Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Karin M.J. van Nieuwkerk is active.

Publication


Featured researches published by Karin M.J. van Nieuwkerk.


Hepatology | 2013

Population-based epidemiology, malignancy risk, and outcome of primary sclerosing cholangitis.

Kirsten Boonstra; Rinse K. Weersma; Karel J. van Erpecum; Erik A. J. Rauws; B.W. Marcel Spanier; Alexander C. Poen; Karin M.J. van Nieuwkerk; Joost P. H. Drenth; Ben J. Witteman; Hans Tuynman; Anton H. Naber; Paul J. Kingma; Henk R. van Buuren; Bart van Hoek; Frank P. Vleggaar; Nan van Geloven; Ulrich Beuers; Cyriel Y. Ponsioen

Extensive population‐based studies are much needed to accurately establish epidemiology and disease course in patients with primary sclerosing cholangitis (PSC). We aimed to obtain population‐based prevalence and incidence figures, insight in disease course with regard to survival, liver transplantation (LT), and occurrence of malignancies, as well as risk factors thereof. Four independent hospital databases were searched in 44 hospitals in a large geographically defined area of the Netherlands, comprising 50% of the population. In addition, all PSC patients in the three Dutch liver transplant centers and all inflammatory bowel disease (IBD) patients in the adherence area of a large district hospital were identified. All medical records were reviewed on‐site, verifying diagnosis. Five hundred and ninety PSC patients were identified, resulting in an incidence of 0.5 and a point prevalence of 6.0 per 100,000. Median follow up was 92 months. Estimated median survival from diagnosis until LT or PSC‐related death in the entire cohort was 21.3 years, as opposed to 13.2 years in the combined transplant centers cohort (n = 422; P < 0.0001). Colorectal carcinoma (CRC) risk was 10‐fold increased, as compared to ulcerative colitis controls, and developed at a much younger age (39 years; range, 26‐64), compared to IBD controls (59 years; range, 34‐73; P = 0.019). Colonoscopic surveillance was associated with significantly better outcome. Conclusion: This study exemplifies that, for relatively rare diseases, it is paramount to collect observational data from large, population‐based cohorts, because incidence and prevalence rates of PSC are markedly lower and survival much longer than previously reported. The selection of a bias‐free, population‐based cohort showed a significantly longer survival, compared to the tertiary referral cohort. CRC can develop at an early age, warranting surveillance from time of PSC diagnosis. (Hepatology 2013; 58:2045–2055)


Inflammatory Bowel Diseases | 2012

Primary sclerosing cholangitis is associated with a distinct phenotype of inflammatory bowel disease

Kirsten Boonstra; Karel J. van Erpecum; Karin M.J. van Nieuwkerk; Joost P. H. Drenth; Alexander C. Poen; Ben J. Witteman; Hans Tuynman; Ulrich Beuers; Cyriel Y. Ponsioen

Background: Primary sclerosing cholangitis (PSC) is strongly associated with inflammatory bowel disease (IBD). The aim of this study was to assess the IBD phenotype associated with PSC in a large well‐phenotyped population‐based PSC cohort using endoscopic and histopathologic criteria. Methods: PSC cases were identified and ascertained, fulfilling well‐established criteria, in 39 hospitals in a geographically defined region of The Netherlands. IBD location was recorded according to the Montreal Classification. As this classification does not consider segmental inflammation, backwash ileitis, or rectal sparing, an additional subgroup analysis was performed in 80 cases and 80 age‐ and sex‐matched IBD controls, reviewing all endoscopy and pathology reports filed between 2000 and 2010. Results: In all, 380 (66%) of a total of 579 PSC patients had coexistent IBD, mainly ulcerative colitis (UC) (75%). Overall, 207 (83%) of the PSC‐UC patients had a pancolitis, 32 (13%) a left‐sided colitis, and 9 (4%) a proctitis only. Seventy (95%) PSC‐Crohns disease (CD) patients had an (ileo)colitis and four (5%) ileitis only. In the subgroup analysis 53 (66%) PSC‐UC patients were identified, 24 (30%) PSC‐CD patients, and three (4%) PSC‐IBD‐U patients. Fifty (94%) PSC‐UC patients had a pancolitis, compared with 32 (62%) matched UC patients (P < 0.001). Left‐sided colitis was seen in 16 (31%) UC controls and in one PSC‐UC patient (P < 0.001). Backwash ileitis and rectal sparing were rare findings (<10%) in the cohorts under study. Conclusions: IBD in PSC patients represents a distinct phenotype in that pancolitis is observed in 94% of PSC‐UC and colitis in 96% of PSC‐CD patients. Backwash ileitis and rectal sparing were rare findings in the PSC‐UC patients. (Inflamm Bowel Dis 2012;)


