Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

No Prognostic Impact of Graft-to-Recipient Weight Ratio on Hepatocellular Carcinoma Recurrence Following Living Donor Liver Transplantation

BACKGROUND The effects of a low graft-to-recipient weight ratio (GRWR) on the prognosis of patients with hepatocellular carcinoma (HCC) are unclear. The present study examined whether the GRWR had an impact on the rate of HCC recurrence following living donor liver transplantation (LDLT). MATERIAL AND METHODS This retrospective observational single-center study included 856 patients who underwent LDLT for HCC between January 2006 and December 2016 at Asan Medical Center and evaluated the association between GRWR and post-transplant tumor recurrence. RESULTS Of the 856 patients who underwent LDLT for HCC, 54 (6.3%), 272 (31.8%), 274 (32.0%), and 256 (29.9%) had GRWR <0.8%, 0.8-0.99%, 1.0-1.19%, and ≥1.2%, respectively. Analysis of all patients revealed that the disease-free survival (DFS; P=0.545) and overall survival (OS; P=0.313) rates were not different in these 4 groups. Subgroups analyses also showed that GRWR did not influence survival rates in patients within (DFS: P=0.398; OS: P=0.676) and beyond (DFS: P=0.602; OS: P=0.649) the Milan criteria, or in patients with alpha-fetoprotein-des-γ-carboxyprothrombin-tumor volume scores <5log (DFS: P=0.633; OS: p=0.285) and ≥5log (DFS: P=0.674; OS: P=0.906). CONCLUSIONS GRWR less than 0.8% did not demonstrate a noteworthy prognostic influence on the oncological results among patients who had undergone LDLT for HCC. High-volume multi-center studies are necessary to validate these findings.

Achieving 400 Living Donor Liver Transplantations Annually During the COVID-19 Pandemic: A Single-Center Experience

BACKGROUND

The COVID-19 pandemic has had a major impact on liver transplantation (LT) and living donor programs globally.

PURPOSE

In this study, we aimed to present the principles and strategies of our LT program during the pandemic period and describe its achievements.

BASIC PROCEDURES

We retrospectively reviewed the outcomes of 1417 LTs performed at Asan Medical Center, Seoul, Korea, from 2020 to 2022. Of these, 216 recipients who received transplants from deceased donors were excluded, and 1201 recipients who received transplants from 1268 live donors were included in the study, including 38 children <18 years old.

MAIN FINDINGS

Among the 1201 living donor LT (LDLT) recipients, the most common indication for LT was unresectable hepatocellular carcinoma (315/1163, 27.1%) in adults and biliary atresia (29/38, 76.3%) in pediatric recipients. Emergency LDLT was performed in 40 patients (3.3%). The median model of end-stage liver disease and pediatric end-stage liver disease scores were 13.9 ± 7.2 and 13.8 ± 7.1, respectively. In-hospital mortality of recipients was higher than usual at 2.2%, but the cause of death was not related to COVID-19 infection. Of the 1268 live donors who underwent hepatectomy for liver donation, 660 (52.1%) underwent hepatectomy using a minimally invasive approach. Although 17 (1.3%) live donors experienced major complications, there were no serious life-threatening complications and no mortality.

CONCLUSION

Even in a pandemic era, a team with well-established infection control protocols, patient-tailored surgical strategies, and thorough perioperative care can maintain LDLT at a similar quantitative and qualitative level as in a non-pandemic era.

Donor sex and donor-recipient sex disparity do not affect hepatocellular carcinoma recurrence after living donor liver transplantation

Purpose

Studies have yielded contradictory results on whether donor sex and donor-recipient sex disparity affect hepatocellular carcinoma (HCC) recurrence after living donor liver transplantation (LDLT). The present study assessed whether donor sex or donor-recipient sex disparity affects HCC recurrence after LDLT at a high-volume center.

Methods

This study included 772 HCC patients who underwent LDLT between January 2006 and December 2015 at Asan Medical Center. Patients were divided into 4 groups based on the sex of the donor and recipient: male-to-male (n = 490, 63.5%), male-to-female (n = 75, 9.7%), female-to-male (n = 170, 22.0%), and female-to-female (n = 37, 4.8%).

Results

Disease-free survival (DFS; P = 0.372) and overall survival (OS; P = 0.591) did not differ significantly among the 4 groups. DFS also did not differ significantly between LDLT recipients with male and female donors (P = 0.792) or between male and female recipients (P = 0.084). After patient matching with an α-FP/des-γ-carboxy prothrombin/tumor volume score cutoff of 5logs, donor-recipient sex disparity did not significantly affect DFS (P = 0.598) or OS (P = 0.777). There were also no differences in DFS in matched LDLT recipients with male and female donors (P = 0.312) or between male and female recipients (P = 0.374).

Conclusion

Neither donor sex nor donor-recipient sex disparity significantly affected posttransplant HCC recurrence.

Validation of quantitative prognostic prediction using ADV score for resection of hepatocellular carcinoma: A Korea-Japan collaborative study with 9200 patients

BACKGROUND

A score derived from the concentrations of α-fetoprotein (AFP) and des-γ-carboxy prothrombin (DCP) and tumor volume (TV), called ADV score, has been shown to be prognostic of hepatocellular carcinoma (HCC) recurrence following hepatic resection (HR) or liver transplantation.

METHODS

This multicenter, multinational validation study included 9200 patients who underwent HR from 2010 to 2017 at 10 Korean and 73 Japanese centers, and were followed up until 2020.

RESULTS

AFP, DCP, and TV showed weak correlations (ρ ≤ .463, r ≤ .189, p < .001). Disease-free survival (DFS), overall survival (OS), and post-recurrence survival rates were dependent on 1.0 log and 2.0 log intervals of ADV scores (p < .001). Receiver operating characteristic (ROC) curve analysis showed that ADV score cutoffs of 5.0 log for DFS and OS yielded the areas under the curve ≥ .577, with both being significantly prognostic of tumor recurrence and patient mortality at 3 years. ADV score cutoffs of ADV 4.0 log and 8.0 log, derived through K-adaptive partitioning method, showed higher prognostic contrasts in DFS and OS. ROC curve analysis showed that an ADV score cutoff of 4.2 log was suggestive of microvascular invasion, with both microvascular invasion and an ADV score cutoff of 4.2 log showing similar DFS rates.

CONCLUSIONS

This international validation study demonstrated that ADV score is an integrated surrogate biomarker for post-resection prognosis of HCC. Prognostic prediction using ADV score can provide reliable information that can assist in planning treatment of patients with different stages of HCC and guide individualized post-resection follow-up based on the relative risk of HCC recurrence.

