Immunodiagnostics

Human pepsinogens (mainly pepsinogen I and pepsinogen II) are the major inactive precursor forms of the digestive enzyme pepsin which play a crucial role in protein digestion. The levels and ratios of human pepsinogens have demonstrated potential as diagnostic biomarkers for gastrointestinal diseases, particularly gastric cancer. Nanobodies are promising tools for the treatment and diagnosis of diseases, owing to their unique recognition properties. In this study, recombinant human pepsinogens proteins were expressed and purified as immunized antigens...

Canine circovirus (CanineCV) is an emerging pathogen in domestic dogs, detected in multiple countries in association with varying clinical and pathological presentations including diarrhoea, vasculitis, granulomatous inflammation, and respiratory signs. Understanding the pathology of CanineCV is confounded by the fact that it has been detected in asymptomatic dogs as well as in diseased dogs concurrently infected with known pathogens. Recombinantly expressed self-assembling Virus-like particles (VLPs) lack viral genomic material but imitate the capsid surface conformations of wild type virion, allowing arrays of biological applications including subunit vaccine development and immunodiagnostics...

The world is facing a measles resurgence, and improved diagnostic tests for measles infection are an urgent World Health Organization research priority. Detection of measles-specific immunoglobulin M (IgM) as a standard diagnostic test has low positive predictive value in elimination settings, and there is a need for new biomarkers of measles infection to enable enhanced surveillance and response to outbreaks. We demonstrate the detection of measles-specific dimeric immunoglobulin A (dIgA) in patients with confirmed measles infections using a new indirect enzyme-linked immunosorbent assay protocol that selects for the dIgA fraction from total IgA in the blood...

BACKGROUND: Cystic echinococcosis (CE) is an endemic disease in southern Chile. The aim of this study was to ascertain the prevalence of CE among relatives of patients who underwent surgical intervention for this disease in Cautín, a province of southern Chile. METHODOLOGY/PRINCIPAL FINDINGS: Cross-sectional study. Relatives of patients who underwent surgery for hepatic echinococcosis (HE), who lived at the same address, during the period 2000-2020 were studied...

Therapeutic drug monitoring (TDM) of tumor necrosis factor-α (TNFα)-inhibitors adalimumab and infliximab is important to establish optimal drug dose and maximize treatment efficacy. Currently, TDM is primarily performed with ELISA techniques in clinical laboratories, resulting in a long sample-to-result workflow. Point-of-care (POC) detection of these therapeutic antibodies could significantly decrease turnaround times and allow for user-friendly home-testing. Here, we adapted the recently developed bioluminescent dRAPPID (dimeric Ratiometric Plug-and-Play Immunodiagnostics) sensor platform to allow POC TDM of infliximab and adalimumab...

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease that requires precise diagnosis for effective treatment. However, the diagnostic value of carbohydrate antigen 19 - 9 (CA19-9) is limited. Therefore, this study aims to identify novel tumor-associated autoantibodies (TAAbs) for PDAC diagnosis. METHODS: A three-phase strategy comprising discovery, test, and validation was implemented. HuProt™ Human Proteome Microarray v3...

To evaluate the potential of zinc finger protein 1 (ZPR1) as a diagnostic biomarker and explore the underlying role for esophageal squamous cell carcinoma (ESCC). A human proteome microarray was customized to identify anti-ZPR1 autoantibody, and enzyme-linked immunosorbent assay (ELISA) was adopted to assess the diagnostic performance of anti-ZPR1 autoantibody in 294 patients with ESCC and 294 normal controls. The expression of ZPR1 protein was measured by immunohistochemistry. The effect of ZPR1 on the proliferation, migration, and invasion of ESCC cells was investigated through CCK-8, wound healing, and Transwell assays...

Specific immunoglobulin E immunodiagnostics is becoming a convenient way to identify allergic patients and their specific allergies. These results are comparable to skin testing and may be more accessible for some populations. Each allergen contains thousands of molecules but only a few of these molecules are allergenic to humans. Each allergen has a number of individual components-generally proteins-which have different characteristics that may impact the effects of sensitization. Identification of the specific component allows for differentiation of the true allergies and can help to determine the risk of a significant clinical response...

BACKGROUND: Children exposed to a tuberculosis (TB) index case are at risk of TB infection and disease. OBJECTIVES: The aim of this study was to describe the proportion of child contacts who developed TB infection or disease after exposure and to assess the diagnostic pathways and adherence to current guidelines. METHODS: Retrospective observational study including children ≤16 years of age who had contact to a TB index case between January 2019 and July 2021...

The early diagnosis of leprosy serves as an important tool to reduce the incidence of this disease in the world. Phage display (PD) technology can be used for mapping new antigens to the development of immunodiagnostic platforms. Our objective was to identify peptides that mimic Mycobacterium leprae proteins as serological markers using phage display technology. The phages were obtained in the biopanning using negative and positive serum from household contacts and leprosy patients, respectively. Then, the peptides were synthesized and validated in silico and in vitro for detection of IgG from patients and contacts...

