The Immunomodulating Effects of Thalidomide and Dexamethasone in a Murine Cardiac Allograft Transplantation Model

Purpose@#The immunomodulatory effects of thalidomide (TM) and dexamethasone (DX) on immune cells and their co-stimulatory, co-inhibitory molecules in vitro and in vivo have been previously reported. The current study investigated the effects of TM and the combinatorial treatment with DX on immune cells using a murine cardiac allograft transplantation model. @*Materials and Methods@#Intraabdominal transplant of cardiac allografts from BALB/c (H-2d ) donors to C57BL/6 (H-2b ) recipients was performed. After transplantation, mice were injected daily with TM or DX or a combination of both TM and DX (TM/DX) by intraperitoneal route until the time of graft loss. CD4+ T cell subsets and CD11c+ cells in the peripheral blood mononuclear cells and spleen were examined and quantified with flow cytometry. Serum IL-6 levels were measured by enzyme-linked immunosorbent assay on day 7. @*Results@#The mean graft survivals were 6.86 days in the untreated group, and 10.0 days in the TM/DX group (p<0.001). The TM/DX treatment affected the CD4+ T cell subsets without suppressing the total CD4+ T cell population. The CD4 + FOXP3+ /CD4+ CD44hi T cell ratio increased. Increase in cell counts and median fluorescence intensity on CD11c+ CD85k+ with TM/DX were observed. The inhibition of pro-inflammatory cytokine interleukin-6 was also observed. @*Conclusion@#These outcomes suggest the immunomodulating effect of the TM/DX combinatorial treatment. In conclusion, TM/ DX combination may be a promising immunomodulatory approach for preventing allograft rejection and improving graft survival by inducing tolerance in transplantation.

Systemic Immunomodulatory Effects of Combinatorial Treatment of Thalidomide and Dexamethasone on T Cells and Other Immune Cells

Purpose@#In organ transplantation, the need for immune modulation rather than immune suppression has been emphasized. In this study, we investigated whether combinatorial treatments of with thalidomide (TM) and dexamethasone (DX) might be new approaches to induce systemic immunomodulation on T cells and other immune cells that regulate the expression of co-inhibitory molecules. @*Materials and Methods@#Naïve splenic T cells from C57BL/6 mice were sort-purified and cultured in vitro for CD4+ T cell proliferation and regulatory T cell (Treg) conversion in the presence of TM or/and DX. Expression of cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) and programmed death-1 (PD-1) in proliferated and converted T cells was quantified by flow cytometry. We also quantified in vivo expression of CTLA-4 and PD-1 on splenic CD4+ T cells and other immune cells isolated from TM- or/and DX-treated mice. Mixed lymphocytes reactions (MLR) were performed to evaluate the capacity of immune cells in carrying out immune responses. @*Results@#CTLA-4 expressions in effector T cells in vivo and in Tregs in vivo/vitro significantly increased upon TM/DX combinatorial treatment. Corresponding to increased CTLA-4 expression in T cells, the expression of ligand molecules for CTLA-4 significantly increased in splenic dendritic cells in TM/DX-treated groups. In addition, MLR results demonstrated that splenocytes isolated from TM/DX-treated mice significantly suppressed the proliferation of T cells isolated from other strains. @*Conclusion@#Based on these results, we suggest that TM/DX combinatorial treatments might be efficient immunomodulatory methods for regulating T cell immunity.

Insulin Secretion and Insulin Resistance Trajectories over 1 Year after Kidney Transplantation: A Multicenter Prospective Cohort Study

