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The reconstruction of clonal families (CFs) in B-cell receptor (BCR) repertoire analysis is a crucial step to understand the adaptive immune system and how it responds to antigens. The BCR repertoire of an individual is formed throughout life and is diverse due to several factors such as gene recombination and somatic hypermutation. The use of Adaptive Immune Receptor Repertoire sequencing (AIRR-seq) using next generation sequencing enabled the generation of full BCR repertoires that also include rare CFs. The reconstruction of CFs from AIRR-seq data is challenging and several approaches have been developed to solve this problem. Currently, most methods use the heavy chain (HC) only, as it is more variable than the light chain (LC). CF reconstruction options include the definition of appropriate sequence similarity measures, the use of shared mutations among sequences, and the possibility of reconstruction without preliminary clustering based on V- and J-gene annotation. In this study, we aimed to systematically evaluate different approaches for CF reconstruction and to determine their impact on various outcome measures such as the number of CFs derived, the size of the CFs, and the accuracy of the reconstruction. The methods were compared to each other and to a method that groups sequences based on identical junction sequences and another method that only determines subclones. We found that after accounting for data set variability, in particular sequencing depth and mutation load, the reconstruction approach has an impact on part of the outcome measures, including the number of CFs. Simulations indicate that unique junctions and subclones should not be used as substitutes for CF and that more complex methods do not outperform simpler methods. Also, we conclude that different approaches differ in their ability to correctly reconstruct CFs when not considering the LC and to identify shared CFs. The results showed the effect of different approaches on the reconstruction of CFs and highlighted the importance of choosing an appropriate method. [ABSTRACT FROM AUTHOR]

Background: In patients with rheumatoid arthritis (RA) different joints were shown to share the same dominant T-cell clones, suggesting shared characteristics of the inflammatory process and indicating that strategies to selectively target the antigen receptor might be feasible. Since T- and Blymphocytes closely interact in adaptive responses, we analysed to what extent different joints also share dominant B-cell clones. Methods: In 11 RA patients, quantitative B-cell receptor (BCR) repertoire analysis was performed in simultaneously obtained samples from inflamed synovial tissue (ST) from distinct locations within one joint, from multiple joints, from synovial fluid (SF) and peripheral blood (PB). Results: ST biopsies from different locations in the same joint showed clear overlap in the top-25 dominant BCR clones (16.7%, SD 12.5), in the same range as the overlap between ST and SF in the same joint (8.0%, SD 8.8) and the overlap between ST-ST between different joints (9.1%, SD 8.2), but clearly higher than the overlap between ST and PB (1.7%, SD 2.4; p<0.05) and SF and PB (2.7%, SD 4.1; p<0.05). Interestingly, these figures were substantially lower than the overlap observed in previous T-cell clonality studies. Conclusions: We conclude that in RA BCR clonal responses may be more localized than TCR clonal responses, pointing to antigen-selective influx, proliferation and/or maturation of B-cells. B lineage cells in the SF may adequately represent the dominant BCR clones of the ST, which is in contrast to T-cells. Collectively, the presence of shared B- and especially T-cells in different joints from the same patient suggests that approaches might be feasible that aim to develop antigen-receptor specific targeting of lymphocyte clones in RA as an alternative tomore generalized immunosuppressive strategies. [ABSTRACT FROM AUTHOR]

A 32-year-old healthy woman was seen two days after a complicated c-section with abdominal pain and vomiting. Inflammatory parameters were high and imaging showed a dilatated colon with intestinal pneumatosis. Surgical exploration showed an iatrogenic perforation of the coecum. Therefore, an ileocecal resection with primary anastomosis was performed. Full recovery occurred two weeks later.

Hyper-IgD syndrome (HIDS) is a rare, severe hereditary autoinflammatory disease characterised by periodic fevers, elevated serum IgD levels and a wide range of symptoms. Although a few randomised controlled trials have been performed in this disorder, there are no straightforward treatment protocols and none of the potential therapies are registered for this indication. We report a case of a young woman with severe HIDS who failed numerous therapies. Eventually, rational treatment with a monoclonal anti-interleukin 6 receptor antibody was initiated. This therapy resulted in an impressive clinical improvement and reduction in the number of hospital admissions per year. This case report underlines the difficulty of finding a suitable treatment for rare, severe inflammatory diseases. Furthermore, we show that treating patients with targeted therapies may result in clinical benefit for the patient, as well as simultaneously teach us more about the pathophysiology of these rare, relatively understudied diseases., (2015 BMJ Publishing Group Ltd.)

Patients with severe therapy-refractory immune-mediated inflammatory diseases (IMIDs) are increasingly treated with biologics. Since official practice guidelines for these rare diseases are lacking, these drugs are often prescribed off-label. However, treating physicians encounter difficulties and risks when prescribing drugs off-label. Access to these biologics for off-label indications is currently not well organized, which may result in suboptimal care. This also blocks innovation in patient care. In this article we introduce the recently initiated RUBRIC (Rational Use of Biologics in Refractory Immune-mediated inflammatory diseases Consortium) register. This national register documents the efficacy and safety of off-label biologic treatment in combination with the development of treatment protocols and practice guidelines. We believe that the results from this register will ultimately lead to a more evidence-based use of biologics in patients with rare IMIDs, which may also result in better access to these drugs. Ultimately, both the individual patient and the group as a whole will benefit.