Efficacy and safety of adhesion barrier in living-donor liver transplantation with right liver graft to prevent delayed gastric emptying

Delayed gastric emptying (DGE) is a common complication of liver transplantation. This study aimed to clarify the efficacy and safety of the application of an adhesion barrier for preventing DGE in living-donor liver transplantation. This retrospective study included 453 patients who underwent living-donor liver transplantation using a right lobe graft between January 2018 and August 2019, and the incidence of postoperative DGE and complications was compared between patients in whom adhesion barrier was used (n=179 patients) and those in whom adhesion barrier was not used (n=274 patients). We performed 1:1 propensity score matching between the 2 groups, and 179 patients were included in each group. DGE was defined according to the International Study Group for Pancreatic Surgery classification. The use of adhesion barrier was significantly associated with a lower overall incidence of postoperative DGE in liver transplantation (30.7 vs. 17.9%; p =0.002), including grades A (16.8 vs. 9.5%; p =0.03), B (7.3 vs. 3.4%; p =0.08), and C (6.6 vs. 5.5%; p =0.50). After propensity score matching, similar results were observed for the overall incidence of DGE (29.6 vs. 17.9%; p =0.009), including grades A (16.8 vs. 9.5%; p =0.04), B (6.7 vs. 3.4%; p =0.15), and C (6.1 vs. 5.0%; p =0.65). Univariate and multivariate analyses showed a significant correlation between the use of adhesion barrier and a low incidence of DGE. There were no statistically significant differences in postoperative complications between the 2 groups. The application of an adhesion barrier could be a safe and feasible method to reduce the incidence of postoperative DGE in living-donor liver transplantation.

Should we be reluctant to perform pancreatectomy in patients with chronic liver disease? A single center 10-year experience

PURPOSE

Many studies have shown extra-hepatic surgery in patients with chronic liver disease (CLD) with or without portal hypertension can result in complications. The aim of this study was to analyze the results of major pancreatectomy in patients with CLD including cirrhosis and to evaluate their efficacy and safety.

METHODS

We retrospectively reviewed 319 patients undergoing open pancreatoduodenectomy (PD) or distal pancreatectomy (DP) in our center. Those who received PD and DP in patients without CLD were classified into groups A and D, and those with CLD into groups B and C, respectively. Group B and C were subdivided into groups 1 and 2 according to the presence of portal hypertension.

RESULTS

Forty-three patients (13.5%) had CLD. Of the 221 patients who received PD, 25 had CLD. Of the 98 patients who received DP, 18 (Group C) had CLD. In the PD group, patients with portal hypertension (group B1) had longer operative time. However, the transfusion rate and complication rate were not significantly different from other groups. There was no mortality in patients with CLD without portal hypertension (group B2) and the complication and mortality rate was comparable to patients with normal liver function (group A). In the DP group, the transfusion rate, complication rate and mortality rate were significantly higher in patients with portal hypertension (group C1).

CONCLUSIONS

Acceptable outcomes were obtainable following pancreatic surgery in cirrhotic, non-portal hypertensive patients with surgical outcomes equivalent to non-cirrhotic patients.

AbbreviationsCLDchronic liver diseasePDpancreaticoduodenectomyDPdistal pancreatectomy.

Expression Patterns of Tumor Markers in Liver Transplant Recipients Showing Complete Pathological Response of Hepatocellular Carcinoma

Complete pathological response (CPR) is achieved with various pretransplant locoregional treatments for hepatocellular carcinoma (HCC). This study aimed to investigate pretransplant expression of HCC tumor markers in liver transplantation (LT) recipients showing CPR. For the CPR group, 166 patients were selected from a single-institution LT database. Two control groups of 332 patients without HCC and 184 patients with partial pathological response (PPR) were also selected. The model for end-stage liver disease score in the CPR group was 11.5 ± 7.7. The number of transcatheter arterial chemoembolization sessions before LT was one in 68 patients (14.0%), two in 38 patients (22.9%), and three or more in 60 patients (36.1%). A solitary non-viable tumor was identified in 120 (86.4%) of the explant livers and the largest tumor size was 2.4 ± 1.3 cm. Living-donor and deceased-donor LTs were performed in 152 (91.6%) and 14 (8.4%) patients, respectively. The median levels of α-fetoprotein (AFP) and protein induced by Vitamin K absence or antagonist-II (PIVKA-II) measured within two weeks before LT were 4.2 ng/mL and 20 mAU/mL, respectively. These tumor marker levels were comparable to those in the no-HCC control group, but much lower than those in the PPR group (p < 0.001). Receiver operating characteristic curve analysis of AFP and PIVKA-II showed no definite cutoff values for CPR in the cohort of CPR and no-HCC patients, but significant cutoffs of 6.5 ng/mL for AFP and 29 mAU/mL for PIVKA-II were obtained in the cohort of CPR and PPR patients. The 1-, 3- and 5-year HCC recurrence and overall patient survival rates of the CPR group were 5.1% and 93.3%, 7.6% and 89.6%, and 7.6% and 89.6%, respectively. These tumor recurrence rates were much lower than those in the PPR group (p < 0.001). In conclusion, the present study results suggest that normalizing AFP and PIVKA-II after locoregional treatment is indicative of CPR. However, some CPR patients showed high expression of tumor markers; thus, pretransplant values of HCC tumor markers should be interpreted with caution.

Right posterior bile duct stricture after central bisectionectomy or anterior sectionectomy

PURPOSE

Before performing anterior sectionectomy (AS) or central bisectionectomy (CBS), the anatomy of the right posterior bile duct (RPBD) must be cautiously assessed owing to the many variations of the RPBD and its variations could be related to bile duct injury.

METHODS

Clinical data of patients who underwent AS or CBS from 2009 to 2018 were reviewed. The bile duct anatomy according to Okubo's criteria and the right bile duct (RBD) length were evaluated using MRI, and we performed a risk factor analysis of the RPBD stricture (RPBDS).

RESULTS

A total of 68 patients were included. Type A bile ducts were the most common (n = 36, 52.9%). Five (7.2%) patients had RPBDS requiring intervention. RPBDS only occurred in patients with a type A bile duct and a type A portal vein undergoing surgery using the Glissonian sheath approach. Moreover, when the RBD length was > 12 mm, the sensitivity and specificity were 0.8 and 0.889, respectively. In multivariate analysis, RBD length of > 12 mm was significant.

CONCLUSION

A careful review of RPBD anatomy especially in patient with long RBD and caution when using the anterior Glissonian sheath approach might be helpful to prevent RPBDS during AS or CBS.

Twenty-year longitudinal follow-up after liver transplantation: a single-center experience with 251 consecutive patients

Background

The outcomes of liver transplantation (LT) have improved, but actual 20-year survival data have rarely been presented.

Methods

Longitudinal follow-up data of 20-year LT survivors were retrospectively analyzed. The LT database of our institution was searched to identify patients who underwent primary LT from January 2000 to December 2001. The study cohort of 251 patients was divided into three groups 207 adults who underwent living donor LT (LDLT), 22 adults who underwent deceased donor LT (DDLT), and 22 pediatric patients who underwent LT.

Results

Hepatitis B virus-associated liver cirrhosis and biliary atresia were the most common indications for adult and pediatric LT, respectively. Seven patients required retransplantation, including six who underwent DDLT and one who underwent LDLT. Twenty-two patients died within 3 months after LT and 69 died at later intervals. The overall survival rates at 1, 3, 5, 10, and 20 years were 86.4%, 79.6%, 77.7%, 72.8%, and 62.6%, respectively, in the adult LDLT group; 86.4%, 72.7%, 72.7%, 72.7%, and 68.2%, respectively, in the adult DDLT group; and 86.4%, 86.4%, 81.8%, 81.8%, and 77.3%, respectively, in the pediatric LT group (P=0.545). Common immunosuppressive regimens at 20 years included tacrolimus monotherapy, tacrolimus-mycophenolate dual therapy, cyclosporine monotherapy, and mycophenolate monotherapy.