Background@#We investigated the changing patterns of insulin secretion and resistance and risk factors contributing to the development of post-transplant diabetes mellitus (PTDM) in kidney recipients under tacrolimus-based immunosuppression regimen during 1 year after transplantation. @*Methods@#This was a multicenter prospective cohort study. Of the 168 subjects enrolled in this study, we analyzed a total 87 kidney transplant recipients without diabetes which was assessed by oral glucose tolerance test before transplantation. We evaluated the incidence of PTDM and followed up the index of insulin secretion (insulinogenic index [IGI]) and resistance (homeostatic model assessment for insulin resistance [HOMA-IR]) at 3, 6, 9 months, and 1 year after transplantation by oral glucose tolerance test and diabetes treatment. We also assessed the risk factors for incident PTDM. @*Results@#PTDM developed in 23 of 87 subjects (26.4%) during 1 year after transplantation. More than half of total PTDM (56.5%) occurred in the first 3 months after transplantation. During 1 year after transplantation, insulin resistance (HOMA-IR) was increased in both PTDM and no PTDM group. In no PTDM group, the increase in insulin secretory function to overcome insulin resistance was also observed. However, PTDM group showed no increase in insulin secretion function (IGI). Old age, status of prediabetes and episode of acute rejection were significantly associated with the development of PTDM. @*Conclusion@#In tacrolimus-based immunosuppressive drugs regimen, impaired insulin secretory function for reduced insulin sensitivity contributed to the development of PTDM than insulin resistance during 1 year after transplantation.

Insulin Secretion and Insulin Resistance Trajectories over 1 Year after Kidney Transplantation: A Multicenter Prospective Cohort Study

Background@#We investigated the changing patterns of insulin secretion and resistance and risk factors contributing to the development of post-transplant diabetes mellitus (PTDM) in kidney recipients under tacrolimus-based immunosuppression regimen during 1 year after transplantation. @*Methods@#This was a multicenter prospective cohort study. Of the 168 subjects enrolled in this study, we analyzed a total 87 kidney transplant recipients without diabetes which was assessed by oral glucose tolerance test before transplantation. We evaluated the incidence of PTDM and followed up the index of insulin secretion (insulinogenic index [IGI]) and resistance (homeostatic model assessment for insulin resistance [HOMA-IR]) at 3, 6, 9 months, and 1 year after transplantation by oral glucose tolerance test and diabetes treatment. We also assessed the risk factors for incident PTDM. @*Results@#PTDM developed in 23 of 87 subjects (26.4%) during 1 year after transplantation. More than half of total PTDM (56.5%) occurred in the first 3 months after transplantation. During 1 year after transplantation, insulin resistance (HOMA-IR) was increased in both PTDM and no PTDM group. In no PTDM group, the increase in insulin secretory function to overcome insulin resistance was also observed. However, PTDM group showed no increase in insulin secretion function (IGI). Old age, status of prediabetes and episode of acute rejection were significantly associated with the development of PTDM. @*Conclusion@#In tacrolimus-based immunosuppressive drugs regimen, impaired insulin secretory function for reduced insulin sensitivity contributed to the development of PTDM than insulin resistance during 1 year after transplantation.

Effects of Neutralization by Soluble ABH Antigens Produced by Transplanted Kidneys From ABO-Incompatible Secretor Donors

BACKGROUND: Grafts survive despite blood group antigens on the transplant being continuously exposed to antibodies in the blood of recipients in ABO-incompatible kidney transplantation (ABOi KT), owing to the mechanism of accommodation. We analyzed the immunodynamics of soluble ABH antigens in allografts from secretor donors and the influence of such immunodynamics on accommodation and subsequent graft survival in ABOi KT. METHODS: The genotype of a known human β-galactoside α-1,2-fucosyltransferase gene (FUT2), which determines soluble ABH antigen secretor status, was established in 32 donors for ABOi KT at the Severance Hospital, from June 2010 to July 2015. Clinical outcomes of recipients, such as anti-A/B antibody titer change, renal function, and graft survival, were evaluated. RESULTS: Twenty-five donors were secretors (78.1%), and seven were nonsecretors (21.9%). The frequency of anti-A/B IgG or IgM antibody titer elevation or reduction post-transplantation was not significantly related to donor secretor status. However, IgM titer was rapidly reduced in recipients transplanted from nonsecretor donors (P=0.01), which could be explained by the lack of absorption effect of soluble antigens, enhancing the binding of antibodies to antigens in the allografts. Interestingly, soluble ABH antigens did not affect rejection-free graft survival, which may be due to the nature of β-galactoside α-1,2-fucosyltransferase. CONCLUSIONS: Soluble ABH antigens produced by transplanted kidneys from secretor donors played a role in inducing accommodation within three months of KT through neutralization; however, major graft outcomes were not affected.

