M.R. Kok

Dr. M.R. Kok

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Research Focus & Metrics

Academic Career Length

34Years (1993-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 July 2004 in Arthritis & Rheumatism
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Journal Article
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VSVidya Sankar
Vidya Sankar
MBMichael T. Brennan
Michael T. Brennan
MKM.R. Kok
M.R. Kok
RLRose Anne Leakan
Rose Anne Leakan
JSJanine A. Smith
Janine A. Smith
SPStanley R. Pillemer
Stanley R. Pillemer

16 May 2022 in Annals of the Rheumatic Diseases
Verified
Journal Article
Open access
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MBMaarten Boers
Maarten Boers
LHLinda Hartman
Linda Hartman
DODaniela Opris-Belinski
Daniela Opris-Belinski
RBReinhard Bos
Reinhard Bos
MKM.R. Kok
M.R. Kok
MCMaurizio Cutolo
Maurizio Cutolo
Background Low-dose glucocorticoid (GC) therapy is widely used in rheumatoid arthritis (RA) but the balance of benefit and harm is still unclear. Methods The GLORIA (Glucocorticoid LOw-dose in RheumatoId Arthritis) pragmatic double-blind randomised trial compared 2 years of prednisolone, 5 mg/day, to placebo in patients aged 65+ with active RA. We allowed all cotreatments except long-term open label GC and minimised exclusion criteria, tailored to seniors. Benefit outcomes included disease activity (disease activity score; DAS28, coprimary) and joint damage (Sharp/van der Heijde, secondary). The other coprimary outcome was harm, expressed as the proportion of patients with ≥1 adverse event (AE) of special interest. Such events comprised serious events, GC-specific events and those causing study discontinuation. Longitudinal models analysed the data, with one-sided testing and 95% confidence limits (95% CL). Results We randomised 451 patients with established RA and mean 2.1 comorbidities, age 72, disease duration 11 years and DAS28 4.5. 79% were on disease-modifying treatment, including 14% on biologics. 63% prednisolone versus 61% placebo patients completed the trial. Discontinuations were for AE (both, 14%), active disease (3 vs 4%) and for other (including covid pandemic-related disease) reasons (19 vs 21%); mean time in study was 19 months. Disease activity was 0.37 points lower on prednisolone (95% CL 0.23, p<0.0001); joint damage progression was 1.7 points lower (95% CL 0.7, p=0.003). 60% versus 49% of patients experienced the harm outcome, adjusted relative risk 1.24 (95% CL 1.04, p=0.02), with the largest contrast in (mostly non-severe) infections. Other GC-specific events were rare. Conclusion Add-on low-dose prednisolone has beneficial long-term effects in senior patients with established RA, with a trade-off of 24% increase in patients with mostly non-severe AE; this suggests a favourable balance of benefit and harm. Trial registration number NCT02585258.

2 January 2019 in Rheumatology
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Journal Article
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CJCarly A Janssen
Carly A Janssen
MVMartijn A H Oude Voshaar
Martijn A H Oude Voshaar
HVHarald E Vonkeman
Harald E Vonkeman
TJTim L Th. A Jansen
Tim L Th. A Jansen
MJMatthijs Janssen
Matthijs Janssen
MLMart A F J van de Laar
Mart A F J van de Laar
Objectives: To evaluate the efficacy and safety of anakinra in treating acute gout flares in a randomized, double-blind, placebo-controlled, active comparator, non-inferiority (NI) trial.Methods: Patients with a crystal-proven acute gout flare were randomized (1: 1) to treatment with anakinra or treatment as usual (free choice: either colchicine, naproxen or prednisone). The primary end point was the change in pain between baseline and the averaged pain score on days 2–4 measured on a five-point rating scale. NI of anakinra would be established if the upper bound of the 95% CI of the numeric difference in changed pain scores between treatment groups did not exceed the NI limit of 0.4 in favour of treatment as usual, in the per-protocol (PP) and intention-to-treat (ITT) populations, assessed in an analysis of covariance model. Secondary outcomes included safety assessments, improvement in pain, swelling, tenderness and treatment response after 5 days, assessed using linear mixed models and binary logistic regression models.Results: Forty-three patients received anakinra and 45 treatment as usual. Anakinra was non-inferior (mean difference; 95% CI) to treatment as usual in both the PP (–0.13; –0.44, 0.18) and ITT (–0.18; –0.44, 0.08) populations. No unexpected or uncommon (serious) adverse events were observed in either treatment arm. Analyses of secondary outcomes showed that patients in both groups reported similar significant reductions in their gout symptoms.Conclusion: Efficacy of anakinra was shown to be non-inferior to treatment as usual for the treatment of acute gout flares, suggesting that anakinra is an effective treatment alternative for acute gout flares.Trial registration: Het Nederlands Trial Register, www.trialregister.nl, NTR5234

