Sang Il Min

Combined endovenous laser treatment and ambulatory phlebectomy for the treatment of saphenous vein incompetence

Objectives The aim of this retrospective study is to assess the safety and effectiveness of endovenous laser treatment (EVLT) combined with ambulatory phlebectomy (AP) as a single procedure for treating saphenous vein incompetence. Methods The study enrolled 148 patients with saphenofemoral or saphenopopliteal junction reflux associated with saphenous vein incompetence and enlarged branch veins. Patients were treated with EVLT (135 great saphenous veins, 41 small saphenous veins) concomitantly with AP as a single procedure. All patients were followed up by clinical assessment and duplex ultrasound at one week and 12 weeks after the procedure. Results No postprocedural deep vein thrombosis and pulmonary embolism occurred. Saphenous vein recanalization rate at three months was 5.7%. Residual varicosities were found in 11.4% of the patients at three months after procedure, but only 2.3% of those required subsequent interventions. Conclusion Combined EVLT and AP could be a safe and effective treatment modality for the saphenous vein incompetence.

The role of the alternative complement pathway in early graft loss after intraportal porcine islet xenotransplantation.

Background Intraportal islet transplantation (ITx) causes instant blood-mediated inflammatory reaction (IBMIR), resulting in an early loss of transplanted islets. Porcine islets, transplanted intraportally into nonhuman primates (NHPs), induce complement activation, contributing to the development of IBMIR; however, the exact mechanism is not clear. Methods Complement activation were compared after incubation of purified adult porcine islets in 20% human serum with or without complement inhibitors, C1 esterase inhibitor (C1E-inh), anti-factor B, and purified human factor H. Intraportal porcine ITx was performed in diabetic NHPs to which cobra venom factor (CVF), factor H, or none of complement inhibitor was administered during the peritransplant period. The extent of complement activation and function of islet grafts were monitored after ITx. Results The incubation of porcine islets with human serum resulted in generation of C3a, C4d, and factor Bb in the fluid phase. However, the generation of C3a after incubation was suppressed by anti-factor B or factor H, but not by C1E-inh. Moreover, in NHPs with porcine ITx, the administration of CVF or factor H ameliorated the increase in plasma C3a and factor Bb levels, as well as early release of porcine C-peptide after ITx. Furthermore, the functional survival of islet grafts was prolonged in the recipients of the CVF group compared to those in the control group. Conclusions The alternative complement pathway contributes to the development of IBMIR and the early loss of grafts in NHPs with porcine ITx. Complement inhibition during the peritransplant period may be beneficial for the survival of islet grafts.

Moderate-to-severe early-onset hyperuricaemia: a prognostic marker of long-term kidney transplant outcome

BACKGROUND Hyperuricaemia commonly occurs in renal transplant recipients (RTRs), but the effects of post-transplant hyperuricaemia on kidney transplant outcome have not been clearly established. This work was designed to explore the impact of hyperuricaemia on renal transplant outcome. METHODS The authors examined this issue by analysing the clinical outcome of 281 RTRs. Hyperuricaemia (defined as UA > 7.0 mg/dl in men and >6.0 mg/dl in women for at least two consecutive tests, n = 121) was classified as early onset (within 1 year of transplant, n = 90) or late onset (n = 31). Graft function was estimated using the MDRD Study Equation 7 (eGFR(MDRD)). RESULTS As late-onset hyperuricaemia was found to be induced by a progressive decline in the graft function (P < 0.01), data from early-onset hyperuricaemic recipients were used. Early-onset moderate-to-severe hyperuricaemia (defined as UA >or= 8.0 mg/dl) was found to be a significant risk factor for chronic allograft nephropathy (P = 0.035) and a poorer graft survival (P = 0.026) by multivariate analysis, whereas mild hyperuricaemia was not. The impact of moderate-to-severe hyperuricaemia on renal transplant survival was dependent on the duration of exposure. Likewise, the detrimental effect of early-onset hyperuricaemia on the graft function was dependent on UA levels and exposure time. After control of the baseline graft function by analysis of only recipients with a good graft function at 1 year post-transplantation (eGFR(MDRD) > 60 ml/min), moderate-to-severe early-onset hyperuricaemia was also found to be a marker of long-term graft dysfunction and failure. CONCLUSION Moderate-to-severe early-onset hyperuri- caemia may be a prognostic marker of the long-term graft outcome in RTRs, which needs further investigation.

Sequential evolution of IL-17 responses in the early period of allograft rejection.

