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Rare antinuclear antibody (ANA) pattern recognition has been a widely applied technology for routine ANA screening in clinical laboratories. In recent years, the application of deep learning methods in recognizing ANA patterns has witnessed remarkable advancements. However, the majority of studies in this field have primarily focused on the classification of the most common ANA patterns, while another subset has concentrated on the detection of mitotic metaphase cells. To date, no prior research has been specifically dedicated to the identification of rare ANA patterns. In the present paper, we introduce a novel attention-based enhancement framework, which was designed for the recognition of rare ANA patterns in ANA-indirect immunofluorescence images. More specifically, we selected the algorithm with the best performance as our target detection network by conducting comparative experiments. We then further developed and enhanced the chosen algorithm through a series of optimizations. Then, attention mechanism was introduced to facilitate neural networks in expediting the learning process, extracting more essential and distinctive features for the target features that belong to the specific patterns. The proposed approach has helped to obtained high precision rate of 86.40%, 82.75% recall, 84.24% F1 score and 84.64% mean average precision for a 9-category rare ANA pattern detection task on our dataset. Finally, we evaluated the potential of the model as medical technologist assistant and observed that the technologist's performance improved after referring to the results of the model prediction. These promising results highlighted its potential as an efficient and reliable tool to assist medical technologists in their clinical practice. [ABSTRACT FROM AUTHOR]

Classifying epitopes is essential since they can be applied in various fields, including therapeutics, diagnostics and peptide-based vaccines. To determine the epitope or peptide against an antibody, epitope mapping with peptides is the most extensively used method. However, this method is more time-consuming and inefficient than using present methods. The ability to retrieve data on protein sequences through laboratory procedures has led to the development of computational models that predict epitope binding based on machine learning and deep learning (DL). It has also evolved to become a crucial part of developing effective cancer immunotherapies. This paper proposes an architecture to generalize this case since various research strives to solve a low-performance classification problem. A proposed DL model is the fusion architecture, which combines two architectures: Transformer architecture and convolutional neural network (CNN), called MITNet and MITNet-Fusion. Combining these two architectures enriches feature space to correlate epitope labels with the binary classification method. The selected epitope–T-cell receptor (TCR) interactions are GILG, GLCT and NLVP, acquired from three databases: IEDB, VDJdb and McPAS-TCR. The previous input data was extracted using amino acid composition, dipeptide composition, spectrum descriptor and the combination of all those features called AADIP composition to encode the input data to DL architecture. For ensuring consistency, fivefold cross-validations were performed using the area under curve metric. Results showed that GILG, GLCT and NLVP received scores of 0.85, 0.87 and 0.86, respectively. Those results were compared to prior architecture and outperformed other similar deep learning models. [ABSTRACT FROM AUTHOR]

The haemagglutination test (HAT)-field protocol described here is an optimization of the recently published HAT, for the detection of antibodies directed against the receptor binding domain (RBD) of the SARS-Cov-2 virus. HAT and HAT-field are both based on haemagglutination triggered by a single reagent, the IH4-RBD recombinant protein. A sample of IH4-RBD sufficient for several thousand tests or a plasmid encoding IH4-RBD can be obtained from the authors of our first paper. Using titration of IH4-RBD, HAT-field now allows a quantitative assessment of antibody levels in a single step, using a few microliters of whole blood, such as can be obtained by finger prick, and requires only very simple disposable equipment. Because it is based on a single soluble reagent, the test can be adapted very simply and rapidly to detect antibodies against variants of the SARS-CoV-2, or conceivably against different pathogens. HAT-field appears well suited to provide quantitative assessments of the serological protection of populations as well as individuals, and given its very low cost, the stability of the IH4-RBD reagent in the adapted buffer and the simplicity of the procedure, could be deployed pretty much anywhere, including in the poorest countries and the most remote corners of the globe. [ABSTRACT FROM AUTHOR]

Summary Antibody repertoires reveal insights into the biology of the adaptive immune system and empower diagnostics and therapeutics. There are currently multiple tools available for the annotation of antibody sequences. All downstream analyses such as choosing lead drug candidates depend on the correct annotation of these sequences; however, a thorough comparison of the performance of these tools has not been investigated. Here, we benchmark the performance of commonly used immunoinformatic tools, i.e. IMGT/HighV-QUEST, IgBLAST and MiXCR, in terms of reproducibility of annotation output, accuracy and speed using simulated and experimental high-throughput sequencing datasets. We analyzed changes in IMGT reference germline database in the last 10 years in order to assess the reproducibility of the annotation output. We found that only 73/183 (40%) V, D and J human genes were shared between the reference germline sets used by the tools. We found that the annotation results differed between tools. In terms of alignment accuracy, MiXCR had the highest average frequency of gene mishits, 0.02 mishit frequency and IgBLAST the lowest, 0.004 mishit frequency. Reproducibility in the output of complementarity determining three regions (CDR3 amino acids) ranged from 4.3% to 77.6% with preprocessed data. In addition, run time of the tools was assessed: MiXCR was the fastest tool for number of sequences processed per unit of time. These results indicate that immunoinformatic analyses greatly depend on the choice of bioinformatics tool. Our results support informed decision-making to immunoinformaticians based on repertoire composition and sequencing platforms. Availability and implementation All tools utilized in the paper are free for academic use. Supplementary information Supplementary data are available at Bioinformatics online. [ABSTRACT FROM AUTHOR]

Background Home-care robots have been developed as one of the assistive technologies, and benefits and challenges of their use have been debated in many countries. Research teams in Japan, Finland and Ireland carried out a questionnaire to explore perceptions of potential users (older people, family caregivers, and health and social care professionals (HSCPs)) towards the use of home-care robots. As part of a larger tri-country comparative study, this paper reports preliminary findings from the data collected from the online survey of HSCPs in Ireland. Methods Questionnaire was developed iteratively among the research teams in three countries. Questions related to the use of advocates in deciding whether to use home-care robots, desirable functions in such robots, and perceptions of privacy protection. Based on networks of professional and advocacy groups, HSCPs were contacted and 123 respondents took part in the questionnaire, and 46 fully completed the questionnaire. Results Out of 46 respondents (44 female, 1 male and 1 did not wish to specify), 80% answered that they are open to the use of home-care robots. Safety monitoring and alert functions were considered to be most desirable in home-care robots. 76% of the respondents placed importance on the guarantee of entitlement to receiving human care, irrespective of the use of home-care robots. 30% answered that they have a negative impression of robots, to some extent. The overall majority (N=39, 85%) felt strongly that a decision as to whether to use home-care robots should be made by the user, and that the access to data collected in any form by robots requires extra care. Conclusion While there was generally a positive perception of the use of home-care robots among Irish HSCPs, cautious attitudes were evident in the areas of decision-making and privacy. This study was funded by the Pfizer Health Research Foundation. [ABSTRACT FROM AUTHOR]