Conclusions

The present study is the first report of actual 20-year survival data from a Korean high-volume LT center. The graft and patient survival outcomes reflected the early experiences of LT in our institution, with long-term outcomes being similar regardless of graft type and patient age.

Salvage living donor liver transplantation versus repeat liver resection for patients with recurrent hepatocellular carcinoma and Child-Pugh class A liver cirrhosis: A propensity score-matched comparison

Following curative liver resection (LR), resectable tumor recurrence in patients with preserved liver function leads to deciding between a repeat LR and a salvage liver transplantation (LT), if a donor's liver is available. This retrospective study compared survival outcomes and recurrence pattern following salvage living donor LT (LDLT) and repeat LR in patients with recurrent hepatocellular carcinoma (HCC). We reviewed the medical records of patients who underwent repeat LR (n = 163) or LDLT (n = 84) for recurrent HCC following curative resections, between January 2005 and December 2017 at a single institution. A 1:1 propensity score matching led to 42 patients per group. Disease-specific and recurrence-free survival were significantly better in the salvage LDLT group than in the repeat LR group (p = .042; HR = 2.40; 95% CI, 0.69-6.00 and p < .001; HR = 4.23; 95% CI, 2.05-8.71, respectively). Despite significant differences in recurrence patterns between the two groups (p = .019), the patient death rates, after recurrence, were similar for both groups (p = .760). This study indicates that salvage LDLT is superior to repeat LR for treating patients with transplantable, intrahepatic HCC recurrence, even in patients with Child-Pugh class A liver cirrhosis.

Efficacy and Safety Evaluation After Conversion From Twice-Daily to Once-Daily Tacrolimus in Stable Liver Transplant Recipients: A Phase 4, Open-Label, Single-Center Study

BACKGROUND

Simplifying immunosuppressive therapy after liver transplant may improve patient compliance, thereby preventing acute rejection and graft loss. This phase 4, open-label, single-center study was conducted to evaluate the efficacy and safety of twice-daily to once-daily tacrolimus conversion in stable liver transplant recipients.

METHODS

Between May 2017 and January 2019, twice-daily tacrolimus was converted to once-daily tacrolimus in 101 stable recipients at least 12 months post-liver transplant in Asan Medical Center. The doses of both drugs was converted to 1:1, and the target trough level was 5 to 10 ng/mL. We prospectively analyzed graft function, drug compliance, and adverse reactions after switching regimen for 24 weeks.

RESULTS

There was no acute rejection confirmed histologically within 24 weeks, which was the primary endpoint, and there was no chronic rejection, fatal deterioration of liver function, or death in any patient during this period. After conversion, the trough level of tacrolimus decreased, and the mean ± standard deviation differences between the trough level and baseline level were 1.46 (±2.41) ng/mL, 0.43 (±2.08) ng/mL, and 0.07 (±2.73) ng/mL at 3, 12, and 24 weeks after conversion, respectively. Despite transient fluctuations of the trough level, there was no evidence of rejection or graft dysfunction. There were 37 adverse reactions after conversion; most of them were mild, and thrombocytopenia developed in 1 patient as an adverse drug response. Drug compliance improved after conversion according to questionnaire responses.

CONCLUSIONS

The conversion to once-daily tacrolimus in stable liver transplant recipients is an effective and safe therapeutic strategy improving drug compliance.

Fates of retained hepatic segment IV and its prognostic impact in adult split liver transplantation using an extended right liver graft

PURPOSE

When splitting a liver for adult and pediatric graft recipients, the retained left medial section (S4) will undergo ischemic necrosis and the right trisection graft becomes an extended right liver (ERL) graft. We investigated the fates of the retained S4 and its prognostic impact in adult split liver transplantation (SLT) using an ERL graft.

METHODS

This was a retrospective analysis of 25 adult SLT recipients who received split ERL grafts.

RESULTS

The mean model for end-stage liver disease (MELD) score was 27.3 ± 10.9 and graft-recipient weight ratio (GRWR) was 1.98 ± 0.44. The mean donor age was 26.5 ± 7.7 years. The split ERL graft weight was 1,181.5 ± 252.8 g, which resulted in a mean GRWR of 1.98 ± 0.44. Computed tomography of the retained S4 parenchyma revealed small ischemic necrosis in 16 patients (64.0%) and large ischemic necrosis in the remaining 9 patients (36.0%). No S4-associated biliary complications were developed. The mean GRWR was 1.87 ± 0.43 in the 9 patients with large ischemic necrosis and 2.10 ± 0.44 in the 15 cases with small ischemic necrosis (P = 0.283). The retained S4 parenchyma showed gradual atrophy on follow-up imaging studies. The amount of S4 ischemic necrosis was not associated with graft (P = 0.592) or patient (P = 0.243) survival. A MELD score of >30 and pretransplant ventilator support were associated with inferior outcomes.

CONCLUSION

The amount of S4 ischemic necrosis is not a prognostic factor in adult SLT recipients, probably due to a sufficiently large GRWR.

Third retransplantation using a whole liver graft for late graft failure from hepatic vein stent stenosis in a pediatric patient who underwent split liver retransplantation

We present a case of third retransplantation using a whole liver graft in a 13-year-old girl who suffered graft failure and hepatopulmonary syndrome following split liver retransplantation with endovascular stenting of the hepatic and portal veins as an infant. She was diagnosed with biliary atresia-polysplenia syndrome, and thus underwent living donor liver transplantation from her mother at 9 months of age. The first liver graft failed due to stenosis of the portal vein. She underwent the second liver transplantation with a split left lateral section graft. Endovascular stenting was performed to the portal vein stenosis 2 months and hepatic vein stenosis 9 months after transplantation. During the next 9 years, 11 sessions of balloon angioplasty for hepatic vein stent stenosis were performed. Ten years after the second transplantation, she underwent third transplantation using a whole liver graft recovered from a 12-year-old-girl. The double inferior vena cava technique was used for outflow vein reconstruction. The graft portal vein was anastomosed with the stent-containing portal vein stump because it was not possible to remove the stent and the inner diameter of the portal vein stent was large enough. An aorto-hepatic jump graft was used for arterial reconstruction. The patient recovered slowly and is doing well for 6 months posttransplant. In conclusion, because stenting of the hepatic vein or portal vein can induce graft failure leading to late retransplantation, we emphasize secure vascular reconstruction to prevent endovascular stenting during LT in infants.

Prognosis of hepatic epithelioid hemangioendothelioma after living donor liver transplantation

Background

Epithelioid hemangioendothelioma (EHE) is a rare borderline vascular tumor. Due to its rarity and protean behavior, the optimal treatment of hepatic EHE has not yet been standardized. This single-center study describes outcomes in patients with hepatic EHE who underwent living donor liver transplantation (LDLT).

Methods

The medical records of patients who underwent LDLT for hepatic EHE from 2007 to 2016 were reviewed.