In addition to CD4+CD25+Foxp3+ regulatory T (Treg) cells which protect against autoimmune tissue injury, IL-17-producing CD4+ T (Th17) cells have been recently described and shown to play a crucial role in autoimmune injury. It appears that there is a reciprocal developmental pathway between Th17 and Treg cells. Although IL-17 is known to be associated with allograft rejection, the cellular source of IL-17 and the nature of Th17 in the context of allograft rejection remain unknown. In the current study, the dynamics of Treg and IL-17-producing cells after syngeneic and allogeneic transplantation were examined using a wild-type murine cardiac transplantation model. Ly6G+ cells were found to produce IL-17 during the early postoperative period and CD8+ as well as CD4+ T cells were also found to produce IL-17 during alloimmune response. Graft-infiltrating Ly6G+, CD4+, and even CD8+ cells were found to express IL-17 highly compared to those in spleen. Although the frequencies of Th17 and Treg were found to gradually increase in both syngeneic and allogeneic recipients, Th17/Treg ratios were significantly higher in recipients with allograft rejection than in syngeneic recipients. In conclusion, IL-17 is produced by neutrophils during the early postoperative period and subsequently by Th17 and CD8+ T cells during allograft rejection. Th17/Treg imbalance is associated with the development of allograft rejection. This study would provide basic information on Th17 biology for future investigation in the field of transplantation.

Trends in Deceased Organ Donation and Utilization in Korea: 2000-2009

Continuous efforts have been made by the organ donation and transplantation community in Korea to increase organ donation by the deceased. The authors detailed trends of organ donation and utilization over the past 10 yr using data provided by the KONOS. The yearly number of deceased donors has grown gradually since 2003. The number and percentage of old donors (≥50 yr) and donors dying from intracranial hemorrhage has increased continuously. Therefore, the percentage of standard criteria donors (SCD) has been declining significantly, from 94% in 2000 to 79.2% in 2009. The number of organs transplanted per donor (OTPD) has also declined slightly since 2007, from 3.28 in 2007 to 2.95 in 2009. This decline may be attributable to increases in the number and percentage of extended criteria donors (ECD) and donors after cardiac death (DCD), since the OTPD was 2.25 for DCD, 2.5 for ECD, and 3.09 for SCD in 2009. In summary, the makeup of donors has changed significantly. There is an urgent need for establishment of an institutional framework including an independent organ procurement organization and for improvement for the National Transplant Act to increase deceased donor pool and to optimize management of ECD and DCD.

Cold ischemic time is critical in outcomes of expanded criteria donor renal transplantation

The outcomes of expanded criteria donor (ECD) kidneys have been reported to be inferior compared with standard criteria donor (SCD) kidneys. However, the graft survival rate of ECD is not so inferior to SCD in Korea. The purposes of this study were to compare the outcomes of ECD kidneys with SCD kidneys and identify the influencing factors. We retrospectively studied 143 deceased donor transplants from August 2006 to June 2010. The patients were divided into SCD (n = 117) and ECD (n = 26) by UNOS criteria. The one‐ and three‐yr graft survival rates of SCD and ECD (99.1% and 94.4% vs. 100% and 92.9%, respectively, p = 0.15) were not significantly different between groups. The mean cold ischemic time (CIT) was 3.8 ± 2.2 h. When compared the outcome of ECD kidneys with data reported by Organ Procurement and Transplantation Network and the Scientific Registry of Transplant Recipients (OPTN/SRTR) (one‐ and three‐yr graft survival rate: 86.7% and 73.2%), the graft survival rate of our center was superior. In OPTN/SRTR data, transplant with CIT shorter than 11 h was only 20%. The outcomes of ECD grafts are outstanding and comparable with SCD grafts in our center, and the only distinguishing factor is markedly short CIT. Finishing the allocation before organ recovery and immediate operations after recovery could shorten the CIT.

Conversion of Twice-Daily Tacrolimus to Once-Daily Tacrolimus Formulation in Stable Pediatric Kidney Transplant Recipients: Pharmacokinetics and Efficacy

The pharmacokinetics, efficacy and safety of once‐daily tacrolimus formulation (Tac‐OD) were assessed in 34 stable pediatric kidney transplant recipients. Enrolled patients received their dose of twice‐daily tacrolimus formulation (Tac‐BID) on study Days 0 through 7. On the morning of study Day 8, the total daily doses for patients were converted to Tac‐OD on a 1:1 basis and maintained on a once‐daily morning dosing regimen. Tacrolimus pharmacokinetic profiles were obtained on study Days 7, 14 and 28 (after dose adjustment). Although the mean C0 concentrations (4.10 ± 1.16–3.53 ± 1.10 ng/mL, p = 0.004), and AUC0–24 (151.8 ± 41.6–129.8 ± 39.3 ng h/mL, p < 0.001) were decreased significantly after a 1:1 based conversion, there was high interindividual variability. The dose of Tac‐OD was decreased in 26.5% and increased in 44.1% of patients. The resultant tacrolimus dose and pharmacokinetic profiles on study Day 28 were comparable to those on Day 7. There were no serious adverse events. In conclusion, Tac‐BID can be safely converted to Tac‐OD in stable pediatric kidney transplant patients with the heightened therapeutic drug monitoring. Effects of drug conversion on the cardiovascular risk factors, neurological side effects and adherence should be further evaluated.

