Abhi Humar

2,500 living donor kidney transplants: A single-center experience

ObjectiveTo review a single center’s experience and outcome with living donor transplants. Summary Background DataOutcome after living donor transplants is better than after cadaver donor transplants. Since the inception of the authors’ program, they have performed 2,540 living donor transplants. For the most recent cohort of recipients, improvements in patient care and immunosuppressive protocols have improved outcome. In this review, the authors analyzed outcome in relation to protocol. MethodsThe authors studied patient and graft survival by decade. For those transplanted in the 1990s, the impact of immunosuppressive protocol, donor source, diabetes, and preemptive transplantation was analyzed. The incidence of rejection, posttransplant steroid-related complications, and return to work was determined. Finally, multivariate analysis was used to study risk factors for worse 1-year graft survival and, for those with graft function at 1 year, to study risk factors for worse long-term survival. ResultsFor each decade since 1960, outcome has improved after living donor transplants. Compared with patients transplanted in the 1960s, those transplanted in the 1990s have better 8-year actuarial patient and graft survival rates. Death with function and chronic rejection have continued to be a major cause of graft loss, whereas acute rejection has become a rare cause of graft loss. Cardiovascular deaths have become a more predominant cause of patient death; infection has decreased. Donor source (e.g., ideally HLA-identical sibling) continues to be important. For living donor transplants, rejection and graft survival rates are related to donor source. The authors show that patients who had preemptive transplants or less than 1 year of dialysis have better 5-year graft survival and more frequently return to full-time employment. Readmission and complications remain problems; of patients transplanted in the 1990s, only 36% never required readmission. Similarly, steroid-related complications remain common. The authors’ multivariate analysis shows that the major risk factor for worse 1-year graft survival was delayed graft function. For recipients with 1-year graft survival, risk factors for worse long-term outcome were pretransplant smoking, pretransplant peripheral vascular disease, pretransplant dialysis for more than 1 year, one or more acute rejection episodes, and donor age older than 55. ConclusionsThese data show that the outcome of living donor transplants has continued to improve. However, for living donors, donor source affects outcome. The authors also identify other major risk factors affecting both short- and long-term outcome.

Zygomycosis in Solid Organ Transplant Recipients: A Prospective, Matched Case-Control Study to Assess Risks for Disease and Outcome

BACKGROUND Clinical characteristics, risks, and outcomes in solid organ transplant (SOT) recipients with zygomycosis in the era of modern immunosuppressive and newer antifungal agent use have not been defined. METHODS In a matched case-controlled study, SOT recipients with zygomycosis were prospectively studied. The primary outcome measure was success (complete or partial response) at 90 days. RESULTS Renal failure (odds ratio [OR], 3.17; P = .010), diabetes mellitus (OR, 8.11; P < .001), and prior voriconazole and/or caspofungin use (OR, 4.41; P = .033) were associated with a higher risk of zygomycosis, whereas tacrolimus (OR, 0.23; P = .002) was associated with a lower risk of zygomycosis. Liver transplant recipients were more likely to have disseminated disease (OR, 5.48; P = .021) and developed zygomycosis earlier after transplantation than did other SOT recipients (median, 0.8 vs 5.7 months; P < .001). Overall the treatment success rate was 60%. Renal failure (OR, 11.3; P = .023) and disseminated disease (OR, 14.6; P = .027) were independently predictive of treatment failure, whereas surgical resection was associated with treatment success (OR, 33.3; P = .003). The success rate with liposomal amphotericin B was 4-fold higher even when controlling for the aforementioned variables. CONCLUSIONS The risks identified for zygomycosis and for disseminated disease, including those that were previously unrecognized, have implications for further elucidating the biologic basis and for optimizing outcomes in SOT recipients with zygomycosis.

Living liver donor surgery: Report of initial anesthesia experience

Abstract The charts and anesthetic records of 12 patients who donated the left lateral segment of their liver to a related infant or child to treat liver failure were retrospectively reviewed. Blood loss, need for transfusion, fluids administered, surgical length, and perioperative complications were investigated. The records also were examined to determine the hemodynamic stability of patients undergoing donor hepatectomy to assess their need for invasive monitoring. There were no episodes of hypotension or hemodynamic instability. The average operating time was 9.6 ± 1.1 hours. The blood loss was 562 ± 244 mL (range 300 to 1100 mL). Four patients received their own cell saver blood (200 mL, 220 mL, 300 mL, 475 mL), and one patient received 1 U (350 mL) of predonated autologous blood. The average hemoglobin decreased significantly (p = 0.001) from a preoperative value of 14.1 ± 1.2 to 12.3 ± 1.8 g/dL in the recovery room. All patients were extubated in the operating room or recovery room. Patients were discharged home in 6.9 ± 1.3 days (range 5 to 9 days). Living-related liver resection can be performed with noninvasive monitoring and without the need for heterologous blood products.

