Evaluation of Effective Half-Life and Its Impact on Time to Steady State for Oral MeltDose Tacrolimus (LCPT) in De Novo Kidney Transplant Recipients.

BACKGROUND: For extended-release drug formulations, effective half-life (t1/2eff) is a relevant pharmacokinetic parameter to inform dosing strategies and time to reach steady state. Tacrolimus, an immunosuppressant commonly used for the prophylaxis of organ rejection in transplant patients, is available as both immediate- and extended-release formulations. To the best of our knowledge, the t1/2eff of tacrolimus from these different formulations has not yet been assessed. The objective of this study was to characterize the t1/2eff and terminal half-life (t1/2z) of an extended-release once-daily tacrolimus formulation (LCPT) and twice-daily immediate-release tacrolimus (IR-Tac). METHODS: A noncompartmental analysis of pharmacokinetic data obtained from a phase 2 study in de novo kidney transplant recipients receiving either LCPT or IR-Tac was conducted. Intensive blood sampling was performed on days 1, 7, and 14, and tacrolimus whole blood concentrations were measured using a validated liquid chromatography with tandem mass spectrometry method. T1/2eff was estimated using within-participant accumulation ratios. T1/2z was estimated by linear regression of the terminal phase of the concentration versus time profile. RESULTS: The median accumulation ratios of LCPT and IR-Tac on day 14 were 3.18 and 2.06, respectively.The median (interquartile range; IQR) t1/2eff for LCPT at day 14 of dosing was 48.4 (37.4-77.9) hours, whereas the t1/2z was 20.3 (17.6-22.9) hours. For IR-Tac, the median (IQR) t1/2eff and t1/2z on day 14 were 12.5 (8.8-23.0) hours and 12.2 (9.2-15.7) hours, respectively. CONCLUSIONS: Consistent with its prolonged release of tacrolimus, LCPT demonstrated a higher accumulation ratio and a longer t1/2eff compared with IR-Tac. These findings underscore the pharmacokinetic differences between different drug formulations of the same moiety and may help inform dose adjustments for LCPT in kidney transplantation.

Impact of high MELD scores on CMV viremia following liver transplantation.

INTRODUCTION: Advanced liver disease or cirrhosis is associated with an increased risk of infections; however, the impact of high pretransplant model for end-stage liver disease (MELD) score on cytomegalovirus (CMV) viremia after liver transplantation is unknown. METHODS: This single-center, retrospective, cohort study evaluated CMV high-risk (CMV immunoglobulin G D+/R-) liver transplant recipients who received valganciclovir prophylaxis for 3 months between 2009 and 2019. Patients were stratified by pretransplant MELD score of <35 (low MELD) and ≥35 (high MELD). The primary outcome was 12-month CMV viremia, and secondary outcomes included CMV resistance and tissue invasive disease, mortality, biopsy-proven acute rejection (BPAR), leukopenia, and thrombocytopenia. Multivariable Cox proportional-hazards modeling was used to assess the association of MELD score with the time to CMV viremia. RESULTS: There were 162 and 79 patients in the low and high MELD groups, respectively. Pretransplant MELD score ≥35 was associated with an increased risk of CMV viremia (hazard ratio [HR] 1.73; confidence interval 1.06-2.82, p = .03). CMV viremia occurred at 162 ± 61 days in the low MELD group and 139 ± 62 days in the high MELD group. Although BPAR occurred early at 30 days (13-59) in the low-MELD group and at 18 days (11-66) in the high-MELD group (p = .56), BPAR was not associated with an increased risk of CMV viremia (HR 1.55 [0.93-2.60], p = .1). DISCUSSION: MELD scores ≥35 were associated with an increased hazards of CMV viremia. In liver transplant recipients with MELD scores ≥35 who are CMV high-risk, additional CMV intervention may be warranted.

Survival benefit of renal transplantation in octogenarians.

BACKGROUND: Elderly patients are the fastest growing population requiring renal replacement therapy. As previous studies have shown a survival benefit of kidney transplantation compared to dialysis for end-stage renal disease, we sought to evaluate if this survival benefit extends to octogenarians. METHODS: This was a single-center retrospective cohort study of renal allograft recipients ≥80 years transplanted from 1999 to 2014 who were compared to patients listed during the same period that did not proceed to transplantation. A secondary matched group was selected from the UNOS transplant waitlist database. The primary outcome was patient survival. Secondary outcomes included graft survival and rejection incidence. RESULTS: Thirty-three transplanted patients were compared to 71 patients waitlisted at our center and 66 patients from the UNOS database. Patients in the study group were transplanted 20.8 ± 16.1 months after listing. Patient survival was 87.8% at 6 months and 1 year and 71.4% at 3 years. Kidney transplantation was associated with a significant decrease in the risk of death after listing (HR: 0.22, CI: 0.11-0.45, P < .001). CONCLUSION: With escalating life expectancy, kidney transplantation is a suitable treatment option in eligible octogenarians.

A Multidisciplinary Technique for Concurrent Panniculectomy-Living Donor Renal Transplantation.

