Repertoire sequencing of B cells elucidates the role of UNG and mismatch repair proteins in somatic hypermutation in humans

The generation of high-affinity antibodies depends on somatic hypermutation (SHM). SHM is initiated by the activation-induced cytidine deaminase (AID), which generates uracil (U) lesions in the B-cell receptor (BCR) encoding genes. Error-prone processing of U lesions creates a typical spectrum of point mutations during SHM. The aim of this study was to determine the molecular mechanism of SHM in humans; currently available knowledge is limited by the number of mutations analyzed per patient. We collected a unique cohort of 10 well-defined patients with bi-allelic mutations in genes involved in base excision repair (BER) (UNG) or mismatch repair (MMR) (MSH2, MSH6, or PMS2) and are the first to present next-generation sequencing (NGS) data of the BCR, allowing us to study SHM extensively in humans. Analysis using ARGalaxy revealed selective skewing of SHM mutation patterns specific for each genetic defect, which are in line with the five-pathway model of SHM that was recently proposed based on mice data. However, trans-species comparison revealed differences in the role of PMS2 and MSH2 in strand targeting between mice and man. In conclusion, our results indicate a role for UNG, MSH2, MSH6, and PMS2 in the generation of SHM in humans comparable to their function in mice. However, we observed differences in strand targeting between humans and mice, emphasizing the importance of studying molecular mechanisms in a human setting. The here developed method combining NGS and ARGalaxy analysis of BCR mutation data forms the basis for efficient SHM analyses of other immune deficiencies

Metastatic uveal melanoma: Treatment strategies and survival—results from the dutch melanoma treatment registry

Uveal melanoma (UM) is the most common primary intraocular tumor in adults. Up to 50% of UM patients will develop metastases. We present data of 175 metastatic UM patients diagnosed in the Netherlands between July 2012 and March 2018. In our cohort, elevated lactate dehydrogenase level (LDH) is an important factor associated with poorer survival (Hazard Ratio (HR) 9.0, 95% Confidence Interval (CI) 5.63–14.35), and the presence of liver metastases is negatively associated with survival (HR 2.09, 95%CI 1.07–4.08). We used data from the nation-wide Dutch Melanoma Treatment Registry (DMTR) providing a complete overview of the location of metastases at time of stage IV disease. In 154 (88%) patients, the liver was affected, and only 3 patients were reported to have brain metastases. In 63 (36%) patients, mutation analysis was performed, showing a GNA11 mutation in 28.6% and a GNAQ mutation in 49.2% of the analyzed patients. In the absence of standard care of treatment options, metastatic UM patients are often directed to clinical trials. Patients participating in clinical trials are often subject to selection and usually do not represent the entire metastatic UM population. By using our nation-wide cohort, we are able to describe real-life treatment choices made in metastatic UM patients and 1-year surv

Real-world use, safety, and survival of ipilimumab in metastatic cutaneous melanoma in The Netherlands

Item does not contain fulltex

Real-world healthcare costs of ipilimumab in patients with advanced cutaneous melanoma in The Netherlands

Item does not contain fulltex

Factors contributing to variation in the use of multimodality treatment in patients with gastric cancer: A Dutch population based study

Contains fulltext : 183925.pdf (publisher's version ) (Closed access

Factors contributing to variation in the use of multimodality treatment in patients with gastric cancer: A Dutch population based study

Development and application of statistical models for medical scientific researc

Vemurafenib in BRAF-mutant metastatic melanoma patients in real-world clinical practice: prognostic factors associated with clinical outcomes

Item does not contain fulltextThe aim of this population-based study was to identify the factors associated with clinical outcomes in vemurafenib-treated patients and to evaluate outcomes across subgroups of patients with different risk profiles. Data were retrieved from the Dutch Melanoma Treatment Registry. Time to next treatment (TTNT) and overall survival (OS) of all metastatic melanoma patients who received vemurafenib between 2012 and 2015 were assessed using Kaplan-Meier estimates. A risk score was developed on the basis of all prognostic factors associated with TTNT and OS derived from multivariable Cox regression analyses. Patients were stratified according to the presence of prognostic risk factors by counting the number of factors, ranging from 0 to 6. A total of 626 patients received vemurafenib with a median follow-up of 35.8 months. The median TTNT and OS were 4.7 months [95% confidence intervals (CI): 4.4-5.1] and 7.3 months (95% CI: 6.6-8.0). The strongest prognostic factors were serum lactate dehydrogenase (LDH) level, Eastern Cooperative Oncology Group performance score, number of organ sites involved and brain metastases. Patients with a favourable risk profile (no risk factors) had a median TTNT and OS of 7.1 (95% CI: 5.8-8.5) and 15.4 months (95% CI: 10.0-20.9). The median OS more than halved for patients with greater than or equal to 2 risk factors compared with patients with no risk factors. The clinical outcomes of vemurafenib in metastatic melanoma patients with a favourable risk profile are comparable with the results of the trials. Combining prognostic factors into a risk score could be valuable to stratify patients into favourable and poor-prognosis groups

Real-world use, safety, and survival of ipilimumab in metastatic cutaneous melanoma in The Netherlands

Experimentele farmacotherapi

Real-world healthcare costs of ipilimumab in patients with advanced cutaneous melanoma in The Netherlands

Experimentele farmacotherapi

Metastatic Uveal Melanoma: Treatment Strategies and Survival-Results from the Dutch Melanoma Treatment Registry

Experimentele farmacotherapi