M

Marcel D. Posthumus

Martini Ziekenhuis

Publishes on Rheumatoid Arthritis Research and Therapies, Amyloidosis: Diagnosis, Treatment, Outcomes, Spondyloarthritis Studies and Treatments. 59 papers and 3.7k citations.

59Publications
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Humoral responses after influenza vaccination are severely reduced in patients with rheumatoid arthritis treated with rituximab
Sander van Assen, Albert Holvast, C. A. Benne et al.|Arthritis & Rheumatism|2009
Cited by 380

OBJECTIVE: For patients with rheumatoid arthritis (RA), yearly influenza vaccination is recommended. However, its efficacy in patients treated with rituximab is unknown. The objectives of this study were to investigate the efficacy of influenza vaccination in RA patients treated with rituximab and to investigate the duration of the possible suppression of the humoral immune response following rituximab treatment. We also undertook to assess the safety of influenza vaccination and the effects of previous influenza vaccination. METHODS: Trivalent influenza subunit vaccine was administered to 23 RA patients who had received rituximab (4-8 weeks after rituximab for 11 patients [the early rituximab subgroup] and 6-10 months after rituximab for 12 patients [the late rituximab subgroup]), 20 RA patients receiving methotrexate (MTX), and 29 healthy controls. Levels of antibodies against the 3 vaccine strains were measured before and 28 days after vaccination using hemagglutination inhibition assay. The Disease Activity Score in 28 joints (DAS28) was used to assess RA activity. RESULTS: Following vaccination, geometric mean titers (GMTs) of antiinfluenza antibodies significantly increased for all influenza strains in the MTX-treated group and in healthy controls, but for no strains in the rituximab-treated group. However, in the late rituximab subgroup, a rise in GMT for the A/H3N2 and A/H1N1 strains was demonstrated, in the absence of a repopulation of CD19+ cells at the time of vaccination. Seroconversion and seroprotection occurred less often in the rituximab-treated group than in the MTX-treated group for the A/H3N2 and A/H1N1 strains, while seroprotection occurred less often in the rituximab-treated group than in the healthy controls for the A/H1N1 strain. Compared with unvaccinated patients in the rituximab-treated group, previously vaccinated patients in the rituximab-treated group had higher pre- and postvaccination GMTs for the A/H1N1 strain. The DAS28 did not change after vaccination. CONCLUSION: Rituximab reduces humoral responses following influenza vaccination in RA patients, with a modestly restored response 6-10 months after rituximab administration. Previous influenza vaccination in rituximab-treated patients increases pre- and postvaccination titers. RA activity was not influenced.

Meta-Analysis of Genome-Wide Association Studies in Celiac Disease and Rheumatoid Arthritis Identifies Fourteen Non-HLA Shared Loci
Alexandra Zhernakova, Eli A. Stahl, Gosia Trynka et al.|PLoS Genetics|2011
Cited by 364Open Access

Epidemiology and candidate gene studies indicate a shared genetic basis for celiac disease (CD) and rheumatoid arthritis (RA), but the extent of this sharing has not been systematically explored. Previous studies demonstrate that 6 of the established non-HLA CD and RA risk loci (out of 26 loci for each disease) are shared between both diseases. We hypothesized that there are additional shared risk alleles and that combining genome-wide association study (GWAS) data from each disease would increase power to identify these shared risk alleles. We performed a meta-analysis of two published GWAS on CD (4,533 cases and 10,750 controls) and RA (5,539 cases and 17,231 controls). After genotyping the top associated SNPs in 2,169 CD cases and 2,255 controls, and 2,845 RA cases and 4,944 controls, 8 additional SNPs demonstrated P<5 × 10(-8) in a combined analysis of all 50,266 samples, including four SNPs that have not been previously confirmed in either disease: rs10892279 near the DDX6 gene (P(combined) = 1.2 × 10(-12)), rs864537 near CD247 (P(combined) = 2.2 × 10(-11)), rs2298428 near UBE2L3 (P(combined) = 2.5 × 10(-10)), and rs11203203 near UBASH3A (P(combined) = 1.1 × 10(-8)). We also confirmed that 4 gene loci previously established in either CD or RA are associated with the other autoimmune disease at combined P<5 × 10(-8) (SH2B3, 8q24, STAT4, and TRAF1-C5). From the 14 shared gene loci, 7 SNPs showed a genome-wide significant effect on expression of one or more transcripts in the linkage disequilibrium (LD) block around the SNP. These associations implicate antigen presentation and T-cell activation as a shared mechanism of disease pathogenesis and underscore the utility of cross-disease meta-analysis for identification of genetic risk factors with pleiotropic effects between two clinically distinct diseases.

Implementation of a treat-to-target strategy in very early rheumatoid arthritis: Results of the Dutch Rheumatoid Arthritis Monitoring remission induction cohort study
Marloes Vermeer, H. H. Kuper, Monique Hoekstra et al.|Arthritis & Rheumatism|2011
Cited by 143

OBJECTIVE: Clinical remission is the ultimate therapeutic goal in rheumatoid arthritis (RA). Although clinical trials have proven this to be a realistic goal, the concept of targeting at remission has not yet been implemented. The objective of this study was to develop, implement, and evaluate a treat-to-target strategy aimed at achieving remission in very early RA in daily clinical practice. METHODS: Five hundred thirty-four patients with a clinical diagnosis of very early RA were included in the Dutch Rheumatoid Arthritis Monitoring remission induction cohort study. Treatment adjustments were based on the Disease Activity Score in 28 joints (DAS28), aiming at a DAS28 of <2.6 (methotrexate, followed by the addition of sulfasalazine, and exchange of sulfasalazine with biologic agents in case of persistent disease activity). The primary outcome was disease activity after 6 months and 12 months of followup, according to the DAS28, the European League Against Rheumatism (EULAR) response criteria, and the modified American College of Rheumatology (ACR) remission criteria. Secondary outcomes were time to first DAS28 remission and outcome of radiography. RESULTS: Six-month and 12-month followup data were available for 491 and 389 patients, respectively. At 6 months, 47.0% of patients achieved DAS28 remission, 57.6% had a good EULAR response, and 32.0% satisfied the ACR remission criteria. At 12 months, 58.1% of patients achieved DAS28 remission, 67.9% had a good EULAR response, and 46.4% achieved ACR remission. The median time to first remission was 25.3 weeks (interquartile range 13.0-52.0). The majority of patients did not have clinically relevant radiographic progression after 1 year. CONCLUSION: The successful implementation of this treat-to-target strategy aiming at remission demonstrated that achieving remission in daily clinical practice is a realistic goal.