BACKGROUND: Recently, it has been shown that panniculectomy concurrent to living donor renal transplantation is a safe option for management of renal transplant recipients with a large focal pannus. This combined management requires precise coordination of teams. We describe the technique, timing, and sequence for combined renal transplantation and panniculectomy. METHODS: We conducted a retrospective chart review of adult patients (≥18 years old) who underwent simultaneous living donor renal transplantation-panniculectomy from 2015 to 2019. A multi-team approach that included urology, transplant, and plastic surgery was used to perform the combined operations. Typically, the plastic surgery team initiates the operation by performing the panniculectomy. This is followed by kidney transplantation and graft anastomosis. The plastic surgery team then completes the operation with closure of the wound. RESULTS: Twenty patients were identified. Most were male (12:8) with a mean age of 55 years and an average body mass index of 35 kg/m. The mean total operative duration was 394 minutes. On average, 17% of operating time was devoted to panniculectomy. At 90 days follow-up, there was 100% graft survival and all patients had primary graft function. There was a 25% wound complications rate and a 15% reoperation rate. CONCLUSION: By performing panniculectomy first in the sequence, concurrent panniculectomy provides wide exposure and a large operative field for transplantation. Wound closure by plastic surgeons may mitigate the high complication rate commonly seen in obese patients with end-stage renal disease. Future studies are needed to evaluate the cost-benefit of the combined living donor renal transplantation-panniculectomy.

Panniculectomy at the time of living donor renal transplantation: An 8-year experience.

Panniculectomy can be performed as a prophylactic procedure preceding transplantation to enable obese patients to meet criteria for renal transplantation. No literature exists on combined renal transplant and panniculectomy surgery (LRT-PAN). We describe our 8-year experience performing LRT-PAN. A retrospective chart review of all patients who had undergone LRT-PAN from 2010 to 2018 was conducted. Data were collected on patient demographics, allograft survival and function, and postoperative course. Fifty-eight patients underwent LRT-PAN. All grafts survived, with acceptable function at 1 year. Median length of stay was 4 days with a mean operative duration of 363 minutes. The wound complication rate was 24%. Ninety-day readmission rate was 52%, with medical causes as the most common reason for readmission (45%), followed by wound (32%) and graft-related complications (23%). Body mass index, diabetes status, and previous immunosuppression did not influence wound complication rate or readmission (P = .7720, P = .0818, and P = .4830, respectively). Combining living donor renal transplant and panniculectomy using a multidisciplinary team may improve access to transplantation, particularly for the obese and postobese population. This combined approach yielded shorter-than-expected hospital stays and similar wound complication rates, and thus should be considered for patients in whom transplantation might otherwise be withheld on the basis of obesity.

Clinical outcomes of valganciclovir prophylaxis in high-risk (D+/R-) renal transplant recipients experiencing delayed graft function.

BACKGROUND: Cytomegalovirus (CMV) outcomes with valganciclovir prophylaxis in renal transplant recipients experiencing delayed graft function (DGF) are unclear. METHODS: This single center, retrospective, cohort study of CMV high-risk (D+/R- with alemtuzumab induction) deceased donor renal transplant recipients receiving valganciclovir prophylaxis assessed CMV outcomes in patients experiencing DGF (n = 72) versus those with immediate graft function (IGF; n = 66). RESULTS: Cytomegalovirus viremia by 12 months occurred at similar rates in the IGF and DGF groups (30.3% vs 26.4%, respectively, P = 0.71) with 89.7% (35/39) of all cases classified as CMV disease. The median time to CMV viremia post transplant was day 141 and 138 in the IGF and DGF groups, respectively (P = 0.30). The incidence of biopsy-proven acute rejection (BPAR) was higher in the DGF group (18.1% vs 4.6%, P = 0.02) with BPAR preceding CMV in only 1 patient. There was no significant difference in graft loss (1.5% vs 4.2%, P = 0.62) or patient survival (98.5% vs 95.8%, P = 0.62) at 1 year between the IGF and DGF groups, respectively. CONCLUSION: Valganciclovir prophylaxis in patients experiencing DGF yielded similar CMV outcomes up to 1-year post transplant when compared to use in patients with IGF.

Collaborative practice agreement in solid organ transplantation.

Background Given the complexity of solid organ transplant recipients, a multidisciplinary approach is required. To promote medication safety and enable providers to focus on the medical and surgical needs of these patients, our department of pharmacy created a collaborative practice agreement between physicians and pharmacists. Through this agreement, credentialed pharmacists are empowered to provide inpatient services including initiation and adjustment of medications through independent review of laboratory results after multidisciplinary rounds. Objective To evaluate the effect of our collaborative practice agreement on clinical care and institutional finances. Setting An inpatient setting at a large academic medical center. Methods Three transplant pharmacists entered all clinical interventions made on abdominal transplant recipients between September and October 2013 into Quantifi®, a software application that categorizes and assigns a cost savings value based on impact and type of intervention. Main outcome measure The main outcome measures in this study were number and categorization of interventions, as well as estimated cost savings to the institution. Results There were 1060 interventions recorded, an average of 20 interventions per pharmacist per day. The most common interventions were pharmacokinetic evaluations (36%) and dose adjustments (19%). Over the time period, these interventions translated into an estimated savings of $107,634.00, or an annual cost savings of $373,131.20 per pharmacist, or a cost-benefit ratio of 2.65 to the institution. Conclusions Based on our study, implementation of a collaborative practice agreement enables credentialed pharmacists to make clinically and financially meaningful interventions in a complex patient population.