Two Cases of Antibody-Mediated Rejection Following Kidney Transplantation due to HLA-DQB1 Allele-Specific and DQ Alpha Protein-Specific HLA Antibodies

No abstract available.

Initial ABO Antibody Titer as a Variable for Estimating Number of Therapeutic Plasma Exchange prior to ABO Incompatible Kidney Transplantation / 대한수혈학회지

BACKGROUND: Therapeutic plasma exchange (TPE) for desensitization in ABO incompatible kidney transplantation (KT) has raised concerns regarding efficiency and safety. The purpose of this study was to determine the number of TPE prior to KT required to reach target titer for KT according to ABO blood groups. METHODS: The distribution of ABO antibody (Ab) titer of 117 patients was investigated. The relationship between initial ABO Ab and number of TPEs required to reach target titer to ≤1:8 prior to KT was evaluated retrospectively according to blood groups and ABO Ab classes. RESULTS: The initial IgG ABO Ab titers were the highest in blood O group recipients, and the average number±standard deviations (range) of TPEs performed prior to ABO incompatible KT was 3.0±1.1 (0~5) in blood group A, 3.7±1.5 (0~8) in blood group B, and 5.3±1.9 (2~13) in blood group O, respectively. The best correlation was observed in the linear relationship between initial ABO Ab titer and number of TPEs required (y=0.6829x+0.0523, R2=0.946, x=log2 initial ABO Ab titer, y=number of TPE required), regardless of the specific ABO blood group. CONCLUSION: The number of TPEs can be highly deduced from initial ABO Ab titer and our developed equation in desensitization programs would help increase the efficiency of TPE and patient safety.

Sirolimus Combination with Tacrolimus in Kidney Transplant Recipients at High Immunological Risk: Observational Results 3 Years after Transplantation / 대한이식학회지

BACKGROUND: The optimal immunosuppressive strategy for renal transplant recipients at high immunological risk requires clarification. We compared the 3 year outcomes of a sirolimus group (tacrolimus plus sirolimus) to those of a control group (tacrolimus plus mycophenolate mofetil). METHODS: This observational study was an extension of a prospective pilot study. We assessed acute rejection, glomerular filtration rate, adverse events, graft, and patient survival. RESULTS: Overall, 43% of the sirolimus group versus 78% of the control group were still on the initial immunosuppressive regimen at 3 years (P=0.005), and most discontinuations in each group were due to adverse events. No differences were observed between two groups with respect to acute rejection. The mean glomerular filtration rate at 36 months was greater in the sirolimus group than in the control group, but this was not statistically significant (64.0±6.8 mL/min/1.73 m² vs. 61.8±17.1 mL/min/1.73 m², P=0.576). Graft and patient survival were similar in both groups. Importantly, mean tacrolimus through levels were significantly lower in the sirolimus group than in the control group at each time point. No neoplasm was reported in the sirolimus group. In the control group, three cases of neoplasms developed during the study period. CONCLUSIONS: The sirolimus group had a greater number of discontinuations, particularly related to adverse events. Nevertheless, optimal concentration of sirolimus allowed reduced calcineurin inhibitor exposure in high immunologic risk patients, without increasing the risk of acute rejection and graft failure.

Effects of Dipeptidyl Peptidase-4 Inhibitors on Hyperglycemia and Blood Cyclosporine Levels in Renal Transplant Patients with Diabetes: A Pilot Study

