Man Ki Ju

Exchange living-donor kidney transplantation: merits and limitations.

Background. The shortage of donor organs is one of the major barriers to transplantation worldwide. After the success of the direct exchange donor (swap) program in Korea since 1991, we have developed a swap-around program. However, reports on the long-term outcomes of exchange donor programs are scarce. Methods. From September 1995 to September 2006, we performed 1193 cases of renal transplantation, including 398 cases from living-unrelated donors. The living-unrelated donors included 129 exchange donors and 269 nonexchange donors. We compared the outcomes of the exchange program with that of the nonexchange program, and examined the merits and limitations of the exchange program. Results. The reasons for the exchange program were ABO incompatibility (n=84, 65.1%), human leukocyte antigen mismatching beyond our criteria (n=39, 30.2%), or positive lymphocyte crossmatch (n=6, 4.7%). The overall 10-year graft survival (86.3%) of exchange transplantation was comparable with that of nonexchange (82.3%) or one- haplotype matched living-related (81.2%) transplantation (P=0.2994). In multivariate analysis, exchange versus nonexchange donors did not affect graft survival. The proportion of blood-type O donors was much lower in the exchange group (29.5%) than in the nonexchange group (42.4%; P=0.026). Blood-type O kidneys were preferentially allocated to blood-type O recipients (78.9%) in the exchange group as compared with the nonexchange group (54.4%; P=0.007). Conclusion. We achieved excellent outcomes by using a donor exchange program as an option to reduce the donor organ shortage. However, the exchange donor program has no added benefit for blood-type O recipients.

Role of surgical resection for multiple hepatocellular carcinomas

AIM To clarify the role of surgical resection for multiple hepatocellular carcinomas (HCCs) compared to transarterial chemoembolization (TACE) and liver transplantation (LT). METHODS Among the HCC patients who were managed at Yonsei University Health System between January 2003 and December 2008, 160 patients who met the following criteria were retrospectively enrolled: (1) two or three radiologically diagnosed HCCs; (2) no radiologic vascular invasion; (3) Child-Pugh class A; (4) main tumor smaller than 5 cm in diameter; and (5) platelet count greater than 50 000/mm(3). Long-term outcomes were compared among the following three treatment modalities: surgical resection or combined radiofrequency ablation (RFA) (n = 36), TACE (n = 107), and LT (n = 17). The survival curves were computed using the Kaplan-Meier method and compared with a log-rank test. To identify the patients who gained a survival benefit from surgical resection, we also investigated prognostic factors for survival following surgical resection. Multivariate analyses of the prognostic factors for survival were performed using the Cox proportional hazard model. RESULTS The overall survival (OS) rate was significantly higher in the surgical resection group than in the TACE group (48.1% vs 28.9% at 5 years, P < 0.005). LT had the best OS rate, which was better than that of the surgical resection group, although the difference was not statistically significant (80.2% vs 48.1% at 5 years, P = 0.447). The disease-free survival rates were also significantly higher in the LT group than in the surgical resection group (88.2% vs 11.2% at 5 years, P < 0.001). Liver cirrhosis was the only significant prognostic factor for poor OS after surgical resection. Clinical liver cirrhosis rates were 55.6% (20/36) in the resection group and 93.5% (100/107) in the TACE group. There were 19 major and 17 minor resections. En bloc resection was performed in 23 patients, multi-site resection was performed in 5 patients, and combined resection with RFA was performed in 8 patients. In the TACE group, only 34 patients (31.8%) were recorded as having complete remission after primary TACE. Seventy-two patients (67.3%) were retreated with repeated TACE combined with other therapies. In patients who underwent surgical resection, the 16 patients who did not have cirrhosis had higher 5-year OS and disease-free survival rates than the 20 patients who had cirrhosis (80.8% vs 25.5% 5-year OS rate, P = 0.006; 22.2% vs 0% 5-year disease-free survival rate, P = 0.048). Surgical resection in the 20 patients who had cirrhosis did not provide any survival benefit when compared with TACE (25.5% vs 24.7% 5-year OS rate, P = 0.225). Twenty-nine of the 36 patients who underwent surgical resection experienced recurrence. Of the patients with cirrhosis, 80% (16/20) were within the Milan criteria at the time of recurrence after resection. CONCLUSION Among patients with two or three HCCs, no radiologic vascular invasion, and tumor diameters ≤ 5 cm, surgical resection is recommended only in those without cirrhosis.

