Translational Aspects of Behçet’s Disease

__abstract__ De ziekte van Behçet is een multi-factoriele (auto)inflammatoire vascilitis die vooral voorkomt bij mensen uit landen van de Middellandse Zee gebied en langs de voormalige zijderoute naar het Verre Oosten, er zijn ongeveer 600 patiënten in Nederland. Algemeen wordt aangenomen dat omgevings- en genetische factoren een rol spelen bij het ontstaan van de ziekte. Echter, zowel de epidemiologie als de pathofysiologie zijn onduidelijk, studieresultaten spreken elkaar soms tegen. In dit proefschrift wordt de veronderstelling dat de prevalentie van BD afneemt na migratie ter discussie gesteld, verder wordt voor het eerst epidemiologische data van een Nederlands cohort gepresenteerd. Vervolgens worden nieuwe genetische associaties gepresenteerd waaronder een beschermende relatie met NOD2 varianten en een verhoogd risico bij IL12A varianten. Veel inflammatoire cytokines zijn betrokken bij de ziekte van Behçet, weefsel expressie lijkt relevanter dan serum cytokine niveaus. Tot slot worden de nieuwe inzichten vertaald naar nieuwe behandelmodaliteiten. TNF-α blokkers en andere biologicals hebben een duidelijke plaats in de behandeling van refractaire ziekte

Do synovial biopsies help to support evidence for involvement of innate immunity in the immunopathology of Behçet's disease?

Behçet's disease is a complex vasculitis of unknown etiology. Abundant neutrophils suggest the involvement of innate immunity. Cytokines are skewed to the T-helper-1 pattern. Few sterile organs are easily accessible for analysis in Behçet's disease. Cañete and coworkers identify inflamed joints as a feasible model and suggest the involvement of innate immunity in Behçet's disease

Mepolizumab add-on therapy in a real world cohort of patients with severe eosinophilic asthma: response rate, effectiveness, and safety

Introduction: Severe eosinophilic asthma is an incapacitating disease. Mepolizumab, a humanized anti-interleukin-5 monoclonal antibody, proved to be effective as an add-on therapy in patients with severe eosinophilic asthma. However, only data from randomized controlled trials are available and real world data are lacking. Methods: A retrospective observational longitudinal study was conducted in a real world cohort of patients with severe eosinophilic asthma treated with mepolizumab. The primary objective was to determine response rate, based on a global evaluation of treatment effectiveness by the treating pulmonologist. Secondary objectives were to assess exacerbation frequency, systemic maintenance glucocorticoid usage, Asthma Control Questionnaire (ACQ), lung function, and adverse events. Results: Seventy-eight patients were included. Treatment with mepolizumab was considered beneficial and was therefore continued in 75.6% of patients 12 months from the initiation of mepolizumab. The most common reason for drop-out was insufficient response. Secondary objectives: 12 months from the initiation of mepolizumab there was a decrease of 3.2 (CI 2.5–4.1; p < 0.001) severe asthma exacerbations per year, a decrease of ACQ of 0.80 points (CI 0.49–1.12; p < 0.001), and an increase of 3.7 (CI 0.3–7.2; p = 0.034) percent of predicted FEV1 compared to baseline. At baseline 51.3% of patients were treated with systemic glucocorticoid maintenance therapy, compared to 15.4% (p < 0.001) of patients 12 months from the initiation of mepolizumab. No serious adverse events considered to be related to mepolizumab were reported. Conclusion: This study confirms that mepolizumab add-on therapy is effective and safe in a real world cohort of patients with severe eosinophilic asthma

Genome-wide association study in an admixed case series reveals IL12A as a new candidate in Behçet Disease

Introduction: The etiology of Behçet's disease (BD) is unknown, but widely considered an excessive T-cell mediated inflammatory response in a genetically susceptible host. Recent genomewide association studies (GWAS) have shown limited number of novel loci-associations. The rarity and unequal distribution of the disease prevalence amongst different ethnic backgrounds have hampered the use of GWAS in cohorts of mixed ethnicity and sufficient sample size. However, novel statistical approaches have now enabled GWAS in admixed cohorts. Methods: We ran a GWAS on 336 BD cases and 5,843 controls. The cases consisted of Western Europeans, Middle Eastern and Turkish individuals. Participants from the Generation R study, a multiethnic birth cohort in Rotterdam, The Netherlands were used as controls. All samples were genotyped and data was combined. Linear regression models were corrected for population stratification using Genomic Principal Components and Linear Mixed Modelling. Meta-analysis was performed on selected results previously published. Results: We identified SNPs associated at genome-wide significant level mapping to the 6p21.33 (HLA) region. In addition to this known signal two potential novel associations on chromosomes 6 and 18 were identified, yet with low minor allele frequencies. Extended metaanalysis reveal a GWS association with the IL12A variant rs17810546 on chromosome 3. Discussion: We demonstrate that new statistical techniques enable GWAS analyses in a limited sized cohort of mixed ethnicity. After implementation, we confirmed the central role of the HLA region in the disease and identified new regions of interest. Moreover, we validated the association of a variant in the IL2A gene by meta-analysis with previous work. These findings enhance our