Immunological assays based on the detection of circulating fungal biomarkers are helpful in clinical practice for diagnosing invasive fungal infections. Some of these targeting antigenic components are common to several different fungi. Histoplasmosis is a mycosis caused by the dimorphic fungus Histoplasma capsulatum , which in recent years has gained significant relevance due to the increase in the population susceptible to developing severe clinical forms, including those living with HIV/AIDS. Immunological tests that detect cell wall polysaccharide antigens are among the most used laboratory techniques for diagnosing this mycosis...

Immunomodulation therapies have attracted immense interest recently for the treatment of immune-related diseases, such as cancer and viral infections. This new wave of enthusiasm for immunomodulators, predominantly revolving around cytokines, has spurred emerging needs and opportunities for novel immune monitoring and diagnostic tools. Considering the highly dynamic immune status and limited window for therapeutic intervention, precise real-time detection of cytokines is critical to effectively monitor and manage the immune system and optimize the therapeutic outcome...

BACKGROUND: Leptospirosis is a zoonotic disease caused by Leptospira species. Variations in lipopolysaccharide (LPS) structure in Leptospira are known to be associated with the serovar diversity and antigenicity. Development of immunodiagnostics for early detection of leptospirosis based on immune responses against different pathogenic antigens as well as development of vaccines are important. Hence, this study has assessed the immune response generated against leptospiral LPS and whole antigen preparations of pathogenic and saprophytic Leptospira and specific changes in peritoneal cells was also studied to elucidate the cellular responses associated with immune response of Wistar rats...

BACKGROUND: Machine learning (ML) has gained significant attention for classifying immune states in adaptive immune receptor repertoires (AIRRs) to support the advancement of immunodiagnostics and therapeutics. Simulated data are crucial for the rigorous benchmarking of AIRR-ML methods. Existing approaches to generating synthetic benchmarking datasets result in the generation of naive repertoires missing the key feature of many shared receptor sequences (selected for common antigens) found in antigen-experienced repertoires...

Antibodies represent a relatively mature detection means and serve as therapeutic drug carriers in the clinical diagnosis and treatment of cancer-among which monoclonal antibodies (mAbs) currently occupy a dominant position. However, the emergence and development of small-molecule monodomain antibodies are inevitable due to the many limitations of mAbs, such as their large size, complex structure, and sensitivity to extreme temperature, and tumor microenvironments. Thus, since first discovered in Chondroid fish in 1995, IgNAR has become an alternative therapeutic strategy through which to replace monoclonal antibodies, thus entailing that this novel type of immunoglobulin has received wide attention with respect to clinical diagnoses and tumor therapies...

Today, the home pregnancy test is the most frequently performed laboratory test for self-diagnosis (home diagnostic test). It is also the first laboratory test that has been adapted for self-use at home. This is probably because women have always wanted to know the answer to the question: "Am I pregnant or not?" and always preferred to know the answer to this question intimately and in a discreet way. The history of the pregnancy test is also an interesting example of how the discovery of antibodies and the development of in vitro diagnostic methods based on the antigen-antibody reaction were important for the development of laboratory and clinical diagnostics...

Human monkeypox (mpox) has recently become a global public health emergency; however, assays that detect mpox infection are not widely available, largely due to cross-reactivity within the Orthopoxvirus genus. Immunoassay development was largely confined to researchers who focus on biothreats and endemic areas (Central and West Africa) until the 2022 outbreak. As was noted in the COVID-19 pandemic, antigen detection assays, integrated with molecular assays, are necessary to help curb the spread of disease. Antigen-detecting immunoassays offer the advantage of providing results ranging from within min to h and in lateral flow formats; they can be deployed for point-of-care, home, or field use...

High throughput allergen characterization is often based on phage display technique which is limited by the constraints of a prokaryotic expression system such as potential loss of conformational epitopes and lack of post-translational modifications. Replacing the phage display platform with a yeast surface display system could accelerate the immunological characterization of complex structured allergens. Yeast surface display is a powerful technique that allows faster immunochemical characterization of allergens in situ without the need for protein purification...

Fasciola hepatica can cause problems in both animals and humans. Fasciolosis can be diagnosed through the indirect ELISA immunodiagnostic test. Serological diagnosis of Fasciola is based on recombinant antigens secreted by this worm. We used PubMed and Google Scholar databases to review the published literature on 'antigens with immunogenic potential' used in serological tests to identify antibodies against F. hepatica in humans, cattle, and sheep. Studies that investigated diagnostic tests with common reference standards were included in the sensitivity and/or specificity bivariate meta-analysis...

Objectives Previous studies have noted associations between the immunofluorescence patterns of antinuclear autoantibodies (ANA) and the autoimmune responses seen in systemic lupus erythematosus (SLE). In this study, the authors tested the hypothesis of whether ANA patterns predict renal involvement in SLE patients. Method A retrospective study was carried out on consecutive SLE patients who had ANA staining pattern data and who were screened for renal involvement defined as all-stage proteinuria or chronic kidney disease (CKD) at a referral tertiary center in western Saudi Arabia from December 2021 to February 2022...