The presence or absence of terminal sialic acid residues in the sugar moiety attached to the Fc-domain of IgG molecules modulates IgG activity and is associated with autoimmune or infection related inflammation. In a recent paper, Oswald and colleagues suggest that IgG sialylation may occur post IgG secretion from plasma cells, which would be a major issue for therapeutic antibodies injected into patients. In contrast, we argue that previous work rather demonstrates that IgG sialylation occurs within B cells and that the experimental system used by the authors is not suitable to address this critical question. [ABSTRACT FROM AUTHOR]

Objectives The European Single Hub and Access point for paediatric Rheumatology in Europe initiative aimed to optimize care for children with rheumatic diseases. Kawasaki disease (KD) is the most common cause of acquired heart disease in children and an important cause of long-term cardiac disease into adulthood. Prompt diagnosis and treatment of KD is difficult due to the heterogeneity of the disease but is crucial for improving outcome. To date, there are no European internationally agreed, evidence-based guidelines concerning the diagnosis and treatment of KD in children. Accordingly, treatment regimens differ widely. The aim of this study is to provide consensus-based, European-wide evidence-informed recommendations for diagnosis and treatment of children with KD. Methods Recommendations were developed using the EULAR's standard operating procedures. An extensive systematic literature search was performed, and evidence-based recommendations were extrapolated from the included papers. These were evaluated by a panel of international experts via online surveys and subsequently discussed in three consensus meetings, using nominal group technique. Recommendations were accepted when ⩾80% agreed. Results In total, 17 recommendations for diagnosis and 14 for treatment of KD in children were accepted. Diagnostic recommendations included laboratory and imaging workup for complete as well as incomplete KD. Treatment recommendations included the importance of early treatment in both complete and incomplete KD, use of intravenous immunoglobulin, aspirin, corticosteroids for high-risk cases, and other treatment options for those with resistant disease. Conclusion The Single Hub and Access point for paediatric Rheumatology in Europe initiative provides international evidence-based recommendations for diagnosing and treating KD in children, facilitating improvement and uniformity of care. [ABSTRACT FROM AUTHOR]

It has been observed that converting scFv formatted antibodies to full-length IgG often associates with loss of affinity. We aim to address this issue in this paper by establishing an integrated affinity maturation method applying yeast display technology platform. To demonstrate that, we employed a human thrombopoietin receptor targeting antibody named 3D9 which was identified previously from a combinational antibody library in scFv-Fc fusion protein form. We have observed that significant potency loss happened when 3D9 was transformed to full-length IgG form. In this study, we tested whether the potency of the full-length IgG can be improved by affinity maturation of 3D9 using a modified Fab yeast display platform. An efficient CDR3 targeted mutagenesis strategy was designed for Fab library with pre-designed CDR diversity. Next generation sequencing was also used for evaluation of the enrichment process and investigation of sequence-function relationship of the antibody. A variant with improved affinity and higher potency was identified. The study demonstrates that the strategy we used here are efficient for optimizing affinity and activity of full-length IgGs. [ABSTRACT FROM AUTHOR]

BACKGROUND Several studies have examined the relationship between direct antisperm antibody (ASA) levels in semen and pregnancy rate after advanced assisted reproductive technologies (ARTs) but the results have been inconsistent. The aim of our study was to further evaluate the relationship between ASA and pregnancy after IVF or ICSI by systematic review and meta-analysis. METHODS We conducted a systematic Medline search of all relevant full papers on direct semen ASA and pregnancy after IVF or ICSI. Three investigators independently reviewed the papers, followed by group discussion to choose the included papers. Meta-analysis was performed to get an odds ratio (OR) for the effect of ASA on pregnancy using IVF or ICSI. RESULTS The study identified and analyzed 16 valid studies (10 IVF and 6 ICSI). The study characteristics (including the ASA cutoff values) were heterogeneous. Our meta-analysis revealed that the combined OR for failure to achieve a pregnancy using IVF or ICSI in the presence of positive semen ASA was 1.22 (95% CI: 0.84, 1.77) and 1.00 (95% CI: 0.72, 1.38), respectively. The overall (IVF + ICSI) combined OR was 1.08 (95% CI: 0.85, 1.38). CONCLUSION This systematic review and meta-analysis indicate that semen antisperm antibodies are not related to pregnancy rates after IVF or ICSI, suggesting that both forms of ART remain viable options for infertile couples with semen ASA. However, additional, well-designed prospective studies using appropriate ASA cutoff levels are needed to further address this issue. [ABSTRACT FROM AUTHOR]

Studies have been conducted to characterize M. leprae antigens from purified Ieprae bacilli derived from infected armadillos. First, the proteins of the mycobacterial extracts were fractionated by SDS-PAGE. Subsequently, the proteins in the gel were electrophoretically transferred on a strip of nitrocellulose paper by the technique of 'electrophoretic blotting'. The separated bacterial protein bands, thus immobilized on the nitrocellulose paper were made to react immunologically with sera from the lepromatous patients, infected armadillo sera and other experimental mycobacterial antisera. It was observed that a majority of M. leprae proteins contained antigenic determinants also present on proteins of BCG. In addition, only two specific antigen bands of 33KD and 12KD were conspicuously detected by the patients' sera and the infected armadillo sera. These substances were further identified as polysaccharides or glycoproteins since they could only be stained by Schiff's reagent or alcian blue. Only 12KD glycoprotein band reacted with concanavalin A, whereas wheat germ agglutinin (WGA) did not show any reaction with them. These 33KD and 12KD glycoprotein antigens were found to lose their antigenicity after pepsin treatment and can be considered as glycoproteins. Further, radiolabelling experiments showed that 12KD antigen underwent radioiodination under usual conditions, but 33KD glycoprotein Failed to be similarly radiolabelled. It is suggested that these protein antigens have M. Ieprae specific determinants on a cross-reacting component. [ABSTRACT FROM AUTHOR]

The extent of the role of N-linked glycans (N-glycans) in shielding influenza A hemagglutinin (HA) against host antibodies has proved controversial, with different authors making widely different assumptions. One common assumption is that N-glycans physically shield surface residues that are near to glycosylation sites, thereby preventing antibodies from binding to them. However, it is unclear, from existing experimental evidence, whether antibodies that bind close to N-glycans are a rare or commonplace feature of human herd immune responses to influenza AHA. The aim of this paper is to present a computational analysis of mutations in the vicinity of N-glycans that will facilitate a better understanding of their protective role. We identify, from an analysis of over 6000 influenza A H3N2 sequences, a set of residues adjacent to N-glycosylation sites that are highly likely to be involved in antigenic escape from host antibodies. Fifteen of these residues occur within 10 Å of an N-glycosylation site. Hence, we conclude that it is relatively common for antibodies to bind in close proximity to N-glycans on the surface ofHA, with any shielding effect largely attributable to the inability of host antibodies to bind across an N-glycan attachment site, rather than to the physical masking of neighboring residues. [ABSTRACT FROM PUBLISHER]