Utility of QuantiFERON-TB Assay for Prediction of Tuberculosis Development in Kidney Transplant Patients in an Intermediate- Tuberculosis-Burden Country: Lack of Evidence for Enhanced Prediction for Short-Term Tuberculosis Development

INTRODUCTION Although a latent tuberculosis (TB) infection is a risk factor for active TB, the diagnosis of latent TB infection is difficult in end-stage renal disease patients. PATIENTS AND METHODS We retrospectively compared the results of the QuantiFERON-TB (QFT) test and the tuberculin skin test in patients on the waiting list for kidney transplantation (KT), and investigated whether the QFT test can predict TB development in KT recipients in an intermediate-TB-burden country. RESULTS The incidence of post-KT TB was 283 cases/100,000 patient-years among 1274 KT recipients at the Seoul National University Hospital. The overall standardized incidence ratio of TB was 4.358 compared with the general population. A past history of TB infection, smoking history, myocardial infarction after KT, and pneumocystis infection were significant predictors of subsequent TB development (adjusted odds ratios were 3.618, 2.959, 9.993, and 5.708, respectively). Among the 129 recipients who had the QFT test, 42 patients (32.5%) had positive a QFT. At a median follow-up of 8.4 ± 6.8 months, 1 patient with positive QFT results developed TB after KT, and 1 of the 87 patients with negative QFT results developed TB after KT. In both of these 2 cases, active TB developed despite isoniazid prophylaxis. Among 272 patients on the waiting list for KT, the tuberculin skin test and QFT were positive in 22.8% and 35.3%, respectively. The degree of agreement between the 2 tests was poor (κ = 0.352). CONCLUSIONS The QFT test did not predict subsequent short-term TB development. Furthermore, a long-term and larger-scale study is needed to confirm our results.

Efficacy and safety of hepatitis A vaccination in kidney transplant recipients

In recent years, symptomatic hepatitis A virus (HAV) infection has been reported with increasing frequency in Korea. Therefore, HAV vaccination should be considered in kidney transplant recipients (KTRs). The study investigated the efficacy and safety of HAV vaccination in KTRs under modern triple immunosuppressive agents.

Serum Bilirubin Affects Graft Outcomes through UDP-Glucuronosyltransferase Sequence Variation in Kidney Transplantation

Background Oxidative stress is a major mediator of adverse outcome after kidney transplantation. Bilirubin is produced by heme oxygenase-1 (HO-1), catalyzed by UDP-glucuronosyltransferase (UGT1A1), and has potential as an antioxidant. In this study, we investigated the effects of HO-1 and UGT1A1 sequence variations on kidney allograft outcomes. Methods Clinical data were collected from 429 Korean recipients who underwent kidney transplantation from 1990–2008. Genotyping for UGT1A1*28 and HO-1 (A−413T) was performed. Acute rejection and graft survival were monitored as end-points. Results Serum levels of total bilirubin were significantly increased after transplantation (0.41±0.19 mg/dL to 0.80±0.33 mg/dL, P<0.001). Post-transplant 1-year bilirubin level was higher in 6/7 or 7/7 carriers compared with 6/6 homozygotes in terms of the UGT1A1*28 polymorphism (6/6 vs. 6/7 vs. 7/7: 0.71±0.27 vs. 1.06±0.36 vs. 1.10±0.45 mg/dL, P<0.001). According to an additive model of genotype analysis, the 7-allele genotype had a protective effect on the development of acute rejection compared with the 6-allele (odds ratio 0.43, 95% CI 0.25–0.73, P for trend = 0.006). Multivariate Cox regression analysis revealed that individuals carrying the 7-allele had a decreased risk of graft loss, by a factor of 0.36 (95% CI 0.15–0.85, P = 0.019). The HO-1 (A−413T) polymorphism had no effect on serum bilirubin levels or graft outcomes. Conclusions The UGT1A1*28 polymorphism is associated with changes in serum bilirubin and with graft outcome after kidney transplantation.