Chronological alterations in de novo malignancies after living-donor liver transplantation: A cohort study of 1781 recipients using annual comparisons of standardized incidence ratios.

BACKGROUND: De novo malignancies (DNMs) are a major adverse event after solid organ transplantation; however, their characteristics and recent trends after living-donor liver transplantation (LDLT) remain unclear. METHODS: We retrospectively reviewed 1781 primary LDLT recipients (1990-2020) and annually calculated standardized incidence ratios (SIRs) of DNMs compared to the age-adjusted Japanese general population. RESULTS: After 21 845 person-years follow-up, 153 DNM lesions (8.6%) were identified in 131 patients (7.4%). The incidence was 0.007 person-years. DNMs included 81 post-transplant lymphoproliferative disorders (PTLDs), 14 colorectal, 12 lung, and 12 gastric cancers, and so on. Comorbid DNMs significantly worsened recipient survival than those without (p < .001). The 5- and 10-year recipient survival after DNM diagnosis were 65% and 58%, respectively. Notably, SIR1993-1995: 8.12 (95% CI: 3.71-15.4, p < .001) and SIR1996-1998: 3.11 (1.34-6.12, p = .01) were significantly high, but had decreased time-dependently to SIR2005-2007: 1.31 (0.68-2.29, p = .42) and SIR2008-2010: 1.34 (0.75-2.20, p = .33), indicating no longer significant difference in DNMs development. Currently, however, SIR2014-2016: 2.27 (1.54-3.22, p < .001) and SIR2017-2019: 2.07 (1.40-2.96, p < .001) have become significantly higher again, reflecting recent aging of recipients (>50 years) and resultant increases in non-PTLD DNMs. Furthermore, characteristically in LDLT, the fewer the donor-recipient HLA-mismatches, the less the post-transplant DNMs development. CONCLUSION: DNM development after LDLT was significantly higher than in the general population due to higher PTLD incidence (1993-1998), but once became equivalent (2005-2013), then significantly increased again (2014-2019) due to recent recipient aging and resultant increase in solid cancers.

Expanding Selection Criteria in Deceased Donor Liver Transplantation for Hepatocellular Carcinoma: Long-term Follow-up of a National Registry and 2 Transplant Centers.

BACKGROUND: This study compares selection criteria for liver transplant (LT) for hepatocellular carcinoma (HCC) for inclusivity and predictive ability to identify the most permissive criteria that maintain patient outcomes. METHODS: The Scientific Registry of Transplant Recipients (SRTR) database was queried for deceased donor LT's for HCC (2003-2020) with 3-y follow-up; these data were compared with a 2-center experience. Milan, University of California, San Francisco (UCSF), 5-5-500, Up-to-seven (U7), HALT-HCC, and Metroticket 2.0 scores were calculated. RESULTS: Nationally, 26 409 patients were included, and 547 at the 2 institutions. Median SRTR-follow-up was 6.8 y (interquartile range 3.9-10.1). Three criteria allowed the expansion of candidacy versus Milan: UCSF (7.7%, n = 1898), Metroticket 2.0 (4.2%, n = 1037), and U7 (3.5%, n = 828). The absolute difference in 3-y overall survival (OS) between scores was 1.5%. HALT-HCC (area under the curve [AUC] = 0.559, 0.551-0.567) best predicted 3-y OS although AUC was notably similar between criteria (0.506 < AUC < 0.527, Mila n = 0.513, UCSF = 0.506, 5-5-500 = 0.522, U7 = 0.511, HALT-HCC = 0.559, and Metroticket 2.0 = 0.520), as was Harrall's c-statistic (0.507 < c-statistic < 0.532). All scores predicted survival to P < 0.001 on competing risk analysis. Median follow-up in our enterprise was 9.8 y (interquartile range 7.1-13.3). U7 (13.0%, n = 58), UCSF (11.1%, n = 50), HALT-HCC (6.4%, n = 29), and Metroticket 2.0 (6.3%, n = 28) allowed candidate expansion. HALT-HCC (AUC = 0.768, 0.713-0.823) and Metroticket 2.0 (AUC = 0.739, 0.677-0.801) were the most predictive of recurrence. All scores predicted recurrence and survival to P < 0.001 using competing risk analysis. CONCLUSIONS: Less restrictive criteria such as Metroticket 2.0, UCSF, or U7 allow broader application of transplants for HCC without sacrificing outcomes. Thus, the criteria for Model for End-stage Liver Disease-exception points for HCC should be expanded to allow more patients to receive life-saving transplantation.

Safety of advanced laparoscopic hepatectomy for elderly patients: a Japanese nationwide analysis.