Motivation The emergence of a novel strain of betacoronavirus, SARS-CoV-2, has led to a pandemic that has been associated with over 700 000 deaths as of August 5, 2020. Research is ongoing around the world to create vaccines and therapies to minimize rates of disease spread and mortality. Crucial to these efforts are molecular characterizations of neutralizing antibodies to SARS-CoV-2. Such antibodies would be valuable for measuring vaccine efficacy, diagnosing exposure and developing effective biotherapeutics. Here, we describe our new database, CoV-AbDab, which already contains data on over 1400 published/patented antibodies and nanobodies known to bind to at least one betacoronavirus. This database is the first consolidation of antibodies known to bind SARS-CoV-2 as well as other betacoronaviruses such as SARS-CoV-1 and MERS-CoV. It contains relevant metadata including evidence of cross-neutralization, antibody/nanobody origin, full variable domain sequence (where available) and germline assignments, epitope region, links to relevant PDB entries, homology models and source literature. Results On August 5, 2020, CoV-AbDab referenced sequence information on 1402 anti-coronavirus antibodies and nanobodies, spanning 66 papers and 21 patents. Of these, 1131 bind to SARS-CoV-2. Availabilityand implementation CoV-AbDab is free to access and download without registration at http://opig.stats.ox.ac.uk/webapps/coronavirus. Community submissions are encouraged. Supplementary information Supplementary data are available at Bioinformatics online. [ABSTRACT FROM AUTHOR]

I International Immunology i , dxab111, https://doi.org/10.1093/intimm/dxab111 After this paper was accepted, the authors realized that the data in the middle and bottom histograms of Fig. 3C and the right-hand flow cytometry plot of Fig. [Extracted from the article]

Chromatin ImmunoPrecipitation-sequencing (ChIP-seq) experiments have now become routine in biology for the detection of protein-binding sites. In this paper, we present a Markov random field model for the joint analysis of multiple ChIP-seq experiments. The proposed model naturally accounts for spatial dependencies in the data, by assuming first-order Markov dependence and, for the large proportion of zero counts, by using zero-inflated mixture distributions. In contrast to all other available implementations, the model allows for the joint modeling of multiple experiments, by incorporating key aspects of the experimental design. In particular, the model uses the information about replicates and about the different antibodies used in the experiments. An extensive simulation study shows a lower false non-discovery rate for the proposed method, compared with existing methods, at the same false discovery rate. Finally, we present an analysis on real data for the detection of histone modifications of two chromatin modifiers from eight ChIP-seq experiments, including technical replicates with different IP efficiencies. [ABSTRACT FROM AUTHOR]

Acromegaly is predominantly caused by a pituitary adenoma, which secretes an excess of GH resulting in increased IGF1 levels. Most of the GH assays used currently measure only the levels of the 22 kDa form of GH. In theory, the diagnostic sensitivity may be lower compared with the previous assays, which have used polyclonal antibodies. Many GH-secreting adenomas are plurihormonal and may co-secrete prolactin, TSH and a-subunit. Hyperprolactinaemia is found in 30-40% of patients with acromegaly, and hyperprolactinaemia may occasionally be diagnosed before acromegaly is apparent. Although trans-sphenoidal surgery of a GH-secreting adenoma remains the first treatment at most centres, the role of somatostatin analogues, octreotide long-acting repeatable and lanreotide Autogel as primary therapy is still the subject of some debate. Although the normalisation of GH and IGF1 levels is the main objective in all patients with acromegaly, GH and IGF1 levels may be discordant, especially during somatostatin analogue therapy. This discordance usually takes the form of high GH levels and an IGF1 level towards the upper limit of the normal range. Pasireotide, a new somatostatin analogue, may be more efficacious in some patients, but the drug has not yet been registered for acromegaly. Papers published on pasireotide have reported an increased risk of diabetes mellitus due to a reduction in insulin levels. Pegvisomant, the GH receptor antagonist, is indicated - alone or in combination with a somatostatin analogue - in most patients who fail to enter remission on a somatostatin analogue. Dopamine-D2-agonists may be effective as monotherapy in a few patients, but it may prove necessary to apply combination therapy involving a somatostatin analogue and/or pegvisomant. [ABSTRACT FROM AUTHOR]

The incidence of human immunodeficiency virus (HIV) is the rate at which new HIV infections occur in populations. The development of accurate, practical, and cost-effective approaches to estimation of HIV incidence is a priority among researchers in HIV surveillance because of limitations with existing methods. In this paper, we develop methods for estimating HIV incidence rates using multiple biomarkers in biological samples collected from a cross-sectional survey. An advantage of the method is that it does not require longitudinal follow-up of individuals. We use assays for BED, avidity, viral load, and CD4 cell count data from clade B samples collected in several US epidemiologic cohorts between 1987 and 2010. Considering issues of accuracy, cost, and implementation, we identify optimal multiassay algorithms for estimating incidence. We find that the multiple-biomarker approach to cross-sectional HIV incidence estimation corrects the significant deficiencies of currently available approaches and is a potentially powerful and practical tool for HIV surveillance. [ABSTRACT FROM AUTHOR]

Anti-citrullinated protein/peptide antibodies (ACPA) are a hallmark of rheumatoid arthritis (RA) and can be measured using different citrullinated substrates. In this paper we describe a new viral citrullinated peptide - VCP2 - derived from the Epstein-Barr virus-encoded protein EBNA-2 and analyse its potential as substrate for ACPA detection. Analysing sera from 100 RA patients and 306 controls, anti-VCP2 immunoglobulin (Ig)G were found in 66% of RA sera, IgM in 46% and IgA in 39%, compared with less than 3% of control sera. Anti-VCP2 IgG was associated with erosive arthritis, the presence of rheumatoid factor and anti-VCP1 and anti-cyclic citrullinated peptide (CCP) antibodies. Anti-VCP2 antibodies were detected in 1% and anti-VCP1 antibodies in 4% of CCP-negative RA sera; conversely, 3% of the VCP-negative sera were CCP-positive. Taken together, these data suggest that VCP2 could offer a valuable tool for ACPA detection. Inhibition assays showed that two non-overlapping epitopes - a citrulline-glycine stretch shared between VCP1 and VCP2 and the N-terminal portion of the VCP2 sequence - were targeted by anti-VCP2 antibodies. Moreover, in some RA sera that tested positive in CCP and VCP2 assays, preincubation with VCP2 inhibited binding to CCP, whereas in other sera the binding was unaffected. Thus, the reactivity with more than one ACPA substrate might be due in some RA patients to antibody populations with different specificities, and in others to cross-reactive antibody populations. Finally, affinity-purified anti-VCP2 antibodies immunoprecipitated deiminated Epstein-Barr virus nuclear antigen (EBNA-2) from an EBNA-2-transfected cell line, suggesting that viral sequences may be involved in the generation of the ACPA response. [ABSTRACT FROM AUTHOR]

