501/1 116). In the samples with suspicious negative, suspicious positive and positive results of HLA class-Ⅰ、Ⅱ antibodies detected by HLA mixed antigen reagent, the positive detection rates of single antigen HLA Class-Ⅰ reagent were 14.9% (17/114), 41.3% (145/351) and 91.3% (590/646), respectively. The positive detection rates of single antigen HLA Class-Ⅱ reagent were 15.5% (58/375), 26.5% (81/306) and 88.8% (356/401), respectively. Conclusions: In this study, the threshold values of MFI and NBG ratio of HLA mixed antigen reagent screening test are established, and the threshold values are verified by the results of HLA single antigen reagent confirmation test. HLA mixed reagent screening test can be used for screening of HLA antibodies, and if necessary, it should be combined with HLA single antigen confirmatory test for clinical detection of HLA antibodies.

Simultaneous Detection of Antigen and Antibodies of African Swine Fever in a Novel Combo Lateral Flow Assay.

African swine fever (ASF) is a contagious disease of wild boar and domestic pigs notifiable to the World Organisation for Animal Health due to its high socio-economic impact. ASF is caused by the complex ASF virus (ASFV), and it can present different clinical manifestations that can be confused with other diseases; for this reason, laboratory testing is necessary for the proper diagnosis of clinically suspected animals. Despite the efforts put into it over decades, no treatment or safe vaccine is globally available, and disease control is based on early diagnosis and the implementation of strict biosecurity measures. In this context, rapid tests have the potential to accelerate and facilitate the identification of infected animals by giving fast on-site results. In this work, we improved the available point-of-care assays for the diagnosis of the disease by the development of a more specific antigen test and a more sensitive antibody test. This antibody detection test allowed for the earlier detection of infected animals than two commercial indirect ELISAs (statistically significant). Moreover, we developed a combined dual rapid test, unifying, in the same cassette, an antigen detection strip and an antibody detection strip. In this study, we confirmed that this combo approach is a useful tool for implementing rapid tests in the field since it increases the percentage of positive samples detected, even when PCR turns negative, while maintaining a good specificity.

Histoplasma antigens as novel players for the development of new enzyme immunoassays for the serodiagnosis of histoplasmosis: A comparative study of their analytical performance.

Definitive diagnosis of histoplasmosis relies on culture and/or cytology/histopathology; however, these procedures have limited sensitivity and cultures are time-consuming. Antibodies detection by immunodiffusion has low sensitivity in immunocompromised individuals and uses histoplasmin (HMN), a crude antigenic extract, as reagent. Novel protein antigen candidates have been recently identified and produced by DNA-recombinant techniques to obtain standardized and specific reagents for diagnosing histoplasmosis. To compare the analytical performance of novel enzyme-linked immunosorbent assays (ELISAs) for antibodies testing for diagnosing histoplasmosis using different Histoplasma capsulatum antigens as reagents. The H. capsulatum 100kDa protein (Hcp100), the M antigen and its immunoreactive fragment F1 were produced by DNA-recombinant techniques. Galactomannan was purified from both the yeast and mycelial cell walls (yGM and mGM, respectively). The analytical performance of the ELISA tests for the serological detection of antibodies against these antigens was evaluated and compared with those obtained using HMN as reagent. Antibodies detection by the Hcp100 ELISA demonstrated 90.0% sensitivity and 92.0% specificity, versus 43.3% sensitivity and 95.0% specificity of the M ELISA, 33.3% sensitivity and 84.0% specificity of the F1 ELISA, 96.7% sensitivity and 94.0% specificity of the yGM ELISA, 83.3% sensitivity and 88.0% specificity of the mGM ELISA, and 70.0% sensitivity and 86.0% specificity for the HMN ELISA. In summary, Hcp100 is proposed as the most promising candidate for the serodiagnosis of histoplasmosis. The primary immunoreactive element in HMN proved to be GM rather than the M antigen. Nevertheless, a higher incidence of cross-reactions was noted with GM compared to M.

A clinical utility evaluation of dual HIV/Syphilis point-of-care tests in non-clinical settings for screening for HIV and syphilis in men who have sex with men

BackgroundDual point-of-care tests (POCTs) for the simultaneous detection of antibodies to HIV and syphilis have been developed. Since community-based organisations (CBO) are effective providers of HIV and syphilis testing among men who have sex with men (MSM), evaluation of the utility of these dual tests at CBO testing services is a high priority. The aim of this study is to determine the feasibility of performing dual HIV-syphilis POCT testing among both users and providers at these non-clinical sites.MethodsThis evaluation assessed the utility of two lateral flow immunochromatographic antibody technologies for dual screening for HIV/syphilis among MSM seeking testing in four CBO testing services in Spain, Slovenia, Latvia, and Ukraine. The study’s conceptual framework divides the concept of feasibility into two inter-related domains, acceptability, and usability and further breaks it down into six subdomains: learnability, willingness, suitability, satisfaction, efficacy, and effectiveness. The feasibility analysis was performed by calculating the median score in 3 stages (for individual questions, subdomains, and domains), using a summated scores method.ResultsThe final sample included 844 participants, 60 of which were found to be HIV test positive (7.1%) and 61 (7.2%) positive on testing for syphilis. There was a small difference (1.1%) when comparing the results of the two dual POCTs under evaluation to the tests routinely used at each site. The inter-rater agreement showed a high concordance between two independent readings. The analysis of the feasibility for the users of the services indicated good satisfaction, suitability, and willingness. In addition, among 18 providers the total mean score showed good acceptability and usability, good willingness, easy learnability, high suitability, and good efficacy, but lower satisfaction and effectiveness. The operational characteristics of both dual study POCTs were well evaluated by providers.ConclusionsThe introduction of dual HIV and syphilis POCTs in CBO testing services for screening of MSM is feasible, with a high acceptability and usability both for users and providers. Implementation of dual POCTs for HIV and syphilis in CBO testing services is an opportunity for scaling up integrated HIV/syphilis testing for MSM.