1 July 2013 in Atherosclerosis
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Journal Article
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ASAart C. Strang
Aart C. Strang
RBRadjesh J. Bisoendial
Radjesh J. Bisoendial
RKRuud S. Kootte
Ruud S. Kootte
DSDominik M. Schulte
Dominik M. Schulte
GDGeesje M. Dallinga-Thie
Geesje M. Dallinga-Thie
PTPaul P. Tak
Paul P. Tak

20 November 2003 in Human Gene Therapy
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Journal Article
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MKM.R. Kok
M.R. Kok
SYSeiichi Yamano
Seiichi Yamano
BLBeatrijs M. Lodde
Beatrijs M. Lodde
JWJianghua Wang
Jianghua Wang
RCRoss I. Couwenhoven
Ross I. Couwenhoven
BBBruce J. Baum
Bruce J. Baum
Female nonobese diabetic (NOD) mice develop spontaneous autoimmune sialadenitis and loss of salivary flow, and are a widely used model of Sjögren's syndrome. We examined the feasibility of local salivary gland immunomodulatory gene delivery to alter these sequelae in NOD mice. We constructed recombinant adeno-associated virus (rAAV) vectors encoding either human interleukin 10 (rAAVhIL-10) or β-galactosidase (rAAVLacZ, control vector). Mice received rAAVhIL-10 or rAAVLacZ by retrograde submandibular ductal instillation either at age 8 weeks (early, before onset of sialadenitis), or at 16 weeks (late, after onset of sialadenitis). As a systemic treatment control, separate mice received intramuscular delivery of rAAVhIL-10 at each time point. Both submandibular and intramuscular delivery of vector led to low circulating levels of hIL-10. After submandibular administration of rAAVhIL-10, salivary flow rates at 20 weeks for both the early and late treatment groups were significantly higher than for both rAAVLacZ-administered and untreated mice. Systemic delivery of rAAVhIL-10 led to improved salivary flow in the late treatment group. Inflammatory infiltrates in submandibular glands, however, were significantly reduced only in mice receiving rAAVhIL-10 locally in the salivary gland compared with mice receiving this vector intramuscularly, or rAAVLacZ or no treatment. In addition, after submandibular rAAVhIL-10 delivery, NOD mice exhibited significantly lower blood glucose, and higher serum insulin, levels than all other groups, indicating some systemic benefit of this treatment. These studies show that expression of hIL-10 by rAAV vectors can have disease-modifying effects in the salivary glands of NOD mice, and suggest that local immunomodulatory gene transfer may be useful for managing the salivary gland pathology in Sjögren's syndrome.

20 February 2004 in Proceedings of the National Academy of Sciences
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Journal Article
Closed access
AVAntonis Voutetakis
Antonis Voutetakis
MKM.R. Kok
M.R. Kok
CZChangyu Zheng
Changyu Zheng
IBIoannis Bossis
Ioannis Bossis
JWJianghua Wang
Jianghua Wang
BBBruce J. Baum
Bruce J. Baum
The use of critical-for-life organs (e.g., liver or lung) for systemic gene therapeutics can lead to serious safety concerns. To circumvent such issues, we have considered salivary glands (SGs) as an alternative gene therapeutics target tissue. Given the high secretory abilities of SGs, we hypothesized that administration of low doses of recombinant adeno-associated virus (AAV) vectors would allow for therapeutic levels of transgene-encoded secretory proteins in the bloodstream. We administered 10(9) particles of an AAV vector encoding human erythropoietin (hEPO) directly to individual mouse submandibular SGs. Serum hEPO reached maximum levels 8-12 weeks after gene delivery and remained relatively stable for 54 weeks (longest time studied). Hematocrit levels were similarly increased. Moreover, these effects proved to be vector dose-dependent, and even a dosage as low as 10(8) particles per animal led to significant increases in hEPO and hematocrit levels. Vector DNA was detected only within the targeted SGs, and levels of AAV copies within SGs were highly correlated with serum hEPO levels (r = 0.98). These results show that SGs appear to be promising targets with potential clinical applicability for systemic gene therapeutics.