After a steep monotone rise with age, the seroprevalence profiles for human parvovirus B19 (PVB19) display a decrease or plateau between the ages of 20 and 40, in each of 5 European countries. We investigate whether this phenomenon is induced by waning antibodies for PVB19 and, if this is the case, whether secondary infections are plausible, or whether boosting may occur. Several immunological scenarios are tested for PVB19 by fitting different compartmental dynamic transmission models to serological data using data on social contact patterns. The social contact approach has already been shown informative to estimate transmission rates and the basic reproduction number for infections transmitted predominantly through nonsexual social contacts. Our results show that for 4 countries, model selection criteria favor the scenarios allowing for waning immunity at an age-specific rate over the assumption of lifelong immunity, assuming that the transmission rates are directly proportional to the contact rates. Different views on the evolution of the immune response to PVB19 infection lead to altered estimates of the age-specific force of infection and the basic reproduction number. The scenarios which allow for multiple infections during one lifetime predict a higher frequency of PVB19 infection in pregnant women and of associated fetal deaths. When prevaccination serological data are available, the framework developed in this paper could prove worthwhile to investigate these different scenarios for other infections as well, such as cytomegalovirus. [ABSTRACT FROM AUTHOR]

Proinflammatory cytokines have been used for several years in patients with advanced cancer but their administration is typically associated with severe toxicity hampering their application to therapeutically active regimens. This problem can be overcome by using immunocytokines (cytokines fused to antibody or antibody fragments) which selectively deliver the active cytokine to the tumor environment. Preclinical and recent clinical results confirmed that this approach is a very promising avenue to go. We designed an immunocytokine consisting of the scFv(F8) specific to extra-domain A of fibronectin and the very potent human cytokine interleukin-12 (IL12). The heterodimeric nature of IL12 allows the engineering of various immunocytokine formats, based on different combinations of the two subunits (p35 and p40) together with the scFv. In comparison to monomeric or homodimeric cytokines, the construction of a heterodimeric immunocytokine poses many challenges, e.g. gene dosing, stable high-yield expression as well as good manufacture practice (GMP) purification and characterization. In this paper, we describe the successful construction, characterization and production of the heterodimeric immunocytokine F8-IL12. The positive outcome of this feasibility study leads now to GMP production of F8-IL12, which will soon enter clinical trials. [ABSTRACT FROM PUBLISHER]

Boosting is an important tool in classification methodology. It combines the performance of many weak classifiers to produce a powerful committee, and its validity can be explained by additive modeling and maximum likelihood. The method has very general applications, especially for high-dimensional predictors. For example, it can be applied to distinguish cancer samples from healthy control samples by using antibody microarray data. Microarray data are often high-dimensional and many of them are incomplete. One natural idea is to impute a missing variable based on the observed predictors. However, the calculation of imputation for high-dimensional predictors with missing data may be rather tedious. In this paper, we propose 2 conditional mean imputation methods. They can be applied to the situation even when a complete-case subset does not exist. Simulation results indicate that the proposed methods are superior than other naive methods. We apply the methods to a pancreatic cancer study in which serum protein microarrays are used for classification. [ABSTRACT FROM PUBLISHER]

Previous studies have shown the down-regulating in vitro effect of cocoa flavonoids on lymphocyte and macrophage activation. In the present paper, we report the capacity of a long-term rich cocoa diet to modulate macrophage cytokine secretion and lymphocyte function in young rats. Weaned rats received natural cocoa (4% or 10% food intake), containing 32 mg flavonoids/g, for 3 weeks. Spleen immune function was then evaluated through the analysis of lymphocyte composition, their proliferative response and their ability to secrete cytokines and Ig. In addition, the status of activated peritoneal macrophages was established through tumour necrosis factor (TNF)-α secretion. The richest cocoa diet (10%) caused a reduction of TNF-α secretion by peritoneal macrophages showing anti-inflammatory activity. Similarly, although a 10% cocoa diet increased lymphocyte proliferation rate, it down-regulated T helper 2 (Th2)-related cytokines and decreased Ig secretion. These changes were accompanied by an increase in spleen B cell proportion and a decrease in Th cell percentage. In summary, these results demonstrate the functional activity of a cocoa-high dosage in down-regulating the immune response that might be beneficial in hypersensitivity and autoimmunity. [ABSTRACT FROM AUTHOR]

This paper examines the molecular machinery involved in membrane exchange within the plant endomembrane system. A study has been undertaken on β‐COP‐like proteins in plant cells using M3A5, an antibody raised against the conserved sequence of mammalian β‐COP proteins. In mammalian cells, β‐COP proteins are part of a complex named the coatomer, which probably recruits some specific areas of the endomembrane system. Immunofluorescence analyses by confocal laser scanning microscopy showed that β‐COP‐like proteins marked predominantly the plant Golgi apparatus. Other proteins known to be part of a potential machinery for COPI vesicle formation (γ‐COP, β′‐COP and Arf1 proteins) were immunolocalized on the same membraneous structures as β‐COP. Moreover, β‐COP and other COPI antibodies stained the cell plate in dividing cells. It is further shown that, in maize root cells, and in contrast to observations upon mammalian cells, the drug Brefeldin A (BFA) does not induce the release of β‐COP and Arf1 proteins from the Golgi membrane into the cytosol. These data clearly demonstrate that the antibody M3A5 is a valuable marker for studies on trafficking events in plant cells. They also report for the first time the location of COP components in plant tissue at the light level, especially on a model well known for secretion, i.e. the maize root cells. They also suggest that the membrane recruitment machinery may function in a plant‐specific way. [ABSTRACT FROM PUBLISHER]

In this paper we review different aspects of B cell development on the path from the proB cell to the memory B cell and the plasmocyte. Emphasis is given to the positive and negative selection effects mediated by the changing forms of the surface immunoglobulin (Ig) receptor under successive microenvironments. Positive selection is linked to λ chain expression at the pro- and preB cell slage in fetal liver and bone marrow. Negative selection takes place when surface (s)IgM is being cross- linked by autoantigens before the immature B cell can leave, or after it has left, the bone marrow. After somatic mutation, major expansion becomes possible for B cells with high-affinity sIg receptors. This takes place in the germinal centres of the secondary lymphoid organs in the context of major histocompatibility complex (MHC) restriction and provided the necessary T cell help is given. Kinetic data on B cell replenishment in the rodent models are used to draw a schematic view of an established B cell repertoire. [ABSTRACT FROM AUTHOR]

This paper describes the spontaneous occurrence of an autoimmune uveoretinitis in nude (nu/nu) mice reconstituted when 4 weeks old by the grafting of rat embryonic thymus. The uveoretinitis was characterized histologically by progressive loss of the photoreceptor layer, observed in 4.0, 17.6, 42.9% and 71.4% of such mice at 3, 5, 7 and 12 months of age, respectively. Mice with uveoretinitis were shown to have serum IgG antibody reactive by indirect immunofluorescence with retinal photoreceptors, and with interphotoreceptor retinoid-binding protein (IRBP), but not retinal S-antigen, by immunoblotting and ELISA. A uveoretinitis could be adoptively transferred to syngeneic ungrafted nude mice by splenic CD4+ T cells from diseased animals. This is the first experimental model of a (T cell mediated) autoimmune uveoretinitis which develops spontaneously and which is not dependent upon deliberate sensitization with retinal antigens and adjuvants. [ABSTRACT FROM AUTHOR]