BACKGROUND: The use of dipeptidyl peptidase-4 (DPP-4) inhibitors is increasing among renal transplant patients with diabetes. However, the glucose-lowering efficacies of various DPP-4 inhibitors and their effects on blood cyclosporine levels have not been fully investigated. We compared the glucose-lowering efficacies of DPP 4 inhibitors and evaluate their effects on the blood levels of cyclosporine in renal transplant recipients with diabetes. METHODS: Sixty-five renal allograft recipients who received treatment with DPP-4 inhibitors (vildagliptin, sitagliptin, or linagliptin) following kidney transplant were enrolled. The glucose-lowering efficacies of the DPP-4 inhibitors were compared according to the changes in the hemoglobin A1c (HbA1c) levels after 3 months of treatment. Changes in the trough levels of the cyclosporine were also assessed 2 months after treatment with each DPP-4 inhibitor. RESULTS: HbA1c significantly decreased in the linagliptin group in comparison with other DPP-4 inhibitors (vildagliptin –0.38%±1.03%, sitagliptin –0.53%±0.95%, and linagliptin –1.40±1.34; P=0.016). Cyclosporine trough levels were significantly increased in the sitagliptin group compared with vildagliptin group (30.62±81.70 ng/mL vs. –24.22±53.54 ng/mL, P=0.036). Cyclosporine trough levels were minimally changed in patients with linagliptin. CONCLUSION: Linagliptin demonstrates superior glucose-lowering efficacy and minimal effect on cyclosporine trough levels in comparison with other DPP-4 inhibitors in kidney transplant patients with diabetes.

Retinoic Acid-induced Differentiation of Rat Mesenchymal Stem Cells into beta-Cell Lineage / 대한이식학회지

BACKGROUNDS: Type I diabetes mellitus (T1DM), an autoimmune disease, is associated with insulin deficiency due to the death of beta-cells. Bone marrow-derived mesenchymal stem cells (BM-MSCs) are capable of tissue repair and thus are a promising source of beta-cell surrogates. METHODS: In this study, the therapeutic potential of BM-MSCs as beta-cell replacements was analyzed both in vitro and in vivo. First, we used retinoic acid (RA) to induce rat BM-MSCs to differentiate into cells of endodermal/pancreatic lineage. Then, differentiated rat BM-MSCs were syngeneically injected under the renal capsule of rats. RESULTS: Analysis of gene expression revealed that rat BM-MSCs showed signs of early pancreatic development, and differentiated cells were qualitatively and quantitatively confirmed to produce insulin in vitro. In vivo study was performed for short-term (3 weeks) and long-term (8 weeks) period of time. Rats that were injected with differentiated MSCs exhibited a reduction in blood glucose levels throughout 8 weeks, and grafted cells survived in vivo for at least 3 weeks. CONCLUSIONS: These findings show that RA can induce differentiation of MSCs into the beta-cell lineage and demonstrate the potential of BM-MSCs to serve as therapeutic tools for T1DM.

Adult Kidney Transplantation of Pediatric En bloc Kidneys Using a Partial Bladder Wall / 대한이식학회지

Kidney transplantation is a treatment of choice which improves survival and quality of life for patients with end-stage renal disease. Due to the growing waiting list for kidney transplantation, expansion of the donor pool to use of deceased pediatric kidneys is of critical importance. However, the use of pediatric kidneys has been limited due to concerns about early graft failure, hyperfiltration injury, and technical difficulties. Performing ureteroneocystostomy using small pediatric en bloc kidneys is sometimes difficult due to the small diameter and short length of the ureter in the adult kidney recipient. We hereby report on a partial bladder wall transplantation using pediatric en bloc kidneys. Pediatric en bloc kidneys and partial bladder wall from a 12-month-old female donor who weighed 9.13 kg was transplanted into a 49-year-old male recipient. The urinary tract was reconstructed with a partial bladder wall of the donor. At 12 months post-transplantation, Doppler ultrasonograpy and renogram showed stable graft renal function without urological complications. Pediatric en bloc kidney transplantation with a partial bladder wall can be a safe and feasible surgical technique to reduce urological complications.

