Assessment of neuropsychological impairments in regular cannabis users

BackgroundCannabis is the most widely used illicit drug in the world. It is responsible for cognitive dysfunction of memory, speed of information processing, attention, and executive functions. Cognitive performance depends on the level of study, tolerance, and duration of abstinence from cannabis use. This study analyses cognitive function in a large population of regular cannabis consumers taking into account level of education.MethodsA battery of neuropsychological tests using the Cambridge Neuropsychological Test Automated Battery was performed on a population of 58 cannabis users categorized into two groups according to their level of education with a threshold of 12 years of study, and 25 non-users.ResultsIn Attention Switching Task percent correct trials, significant differences were found between the group of cannabis smokers with less than 12 years of study and the non-smoker group (P = 0.022), and between the cannabis users with more than 12 years of study and the non-smoker group (P = 0.008). A significantly lower performance in the Rapid Visual Information Processing (Mean latency, Probability of hit, Total hits, Total misses, Correct rejections) was found in the cannabis users with less than 12 years of study compared with the non-user group.ConclusionIn our population, chronic cannabis users presented divided and sustained attention and working memory disorders. Rapid Visual Information Processing performance may be influenced by education level in cannabis smokers.     

New immunosuppressive agents in transplantation

Immunosuppressive agents have enabled the development of allogenic transplantation during the last 40 years, allowing considerable improvement in graft survival. However, several issues remain such as the nephrotoxicity of calcineurin inhibitors, the cornerstone of immunosuppressive regimens and/or the higher risk of opportunistic infections and cancers. Most immunosuppressive agents target T cell activation and may not be efficient enough to prevent allo-immunization in the long term. Finally, antibody mediated rejection due to donor specific antibodies strongly affects allograft survival.Many drugs have been tested in the last decades, but very few have come to clinical use. The most recent one is CTLA4-Ig (belatacept), a costimulation blockade molecule that targets the second signal of T cell activation and is associated with a better long term kidney function than calcineurin inhibitors, despite an increased risk of acute cellular rejection.The research of new maintenance long-term immunosuppressive agents focuses on costimulation blockade. Agents inhibiting CD40-CD40 ligand interaction may enable a good control of both T cells and B cells responses. Anti-CD28 antibodies may promote regulatory T cells. Agents targeting this costimulation pathways are currently evaluated in clinical trials.Immunosuppressive agents for ABMR treatment are scarce since anti-CD20 agent rituximab and proteasome inhibitor bortezomib have failed to demonstrate an interest in ABMR. New drugs focusing on antibodies removal (imlifidase), B cell and plasmablasts (anti-IL-6/IL-6R, anti-CD38…) and complement inhibition are in the pipeline, with the challenge of their evaluation in such a heterogeneous pathology.