Dialysis patients are both the most likely to benefit from vaccine protection against SARS-CoV-2 and at the highest risk of not developing an immune response. Data from the medical field are thus mandatory. We report our experience with a BNT162b2-mRNA vaccine in a retrospective analysis of 241 dialysis patients including 193 who underwent anti-Spike-Protein-Receptor-Binding-Domain (RBD) IgG analysis. We show that a pro-active vaccine campaign is effective in convincing most patients to be vaccinated (95%) and frequently elicits a specific antibody response (94.3% after two doses and 98.4% after three doses). Only immunocompromised Status is associated with lack of seroconversion (OR 7.6 [1.5-38.2], p = 0.02). We also identify factors associated with low response (last quartile; IgG<500AU/mL): immunocompromised status, age, absence of RAAS inhibitors, low lymphocytes count, high C Reactive Protein; and with high response (high quartile; IgG>7000AU/mL): age; previous SARS-CoV-2 infection and active Cancer. From this experience, we propose a strategy integrating anti-spike IgG monitoring to guide revaccination and dialysis center management in pandemic times.

BACKGROUND The development of an artificial glomerular unit may be pivotal for renal pathophysiology studies at a multicellular scale. Using a tissue engineering approach, we aimed to reproduce in part the specific glomerular barrier architecture by manufacturing a glomerular microfibre (Mf). METHODS Immortalized human glomerular cell lines of endothelial cells (GEnCs) and podocytes were used. Cells and a three-dimensional (3D) matrix were characterized by immunofluorescence with confocal analysis, Western blot and polymerase chain reaction. Optical and electron microscopy were used to study Mf and cell shapes. We also analysed cell viability and cell metabolism within the 3D construct at 14 days. RESULTS Using the Mf manufacturing method, we repeatedly obtained a cellularized Mf sorting human glomerular cells in 3D. Around a central structure made of collagen I, we obtained an internal layer composed of GEnC, a newly formed glomerular basement membrane rich in α5 collagen IV and an external layer of podocytes. The cell concentration, optimal seeding time and role of physical stresses were modulated to obtain the Mf. Cell viability and expression of specific proteins (nephrin, synaptopodin, vascular endothelial growth factor receptor 2 (VEGFR2) and von Willebrandt factor (vWF)) were maintained for 19 days in the Mf system. Mf ultrastructure, observed with EM, had similarities with the human glomerular barrier. CONCLUSION In summary, with our 3D bio-engineered glomerular fibre, GEnC and podocytes produced a glomerular basement membrane. In the future, this glomerular Mf will allow us to study cell interactions in a 3D system and increase our knowledge of glomerular pathophysiology.

Introduction : l’epidemiologie de la maladie renale chez les patients infectes par le virus de l’immunodeficience humaine (VIH) a ete modifiee par l’arrivee des traitements antiretroviraux hautement actifs (TAHA). L’objectif de notre etude est de decrire l’epidemiologie de la maladie renale puis de degager les facteurs de mauvais pronostic dans la population bordelaise de patients infectes par le VIH. Patients et methode : nous avons mene une etude retrospective monocentrique descriptive de cohorte. Tous les patients porteurs du VIH suivis dans le service de nephrologie au centre hospitalo-universitaire de Bordeaux entre 2007 et 2014 ont ete inclus dans l’etude. Les patients ont ete classes en 4 groupes en fonction de leur nephropathie. Resultats : 204 patients ont ete inclus, 47 dans le groupe “ glomerulopathie isolee ”, 102 dans le groupe “ tubulopathie isolee ”, 20 dans le groupe “ atteinte mixte ” et 35 dans le groupe “ absence de nephropathie organique ”. La nephropathie associee au VIH (HIVAN) et la nephropathie a complexe immun (HIVICD) ne representaient que 11,9 % des diagnostics. Les atteintes tubulaires etaient principalement representees par le syndrome de Fanconi (55,7 %). En analyse univariee, les patients atteints de glomerulopathie avaient un moins bon pronostic renal et vital par rapport au groupe “ absence de nephropathie ” (HR = 2,36 ; IC95 = 1,04-5,37) apres 45 mois de suivi median. Cette difference n’etait plus significative en analyse multivariee. Les facteurs de mauvais pronostic etaient l’âge (HR : 1,06 par annee supplementaire ; IC95 1.01 – 1.11 ; p=0.009) et la proteinurie (HR : 1.41 par gramme de proteinurie supplementaire ; IC95 : 1.08 – 1.85 ; p=0.01). Conclusion : nous avons decrit l’epidemiologie de la maladie renale dans une cohorte de patients infectes par le VIH et suivis en nephrologie. Hormis les atteintes tubulaires iatrogenes, l’epidemiologie de la maladie renale est proche de celle de la population generale.