The Effect of Bortezomib on Antibody-Mediated Rejection after Kidney Transplantation

PURPOSE: Recently, bortezomib has been used to treat antibody-mediated rejection (AMR) refractory to conventional treatment such as plasmapheresis, intravenous immunoglobulin, and rituximab. The authors aimed to describe their experiences when bortezomib was used to treat refractory AMR. MATERIALS AND METHODS: Eleven refractory AMR episodes treated with bortezomib were included in this study. The patients received one or two cycles of bortezomib (1.3 mg/m2) on days 1, 4, 8, and 11. RESULTS: Bortezomib effectively reduced antibodies against various targets, including human leukocyte antigen (HLA) class I and II, ABO blood group antigen, and angiotensin II type 1 receptor. Antibodies were depleted or reduced significantly in eight AMR episodes. Overall, there was a significant improvement in the mean estimated glomerular filtration rate (eGFR) at 3 months after therapy (36.91+/-22.15 mL/min/1.73 m2) versus eGFR at time of AMR diagnosis (17.00+/-9.25 mL/min/1.73 m2; p=0.007). All six early-onset AMR episodes (within 6 months post-transplantation) showed full recovery of allograft function. Additionally, three of the five late-onset AMR episodes (>6 months post-transplantation) showed improved allograft function. CONCLUSION: Anti-humoral treatment based on bortezomib might be an effective strategy against refractory AMR caused by various types of antibodies. Notably, this treatment could be more effective in early-onset AMR than in late-onset AMR.

A 12-Month Single Arm Pilot Study to Evaluate the Efficacy and Safety of Sirolimus in Combination with Tacrolimus in Kidney Transplant Recipients at High Immunologic Risk

The optimal immunosuppressive strategy for renal transplant recipients at high immunologic risk remains a topic of investigation. This prospective single arm pilot study was undertaken to evaluate the safety and efficacy of a combined tacrolimus and sirolimus regimen in recipients at immunological high risk and to compare outcomes with a contemporaneous control group received tacrolimus and mycophenolate mofetil. Patients that received a renal allograft between 2010 and 2011 at high risk (defined as panel reactive antibodies > 50%, 4 or more human leukocyte antigen mismatches, or retransplantation) were enrolled. All patients received basiliximab induction and corticosteroids. A total of 28 recipients treated with tacrolimus and sirolimus were enrolled in this study and 69 recipients were retrospectively reviewed as a control group. The sirolimus group showed a higher, but not statistically significant, incidence of biopsy proven acute rejection and a lower glomerular filtration rate than the control group. Furthermore, sirolimus group was associated with significant increases in BKV infection (P = 0.031), dyslipidemia (P = 0.004), and lymphocele (P = 0.020). The study was terminated prematurely due to a high incidence of adverse events. A de novo tacrolimus/sirolimus combination regimen may not be an ideal choice for recipients at high immunological risk.

Sirolimus Conversion Efficacy for Graft Function Improvement and Histopathology in Renal Recipients with Mild to Moderate Renal Insufficiency

This study was designed to evaluate whether sirolimus (SRL) conversion effectively improves renal function and histopathology in calcineurin inhibitor (CNI)-treated renal recipients with mild to moderate renal insufficiency. SRL conversion from CNI was performed in patients who underwent kidney transplantation from 6 months to 5 yr prior to screening. Forty-five patients were enrolled. The effect of SRL conversion on graft function was evaluated, and protocol biopsies were performed preconversion and 1 yr after conversion. Overall graft function after SRL conversion gradually improved, and the improvement in renal function was closely associated with the shorter duration of CNI exposure. When we divided the patients by the duration of CNI exposure, the patients with less than 1 yr of CNI exposure demonstrated significant improvement, but patients with a greater than 1 yr CNI exposure did not exhibit significant improvement. In contrast, protocol biopsies demonstrated no significant improvements in the modified "ah" score or other Banff scores after SRL conversion. Furthermore, the duration of CNI treatment prior to SRL conversion was not associated with histological findings 1 yr after SRL conversion. SRL conversion improved graft function in renal recipients with mild to moderate renal insufficiency, but this effect is not accompanied by histological improvement.