Corticosteroids have been reported to stimulate immunoglobulin (Ig) production by otherwise unstimulated peripheral blood mononuclear cells. In this paper we confirm that observation but report the necessity for an additional minor antigenic stimulus. Lymphocytes cultured with HB101, a complete medium not requiring serum supplement, did not increase Ig production after addition of hydrocortisone, but did if small concentrations (1-10%) of fetal calf serum were added. Various antigens such as Candida, tetanus, and albumin of different sources could substitute for fetal calf sera in allowing corticosteroids to stimulate Ig production in resting lymphocytes. We conclude that corticosteroids do not stimulate Ig production by lymphocytes de novo, rather, corticosteroids greatly enhance the Ig production stimulated by the foreign antigens present in fetal calf sera. [ABSTRACT FROM AUTHOR]

Peripheral blood mononuclear cells from patients with Sjögren's Syndrome spontaneously secrete autoantibodies to the La antigen when cultured in vitro. This paper reports that specific IgG autoantibody production in vitro is suppressed by pre-treatment of CD8+ enriched T cells with rabbit polyclonal antibodies to idiotypes borne by circulating autologous anti-La antibodies. Treatment of this T cell subpopulation with anti-idiotypes specific for circulating anti-La antibodies from other patients or for anti-DNA antibodies was without effect on anti-La antibody production. Similarly anti-La anti-idiotypes had no effect on the production of autoantibodies to other ribonucleoprotein antigens such as nRNP/Sm. These data show that CD8+ T cells are the main targets for anti-idiotypic control in vitro. We suggest that the relative deficit of these cells, plus a surfeit of CD4+ T cells at the site of the pathological lesion within the salivary gland permits localized production of autoantibodies. Thus, dysregulation of the idiotypic network could contribute to the pathogenesis of Sjögren's Syndrome. [ABSTRACT FROM AUTHOR]

Brain-reactive autoantibodies are thought to play an important role in mediating central nervous system (CNS) disorders in systemic lupus erythematosus (SLE), In this paper the developmental occurrence ofthese antibodies in the sera of autoimmune mice, i,e, NZB, NZB/W, MRL/I and BXSB mice were examined. All murine strains tested, whether autoimmune or not, showed some degree of serum reactivity toward brain antigens. Autoimmune mice, however, displayed higher levels of serum brain-reactive antibodies, and at earlier ages, than non-autoimmune mice. Immunofluorescence assays against brain sections and adsorption assays, with both neural and non-neural tissue, indicated a heterogeneity in the specificity of the populations of brain-reactive antibodies present. These studies provide an important step in characterizing the appearance and diversity of brain-reactive autoantibodies, with the goal of better understanding their significance and potential role in mediating CNS dysfunction in SLE. [ABSTRACT FROM AUTHOR]

Patients with the S. aureus hyper IgE syndrome (SAHIGES) have an abnormal IgE response to cell wall and surface antigens of S. aureus. In this paper we describe the detection of IgE antibodies to soluble antigens of staphylococci (S. aureus and S. epidermidis) and qualitative abnormalities of the IgG response lo soluble S. aureus antigens in patients with SAHIGES. These findings may be of pathogenetic importance and help to delineate SAHIGES from other diseases. [ABSTRACT FROM AUTHOR]

Prolonged exposure to antigens may result in high IgG4 antibody titres as was shown in a previous paper (Aalberse et al., 1983b). In novice bee keepers, a shift in the IgGI/IgG4 ratio of the response against phospholipase-A (PLA; a major component of bee venom) occurred. This resulted in an IgG4-dominated response after approximately 2 years of bee-keeping experience. Subject of the present study was the influence of relatively high concentrations of IgG4 antibodies on the biological activity of immune complexes. In the PLA antigen model, it was demonstrated (a) that IgG4-containing immune complexes do not activate complement and (b) that lgG4 antibodies effectively inhibit immune precipitation and complement activation by IgG1 antibodies. Evidence is provided that lgG4 antibodies inhibit binding of Clq to IgG1 in mixed, IgG1- and lgG4-containing complexes. It is proposed that IgG4 antibodies protect against the biological effects of the complement-fixing IgG subclasses. For this reason, determination of the total IgG response or just determination of antibody activity in the complement-fixing isotypes is insufficient in immune-complex diseases. The modulating effect of the non-complement-fixing isotypes should be taken into account to predict the biological activity of the immune complexes. [ABSTRACT FROM AUTHOR]

Because many cases of lymphatic filariasis cannot be diagnosed either clinically or by immunodiagnostic test based on antibody detection, recent efforts have been more directed towards developing methods for detecting parasite antigen in the blood or urine. Using A solid phase (Sepharose 4B) two-site immunoradiometric assay (IRMA) employing hyperimmune rabbit antifilarial antisera, we have previously shown (Hamilton etal; 1984) that essentially all cases of patent (ic. mierofilaremic) infection in patients with bancroftian filariasis can be detected by this semi-quantiialive assay as well as some individuals with amicrofilareirtic (i.e.. 'cryptic') infection. The present communication reports the results of studies that identify a prominent circulating antigen detected by this IRMA in sera from patients with microfilaremia. The antigen was eluted from Sepharose bound rabbit polyelonal antiserum that had been reacted with known antigen positive sera. It was run in SDS-PAGE. blotted to nitrocellulose paper and identified autoradlographically using '-M-Iabelied rabbit antifilarial antiserum. Its high molecular weight ( &tild; 200 kD). stability to acid and boiling, and sensitivity to pronase and periodate suggest its being a glycoprotein. Isolation of this antigen will permit the development of specific reagents (such as monoclonal antibodies) which should enhance both the sensitivity and utility of the currently available antigen detection systems. [ABSTRACT FROM AUTHOR]

IL-2 receptor expression by B cells has previously been considered to be confined to activated normal B cells and, among the B cell leukaemias, to the hairy cells (HC) of hairy-cell leukaemia. In the present paper, using α-Tac monoclonal antibodies in a highly sensitive indirect rosette method, we show that both normal and certain leukaemic B cells other than HC express IL-2 receptors. The density of these receptors is low since they were not detectable by indirect immunofluorescence. Various controls excluded non-specific-reagent or exogenous receptor binding and blocking studies with recombinant IL-2 confirmed the presence of the IL-2 receptors. The significance of the findings is discussed and it is suggested that B cell IL-2 receptor expression without in-vitro activation may be a function of B cell maturity. [ABSTRACT FROM AUTHOR]

This paper reports the results of in-vivo studies on the binding of intravenously injected cationised human IgM rheumatoid factor to glomeruli in mice. Evidence is presented to show that glomerular bound cationised IgM rheumatoid factor can act as an immunoabsorbent binding both endogenous immunoglobulin containing material from the circulation as well as intravenously injected immunoglobulins either in the form of aggregates or immune complexes. [ABSTRACT FROM AUTHOR]