Methanol synthesis process using an autothermal rod-bundle reformer

Document(en) uit de collectie Chemische ProcestechnologieDelftChemTechApplied Science

Genome-wide association study in an admixed case series reveals IL12A as a new candidate in Behçet Disease

PubMedID: 25799145Introduction: The etiology of Behçet's disease (BD) is unknown, but widely considered an excessive T-cell mediated inflammatory response in a genetically susceptible host. Recent genomewide association studies (GWAS) have shown limited number of novel loci-associations. The rarity and unequal distribution of the disease prevalence amongst different ethnic backgrounds have hampered the use of GWAS in cohorts of mixed ethnicity and sufficient sample size. However, novel statistical approaches have now enabled GWAS in admixed cohorts. Methods: We ran a GWAS on 336 BD cases and 5,843 controls. The cases consisted of Western Europeans, Middle Eastern and Turkish individuals. Participants from the Generation R study, a multiethnic birth cohort in Rotterdam, The Netherlands were used as controls. All samples were genotyped and data was combined. Linear regression models were corrected for population stratification using Genomic Principal Components and Linear Mixed Modelling. Meta-analysis was performed on selected results previously published. Results: We identified SNPs associated at genome-wide significant level mapping to the 6p21.33 (HLA) region. In addition to this known signal two potential novel associations on chromosomes 6 and 18 were identified, yet with low minor allele frequencies. Extended metaanalysis reveal a GWS association with the IL12A variant rs17810546 on chromosome 3. Discussion: We demonstrate that new statistical techniques enable GWAS analyses in a limited sized cohort of mixed ethnicity. After implementation, we confirmed the central role of the HLA region in the disease and identified new regions of interest. Moreover, we validated the association of a variant in the IL2A gene by meta-analysis with previous work. These findings enhance our knowledge of genetic associations and BD, and provide further justification for pursuing collective initiatives in genetic studies given the low prevalence of this and other rare diseases. © 2015 Kappen et al

Behcet's disease, hospital-based prevalence and manifestations in the Rotterdam area

Ophthalmic researc

Behcet's Disease Under Microbiotic Surveillance? A Combined Analysis of Two Cohorts of Behcet's Disease Patients

Background: In Behçet’s disease (BD), an auto-inflammatory vasculitis, an unbalanced gut microbiota can contribute to pro-inflammatory reactions. In separate studies, distinct pro- and anti-inflammatory bacteria associated with BD have been identified. Methods: To establish disease-associated determinants, we performed gut microbiome profiling in BD patients from the Netherlands (n = 19) and Italy (n = 13), matched healthy controls (HC) from the Netherlands (n = 17) and Italy (n = 15) and oral microbiome profiling in Dutch BD patients (n = 18) and HC (n = 15) by 16S rRNA gene sequencing. In addition, we used fecal IgA-SEQ analysis to identify specific IgA coated bacterial taxa in Dutch BD patients (n = 13) and HC (n = 8). Results: In BD stool samples alpha-diversity was conserved, whereas beta-diversity analysis showed no clustering based on disease, but a significant segregation by country of origin. Yet, a significant decrease of unclassified Barnesiellaceae and Lachnospira genera was associated with BD patients compared to HC. Subdivided by country, the Italian cohort displays a significant decrease of unclassified Barnesiellaceae and Lachnospira genera, in the Dutch cohort this decrease is only a trend. Increased IgA-coating of Bifidobacterium spp., Dorea spp. and Ruminococcus bromii species was found in stool from BD patients. Moreover, oral Dutch BD microbiome displayed increased abundance of Spirochaetaceae and Dethiosulfovibrionaceae families. Conclusions: BD patients show decreased fecal abundance of Barnesiellaceae and Lachnospira and increased oral abundance of Spirochaetaceae and Dethiosulfovibrionaceae. In addition, increased fecal IgA coating of Bifidobacterium, Ruminococcus bromii and Dorea may reflect retention of anti-inflammatory species and neutralization of pathosymbionts in BD, respectively. Additional studies are warranted to relate intestinal microbes with the significance of ethnicity, diet, medication and response with distinct pro- and inflammatory pathways in BD patients