Results

During 10-year period, four patients, one man and three women, of mean age 41.3±11.1 years, underwent LDLT for hepatic EHE. Based on imaging modalities, these patients were preoperatively diagnosed with EHE or hepatocellular carcinoma, with percutaneous liver biopsy confirming that all four had hepatic EHE. The tumors were multiple and scattered over entire liver, precluding liver resection. Blood tumor markers were not elevated, except that CA19-9 and des-γ-carboxy prothrombin was slightly elevated in one patient. Mean model for end-stage liver disease score was 10.8±5.7. All patients underwent LDLT using modified right liver grafts, with graft-recipient weight ratio of 1.11±0.19, and all recovered uneventfully after LDLT. One patient died due to tumor recurrence at 9 months, whereas the other three have done well without tumor recurrence, resulting in 5-year disease-free and overall patient survival rates of 75% each. The patient with tumor recurrence was classified as a high-risk patient based on the original and modified hepatic EHE-LT scoring systems.

Conclusions

LDLT can be an effective treatment for patients with unresectable hepatic EHEs that are confined within the liver and absence of macrovascular invasion and lymph node metastasis.

National survey of Korean hepatobiliary-pancreatic surgeons on attitudes about the enhanced recovery after surgery protocol

Backgrounds/Aims

The purpose of this study was to investigate attitudes regarding the Enhanced Recovery After Surgery (ERAS) protocol of hepato-biliary-pancreatic (HBP) surgeons in Korea and the extent to which they use the protocol for perioperative management.

Methods

An online survey was conducted among members of the Korean Association of Hepato-Biliary-Pancreatic Surgery (KAHBPS) for eight weeks beginning on August 2019. The questionnaire, which was written in Korean, was based on the latest ERAS guidelines. Total responses were collected from 127 surgeons.

Results

Of the 127 total respondents, the largest proportion (44.9%) were working in Seoul. In terms of established in-hospital clinical pathways (CP), 19.7% of the participating surgeons had and followed a CP in pancreaticoduodenectomy (PD) and 21.3% in hepatectomy. Regarding the ERAS protocol for each surgery, four items (18.2%) regarding PD and seven items (35.0%) related to hepatectomy were followed by more than 50% of respondents.

Conclusions

ERAS guidelines are one of the consensuses for better recovery in perioperative management of patients undergoing major surgeries and encompass the overall process of patient recovery including patient education, pain control, physiologic balance, and perioperative nutrition. A novel project is needed to successfully implement an evidence-based enhanced recovery strategy.

Over 500 Liver Transplants Including More Than 400 Living-Donor Liver Transplants in 2019 at Asan Medical Center

BACKGROUND

More than 400 liver transplants were performed at Asan Medical Center (AMC) in 2011, and over 500 liver transplants including 420 living-donor liver transplants (LDLTs) were performed in 2019. Herein, we report the methodology of these procedures.

METHODS

Since the first adult LDLTs at AMC using the left and right lobes were successfully performed, various innovative techniques and approaches have been developed: modified right lobe, dual graft, donor exchange for ABO incompatibility, expansion of indications and no-touch techniques for hepatocellular carcinoma, intraoperative cine-portogram and additional intervention for large collaterals, management of portal vein thrombosis (PVT) and stenosis, salvage LDLT after major hepatectomy, and timely LDLT for patients with acute-on-chronic liver failure.

RESULTS

Four hundred twenty LDLTs in 403 adult and 17 pediatric patients and 85 deceased-donor liver transplants in 74 adult and 11 pediatric patients were performed. The number of deceased-donor liver transplants remained constant since 2011, but the number of LDLTs increased steadily. One hundred thirty patients (25.7%) required urgent liver transplantations and 24 patients with acute-on-chronic liver failure underwent LDLT. PVT including grade 1,2,3, and 4 was reported in 91 patients (18.0%), and Yerdel's grade 2, 3, and 4 PVT was reported in 47 patients (51.6%); all patients with PVT were successfully treated. Adult LDLTs for hepatocellular carcinoma and ABO incompatibility accounted for 52.6% and 24.3% of the cases, respectively. In-hospital mortality in 2019 was 2.97%.

CONCLUSION

Continual efforts to overcome challenging problems in LDLT with various innovations and dedication of the team members during the perioperative period to improve patient outcomes were crucial in increasing the number of liver transplantations at Asan Medical Center.

Feasibility and safety of bisegmentectomy 7-8 while preserving hepatic venous outflow of the right liver - A retrospective cohort study

BACKGROUND

When a hepatic tumor is deeply located in segments 7 and 8 around the right hepatic vein (RHV), right hemihepatectomy (RH) could be excessive owing to the resection of large tumor-free segments. This study aimed to evaluate the feasibility and safety of bisegmentectomy 7-8 (S7-8) and to compare its surgical outcomes with those of RH.

MATERIALS AND METHODS

Consecutive patients who underwent S7-8 and RH were enrolled in this study. In the S7-8 group, 14 patients with an obvious inferior right hepatic vein (IRHV) (median: 6 mm; range: 3.6-8.8 mm) underwent S7-8 without hepatic vein reconstruction. RHV reconstruction was performed in six patients without an IRHV, involving direct anastomosis of the RHV in five patients and reconstruction using a cryo-preserved iliac vein in one patient.

RESULTS

A total of 61 patients were included (20 in S7-8 group; 41 in RH group). No significant differences were observed other than higher a model of end-stage liver disease score in the RH group than in the S7-8 group (7 [6-20] vs. 6 [6-9], P = 0.003). Post-hepatectomy liver failure including severe grades was more frequent in the RH group (43.9% vs. 10%, P = 0.008). In the S7-8 group, two patients with direct RHV reconstruction had RHV anastomosis obstruction, and eventually required insertion of a metallic stent. However, computed tomography performed 4 weeks after the operation showed intact venous outflow of the right liver in the S7-8 group.

CONCLUSION

S7-8 can be performed safely in selected patients with a thick IRHV. For patients with no obvious IRHV, RHV reconstruction could be a good surgical strategy to retain venous outflow of the right liver with feasible outcomes.

Once-daily, prolonged-release tacrolimus vs twice-daily, immediate-release tacrolimus in de novo living-donor liver transplantation: A Phase 4, randomized, open-label, comparative, single-center study

Randomized, open-label, comparative, single-center, Phase 4, 24-week study comparing pharmacokinetics (PK), safety, and efficacy of once-daily, prolonged-release tacrolimus (PR-T) with twice-daily, immediate-release tacrolimus (IR-T) in adult de novo living-donor liver transplant (LDLT) recipients in Korea. All patients received intravenous tacrolimus from Day 0 (transplantation) for 4 days and were randomized (1:1) to receive oral PR-T or IR-T from Day 5. PK profiles were taken on Days 6 and 21. Primary endpoint: area under the concentration-time curve over 24 hour (AUC_0-24 ). Predefined similarity interval for confidence intervals of ratios: 80%-125%. Secondary endpoints included: tacrolimus concentration at 24 hour (C₂₄ ), patient/graft survival, biopsy-confirmed acute rejection (BCAR), treatment-emergent adverse events (TEAEs). One-hundred patients were included (PR-T, n = 50; IR-T, n = 50). Compared with IR-T, 40% and 66% higher mean PR-T daily doses resulted in similar AUC_0-24 between formulations on Day 6 (PR-T:IR-T ratio of means 96.8%), and numerically higher AUC_0-24 with PR-T on Day 21 (128.8%), respectively. Linear relationship was similar between AUC_0-24 and C₂₄ , and formulations. No graft loss/deaths, incidence of BCAR and TEAEs similar between formulations. Higher PR-T vs IR-T doses were required to achieve comparable systemic exposure in Korean de novo LDLT recipients. PR-T was efficacious; no new safety signals were detected.

