Impact of COVID-19 on 2020 transplant activity and waiting lists in France✰,✰✰.

The COVID-19 pandemic strongly affected organ procurement and transplantation in France, despite the intense efforts of all participants in this domain. In 2020, the identification and procurement of deceased donors fell by 12% and 21% respectively, compared with the mean of the preceding 2 years. Similarly, the number of new registrations on the national waiting list declined by 12% and the number of transplants by 24%. The 3-month cumulative incidence of death or drop out for worsening condition of patients awaiting a liver transplant was significantly greater in 2020 compared to the previous 2 years. Continuous monitoring at the national level of early post-transplant outcomes showed no deterioration for any organ in 2020. At the end of 2020, less than 1% of transplant candidates and less than 1% of graft recipients - of any organ - had died of COVID-19.

[Evolution of the access to the kidney transplantation in France of foreign patients and French patients living in overseas territories]. / Évolution de l'accès à la greffe rénale en France des patients étrangers ou résidant outre-mer.

In France, foreign patients, whether resident or not in France, can register on the national waiting list under administrative and financial conditions. We performed a retrospective analysis to evaluate the access to kidney transplantation on a cohort 2004-2008, using the national registry. Among the 14,732 patients registered during this period, 15.3% are of non-French nationality (3.4% other European, 5.9% North African, 3.9% sub-Saharan African, 2.9% other). Among the 84.6% of French nationality, 3.3% are living in French overseas territories. Compared to the 17.6-month median waiting time of the cohort, median waiting time differs significantly between groups, from 15.7 months for mainland French patients to 36 months for sub-Saharan African patients. Despite the regular development of the allocation rules, these disparities in access to transplantation are mainly, but not completely, explained by blood group or HLA matching difficulties. After adjustment for the other factors known to be significantly linked to a difficult access to transplantation, North and sub-Saharan African patients have the worst difficulties. Future research should consider nonmedical factors, such as socio-economic or socio-cultural factors, potentially relevant to avoid disparities in access to transplantation and should aim at developing specific interventions.

[The role of the French Agence de la biomédecine in lung transplantation]. / Le rôle de l'Agence de la biomédecine dans la greffe pulmonaire.

The Agence de la biomédecine is a public institution in charge of organs tissues cells transplantation, reproduction, embryology and genetics. It interacts with the hospital coordinators and the transplant teams and ensure the regulation of organ retrieval and allocation. Its strategic missions are the revision of the graft allocation rules and the optimization of transplant organization. These last years, after redefining the graft selection criteria, the activity of lung transplantation increased drastically. The lung procurement efficacy must be still improved, while various machines of perfusion are going to be available. In July 2007, a national priority status for the patients with a life-threatening condition in the very short-term was put in place. The use of a graft allocation score taking into account the urgency and the individual benefit from transplantation is in evaluation. The optimization of the patient access to the waiting list needs a network approach of the end-stage lung diseases.

[Distribution of chromosome breakage point induced by arabinosylcytosine on in-vitro human lymphocytes]. / Distribution des points de cassure chromosomique induits par l'arabinosyl cytosine sur des lymphocytes humains in vitro

The cytogenetic effects of arabinosyl cytosine on human leukocytes in vitro has been studied using continuous and discontinuous treatments. Optimum activity occurs at the end of the S period. Interchromosomal distribution of breaks is non-random. The hypothesis of a very late replication for some chromatid segments is discussed. The relations between banding and the position of breaks are discussed.

[Effect of mitomycin C on the structure of human chromosomes observed in metaphase after labelling by moderate thermal denaturation]. / Effets de la mitomycine C sur la structure des chromosomes humains obwervés en métaphase aprés marquage par dénaturation thermique ménagée

Mitomycin C induced chromosome rearrangements were analysed in cultured human leukocytes by reverse banding technique. Breaks and chromosomal exchanges involved preferentialy the entromeric region of some chromosomes (1, 5, 9, 16, and 20). Associations between acrocentric chromosomes was not found to be increased. But acrocentric associations with centromeric regions were frequently present. The differences between the mechanism of exchanges and breaks are discussed. The part of heterochromatin in post replication DNA repair is considered.