Invasive pulmonary aspergillosis after solid organ transplantation: diagnosis and treatment based on 28 years of transplantation experience.

Invasive pulmonary aspergillosis (IPA) is a serious and lethal complication among organ transplant recipients. This report described the clinical manifestations and treatment of IPA over a 28-year period. From January 1979 to December 2007, 3215 organ transplant patients (2954 kidney and 261 liver recipients) were enrolled in the study. Nine patients developed IPA (7 kidney and 2 liver recipients), yielding an incidence of 0.003% (9/3215). Five IPA patients (55.6%) were diagnosed by transbronchial lung biopsy or autopsy, and 3 (33.3%) by sputum culture study. One patient was diagnosed through clinical manifestations and observations of IPA characteristics on chest X ray. We used amphotericin B (n = 4; 44.4%), voriconazole (n = 2; 22.2%), or fluconazole (n = 1; 11.1%) as the primary antifungal agents, but 2 patients could not receive antifungal agents due to rapid disease progression and sequential mortality. This study showed a high mortality rate among IPA patients (55.6%; 5/9). Only patients who received early antifungal agent thereby after a prompt diagnosis recovered from IPA. This survival advantage warrants careful monitoring for invasive fungal infections after organ transplantation with immediate administration of antifungal agents or surgical intervention.

Pretransplant soluble CD30 level has limited effect on acute rejection, but affects graft function in living donor kidney transplantation.

Background. Serum soluble CD30 (sCD30) levels might be a useful marker of immunologic status in pre transplant (Tx) recipients. We retrospectively correlated preTx sCD30 levels (high versus low) on postTx graft survival, incidence of acute rejection, and graft function using stored preTx serum. Methods. Of 254 recipients who underwent kidney Tx, 120 recipients were enrolled under the uniform criteria (living donor, age >25 years, viral hepatitis free, diabetes free). Results. The preTx sCD30 was not significantly associated with differences in graft survival rate during 47.5±11.4 months of follow-up (P=0.5901). High sCD30 (≥115 U/ml) was associated with a higher incidence of clinically or pathologically defined acute rejection than low sCD30, but the difference was not statistically significant (33.9% vs. 22.4%, P=0.164). The response rate to antirejection therapy in patients with high sCD30 was inferior to those with low sCD30, but also was not statistically significant (33.3% vs. 7.7%, P=0.087). However, mean serum creatinine levels in high sCD30 patients at one month, one year, and three years postTx were significantly different from those with low sCD30 (P<0.05). In multiple regression analysis, acute rejection episodes, donor age, kidney weight/recipient body weight ratio, and preTx sCD30 levels were independent variables affecting the serum creatinine level three years postTx. Conclusion. PreTx sCD30 level has a limited effect on the incidence of acute rejection and response to antirejection treatment, but inversely and independently affects serum creatinine level after living donor kidney transplantation.

Chronologically different incidences of post‐transplant malignancies in renal transplant recipients: single center experience