Outcome of ABO-incompatible adult living-donor liver transplantation for patients with hepatocellular carcinoma

BACKGROUND & AIMS

Living-donor liver transplantation (LDLT) can simultaneously cure hepatocellular carcinoma (HCC) and underlying liver cirrhosis, improving long-term results in patients with HCC. ABO-incompatible LDLT could expand the living-donor pool, reduce waiting times for deceased-donor liver transplantation, and improve long-term survival for some patients with HCC.

METHODS

We retrospectively reviewed the medical records of patients undergoing LDLT for HCC from November 2008 to December 2015 at a single institution in Korea. In total, 165 patients underwent ABO-incompatible and 753 patients underwent ABO-compatible LDLT for HCC. ABO-incompatible recipients underwent desensitization to overcome the ABO blood group barrier, including pretransplant plasma exchange and rituximab administration (300-375 mg/m² /body surface area).

RESULTS

We performed 1:1 propensity score matching and included 165 patients in each group. 82.4% of ABO-incompatible and 83.0% of -compatible LDLT groups had HCC within conventional Milan criteria, respectively, and 92.1% and 92.7% of patients in each group had a Child-Pugh score of A or B. ABO-incompatible and -compatible LDLT groups were followed up for 48.0 and 48.7 months, respectively, with both groups showing comparable recurrence-free survival rates (hazard ratio [HR] 1.14; 95% CI 0.68-1.90; p = 0.630) and overall patient-survival outcomes (HR 1.10; 95% CI 0.60-2.00; p = 0.763).

CONCLUSIONS

These findings suggested that ABO-incompatible liver transplantation is a feasible option for patients with HCC, especially for those with compensated cirrhosis with HCC within conventional Milan criteria.

LAY SUMMARY

Despite hypothetical immunological concerns that the desensitization protocol for breaking through the ABO blood group barrier might have a negative impact on the recurrence of hepatocellular carcinoma, our experience demonstrated no significant differences in the long-term overall survival and recurrence-free survival rates between patients receiving ABO-compatible or ABO-incompatible liver transplantation. In conclusion, results from our institution indicated that ABO-incompatible living-donor liver transplantation constitutes a potentially feasible option for patients with hepatocellular carcinoma, especially those with compensated cirrhosis with hepatocellular carcinoma within conventional Milan criteria.

Long-term results of laparoscopic liver resection for the primary treatment of hepatocellular carcinoma: role of the surgeon in anatomical resection

BACKGROUND

Liver resection is a potentially curative therapy for hepatocellular carcinoma (HCC). LLR is a newly developed and safe technique associated with shorter hospital stay, less pain, better cosmetic outcomes, and similar complication rates as open surgery; however, data on its long-term outcomes remain scarce.

METHODS

We retrospectively examined the clinical and follow-up data of 234 patients who underwent LLR (performed by a single surgeon in all cases) for the primary treatment of HCC between July 2007 and December 2015 at Asan Medical Center.

RESULTS

The mean patient age was 55.63 (range 31-76) years; 167 were men. The median follow-up duration was 38 (range 6-116) months. A total of 227 patients (97.0%) had Child-Turcotte-Pugh grade A disease. Of them, 167 (71.4%) underwent anatomical resections and 63 (28.6%) underwent non-anatomical partial hepatectomies. Overall survival rates were 98.3, 91.7, and 87.1%, and recurrence-free survival rates were 82.1, 67.5, and 55.3% at 1, 3, and 5 years, respectively. In Cox regression analysis, anatomical resection was a risk factor for recurrence (univariate analysis: hazard ratio [HR] 0.49; 95% confidence interval [CI] 0.31-0.75; p = 0.001; multivariate analysis: HR 0.59; 95% CI 0.38-0.94; p = 0.025).

CONCLUSIONS

LLR is an acceptable primary treatment for patients with HCC with good hepatic function and with an appropriate anatomical structure, and is associated with improved prognosis. LLR can achieve lower recurrence rates through anatomical resection.

Metformin-associated Chemopreventive Effects on Recurrence After Hepatic Resection of Hepatocellular Carcinoma: From In Vitro to a Clinical Study

BACKGROUND/AIM

We investigated metformin-induced cytotoxic effects in vitro and assessed the chemopreventive effects of metformin in patients undergoing hepatic resection (HR) for hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

This study consisted of laboratory and clinical studies.

RESULTS

In vitro study using HCC cell lines revealed noticeable cytotoxic effects of metformin, that were largely weaker than those of sorafenib. In the clinical study, no statistical differences were found in tumor recurrence or overall survival between metformin and control groups. In contrast, there was a non-significant difference in tumor recurrence between metformin and propensity score-matched control groups, but there was a significant difference in overall patient survival. Metformin administration was an independent risk factor for patient survival.

CONCLUSION

In conclusion, our in vitro laboratory study demonstrated the presence of cytotoxic effects of metformin. Metformin administration was associated with reduced tumor recurrence and helped induce significant improvements in overall patient survival in patients who underwent HR for HCC.

Dual-graft adult living donor liver transplantation with ABO-incompatible graft: short-term and long-term outcomes

ABO-incompatible (ABOi) dual-graft (DG) adult living donor liver transplantation (ALDLT) is not commonly performed due to its inherently intricate surgical technique and immunological complexity. Therefore, data are lacking on the short- and long-term clinical outcomes of ABOi DG ALDLT. We performed a retrospective study by reviewing the medical records of patients who underwent ABOi DG ALDLT between 2008 and 2014. Additionally, computed tomography volumetric analysis was conducted to assess the graft regeneration rate. The mean age of a total of 28 recipients was 50.2 ± 8.5 years, and the mean model for end-stage liver disease score was 12.2 ± 4.6. The 1-, 3-, and 5-year patient survival rate was 96.4% during the mean follow-up period of 57.0 ± 22.4 months. The 1-, 3-, and 5-year graft survival rate was 96.4%, 94.2%, and 92.0%, respectively, and no significant differences were observed between ABO-compatible (ABOc) and ABOi grafts (P = .145). The biliary complication rate showed no significant difference (P = .195) between ABOc and ABOi grafts. Regeneration rates of ABOi grafts were not significantly different from those of ABOc grafts. DG ALDLT with ABOi and ABOc graft combination seems to be a feasible option for expanding the donor pool without additional donor risks.

Successful introduction of Model for End-stage Liver Disease scoring in deceased donor liver transplantation in Korea: analysis of first 1 year experience at a high-volume transplantation center

Backgrounds/Aims

Model for End-stage Liver Disease (MELD) score was adopted in June 2016 in Korea.

Methods

We analyzed changes in volumes and outcomes of deceased donor liver transplantation (DDLT) for 1 year before and after introduction of MELD scoring at Asan Medical Center.