Sent of some patients with systematic lupus erythematosus (SLE) contain IgG autoantibodies (F-&42sline;) which have been shown to stabilize the cell bound classical pathway C3 convertase of complement, C&42sline;. C&42sline; is susceptible to inactivation by the plasma protein C4bp while stabilized C&42sline; is relatively resistant to C4bp. The present study demonstrates that F-&42sline; by itself does not induce activation of the classical pathway in vitro but that it is able to modulate the immune complex-induced consumption of C2 and C3 in whole serum. Incubation of incremental concentrations of F-&42sline; with normal human serum (NHS) for 30 min at 30°C did not result in detectable consumption of Clq, C4, C2 and C3. However, when soluble immune aggregates or immune complexes were incubated in NHS together with 100 u/ml of F-&42sline;, a significant increase in consumption of C3 was seen as compared to the reaction mixture containing immune complexes or F-&42sline; alone. In addition the presence of F-&42sline; during the immune complex mediated consumption of complement was associated with relative protection of C2 consumption. (Fab)'2 and Fab' fragments of F-&42sline; behaved as intact F-&42sline;, except that their activities on a molar bask were less than that of intact F-&42sline;. The results presented in this paper suggest that F-&42sline; may play a regulatory role in the immune complex-mediated consumption at C2 and C3 in vivo. [ABSTRACT FROM AUTHOR]

The antigen-induced DNA synthesis in vitro in lymphocytes from patients with acute Plasmodium falciparum malaria was investigated. The patients and healthy controls from Sweden or Colombia were the same as those studied in the accompanying paper (Troye-Blomberg el al., 1983). The malarial antigens used were sonicated membrane preparations or purified and concentrated supernatants from in vitro cultures of P. facliparum, similar preparations derived from normal human erythrocytes served as control antigen. In the patients' lymphocytes P. falciparum antigens induced a weak or moderate but significant stimulation of DNA synthesis, peaking after 3-4 days of incubation. This early response was specific for P. faleiparum since it was not obtained with lymphocytes from healthy donors nor with those from patients with acute P. vivax or P. ovale malaria. No antigen-induced response was seen in about half of the P.falciparum patients. However in a few negative eases, available for consecutive testing, positive reactions were seen with lymphocytes taken 2 weeks after infection when the blood of these patients was free of parasites. The early response induced in patients' lymphocytes to the P. falciparum antigens was not obtained with RBC antigen, however, these preparations frequently induced a response rising to significant levels later during incubation (day 5-6)- Similar delayed responses were obtained when either- patients' or control donors' lymphocytes were exposed to the P. falciparum antigens. This indicates that both the RBC and the parasite preparations contained mitogenic substances affecting human lymphocytes in general and easily obscuring the P, falciparum specific responses seen only in the patients. This latter response was relatively low and short lived, suggesting that it reflected a secondary in vitro stimulation of in vivo primed lymphocytes and that it was regulated by suppressor mechanisms. [ABSTRACT FROM AUTHOR]

This paper describes an IgA related protein Via which occurred in the serum and urine ofa patient with multiple myeloma. The protein was isolated from urine, it had a molecular mass of 70,000 daltons. It was shown to be a two chain IgA half molecule, consisting of a deleted α heavy chain, with a molecular mass of 42,000 daltons, which was disulphide linked to a normal κ type light chain. Fabc fragments were produced from an unrelated myeloma IgA. These had the same biochemical properties as protein Via, except for the absence of the disulphide linkage between the deleted heavy chains and the light chains. Protein VIa and the Fabc fragments could both be cleaved by IgAl protease from Streptococcus sanguis, which indicates the presence of the α1 hinge region. An inventory of its antigenic determinants and their similarity to those of previously characterized F(abc)2 fragments, indicates that protein VIa, like the Fabc fragments, contains the CH1 and CH2 domains, but lacks most of the CH3 domain. The fact that cleavage by IgAl protease from S. Sanguis yields a Fab fragment but fails to yield a CH2 domain demonstrates that cleavage by the enzyme is not only restricted to the Pro222-Thr228 bond in the IgAI hinge region. [ABSTRACT FROM AUTHOR]

Motor end-plate disease (Med) in mice is associated with complex immunological abnormalities which are shared by the heterozygous + /MedJ mice, which exhibit no or mild clinical manifestations, and by MedJ/MedJ mice which die from this neuromuscular disorder. In the present paper we extend our immunological data with the study of splenic lymphocyte subsets with Lyt monoclonal antibodies. Both MedJ/ MedJ and +/MedJ 14-18 day old mice have high Lytl+/Lyt2&plus ratios, with higher Lytl + and reduced Lyt2+ lymphocyte pools as compared to normal mice. This correlates with the low suppressive function previously described, but is unexpected in view of the low helper function as measured by the response to SRBC immunization. Adult +/MedJ mice recovered normal T lymphocyte subset levels, while the small group of MedJ/MedJ mice that escapes death but continues to suffer from the neuromuscular illness maintains high Lyti+/Lyt2+ ratios. [ABSTRACT FROM AUTHOR]

The initiation of cytoplasmic Ig synthesis in differentiating B cells is accompanied by the start of cytoplasmic J chain production. As the cell matures further. J chain synthesis ceases (unless it is producing dimeric IgA or 19S IgM). In consequence, it is common to find Ig-positive, J chain-negative cells in reactive lymphoid tissue. However, the reverse pattern (Ig-negative! J chain-positive), which would indicate J chain production unaccompanied by Ig synthesis, has not been reported. In this paper we describe the detection of such cells in reactive human lymphoid tissue by a double immunoenzymatic labelling technique. Furthermore, retrospective immunohistological analysis of 90 cases of human high-grade lymphoma revealed three cases in which the neoplastic cells appeared to synthesize J chain but not Ig. These findings suggest that the term J chain disease might be introduced to describe this new class of lymphoid neoplasm. However, it is pointed out that immunochemical categories of human B lymphoproliferative diseases based upon patterns of Ig synthesis are often in direct conflict with histological categories (cf. mu chain-producing neoplasms) and the term J chain disease cannot therefore be recommended. It is probable that further cases of J chain-positive, Ig-negative lymphoid neoplasms, covering a range of histological categories, will be described in the future. [ABSTRACT FROM AUTHOR]

In this paper we use a sensitive, 125I-anti-immunoglobulin-binding assay, recently adapted for use with tissue homogenates as targets, to demonstrate autoantibodies to brain, liver and heart in the sera of normal persons. Quantitative absorption analyses demonstrated that the autoantigens detected were in each case organ-specific, and the brain autoantigen was shown to be present In equal amounts on cerebral cortex, cerebral white matter and cerebellar cortex. The autoantibodies were shown to be IgM in nature by gel filtration studies and experiments where IgM was reduced to monomers, and were found to bind equally well at 4, 20 and 37 C. Cross-reactions with brain, liver and heart of rat and dog were unpredictable and usually weak. Parallel studies with kidney homogenates failed to detect anti-kidney autoantibodies, but immunofluorescence studies on frozen sections revealed large amounts of immunoglobulin in normal kidneys, mainly on glomerular and tubular basement membranes, raising the possibility that autoantibodies to kidney are present but that the autoantigen sites are saturated in vivo. Sera from patients with multiple sclerosis were indistinguishable from normal sera in their binding to brain homogenate, and CSF from five patients with multiple sclerosis did not bind at all to brain homogenate. The theoretical and practical significance of multiple IgM autoantibodies in normal persons, and the organ specificity of the autoantibodies, is discussed. [ABSTRACT FROM AUTHOR]