The incidence of malignancy in transplant recipients is known to be higher than the same in the general population. However, the types of malignancies vary geographically, and the relative risks (RR) for malignancy in transplant recipients, compared with that of the general population, also differ country‐by‐country. In this study, we investigated the incidence and characteristics of malignancies after renal transplantation in a single center. A total of 2630 renal recipients who underwent surgery between April 1979 and June 2007 were enrolled in this study. The cumulative and interval incidences of malignancies were calculated for every 3 years post‐transplantation. One‐hundred ninety cases of postrenal transplant malignancies among 177 recipients (6.73%) were reported until 2007. The post‐transplant malignancies were detected from 6 to 290 months after transplantation, with a mean duration of 112.6 ± 66.0 months. Skin cancer [35 (18.4%)] was the most common post‐transplant malignancy, followed by thyroid [25 (13.2%)], stomach [22 (11.6%)], colorectal [22 (11.6%)], and urologic cancers [19 (10.0%)]. As the post‐transplant period increased, the interval incidence of malignancy correspondingly increased. Virus‐related malignancies, such as Kaposi’s sarcoma and cervical cancer, developed earlier within the post‐transplant period, while urologic cancer, colorectal cancer developed late in the post‐transplant period. The recipient’s age at the time of transplantation was the sole independent risk factor for post‐transplant malignancy based on the multivariate analysis (RR = 2.723, P < 0.0001 in the >50‐year‐old age group). We should establish strategies for post‐transplant malignancy‐screening based on the recipient’s age at the time of transplantation, the post‐transplant interval, and the national trend of post‐transplant malignancy.

Is the Affinity Column–Mediated Immunoassay Method Suitable as an Alternative to the Microparticle Enzyme Immunoassay Method as a Blood Tacrolimus Assay?

BACKGROUND Tacrolimus is a potent immunosuppressive drug used in organ transplantation. Because of its substantial toxic effects, narrow therapeutic index, and interindividual pharmacokinetic variability, therapeutic drug monitoring of whole-blood tacrolimus concentrations has been recommended. We investigated the comparability of the results of 2 immunoassay systems, affinity column-mediated immunoassay (ACMIA) and microparticle enzyme immunoassay (MEIA), comparing differences in the tacrolimus concentrations measured by the 2 methods in relation to the hematologic and biochemical values of hepatic and renal functions. METHODS A total of 154 samples from kidney or liver transplant recipients were subjected to Dimension RxL HM with a tacrolimus Flex reagent cartilage for the ACMIA method and IMx tacrolimus II for the MEIA method. RESULTS Tacrolimus concentrations measured by the ACMIA method (n = 154) closely correlated with those measured by the MEIA method (r = 0.84). The Bland-Altman plot using concentration differences between the 2 methods and the average of the 2 methods showed no specific trends. The tacrolimus levels determined by both the MEIA method and the ACMIA method were not influenced by hematocrit levels, but the difference between the 2 methods (ACMIA - MEIA) tended to be larger in low hematocrit samples (P < .001). CONCLUSION The ACMIA method used for a tacrolimus assay is precise and has advantages, including the lack of a required pretreatment procedure. Furthermore, it is only slightly influenced by the hematologic or biochemical status of the samples.

Renal transplantation in sensitized recipients with positive luminex and negative CDC (complement-dependent cytotoxicity) crossmatches.

Recently, Luminex‐crossmatch (LumXm) was introduced. The aim of this study was to evaluate clinical outcomes in sensitized recipients with a positive Luminex‐crossmatch (LumXm (+)) and a negative complement‐dependent cytotoxicity crossmatch (CDCXm (−)) after renal transplantation. Fifty‐five renal transplant recipients with a CDCXm (−) and PRA class I or II ≥20% were enrolled in this study between February 2008 and December 2010 at Severance Hospital. Eighteen patients displayed LumXm (+) defined as LumXm positive class I or II and 37 patients displayed LumXm (−). Mean duration of follow‐up was 18.9 ± 8.3 months. During this period, no patient death or graft loss occurred. The incidence of biopsy‐proven or clinically presumed rejection was higher in the LumXm (+) group (n = 12, 66.7%) than in the LumXm (−) group (n = 6, 18.2%) (P = 0.001). All biopsy‐proven acute rejections (n = 12) were diagnosed as acute cellular rejection. No significant difference in mean serum creatinine level or eGFR was observed between the groups at 18 months post‐transplantation. The short‐term outcome of renal transplantation in sensitized patients with a LumXm (+) and a CDCXm (−) may be considered to be acceptable. However, patients with a LumXm (+) have a substantially higher immunological risk for the development of acute cellular rejection.