Hepatology | 2014

Serum immunoglobulin G4 and immunoglobulin G1 for distinguishing immunoglobulin G4‐associated cholangitis from primary sclerosing cholangitis

Kirsten Boonstra; Emma L. Culver; Lucas Maillette de Buy Wenniger; Marianne J. Van Heerde; Karel J. van Erpecum; A.C. Poen; Karin M.J. van Nieuwkerk; B.W. Marcel Spanier; Ben J. Witteman; Hans A.R.E. Tuynman; Nan van Geloven; Henk R. van Buuren; Roger W. Chapman; Eleanor Barnes; Ulrich Beuers; Cyriel Y. Ponsioen

The recent addition of immunoglobulin (Ig)G4‐associated cholangitis (IAC), also called IgG4‐related sclerosing cholangitis (IRSC), to the spectrum of chronic cholangiopathies has created the clinical need for reliable methods to discriminate between IAC and the more common cholestatic entities, primary (PSC) and secondary sclerosing cholangitis. The current American Association for the Study of Liver Diseases practice guidelines for PSC advise on the measurement of specific Ig (sIg)G4 in PSC patients, but interpretation of elevated sIgG4 levels remains unclear. We aimed to provide an algorithm to distinguish IAC from PSC using sIgG analyses. We measured total IgG and IgG subclasses in serum samples of IAC (n = 73) and PSC (n = 310) patients, as well as in serum samples of disease controls (primary biliary cirrhosis; n = 22). sIgG4 levels were elevated above the upper limit of normal (ULN = >1.4 g/L) in 45 PSC patients (15%; 95% confidence interval [CI]: 11‐19). The highest specificity and positive predictive value (PPV; 100%) for IAC were reached when applying the 4× ULN (sIgG4 > 5.6 g/L) cutoff with a sensitivity of 42% (95% CI: 31‐55). However, in patients with a sIgG4 between 1× and 2× ULN (n = 38/45), the PPV of sIgG4 for IAC was only 28%. In this subgroup, the sIgG4/sIgG1 ratio cutoff of 0.24 yielded a sensitivity of 80% (95% CI: 51‐95), a specificity of 74% (95% CI: 57‐86), a PPV of 55% (95% CI: 33‐75), and a negative predictive value of 90% (95% CI: 73‐97). Conclusion: Elevated sIgG4 (>1.4 g/L) occurred in 15% of patients with PSC. In patients with a sIgG4 >1.4 and <2.8 g/L, incorporating the IgG4/IgG1 ratio with a cutoff at 0.24 in the diagnostic algorithm significantly improved PPV and specificity. We propose a new diagnostic algorithm based on IgG4/IgG1 ratio that may be used in clinical practice to distinguish PSC from IAC. (Hepatology 2014;59:1954–1963)


Liver International | 2014

Rising incidence and prevalence of primary biliary cirrhosis: a large population-based study.

Kirsten Boonstra; Anton E. Kunst; Hans Tuynman; Alexander C. Poen; Karin M.J. van Nieuwkerk; Ellen M. Witteman; Dörte Hamann; Ben J. Witteman; Ulrich Beuers; Cyriel Y. Ponsioen

Large population‐based studies are much needed to accurately establish the epidemiology of primary biliary cirrhosis (PBC). We aimed to collect all PBC patients in a geographically defined area to evaluate the epidemiology of PBC and examine the possible association of PBC with smoking, age at menarche, age at first pregnancy and number of pregnancies.


Clinics and Research in Hepatology and Gastroenterology | 2016

Adherence to ribavirin in chronic hepatitis C patients on antiviral treatment: Results from a randomized controlled trial using real-time medication monitoring.