This paper reports a magnetic solid-phase sandwich enzyme immunoassay for specific IgE antibodies in human sera. Crude extracts of grass pollen bound to magnetic polyacrylamide agarose beads were mixed with human serum to be tested. After washing in a magnetic rack, the beads were incubated with the glucose-oxidase-labelled sheep anti-IgE. The enzyme activity associated with the beads was measured by colorimetric assay. Results obtained from sixty-one human sera, as measured by the magnetic enzyme immunoassay, gave a linear correlation coefficient of 0.98 with the values as determined by radio-immunoassay. This procedure, which allows the grass pollen specific IgE in human sera, to be measured, is easy to perform, reproducible and may avoid the use of radioactive compounds. [ABSTRACT FROM AUTHOR]

Investigation of the nature of the increased erythrocyte-antibody (EA) binding activity of peripheral blood lymphocytes (PHL) from rheumatoid arthritis (RA) patients reported in the preceding paper has revealed that IgG is the active class of antibody in this rosette formation. Some IgM binding also occurs. SRBC sensitized with F(ab)2 preparations of IgG do not give rosette formation even at high concentrations. EA binding is inhibited by prior incubation of lymphocytes with heat-aggregated human IgG but antigen-antibody complexes did not give significant inhibition. The majority of these rosettes were found to be stable at 4°C. and room temperature but labile at 37°C. Enzyme studies with pronase, trypsin, neuraminidase and treatment with sodium azide gave results strongly supporting the conclusion that the increased binding observed is increased Fc-receptor activity. This activity appears not to be a result of Fc binding by cell-bound rheumatoid factor. A range of titres of antibody and of IgG was used to sensitize erythroeytes to form EA and the enhanced EA-rosette formation by PBI, from RA patients occurred throughout the range of concentrations of sensitizing antibody. Significantly more EA were bound by individual lymphocytes from RA patients than control subjects. This data suggest that the Fc receptors on RA lymphocytes are more avid for FA than receptors on lymphocytes from healthy people. [ABSTRACT FROM AUTHOR]

This paper reports the properties of purified human F antigen (liver-specific antigen). Homgenates of liver in 0.25 M sucrose were centrifuged at 105,000 g. The supernatants were chromatographed on Sepharose 6-Band tour major peaks were separated. The third peak proved to be predominantly F antigen. This fraction was subsequently subjected to DEAM-cellulose column chromatography and F antigen was eluted at a concentration less than 0.2 M NaCl in 0.01M sodium phosphate huller (pH 7.2). Finally, purified F antigen was obtained alter preparative isoelectric focusing. Purified human F antigen was found to have a mol. wt between 40,000 and 80,000, a pl of 6.5-6.7 and a density of 1.26. It is a protein antigen and contains on detectable carbodhydrate or lipid. No differences were found in purified F-antigen preparations from several species when tested by sodium dodecyl sulphate (DS) disc gel electrophoresis. Immunofluorescent studies showed that F antigen was homogeneously distributed in the cytoplasm of liver cells but was not present on the cell surface. Immunization of guinea-pigs with purified human liver-specific protein did not induce antibody to the F antigenic determinant defined by mouse anti-F antiserum. It did, however, induce antibodies to two human liver antigens. One of these seems to be a human-specific determinant on the F antigen molecule and the other appears to be a separate molecule which is similar in molecular weight and electrophoretic mobility to the F-antigen molecule. [ABSTRACT FROM AUTHOR]

The role of the spleen in humoral antibody formation and in the pathogenesis of immune thyroiditis was studied by splenectomizing four monkeys (Macaca mulatta) prior to thyroid isoimmunization. Splenectomized animals, as well as intact controls, were subjected to sequential immunizations and the course of the immune disease was followed by periodic thyroid biopsies and frequent humoral antibody measurements over a period exceeding 1 yr. Extirpation of the secondary lymphoid organ markedly inhibited agglutinating antibody response, prevented formation of complement-fixing antibodies, but had no effect on thyrocytotoxic antibodies. In animals subjected to immunization in complete adjuvant a trend towards a decrease in serum complement levels was evident at the terminal stages of the experiments. Despite the inhibitory effects on some immunological parameters, splenectomy in monkeys prior to thyroid isoimmunization did not interfere with the initiation and progression of pathological processes in the thyroid. Indeed in all splenectomized animals immunized with thyroid plus complete adjuvant, fibrotic thyroid lesions (4+) with virtual obliteration of thyroid follicles were evident, in some as early as 120 days after primary immunization; in contrast, non-fibrotic and less severe lesions were noted in the intact animal despite being repeatedly subjected to similar immunization procedures over a period of 340 days. Immunization in the absence of complete adjuvant did not induce thyroid lesions in the presence or absence of spleen. In all animals with severe thyroid lesions, thyroid function decreased as revealed by T4 and 131I-T3 resin uptake measurements. Paper electrophoresis of serum specimens from a monkey subjected to thyroid isoimmunization in complete adjuvant (and after equilibration with 125I-T4) showed a pronounced retention of 125I-T4 radioactivity at the gamma globulin region indicating formation of antibodies to thyroxine. On the other hand, in sera with a low thyroid antibody titre as in splenectomized monkeys or in those animals immunized within complete adjuvant, T4-binding antibodies were not evident. It is concluded that removal of the spleen prior to thyroid isoimmunization in monkeys, rather than inhibiting the severity of the disease may even aid and abet immunopathogenic events destructive to the thyroid. [ABSTRACT FROM AUTHOR]

Target cell killing by lymphocytes can be induced by appropriate antibody complexed to target cell antigens. In this paper it is shown that this form of lymphocyte mediated cytotoxicity is susceptible to inhibition by third party immune complexes which compete with target cell bound antibody for receptors for immunoglobulin on the cytotoxic lymphocytes. The physical state of the complexes is investigated in relation to their inhibitory efficiency. Evidence is presented to show that soluble complexes which exist in antigen-antibody equilibrium or slight antigen excess are the most effective inhibitors. No evidence could be obtained to support the hypothesis that soluble immune complexes can induce indiscriminate cytotoxic activity in lymphocytes. The biological significance of this effect is discussed in relation to chronic inflammatory diseases. [ABSTRACT FROM AUTHOR]