BACKGROUND: Although basic laparoscopic hepatectomy (LH) has become the standard procedure for hepatectomy, the safety of advanced LH remains to be clarified, especially in elderly patients. We investigated the safety of advanced LH in elderly Japanese patients. METHODS: Elderly patients (≥ 65 years) who underwent advanced LH between 2016 and 2021 were analyzed using a nationwide claims database in Japan. The perioperative outcomes of patients who underwent open hepatectomy (OH group) or LH (LH group) were compared using propensity score matching (PSM). The primary outcome was in-hospital mortality. The E-value method was performed to assess the strength of the outcome point estimates against possible unmeasured confounding factors. RESULTS: Among 5,021 patients, eligible patients were classified into the OH (n = 4,152) and LH (n = 527) groups. The median patient age was 74 years in both groups. Hepatocellular carcinoma and metastatic liver tumors were the major indications for hepatectomy (OH: 52.5% versus 30.6%; LH: 60.7% versus 26.4%). After PSM, in-hospital mortality rates for OH and LH were 1.7 and 0.76%, respectively. The risk ratio was 0.45 (95% confidence interval, 0.16-1.25; E-value = 3.87). Compared with OH, LH was associated with a longer anesthesia time (411 versus 432 min), lower rate of blood product use (red blood concentrate: 33.5% versus 20.3%; fresh frozen plasma: 29.2% versus 17.1%), and shorter hospital stay (13 versus 12 days). CONCLUSIONS: In elderly patients, the safety of advanced LH was similar to that of advanced OH, or might be better in Japan under the current policy of hospital accreditation.

Reappraisal of Donor Age in Liver Transplantation: NASH as a Potential Target to Safely Utilize Old Liver Grafts.

BACKGROUND: With the chronic shortage of donated organs, expanding the indications for liver transplantation (LT) from older donors is critical. Nonalcoholic steatohepatitis (NASH) stands out because of its unique systemic pathogenesis and high recurrence rate, both of which might make donor selection less decisive. The present study aims to investigate the usefulness of old donors in LT for NASH patients. METHODS: The retrospective cohort study was conducted using the Scientific Registry Transplant Recipient database. The cohort was divided into 3 categories according to donor age: young (aged 16-35), middle-aged (36-59), and old donors (60-). Multivariable and Kaplan-Meier analyses were performed to compare the risk of donor age on graft survival (GS). RESULTS: A total of 67 973 primary adult donation-after-brain-death LTs (2002-2016) were eligible for analysis. The multivariable analysis showed a reduced impact of donor age on GS for the NASH cohort (adjusted hazard ratio = 1.13, 95% confidence interval, 1.00-1.27), comparing old to middle-aged donors. If the cohort was limited to NASH recipients plus 1 of the following, recipient age ≥60, body mass index <30, or Model of End Stage Liver Disease score <30, adjusted hazard ratios were even smaller (0.99 [0.84-1.15], 0.92 [0.75-1.13], or 1.04 [0.91-1.19], respectively). Kaplan-Meier analysis revealed no significant differences in overall GS between old- and middle-aged donors in these subgroups (P = 0.86, 0.28, and 0.11, respectively). CONCLUSIONS: Donor age was less influential for overall GS in NASH cohort. Remarkably, old donors were equivalent to middle-aged donors in subgroups of recipient age ≥60, recipient body mass index <30, or Model of End Stage Liver Disease score <30.

Properdin inhibition ameliorates hepatic ischemia/reperfusion injury without interfering with liver regeneration in mice.

Hepatic ischemia/reperfusion injury (IRI) often causes serious complications in liver surgeries, including transplantation. Complement activation seems to be involved in hepatic IRI; however, no complement-targeted intervention has been clinically applied. We investigated the therapeutic potential of Properdin-targeted complement regulation in hepatic IRI. Male wild-type mice (B10D2/nSn) were exposed to 90-minute partial hepatic IRI to the left and median lobes with either monoclonal anti-Properdin-antibody (Ab) or control-immunoglobulin (IgG) administration. Since the complement system is closely involved in liver regeneration, the influence of anti-Properdin-Ab on liver regeneration was also evaluated in a mouse model of 70% partial hepatectomy. Anti-Properdin-Ab significantly reduced serum transaminases and histopathological damages at 2 and 6 hours after reperfusion (P <0.001, respectively). These improvements at 2 hours was accompanied by significant reductions in CD41+ platelet aggregation (P =0.010) and ssDNA+ cells (P <0.001), indicating significant amelioration in hepatic microcirculation and apoptosis, respectively. Characteristically, F4/80+ cells representing macrophages, mainly Kupffer cells, were maintained by anti-Properdin-Ab (P <0.001). Western blot showed decreased phosphorylation of only Erk1/2 among MAPKs (P =0.004). After 6 hours of reperfusion, anti-Properdin-Ab significantly attenuated the release of HMGB-1, which provokes the release of proinflammatory cytokines/chemokines (P =0.002). Infiltration of CD11b+ and Ly6-G+ cells, representing infiltrating macrophages and neutrophils, respectively, were significantly alleviated by anti-Properdin-Ab (both P <0.001). Notably, anti-Properdin-Ab did not affect remnant liver weight and BrdU+ cells at 48 hours after 70% partial hepatectomy (P =0.13 and 0.31, respectively). In conclusion, Properdin inhibition significantly ameliorates hepatic IRI without interfering with liver regeneration.