Lotte G. van Vlerken; Faydra I. Lieveld; Suzanne van Meer; Ger H. Koek; Karin M.J. van Nieuwkerk; Pieter Friederich; Joop E. Arends; Peter D. Siersema; David M. Burger; Karel J. van Erpecum

BACKGROUND AND OBJECTIVE Adherence is essential in antiviral therapy for chronic hepatitis C. We investigated the effect of real-time medication monitoring on adherence to ribavirin. METHODS In this randomized controlled trial, patients in the intervention group received a medication dispenser that monitored ribavirin intake real-time during 24 weeks PEG-interferon/ribavirin±boceprevir or telaprevir. Patients in the control group received standard-of-care. Adherence was also measured by pill count. RESULTS Seventy-two patients were assigned to either intervention (n=35) or control groups (n=37). Median adherence by pill count was 96% (range: 43%-100%) with 30 (94%) of patients exhibiting≥80% adherence. Perfect adherence (i.e. 100%) was similar in intervention and control groups: 22 (85%) vs. 15 (75%) (P=0.47). Adherences by real-time medication monitoring and by pill count did not correlate (R=0.19, P=0.36). No predictors of poor adherence could be identified. Ribavirin trough levels after 8 weeks (median: 2.4 vs. 2.7mg/L, P=0.30) and 24 weeks (median: 3.0 vs. 3.0mg/L, P=0.69), and virological responses did not differ between intervention and control groups. CONCLUSIONS Adherence to ribavirin during PEG-interferon containing therapy in chronic hepatitis C is high. Real-time medication monitoring did not influence adherence to ribavirin, plasma ribavirin levels or virological responses.


European Radiology | 2014

Non-invasive evaluation of liver fibrosis: a comparison of ultrasound-based transient elastography and MR elastography in patients with viral hepatitis B and C

Anneloes E. Bohte; Annikki de Niet; Louis Jansen; Shandra Bipat; A.J. Nederveen; Joanne Verheij; Valeska Terpstra; Ralph Sinkus; Karin M.J. van Nieuwkerk; Rob J. de Knegt; Bert C. Baak; Peter Lm Jansen; H.W. Reesink; Jaap Stoker


Journal of Hepatology | 2015

Surveillance for hepatocellular carcinoma is associated with increased survival : Results from a large cohort in the Netherlands

Suzanne van Meer; Robert A. de Man; Minneke J. Coenraad; Dave Sprengers; Karin M.J. van Nieuwkerk; Heinz-Josef Klümpen; Peter L. M. Jansen; Jan N. M. IJzermans; Martijn G. van Oijen; Peter D. Siersema; Karel J. van Erpecum


Abdominal Imaging | 2014

Comparison of interobserver agreement of magnetic resonance elastography with histopathological staging of liver fibrosis

Jurgen H. Runge; Anneloes E. Bohte; Joanne Verheij; Valeska Terpstra; Aart J. Nederveen; Karin M.J. van Nieuwkerk; Rob J. de Knegt; Bert C. Baak; Peter L. M. Jansen; Ralph Sinkus; Jaap Stoker


CardioVascular and Interventional Radiology | 2015

Percutaneous Irreversible Electroporation of a Large Centrally Located Hepatocellular Adenoma in a Woman with a Pregnancy Wish

Hester J. Scheffer; Marleen C. A. M. Melenhorst; Aukje A. J. M. van Tilborg; Karin Nielsen; Karin M.J. van Nieuwkerk; Richard A. de Vries; Petrousjka van den Tol; Martijn R. Meijerink


Hepatology International | 2014

Increased cancer risk in a large population-based cohort of patients with primary biliary cirrhosis: follow-up for up to 36 years

Kirsten Boonstra; Robin Bokelaar; Hans Tuynman; Alexander C. Poen; Karin M.J. van Nieuwkerk; Ellen M. Witteman; Dörte Hamann; Ben J. Witteman; Ulrich Beuers; Cyriel Y. Ponsioen

Collaboration


Dive into the Karin M.J. van Nieuwkerk's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Ben J. Witteman

Wageningen University and Research Centre

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Karel J. van Erpecum

Brigham and Women's Hospital

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Peter D. Siersema

Radboud University Nijmegen

View shared research outputs
Top Co-Authors

Avatar

Bart van Hoek

Leiden University Medical Center

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Joost P. H. Drenth

Radboud University Nijmegen

View shared research outputs
Researchain Logo
Decentralizing Knowledge