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A great number of vaccinated patients develop specific anti-tetanus toxoid IgE, but usually do not undergo any adverse effect. Most of the allergic reactions to tetanus toxoid vaccine usually present with unspecific symptoms of local inflammation. In the presence of severe reactions, and in a special way if the vaccine is provided together with other drugs, it is difficult to establish which is the harmful drug responsible for IgE-mediated adverse reaction. A patient with an anaphylactic reaction after the administration of Toxoid Tetanic (TT) along with several drugs is described. All skin test were negative. The basophils activation test (BAT) in a clear way, identified TT as the allergen that triggered anaphylaxis. The results achieved demonstrates the usefulness of BAT to clarify patients with hypersensibility to tetanus toxoide when the clinic is severe and the vaccine has been administered together with other drugs., (Copyright © 2017 Elsevier B.V. All rights reserved.)

This study was designed to determine the sensitivity and reproducibility of recovering anti-streptolysin O titres (ASOT) from dried blood spot (DBS) samples, a methodologic subcomponent of the penicillin pharmacokinetic studies in children receiving secondary prophylaxis with intramuscular benzathine penicillin for acute rheumatic fever., (Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.)

The advantages of chicken (Gallus gallus domesticus) antibodies as immunodiagnostic and immunotherapeutic biomolecules has only been recently recognized. Even so, chicken antibodies remain less-well characterized than their mammalian counterparts. This review aims at providing a current overview of the structure, function, development and generation of chicken antibodies. Additionally, brief but comprehensive insights into current knowledge pertaining to the immunogenetic framework and diversity-generation of the chicken immunoglobulin repertoire which have contributed to the establishment of recombinant chicken mAb-generating methods are discussed. Focus is provided on the current methods used to generate antibodies from chickens with added emphasis on the generation of recombinant chicken mAbs and its derivative formats. The advantages and limitations of established protocols for the generation of chicken mAbs are highlighted. The various applications of recombinant chicken mAbs and its derivative formats in immunodiagnostics and immunotherapy are further detailed., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Colorectal cancer (CRC) is the second leading cause of cancer deaths in the US and Western world. Despite increased screening and advances in treatment, the mortality rate (ca. 50,000/year) and high national health-care burden for CRC are likely to remain high unless an effective non-invasive screening test for CRC is instituted for a large segment of the population. Blood-based protein biomarkers hold great promise for early disease diagnosis and personalized medicine; yet robust and reproducible multiplexing platforms and methodologies have lagged behind their genomic counterparts. Here, we report the development of a novel, multiplexed, hybrid immunoassay for CRC that is formatted on barcoded VeraCode™ micro-beads, which have until now only been used for genomic assays. The method combines a sandwich immunoassay format for detection of serum protein biomarkers with an antigen assay for autoantibody detection. The serum protein biomarkers CEA and GDF15 as well as autoantibodies to the p53 tumor associated antigen (TAA) were used to exemplify the method. This multiplex biomarker panel was configured to run on Illumina's holographically barcoded VeraCode™ micro-bead platform, which is capable of measuring hundreds of analytes simultaneously in a single well from small volumes of blood (<50 μL) using a 96-well industry standard microtiter plate. This novel use of the VeraCode™ micro-bead platform translates into a potentially low volume, high throughput, multiplexed assay for CRC, for the purposes of biomarker validation, as well as patient screening, diagnostics and prognostics. In an evaluation of a 186 patient sera training set (CRC and normal), we obtained a diagnostic sensitivity of 54% and a specificity of 98%. We anticipate that by expanding and refining the biomarkers in this initial panel, and performing more extensive clinical validations, such an assay could ultimately provide a basis for CRC population screening to complement the more invasive, expensive and low throughput (but highly sensitive and specific) colonoscopy., (© 2013. Published by Elsevier B.V. All rights reserved.)

Administration of biopharmaceutical products can generate immune response that may severely impact the safety or efficacy of the products. Immunogenicity evaluation, required by regulatory agencies, relies on well developed and validated assays. Key to such assay development is the determination of a cut point during assay validation. Although many methods have been suggested in literature, they are either too complicated to be of practical use by scientists without ready assistance of statisticians or lacking statistical justification. In this paper, we discuss statistical considerations on cut point analysis in immunogenicity assay validation, with a focus on data normalization, outlier detection, and cut point calculation. Also provided is a statistical procedure for cut point determination which maintains a good balance between statistical rigor and implementation simplicity. To facilitate the implementation of the procedure, a software tool is developed, using R language, to automate the proposed process. Taken together the proposed approach renders scientists a practical guide for cut point determination., (Copyright © 2012 Elsevier B.V. All rights reserved.)