This paper describes the course of infection and the immunological response in thymus-deprived and normal CBA mice after intradermal inoculation with promastigotes of L. tropica. Infection of normal mice resulted in the development of a cutaneous ulcer healing within 12 weeks. As the infection progressed and the draining lymph nodes increased in weight, changes in the paracortical and follicular regions were accompanied by the development of delayed hypersensitivity and the production of antibodies detectable by immunofluorescence and a parasite agglutination test. Lesions in thymectomized irradiated mice healed more slowly and the draining lymph nodes were smaller than in normal mice. Follicular reactions were feeble and paracortical activity depressed. The most noticeable feature of these lymph nodes was a persistent and intense macrophage infiltration. Delayed hypersensitivity and antibodies detectable by immunofluorescence were correspondingly low; but parasite agglutinating antibody was not depressed. The course of infection and immunological response of a control group of sham thymectomized, irradiated mice resembled that of normal mice. These experiments indicate that thymus-dependent cell populations play an important role in the response of mice to infection with L. tropica. [ABSTRACT FROM AUTHOR]

In this paper the specificity of the skin-reactive guinea-pig immunoglobulin in the homologous PCA test has been reconsidered. Extensive purification of this immunoglobulin by chromatographic methods results in the isolation of a small fraction or medium speed immunoglobulins that contains all skin reactivity. No correlation could be found with the 7S immunoglobulins IgGγ1 and Igγ1A suggesting a separate class of biologically active immunoglobulins. The PCA active antibody belongs to either an IgG subclass or is a heat stable homocytotropic antibody. Rabbit and chicken antisera against isolated fractions of guinea-pig immunoglobulins show the existence of 7S subclasses. Some suggestions for a revised nomenclature are given. [ABSTRACT FROM AUTHOR]

The article discusses various papers published within the issue including one by Samira Saadoun and colleagues on disease induction using passive transfer of immunoglobulin G from patients with neuromyelitis optica, another by Corinne Bachelin on the ability of Schwann cells to migrate and integrate with polysialylated neural cell adhesion molecule and one Stefania Corti on the beneficial effect of spinal cord-derived neural stem cells on the phenotype of murine spinal muscular atrophy.

Background Rituximab is an anti-CD20 chimeric monoclonal antibody that depletes pre-plasma B cells. It is used in paediatric rheumatology for conditions including juvenile systemic lupus erythematosus (jSLE), juvenile dermatomyositis (JDM), vasculitides and refractory juvenile idiopathic arthritis (JIA). We aim to describe the cohort of patients treated with rituximab in the Scottish Paediatric and Adolescent Rheumatology Network (SPARN) in a 5-year period, and assess the need for a network guideline. Methods A review of paper and electronic case records. Patients seen within the SPARN network who received Rituximab between 2014 and 2018 were included. Results Vasculitis Rituximab was given to 16 patients in 5 different SPARN centres between 2014 and 2018. Male: Female ratio was 1:4.3. Mean age at first dose of rituximab was 12.75 years. Mean disease duration pre rituximab was 1 year. 8 (50%) patients had jSLE, 7 multisystem and 1 isolated lupus nephritis. 3 had ANCA-positive vasculitis and 5 had other conditions. (1 had RF+ve JIA; 1 severe panuveitis; 1 had an unspecified autoinflammatory condition; 1 had COPA syndrome with severe interstitial lung disease and 1 had autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). Documentation of pre-rituximab checks was poor. Baseline bloods were done in all 16 patients. 11 patients had lymphocyte subsets and 13 immunoglobulins documented. Disease-specific antibodies were measured in all patients in whom applicable (11). 11 had a chest x-ray prior to rituximab. In 9 cases a pre-rituximab pregnancy test was indicated: none were documented. In only 3 patients was a pre-rituximab history of recent infections documented. In 8 patients a discussion regarding treatment risks and benefits was documented. Post-infusion lymphocyte subset monitoring was variable but documented in 15. 1 patient was never B cell deplete. 9 never fully reconstituted. RTX dose information was available for 14. All received doses of 750mg/m2 with 6 having the dose capped at 1g. Dose frequency information was available for all. The majority (9) received 2 doses. Of the rest, 1 patient received a single dose. 3 received 3 doses, 2 had 4 and 1 had 5. All patients in whom information was available, received pre-medication with paracetamol, chlorphenamine and methylprednisolone (n = 14). 4 patients had side effects noted (rash/itch in 1, anaphylaxis in 1, facial flushing in 1 and post-infusion infection in 1). Clinical response was clearly documented in 8 patients, 7 of whom showed clinical improvement (2 had systemic jSLE, 2 had ANCA +ve vasculitis, 1 had isolated lupus nephritis, 1 had COPA syndrome and 1 had RF+ JIA). Conclusion Rituximab is used for a range of conditions and in a number of centres within SPARN. This review highlights variation in and poor documentation of pre-rituximab discussions and investigations, prescribing, monitoring and response. A SPARN rituximab protocol is being developed to address this. Conflicts of Interest The authors declare no conflicts of interest. [ABSTRACT FROM AUTHOR]

The article presents an index related to subject terms that appear in papers published in the 1991 issue of the journal "Clinical & Experimental Immunology." Some of the terms are anti-mitochondrial antibodies, anti-phospholipid antibodies, antibodies, antibody production, antigens, apheresis, arthritis, atopic dermatitis, autoantihodies, autoantigen, autoimmune diseases, autologous mixed leucocyte reaction, autoreactive T cells, cancer, carrier detection, cell cycle, cell-mediated cytotoxicity and cerebrospinal fluid.

The method for determination of anti-thyroid antibodies in extracts of dried whole blood on filter paper was described. Antibodies in dried blood were stable at room temperature for at least 1 month and were extracted well by overnight elution. This simple method requires only a minimal 30 μl of venous blood and would enable large-scale screening for autoimmune thyroid diseases. [ABSTRACT FROM AUTHOR]

Understanding refolding pathways of recombinant antibody fragments is essential for efficient production of these proteins of high biomedical significance. The recombinant VL domain of mouse anti-human ferritin antibody F11 formed two distinct functional conformations obtained by refolding from bacterial inclusion bodies using two different procedures. Involvement of a dialysis step at pH 2–3 resulted in the VL-1 conformation with fluorescence of the highly conserved Trp-35 residue quenched by the spatially proximal disulfide bond. This conformation was identical to the ‘native’ VL domain folded in host cells and purified from the cytoplasm. In the absence of the acidic dialysis step, the VL domain adopted a previously unreported conformation, VL-2, that demonstrated prominent fluorescence due to a local structural disorder around Trp-35. Furthermore, VL-2 showed changes in secondary structure and significantly lower stability as determined by differential scanning calorimetry and denaturant-induced unfolding. While more flexible VL-2 binds human ferritin both in solution and after surface adsorption of the antibody domain, the VL-1 conformer needs an adsorption-induced conformational change to allow the access of ferritin to the antigen-binding site. Noteworthy, the two macroscopic conformations constitute kinetically trapped dimers and do not interconvert at elevated temperatures (3 weeks at 37°C or 15 min at 60°C), which indicates a high energetic barrier between them. As a major finding, this paper provides the first description for two stable and functional conformations of an antibody domain. [ABSTRACT FROM AUTHOR]