Browsing by Author "Abbal, Michel"

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Effects of Intraoperative versus Postoperative Administration of Rabbit Antithymocyte Antibodies on 1-Year Renal Function in Renal Transplant Patie
(Başkent Üniversitesi, 2006-06) Kamar, Nassim; Esposito, Laure; Ribes, David; Tkaczuk, Jean; Cointault, Olivier; Lavayssiere, Laurence; Abbal, Michel; Durand, Dominique; Rostaing, Lionel
Objectives: The aim of our study was to prospectively assess 1-year allograft outcomes and the evolution of lymphocyte subsets in a group of renal transplant patients who had received intraoperative rabbit antithymocyte antibodies (RATG). Materials and Methods: We compared 1-year allograft transplant outcomes in renal transplant recipients who had received intraoperative RATG (group 1, n = 53) with the outcomes observed in patients in a historical control group who had received postoperative RATG (group 2, n = 49). RATG were given at the same dosage (1 mg/kg) during the first 3 days, and then the dosage was adapted according to CD2 count, until calcineurin inhibitors were started. Results: The overall dosage of RATG administered was significantly lower in group 1. At day 4, CD2, CD3, and CD19 T-cell subset counts were significantly higher in patients in group 1. From 3 months after transplantation, CD4/CD8 ratios were significantly lower in patients in group 1 because of a rapid regeneration of CD8 T cells. One-year total lymphocyte counts were significantly higher in patients in group 1. There were fewer severe infectious complications in patients in group 1. One-year renal function was better in patients in group 2. Donor age was the only independent factor associated with renal function at both 1 month and 1 year after transplantation. Conclusions: When RATG are infused intraoperatively, a lower total amount of RATG is required to prevent acute rejection as compared with postoperative RATG infusion. Consequently, fewer serious lymphopenia-associated complications are observed during the first year after transplantation
Impact of Rituximab Therapy on Response to Tetanus Toxoid Vaccination in Kidney-Transplant Patients
(Başkent Üniversitesi, 2010-03) Puissant-Lubrano, Benedicte; Blancher, Antoine; Fort, Marylise; Abbal, Michel; Kamar, Nassim; Rostaing, Lionel
Objectives: Rituximab is used after kidney transplant to prevention or treat kidney-allograft rejection. However, the impact of rituximab on the ability of patients to respond to tetanus toxoid vaccination has not yet been studied. Materials and Methods: The response to tetanus toxoid vaccination was analyzed in 39 kidney-transplant recipients immunosuppressed by corticoids, antiproliferative agents, and/or calcineurin inhibitors. Thirteen patients had previously received rituximab (group 1), 26 patients had not (group 2). Response to control bacterial antigens and immunologic parameters (lymphocyte count, B-cell subsets, serum immunoglobulin level) were analyzed before and at 1 month after vaccination. Thirty healthy blood donors were used as controls for the before-vaccination immunologic parameters. Results: Before vaccination, neither patient group differed from controls in serum levels of immunoglobulins and antibodies against bacterial antigens, but they did display lower levels of CD4 T cells and B cells compared with controls. Responders to the tetanus toxoid vaccination were slightly fewer in group 1 (4/13) than in group 2 (16/26), but the intensity of the anti-tetanus toxoid response was not significantly different between these 2 groups. None of the parameters studied at the time of vaccination (anti-tetanus toxoid level, peripheral B or CD4 T-cell count, memory B-cell subsets, treatment with rituximab, time since transplant) were associated with an ability to respond to vaccination. The ability to respond to vaccination and graft outcomes were not correlated in each patient group. Conclusions: Rituximab impaired the secondary immune response after tetanus toxoid vaccination, but did not abolish it in all patients.