In vivo, the activity of antibodies relies critically on properties of both the variable domain, responsible for antigen recognition, and the constant domain, responsible for innate immune recognition. Here, we describe a flexible, microsphere-based array format for capturing information about both functional ends of disease-specific antibodies from complex, polyclonal clinical serum samples. Using minimal serum, we demonstrate IgG subclass profiling of multiple antibody specificities. We further capture and determine the subclass of epitope-specific antibodies. The data generated in this array provides a profile of the humoral immune response with multi-dimensional metrics regarding properties of both variable and constant IgG domains. Significantly, these properties are assessed simultaneously, and therefore information about the relationship between variable and constant domain characteristics is captured, and can be used to predict functions such as antibody effector activity., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Rheumatoid factors are antibodies directed against IgG that may confound immunogenicity testing for therapeutic monoclonal antibodies. We developed antigen-binding assays to monitor anti-drug-antibody (ADA) responses against infliximab and adalimumab using F(ab')2 fragments of the drug. This avoids possible detection of rheumatoid factor activity. During development of these assays, a number of sera from patients before treatment as well as several healthy control sera were tested positive. None of these sera contained antibodies specific for the therapeutic mAb. Instead, they were found to contain anti-hinge antibodies. We demonstrate that this aspecific antibody binding can be inhibited by adding F(ab')2 of intravenous immunoglobulin (IVIG), which consists of pooled polyclonal IgG derived from plasma. Using this protocol, anti-infliximab antibodies can be measured specifically without interference by anti-hinge antibodies., (Copyright © 2011 Elsevier B.V. All rights reserved.)

The pattern recognition receptors (PRRs) of the innate immune system are the first defence line of the immune system. Toll-like receptors (TLRs) are the most well known and the best examined of the PR receptors. In the last years TLRs had been studied in different ways resulting in a lot of new insights in the function and signalling pathways of these receptors. However, it was not possible to investigate individual combinations of the TLRs and their specific ligands, because of the complex network in immune signalling resulting in interference with each other. This work shows a new cell-based assay, established for the analysis of single PRRs or heterodimers. For this purpose NIH3T3 (mouse fibroblasts) were stably transfected with the NF-kappaB-inducible reporter gene secreted alkaline phosphatase (SEAP) together with the corresponding combinations of human TLRs and their co-receptors (e.g. TLR1/2, TLR2/6 and TLR4/CD14). The specificity of the respective cell lines was shown by induction with variations of specific and unspecific ligands (immune-stimulating components of microorganisms or synthetic ligands). Analysis via the NF-kappaB-dependent reporter gene SEAP allows a direct way to detect the human TLR-activity. Our results showed that this assay is highly sensitive and specific for the respective ligands. For the synthetic ligands Pam(2)CysSK(4) the assay demonstrates a detection limit of 1 pg/ml for TLR2/6. In summary, this test system allows the investigation of individual human PRR-receptors in a highly specific way, without interference with other immune components opening new avenues for novel insights in the innate immune system and its applications., (Copyright 2010 Elsevier B.V. All rights reserved.)

An original technique for obtaining stable conjugates using colloid carbon particles as indicator labels has been developed. The reliability and stability of the diagnostic reagents obtained is provided by covalent binding of various affine compounds on the surface of carbon particles. The stability of the reagents has been studied under various storage conditions for 3-10 years. It was shown that even when storage conditions were outside the optimal range, some conjugates preserved their analytical characteristics for 10 years. A number of systems for analytical detection of various ligands have been designed based on the carbon-protein conjugates synthesized. The major characteristics of these systems are their high sensitivity and specificity, reliability, and reproducibility, simplicity in operation, and quick results.

Cell line-based bioassays are becoming increasingly popular for assessment of biological activities of cytokines primarily because these are easy to perform and are not subject to donor variation. A well characterised cell line with world wide availability would further minimise the inter-assay variations. C57BL/6 mice derived T cell line; CTLL-2 fits this criterion. We explored the potential of CTLL-2 cells to develop a bioassay to detection of murine (m) IL12 and mIL18. Both cytokines have shown significant activity against a number of cancers and importantly, act synergistically via mutual upregulation of each other's receptors. The preliminary flow cytometric analyses of immunostained CTLL-2 cells showed that approximately 65% expressed mIL12 and approximately 5% expressed mIL18 receptors suggesting that these may respond to mIL12. As predicted, cells incubated with different doses of mIL12 or mIL18 for 72 h were responsive to mIL12 and not to mIL18. However, when pre-treated with mIL12 for 24 h prior to incubation with mIL18, there was a significant enhancement in response. The sensitivity of the response was comparable to that obtained using the conventional splenocyte-based IFNgamma release assay. The cytokine specificity of the response was proven unequivocally when significant reduction in CTLL-2 response was observed in the presence of the relevant neutralising antibodies. Finally, we could successfully detect lowest doses of approximately 0.1 pg/microL mIL12 or 40 pg/mL of mIL18 in cell supernatants in a cytokine specific manner, which is lower than the resting levels of these cytokines in mouse sera. Again the sensitivity was comparable to that observed in the conventional IFNgamma release assay. Hence, we have demonstrated the potential of CTLL-2-based bioassay to detect biologically active mIL12 and mIL18 in biological samples accurately and reproducibly.