Results

There were 64 cases of DDLT in 1 year before MELD introduction and 106 in 1 year after MELD introduction, an increase of 65%. The volume of DDLTs abruptly increased during first 3 months, but then returned to its usual level before MELD introduction, which indicated 3-month depletion of accumulated recipient pool with high MELD scores. The number of pediatric DDLT cases increased from 3 before MELD introduction to 11 after it, making up 21.4% and 47.8% of all cases of pediatric liver transplantation, respectively. The number of cases of retransplanted DDLTs increased from 4 to 27, representing 6.3% and 25.5% of all DDLT cases, respectively. The number of status 1 DDLT cases increased from 5 to 12, being 7.8% and 11.3% of all cases. Patient survival outcomes were similar before and after MELD introduction.

Conclusions

The number of DDLTs temporarily increased after adoption of MELD scoring due to accumulated recipient pool with high MELD scores. The numbers of retransplanted and pediatric DDLT cases significantly increased. Patient survival in adult and pediatric DDLT was comparable before and after adoption of MELD scoring. These results imply that Korean MELD score-based allocation system was successfully established within its first year.

Prognostic effect of transarterial chemoembolization-induced complete pathological response in patients undergoing liver resection and transplantation for hepatocellular carcinoma

Transarterial chemoembolization (TACE)-induced complete pathological response (CPR) is known to improve postresection outcomes of hepatocellular carcinoma (HCC). We aimed to assess the prognostic effects of CPR after preoperative TACE for HCC in patients who underwent hepatic resection (HR) or liver transplantation (LT). The clinical outcomes of patients showing CPR after HR (n = 110) or LT (n = 233) were analyzed. The control groups comprised patients with minimal recurrence risk as naïve single HCC ≤ 2 cm for HR (n = 476), and 1 or 2 HCCs ≤ 2 cm for LT (n = 184). Among HR study patients, 1-, 3-, and 5-year tumor recurrence rates were 18.5%, 50.6%, and 58.7% respectively, which were higher than those of controls (P < 0.001). The 1-, 3-, and 5-year patient survival rates were 97.8%, 82.0%, and 69.1%, respectively, which were lower than those of controls (P < 0.001). Among LT study patients, 1-, 3-, and 5-year tumor recurrence rates were 4.1%, 7.9%, and 7.9%, respectively, which were higher than those of controls (P = 0.019). The 1-, 3-, and 5-year patient survival rates were 92.7%, 89.2%, and 86.9%, respectively, which were not different than those of controls (P = 0.11). LT recipients had lower recurrence and higher survival rates compared with HR patients (P < 0.001). The tumor recurrence site was mainly intrahepatic in HR patients. There was no difference between the incidences of extrahepatic recurrence in the HR study group and all-site recurrence in the LT study group (P = 0.61). We concluded that the prognostic effect of TACE-induced CPR for HCC patients appears to be limited to downstaging. LT recipients benefited more from CPR than HR patients. Liver Transplantation 23 781-790 2017 AASLD.

In Situ Split Liver Transplantation for 2 Adult Recipients: A Single-Center Experience

Background Material and Methods Results Conclusions.

Longterm prognosis of combined hepatocellular carcinoma-cholangiocarcinoma following liver transplantation and resection

Combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CC) is a rare disease. We investigated the clinicopathological features of cHCC-CC and compared the longterm outcomes following liver transplantation (LT) and hepatic resection (HR). We identified 32 LT patients with cHCC-CC through an institutional database search. The HR control group (n = 100) was selected through propensity score-matching. The incidence of cHCC-CC among all adult LT patients was 1.0%. Mean patient age was 53.4 ± 6.7 years, and 26 patients were male. Thirty patients had hepatitis B virus infection. All patients of cHCC-CC were diagnosed incidentally in the explanted livers. Mean tumor diameter was 2.5 ± 1.3 cm, and 28 patients had single tumors. Tumor stage was stage I in 23 and II in 9. Concurrent hepatocellular carcinoma (HCC) was detected in 12 patients with stage I in 5 and II in 7. Mean tumor diameter was 1.9 ± 1.2 cm, and 5 had single tumors. Tumor recurrence and survival rates were 15.6% and 84.4% at 1 year and 32.2% and 65.8% at 5 years, respectively. Patients with very early stage cHCC-CC (1 or 2 tumors ≤ 2.0 cm) showed 13.3% tumor recurrence and 93.3% patient survival rates at 5 years, which were significantly improved than those with advanced tumors (P = 0.002). Tumor recurrence and survival rates did not differ significantly between the LT and HR control groups (P = 0.22 and P = 0.91, respectively); however, postrecurrence patient survival did (P = 0.016). In conclusion, cHCC-CC is rarely diagnosed following LT, and one-third of such patients have concurrent HCC. The longterm posttransplant prognosis was similar following LT and HR. Very early cHCC-CC resulted in favorable posttransplant prognosis, thus this selection condition can be prudently considered for LT indication. Liver Transplantation 23 330-341 2017 AASLD.

Preoperative prognostic values of α-fetoprotein (AFP) and protein induced by vitamin K absence or antagonist-II (PIVKA-II) in patients with hepatocellular carcinoma for living donor liver transplantation

BACKGROUND

Adult living donor liver transplantation (LDLT) is one of the best treatments for hepatocellular carcinoma (HCC). However, when recurrence of HCC after LDLT occurs, the prognosis is poor because of rapid progression. Preoperative level of α-fetoprotein (AFP) and protein induced by vitamin K antagonist-II (PIVKA-II) reportedly correlate with recurrence of HCC after LDLT.

METHODS

We examined AFP and PIVKA-II preoperatively as predictors of HCC recurrence in 461 patients who underwent LDLT using right liver graft for HCC from May 2007 to December 2013.

RESULTS

Among these, 77 patients (16.7%) who experienced recurrence were retrospectively reviewed. Multivariate analysis revealed tumor size >5 cm, AFP >150 nag/mol and PIVKA-II >100 maul/mol as significant independent risk factors for recurrence. The median time to recurrence was 10 months. The median survival time after recurrence was 26 months, and the 1-, 3- and 5-year survival rates after recurrence were 80.5%, 58%, and 28.3% respectively.

CONCLUSIONS

Preoperatively, not only morphology of the tumor but also AFP and PIVKA-II levels can offers important information for the recurrence after LDLT for HCC. Thus, combination of tumor markers might be used for expansion of pre-existing strict selection criteria of liver transplantation for HCC.

Portal vein stenting as a significant risk factor for biliary stricture in adult living donor liver transplantation

BACKGROUND

Although perioperative portal vein (PV) stent implantation is an effective treatment for steno-occlusive disease in adult living donor liver transplantation (LDLT) recipients, we experienced high incidence of biliary anastomotic strictures (BAS) after PV stenting. In this study, we sought to clarify the relation between BAS and PV stenting and to suggest the possible mechanism of BAS and measures to reduce its incidence.

METHODS

We retrospectively analyzed 44 LDLT recipients who underwent PV stent implantation across the line of PV anastomosis regardless of the location of steno-occlusion (stent group) and their matched controls (non-stented LDLT recipients, n=131).

RESULTS

The incidence of BAS was higher in patients in the stent group than that in the control group (43.2% vs 17.6%, P=0.001). Cumulative 6-month and 1-, 2- and 5-year BAS rates were 31.8%, 34.1%, 41.4% and 43.2%, respectively, in the stent group and 13.0%, 13.8%, 16.1% and 17.8%, respectively, in the control group (P=0.001). Multivariate analysis revealed that PV stenting was an independent risk factor for BAS.