One Thousand Consecutive Primary Liver Transplants Under Tacrolimus Immunosuppression: A 17- to 20-Year Longitudinal Follow-Up

Background. Tacrolimus has proven to be a potent immunosuppressive agent in orthotopic liver transplantation (OLT). The aim of this study is to examine its long-term efficacy and safety. Methods and Results. One thousand consecutive primary OLTs performed between August 1989 and December 1992 and maintained under tacrolimus-based immunosuppression were followed up until January 2009. Patient and graft survivals with corresponding causes of death and retransplantation, maintenance immunosuppression, and adverse effects were examined. The study population includes 600 males and 400 females comprising 166 children, 630 adults, and 204 seniors. The mean follow-up was 17.83 (range, 16.1–19.50) years. The overall 20-year actuarial patient and graft survivals were 35.8% and 32.6%, respectively. At the last follow-up, 442 patients were alive; 133 (77.1%) children, 265 (34.5%) adults, and 44 (16.1%) seniors (P=0.0001). After the first post-OLT year, cardiopulmonary events, recurrence of primary disease, and malignancy were the main causes of death. Overall, 183 recipients underwent retransplants; mainly for primary nonfunction, hepatic artery thrombosis, and recurrent primary disease, 180 required dialysis, and 45 underwent kidney transplant. A total of 97.7% of the survivors were on tacrolimus and 26.2% were also receiving adjunctive immunosuppressants at the last follow-up. Conclusions. The overall 20-year actuarial patient and graft survivals were 35.8% and 32.6%, respectively, with significantly better survival among children. Age-related complications, recurrence of primary disease, and malignancy were the major causes of late graft loss. Graft loss related to immunologic reasons was rare. The prevention of recurrent disease and newer immunosuppressive regimen will further improve these results.

Regulatory Dendritic Cell (DCreg) Cell Infusion in Living Donor Liver Transplantation

Background Based on strong preclinical data showing that regulatory dendritic cells (DCreg) of donor origin can promote long-term graft survival in rodents and suppress allograft rejection in non-human primates, we have embarked on a first-in-human phase I/II safety and preliminary efficacy trial of donor-derived DCreg in living donor liver transplantation (LTx). Methods In the study protocol, DCreg are generated from elutriated monocytes isolated from the leukapheresed donor,14-28 days (d) before transplant. The donor-derived DCreg are infused iv (target range 2.5-10.106/kg) 7 d before transplant (d −7), while a half dose of MPA is administered from d −7 to d 0. Standard-of-care immunosuppression (steroid, MPA, tacrolimus) is administered post-LTx, and in those patients that meet eligibility criteria for weaning, immunosuppressive therapy is gradually withdrawn, starting with MPA reduction 6 mths post-LTx. Sequential immunological analyses are conducted on recipient blood and tissue samples to track the donor-derived DCreg, evaluate anti-donor reactivity and examine potential mechanisms of immune hyporesponsiveness. In the first LTx recipient (HLA-B12+) to receive donor-derived (HLA-A3+) DCreg, peripheral blood samples were obtained before and after cell infusion; native liver tissue was obtained at the time of graft implantation. Results Donor-derived DCreg generated for infusion were HLA-DR+, CD1c−, CD11c+, CD83−, IRF4lo and expressed a high programed death ligand-1 (PD-L1):CD86 ratio. In parallel small scale in vitro functional analyses, the DCreg failed to respond to LPS, and induced donor-specific hyporesponsiveness of recipient CD4 and CD8 T cells. The donor-derived DCreg (HLA-A3+) displaying a similar phenotype to that exhibited pre-infusion, were detected in whole blood immediately after completion of the cell infusion that comprised 5.106 DCreg/kg (450.106 total DCreg). No infusion reaction or cytokine release response was observed. Three days post-infusion (d −4), HLA-A3+ donor-derived DC could no longer be detected in blood, although a small population of DC co-expressing both recipient (HLA-B12) and donor MHC (HLA-A3), ie cross-dressed DC, were evident in the circulation. At the time of transplant, before graft implantation, cross-dressed (HLA-A3+B12+) DC could also be detected in non-parenchymal cell populations isolated from the diseased native liver. Using a 14-color panel of mAbs, these tissue-resident cross-dressed DC were PD-L1hi, IRF4lo and Foxp3hi Conclusions After safe infusion of donor-derived DCreg into a prospective living donor LTx recipient, cross-dressed DC were detected in the peripheral blood within a few days and in the native diseased liver at the time of graft implantation. These cross-dressed DC, that appear to have acquired donor MHC from the infused DCreg, exhibit low levels of the DC transcription/maturation factor IRF4 and high levels of PD-L1 and Foxp3, suggesting possible in vivo regulatory function.