In this work, we analyzed serological responses of paracoccidioidomycosis (PCM) patients to membrane and extracellular antigens (Mexo) of Paracoccidioides brasiliensis by ELISA, immunoblot technique and immunofluorescence assays to identify a specific antigen profile. Among 140 PCM serum samples analyzed, a homogeneous IgG response to Mexo was observed. The specificity of this antigen was 96.6% in relation to control sera and 81.2% to sera from patients with diverse infections. Patients undergoing treatment for more than 1 year showed a reduced antibody response against Mexo. These results suggest that the presence of anti-Mexo antibodies might be an indicator of active disease. A protein from Mexo with a molecular weight of 28 kDa (Pb28) was the most specific antigen in humoral immune responses to PCM, since it reacted with 100% of patient sera and did not react with heterologous serum samples tested. This protein was purified by molecular filtration chromatography in FPLC system and, when tested by immunoblotting, it maintained its reactivity and specificity of 100% with PCM sera. The Pb28 N-terminal amino acid sequence comparison analysis in the non-redundant GenBank database at NCBI revealed no significant homology to known PCM proteins or to other fungal proteins of known function. Since the 28-kDa protein of P. brasiliensis seems to be specific for PCM, it can be used as an alternative antigen in immunoblotting diagnostic methods.

Background and Objective: The practical value of immunological diagnosis of bird-breeder's disease (BBD) is controversial, because of difficulties in distinguishing active disease patients from simple contact subjects. The aim of this study was to determine the diagnostic and prognostic value of (a) presumed disease-associated antibodies precipitating pigeon antigens (immunoglobulin A (IgAp) and P2 component), (b) characterization of specific isotypes (IgG, IgM, and IgA), and (c) antibody kinetics after antigen eradication., Methods: 405 subjects (775 sera) in contact with birds were studied [by means of co-immunoelectrodiffusion (Co-IED) and enzyme-linked immunofiltration (ELIFA)] with soluble extracts of pigeon droppings and squab crop milk. These patients were divided into two groups based on the final clinical evaluation of the patients' physicians, which was taken as the gold standard (positive in 90 and negative in 315 cases)., Results: On the basis of this gold standard, the detection of presumed disease-associated precipitating antibodies by Co-IED had a specificity of 95.5%, a sensitivity of 98.7%, an accuracy of 98%, and positive and negative predictive values of 95.5% and 98.7%, respectively. Most of the patients with a final positive diagnosis of BBD had specific IgG, IgM, and IgA antibodies by ELIFA. After antigen eradication, anti IgAp and/or P2 antibodies disappeared more rapidly than other precipitating systems., Conclusion: Identification by Co-IED of precipitating immune complexes IgAp and/or P2 significantly reinforces the intrinsic credibility of immunological diagnosis of BBD. Compared to these presumed disease-associated precipitating antibodies, detection and time course of specific IgM, IgA antibodies, provided no additional diagnostic value or prognostic arguments to judge disease activity after antigen eradication.

An improved method of assessment of the human immune response against Mycobacterium tuberculosis antigens will assist the development of new vaccines or diagnostic reagents. In this study, we have analyzed human T cell responses to culture filtrate fractions (CFF) of actively replicating M. tuberculosis strain H37Rv using peripheral blood mononuclear cells from healthy PPD skin test positive and negative individuals. Adsorption of CFF onto polystyrene microspheres, that were approximately the size of the M. tuberculosis (bead-adsorbed antigens, BAA) significantly enhanced IFN-gamma production compared to soluble antigens (SA) in PPD skin test positive individuals in an antigen-specific manner. Further, BAA induced activation of both CD4(+) and CD8(+) T cell subsets. However, CD4(+) responses in general were higher and their antigenic repertoire was wider than the CD8(+) responses. By contrast, CD8(+) responses were strongest to the lower molecular weight BAA. When CFF were chemically coupled to carboxyl modified microspheres (bead-coupled antigens, BCA), induction of IFN-gamma was similar to BAA. Enhancement of T cell responses to particulate M. tuberculosis antigens may prove useful in vaccine design strategies.

