Algorithms for the Testing of Tissue Donors for Human Immunodeficiency Virus, Hepatitis B Virus, and Hepatitis C Virus.

BACKGROUND: Although transmission of pathogenic viruses through human tissue grafts is rare, it is still one of the most serious dreaded risks of transplantation. Therefore, in addition to the detailed medical and social history, a comprehensive serologic and molecular screening of the tissue donors for relevant viral markers for human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) is necessary. In the case of reactive results in particular, clear decisions regarding follow-up testing and the criteria for tissue release must be made. METHODS: Based on the clinical relevance of the specific virus markers, the sensitivity of the serological and molecular biological methods used and the application of inactivation methods, algorithms for tissue release are suggested. RESULTS: Compliance with the preanalytical requirements and assessment of a possible hemodilution are mandatory requirements before testing the blood samples. While HIV testing follows defined algorithms, the procedures for HBV and HCV diagnostics are under discussion. Screening and decisions for HBV are often not as simple, e.g., due to cases of occult HBV infection, false-positive anti-HBc results, or early window period positive HBV NAT results. In the case of HCV diagnostics, modern therapies with direct-acting antivirals, which are often associated with successful treatment of the infection, should be included in the decision. CONCLUSION: In HBV and HCV testing, a high-sensitivity virus genome test should play a central role in diagnostics, especially in the case of equivocal serology, and it should be the basis for the decision to release the tissue. The proposed test algorithms and decisions are also based on current European recommendations and standards for safety and quality assurance in tissue and cell banking.

Overview of the Regulatory Oversight Implemented by the French Regulatory Authorities for the Clinical Investigation of Gene Therapy and Cell Therapy Products.

Advanced therapy medicinal products, a new class of products with promising therapeutic effects, have been classified as medicinal products and as such should be developed according to a well-structured development plan, to establish their quality, safety and efficacy profile and conclude, at the time of the marketing authorisation evaluation, on a positive risk/benefit balance for patients. An important part of this development plan is achieved through clinical trials, which have also to be approved according to a well-established regulatory process, prior any initiation. This chapter is dedicated to describe the regulatory pathway to be followed in France, before initiating any clinical trial with those investigational advanced therapy medicinal products. In France, to get the final authorisation to initiate a clinical trial, the legislation imposes to run in parallel two independent but complementary authorisation procedures. The first procedure is aimed at assessing the ethical aspect of the biomedical research, while the second has to review the safety and regulatory aspects. A third procedure has to be envisaged where in case the investigational product consists or contains a genetically modified organism. The French system herein described is in line with the EU regulation on clinical trial and follows the respective deadlines for granting the final approval. The complexity of the procedure is in fact more due to the complexity of the products and protocols to be assessed than to the procedure itself which is now very close to the well-known procedure applied routinely for more conventional chemical or biological candidate medicinal products.

Risk of tumorigenicity in mesenchymal stromal cell-based therapies--bridging scientific observations and regulatory viewpoints.

In the past decade, the therapeutic value of mesenchymal stromal cells (MSCs) has been studied in various indications, thereby taking advantage of their immunosuppressive properties. Easy procurement from bone marrow, adipose tissue or other sources and conventional in vitro expansion culture have made their clinical use attractive. Bridging the gap between current scientific knowledge and regulatory prospects on the transformation potential and possible tumorigenicity of MSCs, the Cell Products Working Party and the Committee for Advanced Therapies organized a meeting with leading European experts in the field of MSCs. This meeting elucidated the risk of potential tumorigenicity related to MSC-based therapies from two angles: the scientific perspective and the regulatory point of view. The conclusions of this meeting, including the current regulatory thinking on quality, nonclinical and clinical aspects for MSCs, are presented in this review, leading to a clearer way forward for the development of such products.

Arboviral Risk Associated with Solid Organ and Hematopoietic Stem Cell Grafts: The Prophylactic Answers Proposed by the French High Council of Public Health in a National Context.

Diseases caused by arboviruses are on the increase worldwide. In addition to arthropod bites, most arboviruses can be transmitted via accessory routes. Products of human origin (labile blood products, solid organs, hematopoietic stem cells, tissues) present a risk of contamination for the recipient if the donation is made when the donor is viremic. Mainland France and its overseas territories are exposed to a complex array of imported and endemic arboviruses, which differ according to their respective location. This narrative review describes the risks of acquiring certain arboviral diseases from human products, mainly solid organs and hematopoietic stem cells, in the French context. The main risks considered in this study are infections by West Nile virus, dengue virus, and tick-borne encephalitis virus. The ancillary risks represented by Usutu virus infection, chikungunya, and Zika are also addressed more briefly. For each disease, the guidelines issued by the French High Council of Public Health, which is responsible for mitigating the risks associated with products of human origin and for supporting public health policy decisions, are briefly outlined. This review highlights the need for a "One Health" approach and to standardize recommendations at the international level in areas with the same viral epidemiology.