Muscle-specific kinase (MuSK) myasthenia gravis (MG) is a neuromuscular autoimmune disease belonging to a growing group of IgG4 autoimmune diseases (IgG4-AIDs), in which the majority of pathogenic... Show moreMuscle-specific kinase (MuSK) myasthenia gravis (MG) is a neuromuscular autoimmune disease belonging to a growing group of IgG4 autoimmune diseases (IgG4-AIDs), in which the majority of pathogenic autoantibodies are of the IgG4 subclass. The more prevalent form of MG with acetylcholine receptor (AChR) antibodies is caused by IgG1-3 autoantibodies. A dominant role for IgG4 in autoimmune disease is intriguing due to its antiinflammatory characteristics. It is unclear why MuSK autoantibodies are predominantly IgG4. We hypothesized that MuSK MG patients have a general predisposition to generate IgG4 responses, therefore resulting in high levels of circulating IgG4. To investigate this, we quantified serum Ig isotypes and IgG subclasses using nephelometric and turbidimetric assays in MuSK MG and AChR MG patients not under influence of immunosuppressive treatment. Absolute serum IgG1 was increased in both MuSK and AChR MG patients compared to healthy donors. In addition, only MuSK MG patients on average had significantly increased and enriched serum IgG4. Although more MuSK MG patients had elevated serum IgG4, for most the IgG4 serum levels fell within the normal range. Correlation analyses suggest MuSK-specific antibodies do not solely explain the variation in IgG4 levels. In conclusion, although serum IgG4 levels are slightly increased, the levels do not support ubiquitous IgG4 responses in MuSK MG patients as the underlying cause of dominant IgG4 MuSK antibodies. Show less
Therapeutic proteins have been successfully developed for advancing medical treatments. They are usually large molecules produced by host cells and have a high degree of complexity compared to... Show moreTherapeutic proteins have been successfully developed for advancing medical treatments. They are usually large molecules produced by host cells and have a high degree of complexity compared to synthetic small molecule-based therapeutics. The complexity is mainly attributed to the heterogenic nature of post-translational modifications (PTMs). Glycosylation is one of the main drivers of protein heterogeneity. Since each modification may potentially impact the safety and efficacy, analyticalmethods for the structural and functional characterization of protein-based therapeutics are highly demanded. This thesis presents novel mass spectrometry (MS)-based methods for the analysis of therapeutic glycoproteins. It covers aspects of glycobioinformatics and sample preparation for improved bottom-up glycoproteomic analysis. Further, the profiling of complex intact glycoproteins by matrix-assisted laser desorption ionization (MALDI) Fourier transform ion cyclotron resonance (FT-ICR) MS is demonstrated. Finally, Fc gamma receptor III affinity chromatography combined with online MS detection is presented for novel proteoform-resolved structure-function insights of monoclonal antibodies. Show less
Clerc, F.; Novokmet, M.; Dotz, V.; Reiding, K.R.; Haan, N. de; Kammeijer, G.S.M.; ... ; IBD-BIOM Consortium 2018
This thesis describes new knowledge of FNAIT in preparation of a national wide screening program. It illustrates the prevalence of FNAIT among pregnant women and the risk of adverse outcome,... Show moreThis thesis describes new knowledge of FNAIT in preparation of a national wide screening program. It illustrates the prevalence of FNAIT among pregnant women and the risk of adverse outcome, outlines current management, evaluates risks of missing a diagnosis of FNAIT, studies the efficacy of a lower dose of immunoglobulins in preventing bleedingcomplications,shows the time of bleeding onset of fetal ICH during pregnancy and illustrates the longterm outcome of children with ICH. Show less
Glycosylation is the most abundant and complex protein modification, and can have a profound structural and functional effect on the conjugate. The oligosaccharide fraction is recognized to be... Show moreGlycosylation is the most abundant and complex protein modification, and can have a profound structural and functional effect on the conjugate. The oligosaccharide fraction is recognized to be involved in multiple biological processes, and to affect proteins physical properties, and has consequentially been labeled a critical quality attribute of biopharmaceuticals. Additionally, due to recent advances in analytical methods and analysis software, glycosylation is targeted in the search for disease biomarkers for early diagnosis and patient stratification. Biofluids such as saliva, serum or plasma are of great use in this regard, as they are easily accessible and can provide relevant glycosylation information. Thus, as the assessment of protein glycosylation is becoming a major element in clinical and biopharmaceutical research, this review aims to convey the current state of knowledge on the N-glycosylation of the major plasma glycoproteins alpha-1-acid glycoprotein, alpha-1-antitrypsin, alpha-1B-glycoprotein, alpha-2-HS-glycoprotein, alpha-2-macroglobulin, antithrombin-III, apolipoprotein B-100, apolipoprotein D, apolipoprotein F, beta-2-glycoprotein 1, ceruloplasmin, fibrinogen, immunoglobulin (Ig) A, IgG, IgM, haptoglobin, hemopexin, histidine-rich glycoprotein, kininogen-1, serotransferrin, vitronectin, and zinc-alpha-2-glycoprotein. In addition, the less abundant immunoglobulins D and E are included because of their major relevance in immunology and biopharmaceutical research. Where available, the glycosylation is described in a site-specific manner. In the discussion, we put the glycosylation of individual proteins into perspective and speculate how the individual proteins may contribute to a total plasma N-glycosylation profile determined at the released glycan level. Show less
UVA 1 therapy is a relatively new form of light therapy for atopic dermatitis. We describe that after 4 weeks of UVA-1 patients were better capable to maintain clinical improvement than after 3... Show moreUVA 1 therapy is a relatively new form of light therapy for atopic dermatitis. We describe that after 4 weeks of UVA-1 patients were better capable to maintain clinical improvement than after 3 weeks of therapy. Furthermore, UVA 1 therapy proved to be better than placebo therapy in patients with dyshidrotic eczema. Also, we described the favorable effect of UVA 1 therapy in chronic, generalized lichen ruber planus. Because of deep penetration of UVA 1, it could not only influence dermal inflammatory infiltrates in T-cell mediated diseases mentioned above, but also reach circulating activated B-cells in dermal capillaries in SLE. We investigated the effect of 6 and 12 J/cm2 UVA 1 in SLE patients, in a double-blinded, placebo-controlled, cross over study. Three weeks of 12 J/cm2 resulted in improved disease activity and proved to be more effective than placebo. Furthermore, a decrease of auto-antibody titers was observed in several patients. In vitro we showed that 40% of UVA 1 reached the dermis and increasing numbers of PBMCs died after rising doses of UVA-1. Also, immunoglobulin production by activated B cells decreased after increasing doses of UVA 1. It would be interesting to investigate UVA 1 therapy for other auto immune diseases. Show less