CONCLUSIONS

Although PV stent implantation is a reliable treatment modality for steno-occlusive PV in adult LDLT recipients, innovative methods to prevent the PV stent from crossing the line of PV anastomosis may be necessary to reduce the incidence of postoperative BAS.

Donor Safety and Recipient Liver Function After Right-Lobe Liver Transplantation From Living Donors With Gilbert Syndrome

BACKGROUND

Donor safety is the most important aspect in living-donor liver transplantation (LDLT). Gilbert syndrome is an autosomal recessive condition that is a common cause of isolated unconjugated hyperbilirubinemia, and its prevalence is not negligibly low in the general population. This study intended to assess donor safety and recipient liver function after LDLT with the use of right liver grafts from living donors with Gilbert syndrome.

METHODS

Among 2,140 right liver transplantations performed from January 2002 to December 20113 at our institution, we identified 12 living donors (0.6%) who showed a preoperative serum total bilirubin level of ≥2 mg/dL. These donors were clinically diagnosed with Gilbert syndrome. The clinical outcomes of these donors and their recipients were analyzed retrospectively.

RESULTS

The mean donor age was 24.6 ± 7.1 years, and 11 donors were male. All subjects met the preoperative evaluation conditions for right liver donation except for the level of unconjugated hyperbilirubinemia. The mean serum total bilirubin level of the donors was 2.23 ± 0.20 mg/dL before and 1.79 ± 0.61 mg/dL 1 year after right liver donation. The preoperative donor direct bilirubin level was 0.43 ± 0.19 mg/dL. The preoperative indocyanine green retention rate at 15 minutes was 8.2 ± 2.8%. All donors and recipients recovered uneventfully and were alive at the time of writing. The recipient serum total bilirubin level was 1.29 ± 0.47 mg/dL 1 year after LDLT.

CONCLUSIONS

We suggest that LDLT with living donors with Gilbert syndrome can be safely performed, but that a meticulous preoperative evaluation is vital to maximize donor safety.

The dermal stem cell factor and c-kit are overexpressed in melasma

BACKGROUND

The pathogenesis of melasma has not yet been clearly demonstrated. We tried to determine whether the stem cell factor (SCF) and its receptor c-kit are involved in the mechanism of hyperpigmentation of melasma because this factor is highly implicated in the stimulation of melanocyte function in vitro and in vivo.

OBJECTIVES

The present study was conducted to investigate the expression of SCF and c-kit on the lesions of melasma compared with nonlesional skin.

PATIENTS/METHODS

Skin samples were obtained from lesional and nonlesional facial skin of 60 Korean women with melasma. Immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis was performed to determine the expression of SCF and c-kit in melasma.

RESULTS

The expression of SCF was significantly increased at the lesional dermis compared with nonlesional dermis. However, there was no significant difference in the expression of SCF in lesional and nonlesional epidermis. The expression of c-kit was significantly increased at lesional epidermis compared with nonlesional skin. RT-PCR of SCF and c-kit mRNAs demonstrated increased expression of both types of transcripts in the lesional skin compared with nonlesional skin.

CONCLUSIONS

These results suggest that the increased expression of SCF in the dermis and of c-kit in the epidermis play an important role in the mechanism of hyperpigmentation in melasma.

Expression and function of peroxisome proliferator-activated receptors in human melanocytes

BACKGROUND

Peroxisome proliferator-activated receptors (PPARs) belong to the superfamily of nuclear receptors that heterodimerize with the retinoic X receptor. Agonists of PPAR have been known to play an important role in cellular responses including proliferation and differentiation. The expression and function of PPARs have not been investigated in human melanocytes, although they have been widely demonstrated in keratinocytes of the skin.

OBJECTIVES

To investigate the expression of PPARs in human melanocytes and the effects of PPAR activators on melanocyte growth and melanogenesis.

METHODS

We used immunocytochemistry and Western blot analysis to determine whether PPARs are expressed in melanocytes. To investigate further expression of PPAR subtypes, reverse transcriptase-polymerase chain reaction analysis was performed using PPAR subtype-specific oligonucleotides. The cell proliferation was measured using the Coulter counter. The effects on pigmentation were investigated with measurement of melanin contents, tyrosinase activity and its expression.

RESULTS

The mRNA of all three PPAR subtypes, PPAR-alpha, PPAR-beta/delta and PPAR-gamma, were expressed in melanocytes. Activators for PPAR-alpha (WY-14643) and PPAR-gamma (ciglitazone) inhibited proliferation of melanocytes in a dose-dependent manner, whereas bezafibrate, a preferential activator for PPAR-beta/delta, had no effect. This growth inhibition was accompanied by the morphological change of the melanocytes to an activated form with an increased number of dendrites and enlarged cell area compared with the control. The WY-14643 and ciglitazone also appeared to stimulate the melanin synthesis of melanocytes. This increase in pigmentation was due to stimulation of the tyrosinase activity without an increase in the expression of tyrosinase.

CONCLUSIONS

PPARs are expressed in human melanocytes and PPAR-alpha and PPAR-gamma activators inhibit melanocyte growth and stimulate melanogenesis.

Melasma: histopathological characteristics in 56 Korean patients

BACKGROUND

Melasma is a common acquired symmetrical hypermelanosis characterized by irregular light to dark brown macules and patches on sun-exposed areas of the skin. Its histopathological characteristics are not fully understood.

OBJECTIVES

To characterize the histopathological features of facial melasma skin in comparison with adjacent normal skin.

METHODS

Biopsies were taken from both melasma lesional skin and adjacent perilesional normal skin in 56 Korean women with melasma. The sections were stained using haematoxylin and eosin, Fontana-Masson, diastase-resistant periodic acid-Schiff, Masson trichrome and Verhoeff-van Gieson stains, and immunostaining for melanocytes. Data on the changes in number of melanocytes and melanin contents of the epidermis were analysed by a computer-assisted image analysis program. The ultrastructure of the skin was also examined.

RESULTS

The amount of melanin was significantly increased in all epidermal layers in melasma skin. The staining intensity and number of epidermal melanocytes increased in melasma lesions. Lesional skin showed more prominent solar elastosis compared with normal skin. Melanosomes increased in number and were more widely dispersed in the keratinocytes of the lesional skin. Lesional melanocytes had many more mitochondria, Golgi apparatus, rough endoplasmic reticulum and ribosomes in their cytoplasm. A dihydroxyphenylalanine reaction was apparent in the cisternae and vesicles of the trans-Golgi network in melanocytes from lesional skin.

CONCLUSIONS

Melasma is characterized by epidermal hyperpigmentation, possibly caused both by an increased number of melanocytes and by an increased activity of melanogenic enzymes overlying dermal changes caused by solar radiation.

Negative regulation of filamentous growth and flocculation by Lkh1, a fission yeast LAMMER kinase homolog

We have isolated a full-length cDNA clone that encodes for a Schizosaccharomyces pombe homolog of the dual-specificity protein kinase of the LAMMER family, lkh1 (lammer kinase homolog). The proposed Lkh1 protein contains 575 amino acids. The lkh1(+) null mutant is viable, but exhibits flocculation upon reaching stationary phase in liquid media and filamentous adhesion growth on solid media. Analysis of the flocculation activity of the lkh1(+) null mutant indicates that asexual aggregation of S. pombe cells into floccules is divalent cation-dependent and galactose-specific. We also demonstrate that the Saccharomyces cerevisiae LAMMER kinase homolog, Kns1, can substitute for the Lkh1 function in S. pombe.