Corona virus – A natural catastrophe

Viruses, ultra-microscopic structures mainly are pathogens, which affect the human beings by causing endemic, epidemic and even pandemic diseases. Coronaviruses (CoV) - large family of enveloped viruses containing single stranded RNA, belong to the family: Coronaviridae, order: Nidovirales. Zoonotic coronaviruses have emerged in recent years to cause human outbreaks such as SARS - severe acute respiratory syndrome, MERS - Middle East respiratory syndrome and coronavirus disease 2019 (COVID-19). SARS-like CoVs observed in horse shoe bats like Rhinolophus macrotis &amp; R.sinicus which shed the virus in saliva and urine transmitting to human beings during the processing of bat meat. SARS-CoV-2 virions attach to human cells manifested as a respiratory infection. The clinical spectrum of illness varies from no symptoms or mild respiratory symptoms to severe, rapidly progressive pneumonia, acute respiratory distress syndrome, septic shock, or multi organ failure resulting in death. There are many ways of diagnosis of COVID-19 through thermal checking for fever, symptoms like severe cough, cold etc., lung X-ray, antibody detection and PCR tests. ‘Prevention is better than cure’, a common proverb has lot of meaning in the present pandemic. Physical distancing, wearing mask in public places, sanitizing hands are now considered as most important steps in preventing COVID-19. Recently designated Omicron subvariant JN.1 is spreading causing the disease among the people. Probiotic drinks play an important role in inhibiting the ACE inhibiting biopeptide, preventing virus fusion to human lung cells and studies are going on in this aspect. Globally many vaccines have been released and used providing the immunity against the COVID-19. The present review article focuses on virus, classification, place of coronavirus, its impact on humans, clinical manifestation, prevention and control measures.

Diagnostic accuracy of a novel point-of-care test for simultaneous detection of anti-transglutaminase IgA and anti-deamidated gliadin IgG antibodies.

Point-of-care tests (POCTs) may have a role in detecting undiagnosed cases of Celiac disease (CD). We assessed the diagnostic accuracy of a novel POCT, compared with the conventional serological methods, for simultaneous anti-transglutaminase (tTG) IgA and anti-deamidated gliadin (DGP) IgG antibody detection. Furthermore, we evaluated the effect of different biological matrices (whole blood and serum) on test performance. Serum and whole blood from celiac or suspected celiac patients who underwent duodenal biopsy were assayed for the presence of anti-tTG IgA and anti-DGP IgG both with the reference standard methods (Thermo Fisher Scientific, Uppsala, Sweden) and with the POCT (PRIMA Lab SA, Balerna, Switzerland). 266 sera (101 negative and 165 positive) and 60 whole blood samples (34 positive and 26 negative) were included in the study. POCT for anti-DGP IgG showed a sensitivity of 84.3% and a specificity of 90.1%, with positive (PPV) and negative predictive values (NPV) of 91.07% and 82.73%. POCT for anti-tTG IgA showed a sensitivity of 98.31% and a specificity of 98.02%, with a PPV and NPV of 98.31% and 98.02%. Test accuracies were 86.94% and 98.17%, respectively. The agreement of the results between the two different matrices showed a strong correlation rate: 95% for anti-DGP IgG and 100% for anti-tTG IgA. The anti-tTG IgA/anti-DGP IgG-based POCT showed good diagnostic accuracy with comparable sensitivities and specificities to reference standard methods in detecting CD in symptomatic patients and could be considered as a mass screening test before referring to conventional serology.

Performance Analysis of Serodiagnostic Tests to Characterize the Incline and Decline of the Individual Humoral Immune Response in COVID-19 Patients: Impact on Diagnostic Management.

Serodiagnostic tests for antibody detection to estimate the immunoprotective status regarding SARS-CoV-2 support diagnostic management. This study aimed to investigate the performance of serological assays for COVID-19 and elaborate on test-specific characteristics. Sequential samples (n = 636) of four panels (acute COVID-19, convalescent COVID-19 (partly vaccinated post-infection), pre-pandemic, and cross-reactive) were tested for IgG by indirect immunofluorescence test (IIFT) and EUROIMMUN EUROLINE Anti-SARS-CoV-2 Profile (IgG). Neutralizing antibodies were determined by a virus neutralization test (VNT) and two surrogate neutralization tests (sVNT, GenScript cPass, and EUROIMMUN SARS-CoV-2 NeutraLISA). Analysis of the acute and convalescent panels revealed high positive (78.3% and 91.6%) and negative (91.6%) agreement between IIFT and Profile IgG. The sVNTs revealed differences in their positive (cPass: 89.4% and 97.0%, NeutraLISA: 71.5% and 72.1%) and negative agreement with VNT (cPass: 92.3% and 50.0%, NeutraLISA: 95.1% and 92.5%) at a diagnostic specificity of 100% for all tests. The cPass showed higher inhibition rates than NeutraLISA at VNT titers below 1:640. Cross-reactivities were only found by cPass (57.1%). Serodiagnostic tests, which showed substantial agreement and fast runtime, could provide alternatives for cell-based assays. The findings of this study suggest that careful interpretation of serodiagnostic results obtained at different times after SARS-CoV-2 antigen exposure is crucial to support decision-making in diagnostic management.