Wednesday, December 28, 2011

Association of Immunosuppressive Maintenance Regimens With Posttransplant Lymphoproliferative Disorder in Kidney Transplant Recipients

Association of Immunosuppressive Maintenance Regimens With Posttransplant Lymphoproliferative Disorder in Kidney Transplant Recipients: Background. The association of immunosuppressive regimens (ISRs) with posttransplant lymphoproliferative disorder (PTLD) may be related with the Epstein-Barr virus (EBV) recipient serostatus.
Methods. We selected primary kidney transplant recipients from Organ Procurement Transplant Network/United Network for Organ Sharing database (2000–2009) who were discharged with a functioning graft and were receiving an ISR including an antiproliferative drug and a calcineurin inhibitor as follows: mycophenolate mofetil (MMF)/mycophenolate sodium+tacrolimus (TAC), MMF+cyclosporine A (CsA); mammalian target of rapamycin inhibitor (mTORi)+TAC; and mTORi+CsA. Adjusted risks of PTLD, rejection, death, and graft failure were examined in all recipients and compared between EBV+ and EBV− recipients.

Impact of Early Conversion From Tacrolimus to Sirolimus on Chronic Allograft Changes in Kidney Recipients on Rapid Steroid Withdrawal

Impact of Early Conversion From Tacrolimus to Sirolimus on Chronic Allograft Changes in Kidney Recipients on Rapid Steroid Withdrawal: Background. Calcineurin-inhibitor therapy is a contributing factor to the origin of interstitial fibrosis and tubular atrophy (IFTA).
Methods. We conducted a prospective randomized trial of conversion of tacrolimus to sirolimus at 1-month posttransplant in kidney transplant recipients on rapid steroid withdrawal. We compared the chronic changes (IFTA and sum of Banff chronic scores—Total Score) on protocol biopsies at 1 month, 1 year, and 2 years in all randomized patients. We compared the outcomes between treatment groups and analyzed the impact of previous rejection on the chronic changes.

Early Subclinical Rejection as a Risk Factor for Late Chronic Humoral Rejection

Early Subclinical Rejection as a Risk Factor for Late Chronic Humoral Rejection: Background. Subclinical rejection and interstitial fibrosis and tubular atrophy (IF/TA) in protocol biopsies are associated with outcome. We study the relationship between histologic lesions in early protocol biopsies and histologic diagnoses in late biopsies for cause.
Materials and Methods. Renal transplants with a protocol biopsy performed within the first 6 months posttransplant between 1988 and 2006 were reviewed. Biopsies were evaluated according to Banff criteria, and C4d staining was available in biopsies for cause.
Results. Of the 517 renal transplants with a protocol biopsy, 109 had a subsequent biopsy for cause which showed the following histological diagnoses: chronic humoral rejection (CHR) (n=44), IF/TA (n=42), recurrence of the primary disease (n=11), de novo glomerulonephritis (n=7), T-cell-mediated rejection (n=4), and polyoma virus nephropathy (n=1). The proportion of retransplants (15.9% vs. 2.3%, P=0.058) and the prevalence of subclinical rejection were higher in patients with CHR than in patients with IF/TA (52.3% vs. 28.6%, P=0.0253). Demographic donor and recipient characteristics and clinical data at the time of protocol biopsy were not different between groups. Logistic regression analysis showed that subclinical rejection (relative risk, 2.52; 95% confidence interval, 1.1–6.3; P=0.047) but not retransplantation (relative risk, 6.7; 95% confidence interval, 0.8–58.8; P=0.085) was associated with CHR.
Conclusion. Subclinical rejection in early protocol biopsies is associated with late appearance of CHR.

Monday, December 26, 2011

Reduced Fracture Risk With Early Corticosteroid Withdrawal After Kidney Transplant

Reduced Fracture Risk With Early Corticosteroid Withdrawal After Kidney Transplant:
Corticosteroid use after kidney transplantation results in severe bone loss and high fracture risk. Although corticosteroid withdrawal in the early posttransplant period has been associated with bone mass preservation, there are no published data regarding corticosteroid withdrawal and risk of fracture. We hypothesized lower fracture incidence in patients discharged from the hospital without than with corticosteroids after transplantation. From the United States Renal Data System (USRDS), 77 430 patients were identified who received their first kidney transplant from 2000 to 2006. Fracture incidence leading to hospitalization was determined from 2000 to 2007; discharge immunosuppression was determined from United Networks for Organ Sharing forms. Time-to-event analyses were used to evaluate fracture risk. Median (interquartile range) follow-up was 1448 (808–2061) days. There were 2395 fractures during follow-up; fracture incidence rates were 0.008 and 0.0058 per patient-year for recipients discharged with and without corticosteroid, respectively. Corticosteroid withdrawal was associated with a 31% fracture risk reduction (HR 0.69; 95% CI 0.59–0.81). Fractures associated with hospitalization are significantly lower with regimens that withdraw corticosteroid. As this study likely underestimates overall fracture incidence, prospective studies are needed to determine differences in overall fracture risk in patients managed with and without corticosteroids after kidney transplantation.

Valganciclovir Prophylaxis Versus Preemptive Therapy in Cytomegalovirus-Positive Renal Allograft Recipients: 1-Year Results of a Randomized Clinical Trial

Valganciclovir Prophylaxis Versus Preemptive Therapy in Cytomegalovirus-Positive Renal Allograft Recipients: 1-Year Results of a Randomized Clinical Trial: Background. Cytomegalovirus (CMV) prevention can be achieved by prophylaxis or preemptive therapy. We performed a prospective randomized trial to determine whether renal transplant recipients with a positive CMV serostatus (R+) had a higher rate of CMV infection and disease after transplantation when treated preemptively for CMV infection, compared with primary valganciclovir prophylaxis.
Methods. Prophylaxis was 2×450 mg oral valganciclovir/day for 100 days; preemptive patients were monitored by CMV-polymerase chain reaction (PCR), and after a positive PCR test received 2×900 mg valganciclovir/day for at least 14 days followed by secondary prophylaxis. Valganciclovir dosage was adjusted according to renal function. Patients are followed up for 5 years and initial 12-month data are presented. Two hundred and ninety-six recipients were analyzed (168 donor/recipient seropositive [D+/R+], 128 donor seronegative/recipient seropositive [D−/R+]; 146 receiving prophylaxis and 150 preemptive therapy).
Results. Overall, CMV infection (asymptomatic CMV viral load ≥400 CMV DNA copies/mL proven by CMV-PCR) was significantly higher in recipients under preemptive therapy (38.7% vs. 11.0%, P<0.0001), with the highest incidence in D+/R+ preemptive patients (53.8% vs. 15.6%, P<0.0001). D+/R+ recipients with preemptive therapy also had the highest rate of CMV disease (CMV syndrome and tissue-invasive disease that was clinically diagnosed and biopsy proven) (19.2% vs. 4.4%, P=0.003). Renal function assessed by creatinine clearance was similar for both groups. Graft loss occurred in 7 vs. 4 patients on preemptive versus prophylactic therapy (P>0.05). Tolerability was similar for both treatment groups.
Conclusions. Oral valganciclovir prophylaxis significantly reduces CMV infection and disease, particularly for D+/R+ patients. Hence, our study supports routine prophylaxis for all D+/R+ recipients.