Changes of Kidney Injury Molecule-1 Expression and Renal Allograft Function in Protocol and for Cause Renal Allograft Biopsy / 대한이식학회지

BACKGROUND: Kidney injury molecule-1 (KIM-1) is known as a good ancillary marker of acute kidney injury (AKI) and its expression has also been observed in acute rejection and chronic graft dysfunction. We tested usefulness of KIM-1 as an indicator of acute and chronic renal graft injury by correlating KIM-1 expression with renal graft function and histology. METHODS: A total of 133 zero-time biopsies and 42 follow-up biopsies obtained within 1 year posttransplantation were selected. Renal tubular KIM-1 staining was graded semiquantitatively from 0 to 3 and the extent of staining was expressed as the ratio of KIM-1 positive/CD10 positive proximal tubules using Image J program. RESULTS: KIM-1 was positive in 39.8% of zero-time biopsies. KIM-1 positive cases were predominantly male and had received grafts from donors with older age, deceased donors, and poor renal function at the time of donation, compared with KIM-1 negative cases. KIM-1 expression showed correlation with delayed graft function and acute tubular necrosis. In comparison of KIM-1 expression between stable grafts (n=23) and grafts with dysfunction (n=19) at the time of repeated biopsy, the intensity/extent of KIM-1 staining and renal histology at zero-time did not differ significantly between the two groups. Histologically, KIM-1 expression was significantly increased with both acute and chronic changes of glomeruli, tubules and interstitium, peritubular capillaritis, and arteriolar hyalinosis. CONCLUSIONS: KIM-1 can be used as an ancillary marker of AKI and a nonspecific indicator of acute inflammation and tubulointerstitial fibrosis. However, KIM-1 expression at zero-time is not suitable for prediction of long-term graft dysfunction.

Safety and Efficacy of Conversion from Twice-Daily Tacrolimus to Once-Daily Tacrolimus One Month after Transplantation: Randomized Controlled Trial in Adult Renal Transplantation

PURPOSE: The purpose of this study was to compare once-daily tacrolimus with twice-daily tacrolimus in terms of safety, efficacy, and patient satisfaction. MATERIALS AND METHODS: This prospective, randomized, open-label, multicenter study was conducted at three institutes. Patients in the investigational group were converted from tacrolimus twice daily to the same dose of extended-release tacrolimus once daily at 1 month post-transplantation, while patients in the control group were maintained on tacrolimus twice daily. The efficacies, safeties, and patient satisfaction for the two drugs at 6 months post-transplantation were compared. RESULTS: Sixty patients were enrolled and randomized to the investigational group (28 of 29 patients completed the study) or the control group (26 of 31 patients completed the study). At 6 months post-transplantation, composite efficacy failure rates including the incidences of biopsy-confirmed acute rejection in the investigational and control groups were 0% and 10.7%, respectively; patient survival was 100% in each group. No difference in estimated glomerular filtration rate values were observed at 6 months post-transplantation (p=0.97). The safety and satisfaction profile (immunosuppressant therapy barrier scale) of once-daily tacrolimus was comparable with that of twice-daily tacrolimus (p=0.35). CONCLUSION: Conversion from twice-daily tacrolimus to once-daily tacrolimus one month after transplantation is safe and effective.

Resolution of Ambiguous HLA Genotyping in Korean by Multi-Group-Specific Sequence-Based Typing

PURPOSE: To evaluate a multi-group-specific sequence-based typing (SBT) method for resolving ambiguous results from human leukocyte antigen (HLA) genotyping. MATERIALS AND METHODS: A total of 50 samples that showed ambiguous genotypes for at least two HLA loci from HLA-A, -B, -C and -DRB1 by the conventional SBT assay were evaluated using a new SBT test, the AVITA plus assay. The most likely HLA genotypes for the respective samples considering allele frequencies in Korean were concordant between the AVITA and conventional SBT assays. RESULTS: An average of 3.3 loci among the HLA-A, -B, -C and -DRB1 loci per sample gave results with two or more possible allele combinations with the conventional SBT, and 48 (96.0%) out of 50 showed reduced numbers of possible genotypes for at least one HLA locus with the AVITA. A total of 41, 43, 42, and 38 cases among the 50 samples showed ambiguous results for HLA-A, -B, -C, and -DRB1 typing by the conventional SBT, respectively. The average numbers of possible allele combinations for the respective four HLA loci were 8.2, 6.7, 5.9, and 3.2, and they were reduced to 1.5, 2.2, 4.4, and 1.8, respectively, by the AVITA. Ambiguity was resolved by the AVITA in 33 (80.5%), 31 (72.1%), 17 (40.5%) and 28 (73.7%) samples among the ambiguous cases from the conventional SBT for HLA-A, -B, -C, and -DRB1 typing, respectively. CONCLUSION: The multi-group-specific SBT method considerably reduced the number of ambiguous results, and thus may be useful for accurate HLA typing in clinical laboratories.