Proliferation of Pancreatic Endocrine Cells Using Disaggregation-Expansion-Reaggregation Technology in Isolated Rat Islets

Donor scarcity is a major obstacle for clinical islet transplantation. Hence, the effective use of the limited number of available islets is necessary for successful islet transplantation. We have developed a new technology that could produce pseudo-islets. Morphologic and functional evaluation was performed to test the feasibility of using these cells for transplantation. A 3-step procedure known as disaggregation-expansion-reaggregation (DER) was employed for pseudo-islet preparation. Islets isolated from 200 to 250-g male Lewis rats by collagenase digestion were separated into single cells by trypsinization. These pancreatic endocrine cells (PECs) were expanded by serial passages in culture before being aggregated at a high cell-density in a suspended state. After DER, cells were morphologically analyzed over time, and gene expression evaluated by reverse transcriptase polymerase chain reaction (RT-PCR). Through expansion by passage for 2 weeks in continuous cultures, approximately 1 million PECs were recovered after aggregation. By phase-contrast microscopy, they presented with spherical shapes and similar sizes compared with naïve islets (50-800 microm). RT-PCR results indicated expression of insulin, glucagon, and pancreatic and duodenal homeobox gene 1, which were observed in primary isolated islets as well. The insulin secretion capacity of pseudo-islets was confirmed by enzyme-linked immunosorbent assay. In conclusion, PECs treated with DER showed potential to serve as a cell source for pseudo-islet generation after in vitro cellular expansion. These cells were both morphologically and genetically similar to naïve islets. Our new technique could be a potential method to overcome the scarcity of donor islets in the near future.

Manufacturing of Insulin-Secreting Spheroids with the RIN-5F Cell Line Using a Shaking Culture Method

BACKGROUND There have been many efforts to find methods to increase insulin production by islets or modified cells. Commercially available established cell lines can be a good source of artificial islets. We manufactured sphere-shaped cell clusters composed of insulin-secreting cells from the commercially available RIN-5F cell line. METHODS To generate artificial islets with insulin-secretion functions, we used the RIN-5F cell line. When cells cultured in RPMI-1640 medium containing 10% fetal bovine serum reached near confluency, they were trypsinized for suspension culture at high density, using a horizontal shaker. The cells were maintained for 5 days under 5% CO(2) with humidification. Next, the media from the RIN cell spheroid culture was collected over 5 consecutive days to test for insulin secretion. RESULTS Spheroids of artificial islets exhibited an oval shape with an approximate size of 94.13 ± 20.41 μm on day 5 during the shaking culture. Abnormal outgrowth of spheroids was not observed. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive cells were not detected among the overall spheroids, including the core position. Insulin secretion, measured by enzyme-linked immunosorbent assay, was well maintained in the culture media over 5 days after spheroid formation. CONCLUSION This result suggested that a culture method with shaking can be applied to commercially available established cell lines to generate artificial islets, which might be used for a bioartificial pancreas.

Illumina-microarray analysis of mycophenolic acid-induced cell death in an insulin-producing cell line and primary rat islet cells: New insights into apoptotic pathways involved

Mycophenolic acid (MPA), widely used to prevent organ transplant rejection, may induce toxicity and impair function in beta-cells. Mechanisms of MPA-induced cell death have not been fully explored. In this study, we examined gene expression patterns in INS-1E cells and isolated primary rat islets following MPA treatment using the Illumina-cDNA microarray. The MPA treatment decreases RhoGDI-alpha gene expression, which points to apoptosis by JNK activation through a MAPKs-dependent pathway. A strong association between RhoGDI-alpha and Rac1 activation during MPA-induced apoptosis is also consistent with apoptosis through JNK. Suppression of RhoGDI-alpha using siRNA and gene over-expression both affected the cell death rate, consistent with Rac1 activation and downstream activation of MAPKs signaling. We confirmed that Rac1 protein mediates the interaction between RhoGDI-alpha and JNK signaling. We conclude that MPA-induced cell death in primary beta-cells and an insulin-secreting cell line proceeds through RhoGDI-alpha down-regulation linked to Rac1 activation, with subsequent activation of JNK. The RhoGDI-alpha/Rac1/JNK pathway may present a key to intervention in MPA-induced islet apoptosis.