The reactivities of two panels of anti-HAV human sera from geographically distinct areas (Chile and Spain) to synthetic peptides from the VP1, VP2 and VP3 hepatitis A virus capsid proteins were examined by an enzyme-linked immunosorbent assay (ELISA) procedure. Two and four branched multiple antigenic peptides (MAPs) and palmitoylated peptides were compared with free synthetic sequences for the detection of IgM anti-HAV antibodies in the two panels of human sera. Our results showed that acute hepatitis A patient sera recognized preferentially homogeneous two branched MAPs and palmitic acid conjugated peptides. The palmitoyl-derived VP3(110-121) peptide and the corresponding dimeric MAP were the most sensitive and appropriate for serological studies of HAV-infected patients by ELISA, sensitivity and specificity being higher than 90% and 95%, respectively. These peptide-based tests open up new avenues in the development of peptide-based immunosorbent assays for the detection of acute HAV disease.

This study was performed by the Italian Society of Laboratory Medicine (SIMeL) in order to establish the variability between the different analytical systems currently used in clinical laboratories for the detection of autoantibodies diagnostic of systemic autoimmune disease. Sixteen industrial, and two university laboratories participated in this study which entailed the determination of anti-nuclear (ANA), anti-dsDNA and anti-ENA antibodies in 11 sera from patients with clinically diagnosed systemic rheumatic disease, using reagents produced by these companies and different methodologies (indirect immunofluorescence, immunoenzymatic assay, counterimmunolectrophoresis, immuno and western blotting). We found 93.5% agreement between the methods used for the detection of ANA, 85.2% for anti-dsDNA antibodies, and 86.9% for anti-ENA antibodies. Among the anti-ENA antibodies, regardless of the method used, detection percentages were excellent for anti-RNP and anti-SSB/La (100%), good for anti-SSA/Ro (93%), but unacceptable for the anti-Jo-1 (67%), anti-Scl70 and anti-Sm (47%) antibodies. This further stresses the need for rigorous standardisation of commercial reagents and analytical procedures, as well as the introduction of external quality assessment (EQA) programs, and a complete definition of operative protocols adjusted to the sensitivity and specificity of the various methods.

The utilization of computational models in immunology dates from the birth of the science. From the description of antibody-antigen binding to the structural models of receptors, models are utilized to bring fundamental understandings of the processes together with laboratory measurements to uncover implications of these data. In this review, an historical view of the role of computational models in the immunology laboratory is presented, and short mathematical descriptions are given of fundamental assays. In addition, the range of current uses of models is explored -- especially as seen through papers which have appeared in the Journal of Immunological Methods from volume 1 (1971/1972) to volume 208 (1997). Each paper which introduced a new mathematical, statistical, or computer simulation model, or introduced an enhancement to an instrument through a model in those volumes is cited and the type of computational model noted.

This review discusses the range of methods which are currently available for measuring locomotion and chemotaxis of leukocytes in vitro, their history, and some definitions of terms. Assays of the net migration of large cell populations, such as the filter assay are the most popular and are useful for identifying chemoattractant molecules, but give no direct information about how these molecules influence the speed and direction of cell movement (chemokinesis and chemotaxis). Visual assays including measures of orientation in gradients and time-lapse filming give detailed information about cell paths and direct evidence for chemotaxis and chemokinesis. The polarization assay is a useful visual screening assay. Assays which simulate the situation in living tissues are becoming more popular and include migration through collagen or fibrin gels or through monolayers of vascular endothelium. Locomotion is a complex process, no single assay gives full information and the use of more than one assay is recommended.

In this study we present a strategy for the identification of novel peptide conjugates which may be used to understand the molecular details of the recognition process or to potentially regulate T cell-mediated responses. The approach involves the incorporation of cysteine into a known peptide at a position of interest and subsequent chemical conjugation using thiol-specific agents. Conjugates derived from the nonapeptide QL9 that is recognized by CTL 2C had either enhanced or reduced activity compared to the original cys-peptides. Different classes of thiol-reactive agents (alkyl halides, alkylthiolsulfonates, and disulfides) were tested with increases in activity of over 100-fold. As with standard peptide analogs, the activity depended on the position of the cysteine within the peptide and the nature of the chemically linked functional group. Use of this approach in a cysteine 'scan' of all positions of the original peptide is cost effective and with the availability of many different thiol-specific functional groups will allow the screening of considerably larger libraries of chemically modified peptides than have been used to date. Additionally, these findings may provide insight into the pathogenesis of thiol agents involved in contact sensitivity reactions.

Parasite specific antibody probes were prepared by harvesting lymphocytes from infected tissue and incubating them in vitro to allow the spontaneous secretion of antibodies in the culture medium by antibody secreting B cells present in the lymphocyte cultures. The culture supernatant was then used to screen Western blots of parasite antigens and resulted in the detection of antigens specific for the parasite stages present in the tissue at the time of sampling. Similar antigen recognition patterns were also observed when the cells were taken from the draining lymph nodes but the same pattern was not observed with serum taken from the same animal. The use of antibody probes obtained from in vivo induced antibody secreting B cells (ASC probes) offers a unique and universal approach to study local antibody recognition during infection.