Islet Encapsulation Using Chondrocyte / 대한이식학회지

Diabetes mellitus is one of the leading metabolic diseases that cause an increasing rate of mortality and morbidity. Recently, rather than the current drug treatment, pancreatic islet transplantation has been regarded as a potentially promising strategy for insulin- dependent diabetes mellitus while preventing complications such as kidney damage, vascular damage, nerve damage, and blindness. Recently, a number of advanced islet encapsulation techniques have been designed to enhance the efficiency of islet transplantation, including cell sheet engineering and generation of 3D islet spheroids by high density suspension system (HDSS). Chondrocytes derived from cartilage sources have been used as an encapsulation biomaterial for islets not only for autograft but also for allograft and xenograft transplantation. Cartilage is an avascular, white connective tissue that is rich in extracellular matrix, and expandable in vitro. Hence, this tissue might have immunologically privileged properties that make it an intelligent cell source for manufacture of encapsulation biomaterials. However, cell sheet engineering and HDSS still have their respective limitations, which need to be elucidated. This review will describe the advantages and disadvantages of the current encapsulation techniques in order to provide a comprehensive foundation for further modifications and improvements of tissue engineering for islet transplantation.

Clinical Characteristics and Risk Factors for Renal Cell Carcinoma after Kidney Transplantation / 대한이식학회지

BACKGROUND: The occurrence of malignancy following kidney transplantation has been estimated three to five times the incidence compared to that of the general population. It is estimated that particularly in renal cell carcinoma (RCC), the relative risk increases. The aim of this study was to analyze the characteristics, risk factors, and prognosis of RCC following kidney transplantation. METHODS: Total number of 3,272 kidney recipients who underwent transplantation from April 1979 to December 2012 and patients who had RCC following kidney transplantation were retrospectively reviewed and analyzed. RESULTS: We found that among 232 cases of posttransplant malignancies, 25 recipients were diagnosed with RCC. We have observed in our study that it took an average of 175.2+/-71.0 months to develop RCC after their first kidney transplantation. However, with longer follow up period, interval incidence of RCC increased. Fourteen patients (56%) were diagnosed with RCC 15 years after transplantation. We also found that with reference to the risk factor analysis for posttransplant RCC, the long-term follow-up period was the only independent risk factor. In our study, 21 patients with RCC were treated with radical nephrectomy. Of them, 16 patients survived, and four RCC-related deaths occurred. Furthermore, the patient survival rate of RCC recipients was lower than that of the nonmalignancy group despite the graft survival rate were not different. CONCLUSIONS: We conclude that the incidence of RCC increased in a time-dependent manner following kidney transplantation. Therefore, we strongly recommend the procedure of regular-interval screening for the patients who are on compulsive long-term immunosuppression.

Posttransplant Lymphoproliferative Disorder without Epstein-Barr Virus Presented as Small Bowel Perforation in Renal Transplant Recipient: A Case Report / 대한이식학회지

Posttransplant lymphoproliferative disorder (PTLD) is documented as one of the serious complications leading to mortality particularly in organ transplant recipients receiving immunosuppressive therapy. Extant literature confirms beyond doubt that the most common site of involvement of PTLD is lymph nodes, and rarely involved is the gastrointestinal tract. It is a well-known fact that Epstein-Barr virus (EBV) is a risk factor for PTLD development. In this study, we report a case of PTLD presented as small bowel perforation without EBV infection after long-term immunosuppressive therapy in a renal transplant recipient.