FoxP3 mRNA transcripts and regulatory cells in renal transplant recipients 10 years after donor marrow infusion.

BACKGROUND: We update more favorable 10-year deceased donor kidney transplant survival in 63 recipients infused perioperatively with donor vertebral body bone marrow (DBMC-i) vs. 219 noninfused controls having equivalent immunosuppression and demographics. We questioned if this was associated with putatively regulatory FoxP3 mRNA and cell phenotypes (CD4+CD25+high percentages and high DC2:DC1 ratios) in DBMC-i vs. noninfused controls. METHODS: Baseline studies were performed on peripheral blood lymphocytes (PBLs) vs. marrow in normal laboratory volunteers of CD4+CD25+high percentages and DC2:DC1 by flow cytometry, and FoxP3 mRNA in CD3+ cells by real-time polymerase chain reaction. Similar studies were performed on PBL of the majority of the 10-year patients remaining with graft function: 21 (of the remaining 37) DBMC-i vs. 55 (of the remaining 105) controls. RESULTS: In normal subjects, all parameters were significantly higher in marrow than in PBL, supporting our previous reports of ex vivo DBMC immunoregulation. At 9.8+/-.02 years posttransplant in DBMC-i vs. controls, death-censored percent graft failure was 17.5% vs. 32.9% (P=0.02) with 247.6+/-24 vs. 79.9+/-3.1 (mean+/-SE) FoxP3 copies/5,000 CD3+ cells (P=0.0001). PBL CD4+CD25+high percentages were lower, but DC2:DC1 values higher in both recipient groups than in end-stage renal disease patients who had lower FoxP3 levels (40.8+/-5.9, P<0.0001), consistent with non-CD4+CD25+high T regulatory cells generated long-term posttransplant. Individual higher FoxP3 values correlated with higher iliac crest chimerism in DBMC-i, but not in controls (with 50-fold lower chimerism). In chronically rejecting controls, FoxP3 was further decreased. CONCLUSIONS: Peritransplant DBMC-i has higher 10-year renal transplant acceptance, chimerism, and FoxP3 mRNA in thus-far unclarified regulatory cell phenotypes.

A randomized trial of three renal transplant induction antibodies: early comparison of tacrolimus, mycophenolate mofetil, and steroid dosing, and newer immune-monitoring.

BACKGROUND: New trends in immunosuppression in clinical transplantation include the use of antibody induction agents in protocols that emphasize reduction or avoidance of steroids and calcineurin inhibitors. METHODS: In a randomized trial using three different antibody induction agents in 90 first renal transplant recipients from cadaver donors, group A received Thymoglobulin, group B received Alemtuzumab, and group C received Daclizumab. Maintenance immunosuppression included tacrolimus and mycophenolate in all three arms, and methylprednisolone in groups A and C only (standard clinical institutional practice). The targeted trough level of tacrolimus was between 8 and 10 ng/mL for groups A and C, respectively, with a targeted mycophenolate dose of 1 g twice daily. However, in group B, the target tacrolimus trough level was 4 to 7 ng/mL to reduce long-term nephrotoxicity, with 500 mg twice-daily doses of mycophenolate, without steroid maintenance. RESULTS: In this 15-month median postoperative interval report, there were no notable differences in demographics and patient and graft survivals. Acute rejection rates at 1 year were equivalent, that is, 5 of 30 in all three groups (16.6%). In group B, there was slightly lower renal function at 1 month, but no difference at 1 year. There was also significantly more leukopenia, but a greater percentage of T-regulatory cells and number of Fox-P3 mRNA copies by flow cytometry and semiquantitative polymerase chain reaction analysis, respectively, in group B. CONCLUSIONS: This preliminary analysis indicates that 80% of the patients in group B remained steroid-free 1 year postoperatively, with lower tacrolimus trough levels and no difference in other adverse events.

Cytomegalovirus prophylaxis with valganciclovir in kidney, pancreas-kidney, and pancreas transplantation.