Absence of human papillomavirus DNA in nongenital seborrheic keratosis

Seborrheic keratosis (SK) is a benign epidermal tumor of unknown etiology. Because of its wart-like morphology, human papillomavirus (HPV) has been suggested as a possible causative agent. Viral involvement, however, has not been confirmed yet despite extensive research. The aim of this study was to evaluate the presence of HPV 6/11, 31, 33 DNA in nongenital SK. We analyzed 40 biopsy specimens taken from patients with nongenital SK using in situ polymerase chain reaction (PCR) and PCR with tissue extracts. The SK specimens (n=40), analyzed by in situ PCR, were negative for all HPV probes tested (types 6/11, 31, 33). Control slides (condyloma acuminatum, n=3) were positive for type 6/11, 31, and 33 HPV probes tested. Melasma samples (n=4), the negative controls, were consistently negative. No HPV DNA band was detected by PCR with the tissue extracts from paraffin-embedded SK samples, while condyloma acuminatum, the positive controls, showed DNA bands of the correct molecular weights. Our results show that HPV type 6/11, 31, and 33 cannot be recognized as causative agents for nongenital SK, which is in contrast to the previous studies. Further studies are required to reveal the presence of other types (more than 90) of HPV DNA.

Application of computerized image analysis in pigmentary skin diseases

BACKGROUND

Melanocyte number and the amount of melanin pigment are related to diagnosis and treatment of pigmentary skin diseases. Various histologic methods are used, such as Fontana-Masson stain for melanin pigment or immunohistochemical stain for melanocytes. Recently, computerized image analysis has been applied to many fields to avoid interobserver bias. In this study, we applied a computerized image analysis to assess the melanin content and melanocyte density of human epidermis.

METHODS

We evaluated the skin biopsy specimens (paraffin blocks) from normal human skin (33 +/- 6.6, n = 11) and diseased skins; vitiligo (32 +/- 10.0, n = 8), melasma (35 +/- 8.6, n = 11), and lentigo senilis (40 +/- 7.2, n = 11) (mean age +/- SD). Each specimen was stained with Fontana-Masson for melanin pigments and immunohistochemical method for melanocytes. Quantitative analysis of melanin pigment and melanocyte number (density) were investigated through two methods: (1) two dermatologists measured the visual scales; and (2) computerized image analysis was used to measure melanin content indices (MCI). The data were evaluated using one-way ANOVA.

RESULTS

The visual scale of the Fontana-Masson stain was the highest for lentigo senilis (3.8 +/- 0.40), followed by melasma (2.6 +/- 0.67), normal skin (1.8 +/- 0.60) and vitiligo (0) (P < 0.05). These findings were consistent with objective measurements made by computerized image analysis. MCI values were 120.3 +/- 20.74 for lentigo senilis, 81.1 +/- 19.27 for melasma, 45.5 +/- 16.92 for normal skin, and 0.3 +/- 0.30 for vitiligo in decreasing order (P < 0.05). MC/1E (melanocyte number per 1 mm epidermis) was about two fold larger in lentigo senilis (18.1 +/- 8.92) than melasma (9.7 +/- 2.40) or normal skin (9.3 +/- 2.67) (P < 0.05). MC/1B (melanocyte number per 1 mm basal layer) was about 1.5 fold higher in lentigo senilis (13.5 +/- 4.17), compared to normal skin (9.0 +/- 3.55) (P < 0.05). Melasma showed increased melanocyte numbers compared to normal skin, but it was not statistically significant (P > 0.05).

CONCLUSION

We believe this computerized image analysis could be useful tool for diagnosis and comparison of interval changes in pigmentary diseases like melasma or lentigo senilis by quantifying melanin pigments or melanocytes in skin biopsy specimens.

Acquired reactive perforating collagenosis in a diabetic patient with pulmonary aspergillosis

Reactive perforating collagenosis (RPC) is a rare disorder characterized by transepidermal elimination of altered collagen. The acquired form of RPC manifests in adult life and is accompanied by general pruritus and scratching. Diabetes mellitus and end-stage renal disease are frequently associated with RPC. We describe a case of RPC developing after pulmonary aspergillosis in a 54-year-old man with long-standing insulin-dependent diabetes and discuss possible etiologic relations.

Macular amyloidosis presented as poikiloderma: a case report

We report a 51-year-old Vietnam War veteran with an unusual variant of macular amyloidosis presenting as poikilodermatous skin lesions. The extensive mottled brown pigmentation was checkered with small hypopigmented or normal skin-colored spots and intermingled with telangiectasia. Skin biopsy revealed subepidermal amyloid deposits. There was no evidence of extracutaneous involvements. This case could be easily confused with other true poikiloderma lesions.

Expression of progesterone receptor in human keratinocytes

Despite the various responses of human skin to female sex hormones, cellular and subcellular targets and the mechanisms of action of estrogen and progesterone in human skin are not well understood. The detection of estrogen receptor (ER) and progesterone receptor (PR) in the skin is of great importance to understand the effect of estrogen and progesterone. In primary cultures of human keratinocytes, expression of ER and PR was monitored by immunocytochemistry and reverse transcriptase polymerase chain reaction (RT-PCR). Paraffin embedded skin tissues were stained with monoclonal antibodies to human ER and PR by immunohistochemistry. Cultured human keratinocytes expressed cytoplasmic PR protein and PR mRNA transcripts. By contrast, ER was detected only at the mRNA level. Suprabasal keratinocytes from samples of pruritic urticarial papules, plaques of pregnancy (PUPPP) and psoriasis were stained positively only for PR, while those from samples of erythema nodosum were negative for both ER and PR. Lesional epidermis of PUPPP showed positive PR immunoreactivity, while nonlesional epidermis did not. No other cells in the normal human skin were stained with ER and PR. The present study suggests that by expressing PR human keratinocytes act as targets for progesterone action.

Expression and function of ryanodine receptors in human melanocytes

We investigated the expression of ryanodine receptors (RyRs) in cultured human melanocytes with immunocytochemistry and reverse transcriptase-polymerase chain reaction. With the use of a monoclonal antibody, RyR immunoreactivity was detected in the cytoplasm of melanocytes, and was further confirmed by RT-PCR assay. The PCR products were cut with restriction enzymes specific for each RyR isoform. Using the RyR1-specific restriction enzyme SacI yielded fragments of 300, 100, and 130 base pairs, consistent with the expression of RyR1 isoforms. The function of RyR in Ca(2+) signaling was investigated using single-cell fura-2 imaging. Ryanodine (1 to approximately 100 microM) induced significant elevation of cytoplasmic Ca(2+) in single human melanocytes in a dose-dependent manner. The ryanodine-induced [Ca(2+)](i) increase was inhibited by neomycin. Furthermore, ryanodine inhibited proliferation and stimulated pigmentation of human melanocytes. This study demonstrates that the RyR1 isoform is expressed in cultured human melanocytes, and suggests that the RyR may be involved in regulating the intracellular Ca(2+) responses involved in proliferation and pigmentation of cultured human melanocytes.