Rachel Hellemans

Bio: Rachel Hellemans is an academic researcher from University of Antwerp. The author has contributed to research in topics: Transplantation & Kidney transplantation. The author has an hindex of 7, co-authored 21 publications receiving 164 citations.

Donor-derived cell-free DNA as a biomarker for rejection after kidney transplantation: a systematic review and meta-analysis.

Abstract: A systematic review and meta-analysis were performed to investigate the value of donor-derived cell-free DNA (dd-cfDNA) as a noninvasive biomarker in diagnosing kidney allograft rejection. We searched PubMed, Web of Science and the Cochrane Library for original research papers published between January 1994 and May 2020 on dd-cfDNA fractions in blood of kidney allograft recipients. A single-group meta-analysis was performed by computing pooled estimates for dd-cfDNA fractions using the weighted median of medians or quantile estimation (QE) approach. Weighted median differences in medians (WMDMs) and median differences based on the QE method were used for pairwise comparisons. Despite heterogeneity among the selected studies, the meta-analysis revealed significantly higher median dd-cfDNA fractions in patients with antibody-mediated rejection (ABMR) than patients without rejection or patients with stable graft function. When comparing patients with T cell-mediated rejection (TCMR) and patients with ABMR, our two statistical approaches revealed conflicting results. Patients with TCMR did not have different median dd-cfDNA fractions than patients without rejection or patients with stable graft function. dd-cfDNA may be a useful marker for ABMR, but probably not for TCMR.

Does Kidney Donor Risk Index implementation lead to the transplantation of more and higher-quality donor kidneys?

Abstract: Background: The Kidney Donor Risk Index (KDRI) is a quantitative evaluation of the quality of donor organs and is implemented in the US allocation system. This single-centre study investigates whether the implementation of the KDRI in our decision-making process to accept or decline an offered deceased donor kidney, increases our acceptance rate. Methods: From April 2015 until December 2016, we prospectively calculated the KDRI for all deceased donor kidney offers allocated by Eurotransplant to our centre. The number of the transplanted versus declined kidney offers during the study period were compared to a historical set of donor kidney offers. Results: After implementation of the KDRI, 26.1% (75/288) of all offered donor kidneys were transplanted, compared with 20.7% (136/657) in the previous period (P < 0.001). The median KDRI of all transplanted donor kidneys during the second period was 0.97 [Kidney Donor Profile Index (KDPI) 47%], a value significantly higher than the median KDRI of 0.85 (KDPI 34%) during the first period (P = 0.047). A total of 68% of patients for whom a first-offered donor kidney was declined during this period were transplanted after a median waiting time of 386 days, mostly with a lower KDRI donor kidney. Conclusions: Implementing the KDRI in our decision-making process increased the transplantation rate by 26%. The KDRI can be a supportive tool when considering whether to accept or decline a deceased donor kidney offer. More data are needed to validate this score in other European centres.

Renal association clinical practice guideline in post-operative care in the kidney transplant recipient.

Abstract: These guidelines cover the care of patients from the period following kidney transplantation until the transplant is no longer working or the patient dies During the early phase prevention of acute rejection and infection are the priority After around 3–6 months, the priorities change to preservation of transplant function and avoiding the long-term complications of immunosuppressive medication (the medication used to suppress the immune system to prevent rejection) The topics discussed include organization of outpatient follow up, immunosuppressive medication, treatment of acute and chronic rejection, and prevention of complications The potential complications discussed include heart disease, infection, cancer, bone disease and blood disorders There is also a section on contraception and reproductive issues Immediately after the introduction there is a statement of all the recommendations These recommendations are written in a language that we think should be understandable by many patients, relatives, carers and other interested people Consequently we have not reworded or restated them in this lay summary They are graded 1 or 2 depending on the strength of the recommendation by the authors, and AD depending on the quality of the evidence that the recommendation is based on

Risk factors associated with post–kidney transplant malignancies: an article from the Cancer-Kidney International Network

Abstract: In kidney transplant recipients, cancer is one of the leading causes of death with a functioning graft beyond the first year of kidney transplantation, and malignancies account for 8-10% of all deaths in the USA (2.6 deaths/1000 patient-years) and exceed 30% of deaths in Australia (5/1000 patient-years) in kidney transplant recipients. Patient-, transplant- and medication-related factors contribute to the increased cancer risk following kidney transplantation. While it is well established that the overall immunosuppressive dose is associated with an increased risk for cancer following transplantation, the contributive effect of different immunosuppressive agents is not well established. In this review we will discuss the different risk factors for malignancies after kidney transplantation.

Personalized Therapy for Mycophenolate: Consensus Report by the International Association of Therapeutic Drug Monitoring and Clinical Toxicology

Abstract: When mycophenolic acid (MPA) was originally marketed for immunosuppressive therapy, fixed doses were recommended by the manufacturer. Awareness of the potential for a more personalized dosing has led to development of methods to estimate MPA area under the curve based on the measurement of drug concentrations in only a few samples. This approach is feasible in the clinical routine and has proven successful in terms of correlation with outcome. However, the search for superior correlates has continued, and numerous studies in search of biomarkers that could better predict the perfect dosage for the individual patient have been published. As it was considered timely for an updated and comprehensive presentation of consensus on the status for personalized treatment with MPA, this report was prepared following an initiative from members of the International Association of Therapeutic Drug Monitoring and Clinical Toxicology (IATDMCT). Topics included are the criteria for analytics, methods to estimate exposure including pharmacometrics, the potential influence of pharmacogenetics, development of biomarkers, and the practical aspects of implementation of target concentration intervention. For selected topics with sufficient evidence, such as the application of limited sampling strategies for MPA area under the curve, graded recommendations on target ranges are presented. To provide a comprehensive review, this report also includes updates on the status of potential biomarkers including those which may be promising but with a low level of evidence. In view of the fact that there are very few new immunosuppressive drugs under development for the transplant field, it is likely that MPA will continue to be prescribed on a large scale in the upcoming years. Discontinuation of therapy due to adverse effects is relatively common, increasing the risk for late rejections, which may contribute to graft loss. Therefore, the continued search for innovative methods to better personalize MPA dosage is warranted.