Cytomegalovirus, seen in more than 50% of solid organ transplant recipients, is responsible for numerous direct and indirect consequences, including infection with opportunistic pathogens and allograft rejection. Prophylaxis with intravenous ganciclovir has been the gold standard for prevention; however, intravenous treatment is expensive and carries risks of its own. Oral ganciclovir, to be effective, must be given in large, divided doses. Valganciclovir, the valine ester of ganciclovir, at 900 mg/day, provides oral bioavailability equivalent to that of intravenous ganciclovir and superior to that of oral ganciclovir. This retrospective study assessed the efficacy of 3 months prophylaxis with valganciclovir in kidney, simultaneous pancreas-kidney, and pancreas transplantation. Of 161 patients, all of whom received potent immunosuppressive regimens and were followed for a mean of 440 days, only one developed cytomegalovirus infection, at 120 days post-transplantation. Two patients died, and two others lost their grafts. There were seven incidents of acute rejection. Only seven patients discontinued treatment early, five because of leukopenia. These results suggest that prophylaxis with 900 mg/day of valganciclovir for at least 3 months safely and effectively prevents cytomegalovirus infection in kidney, simultaneous pancreas-kidney and pancreas transplant recipients on highly potent immunosuppression.

Adenovirus infection in pediatric liver and intestinal transplant recipients: utility of DNA detection by PCR.

To evaluate the incidence of adenovirus (AdV) infection in pediatric liver and intestinal transplant recipients, the records of patients with possible AdV infection were reviewed for demographic data, symptomatology, methods of diagnosis, treatment and outcome. To evaluate the impact of polymerase chain reaction (PCR) amplification and identification of AdV DNA as a diagnostic test, the incidence and outcome of AdV before and after the introduction of PCR were compared. Adenovirus infection was identified in 4.1% of liver recipients and 20.8% of intestinal transplant recipients. The overall incidence of AdV did not increase over time, even following the introduction of PCR for virus detection. The higher incidence of AdV in the pediatric intestinal transplant recipients may be attributed to the frequent application of PCR methodology to intestinal biopsy material. Detection of AdV by PCR was associated with reduced mortality compared with detection by culture, either because of earlier detection of invasive disease or because PCR detects the presence of latent as well as active AdV.

Successful treatment of posttransplant lymphoproliferative disease with prolonged rituximab treatment in intestinal transplant recipients.

BACKGROUND: Posttransplant Epstein-Barr virus-associated B-cell lymphoproliferative disease (PTLD) has a higher incidence after intestinal transplantation than after transplantation of other solid organs and is associated with a high mortality. A new anti-CD20 monoclonal antibody, rituximab, has shown efficiency in the treatment of B-cell lymphoma, including PTLD, but its use has not yet been reported in intestinal transplant recipients. METHODS: We retrospectively reviewed five patients who were diagnosed with PTLD from March 1999 to August 2001, after intestinal transplantation. These patients were primarily managed with rituximab, associated with reduction or interruption of immunosuppression and antiviral therapy with ganciclovir and cytomegalovirus immune globulin. Rituximab was administered at weekly doses of 375 mg/m until full remission was ascertained, and the interval between doses was then increased. No patient received chemotherapy. RESULTS: One patient had nonmalignant lymphoproliferation, and four had malignant PTLD, as assessed by histopathology and monoclonality of the tumor. Two pediatric patients had severe generalized disease. All patients had received OKT3 as treatment of rejection before developing PTLD. All tumors showed proliferation of CD20 cells and were positive for Epstein-Barr virus by in situ hybridization. All patients responded to rituximab therapy and have achieved full remission with a follow-up of 3 to 30 (median, 8) months. CONCLUSION: Prolonged rituximab treatment, in association with reduction of immunosuppression and antiviral therapy, is highly efficient as part of the first-line treatment of CD20 B-cell PTLD after intestinal transplantation.