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Background: We conducted a randomized multicenter open-label trial in de novo liver transplant recipients to assess the feasibility and potential benefit of a corticosteroid (CS)-free regimen coupled with tacrolimus (Tac) and dose-intensified mycophenolate mofetil (MMF) further adjusted individually., Methods: Adult liver transplant recipients were randomized on the day of transplantation to a CS-free regimen with Tac and MMF starting at 3 g/d and dose adjusted from day 5 according to mycophenolic acid (MPA) exposure (arm A) or a regimen with CS maintained up to 6 months, Tac and fixed-dose MMF (2 g/d) (arm B). The primary end point was the proportion of patients who experienced treated biopsy-proven acute rejection (BPAR) during the first year posttransplant., Results: One hundred eighty-seven patients were randomized, and 174 comprised the per-protocol population (87 in each arm). The primary objective of noninferiority was met: 7 patients in arm A (8%) and 8 in arm B (9%) experienced treated BPAR in the first year. Two patients in arm A (2%) and 5 in arm B (6%) lost their graft, and 12-month patient survival was similar in both arms (90.8% vs 89.8%; P = 0.86). Adverse events were comparable between arms, except for a lower incidence of de novo diabetes (19.8% vs 32.6%, P = 0.049) and a higher incidence of leukopenia less than 2000/mm (28.6% vs 9.8%; P = 0.001) and neutropenia (26.7% vs 7.9%; P < 0.001) in arm A., Conclusions: Mycophenolate mofetil at intensified and individually adjusted dose in combination with Tac in de novo liver transplant recipients allows CS discontinuation from day 1 posttransplant with good tolerance and very low rejection incidence.

Background: Anti-human leukocyte antigen (HLA) antibody detection in solid-phase flow beads assays can be quenched by complement activation, but the precise mechanism of this interference is not fully elucidated yet., Methods: Using the Luminex flow beads screening assay for detection of anti-HLA antibodies, we analyzed the binding of high concentrations of the pan class I anti-HLA monoclonal antibody W6/32 in neat normal, ethylenediaminetetraacetic acid-treated normal and complement factors C1q, C4/C3, C2, C3, factor B or C5-depleted human sera, using anti-mouse immunoglobulin G as the detection antibody. Complement activation and binding to beads were revealed using anti-human C1q, C4d, and C3d antibodies. To translate our findings to the human setting, we used the class I and class II HLA single-antigen flow beads assays and sera from four patients with high titers of antibodies., Results: Detection of W6/32 did not suffer any interference with C1q and C4/C3-depleted sera. A partial quenching was observed with C2, C3, and factor B-depleted sera, but was more pronounced with the factor B-depleted serum. W6/32 was undetectable in presence of C5-depleted serum. The binding of activation products derived from C3 principally, and also from C4, impaired immunoglobulin G and C1q detection. Accordingly, C4d detection was hindered by deposition of activated C3. Similar findings were obtained with patients' sera., Conclusion: Binding of C4 and C3 activation products is the main responsible for complement interference in flow beads assays. A complete quenching requires complement activation through C3 cleavage and its amplification by the alternative pathway.

Background: Calcineurin inhibitor-induced renal dysfunction is a major problem in liver transplantation. Interleukin-2 receptor antagonist induction followed by delayed tacrolimus (Tac) administration may minimize the renal insult without compromising immunoprotection., Methods: This open, randomized, multicenter trial evaluated the benefit of daclizumab induction with delayed Tac on renal function at 6 months; an observational study was continued for 18 months. Liver transplant patients with a 12-hr serum creatinine (SrC) level less than 180 micromol/L received either delayed Tac with daclizumab induction (n=98) or standard Tac (n=101) both combined with mycophenolate mofetil and steroids. The primary endpoint was the incidence of SrC level more than 130 micrommol/L at 6 months., Results: The incidence was 22.4% with delayed Tac and 29.7% with standard Tac (P=ns), which remained unchanged at 12 months (21.6% and 23.9%) but increasing slightly at 24 months (29.0% and 32.9%), respectively. A post hoc analysis of renal function was done based on patients stratification by SrC at 12 hr (100 micromol/L) showing no difference in SrC values at 6 months regardless of the 12-hr values despite a trend toward better estimated glomerular filtration rate for patients with 12-hr value less than 100 micromol/L in the delayed Tac group. Biopsy-proven acute rejection was similar at 6 months (17.5% and 18.75%), 12 months (23.5% and 23.8%), and 24 months (24.5% and 25.7%), respectively. Patient and graft survival in both groups were comparable and good. Similar types and incidences of adverse events were reported in both groups at all time., Conclusions: Delay of Tac does not benefit renal function in liver transplant recipients with a good renal function at baseline.