Anti-complement 5 antibody ameliorates antibody-mediated rejection after liver transplantation in rats.

Antibody-mediated rejection (AMR) remains a refractory rejection after donor-specific antibody (DSA)-positive or blood-type incompatible liver transplantation (LT), even in the era of pre-transplant rituximab desensitization. This is due to the lack of not only effective post-transplant treatments but also robust animal models to develop/validate new interventions. Orthotopic LT from male Dark Agouti (DA) to male Lewis (LEW) rats was used to develop a rat LT-AMR model. LEW were pre-sensitized by a preceding skin transplantation from DA 4-6 weeks before LT (Group-PS), while sham procedure was performed in non-sensitized controls (Group-NS). Tacrolimus was daily administered until post-transplant day (PTD)-7 or sacrifice to suppress cellular rejections. Using this model, we validated the efficacy of anti-C5 antibody (Anti-C5) for LT-AMR. Group-PS+Anti-C5 received Anti-C5 intravenously on PTD-0 and -3. Group-PS showed increased anti-donor (DA) antibody-titers (P <0.001) and more C4d deposition in transplanted livers than in Group-NS (P <0.001). Alanine aminotransferase (ALT), alkaline phosphatase (ALP), total bile acid (TBA), and total bilirubin (T-Bil) were all significantly higher in Group-PS than in Group-NS (all P <0.01). Thrombocytopenia (P <0.01), coagulopathies (PT-INR, P =0.04), and histopathological deterioration (C4d+h-score, P <0.001) were also confirmed in Group-PS. Anti-C5 administration significantly lowered anti-DA IgG (P <0.05), resulting in decreased ALP, TBA, and T-Bil on PTD-7 than in Group-PS (all P <0.01). Histopathological improvement was also confirmed on PTD-1, -3, and -7 (all P <0.001). Of the 9,543 genes analyzed by RNA sequencing, 575 genes were upregulated in LT-AMR (Group-PS vs. Group-NS). Of these, 6 were directly associated with the complement cascades. In particular, Ptx3, Tfpi2, and C1qtnf6 were specific to the classical pathway. Volcano plot analysis identified 22 genes that were downregulated by Anti-C5 treatment (Group-PS+Anti-C5 vs. Group-PS). Of these, Anti-C5 significantly down-regulated Nfkb2, Ripk2, Birc3, and Map3k1, the key genes that were amplified in LT-AMR. Notably, just two doses of Anti-C5 only on PTD-0 and -3 significantly improved biliary injury and liver fibrosis up to PTD-100, leading to better long-term animal survival (P =0.02). We newly developed a rat model of LT-AMR that meets all the Banff diagnostic criteria and demonstrated the efficacy of Anti-C5 antibody for LT-AMR.

Left Lobe First With Purely Laparoscopic Approach: A Novel Strategy to Maximize Donor Safety in Adult Living Donor Liver Transplantation.

OBJECTIVE: Evaluate outcome of left-lobe graft (LLG) first combined with purely laparoscopic donor hemihepatectomy (PLDH) as a strategy to minimize donor risk. BACKGROUND: An LLG first approach and a PLDH are 2 methods used to reduce surgical stress for donors in adult living donor liver transplantation (LDLT). But the risk associated with application LLG first combined with PLDH is not known. METHODS: From 2012 to 2023, 186 adult LDLTs were performed with hemiliver grafts, procured by open surgery in 95 and PLDH in 91 cases. LLGs were considered first when graft-to-recipient weight ratio ≥0.6%. Following a 4-month adoption process, all donor hepatectomies, since December 2019, were performed laparoscopically. RESULTS: There was one intraoperative conversion to open (1%). Mean operative times were similar in laparoscopic and open cases (366 vs 371 minutes). PLDH provided shorter hospital stays, lower blood loss, and lower peak aspartate aminotransferase. Peak bilirubin was lower in LLG donors compared with right-lobe graft donors (1.4 vs 2.4 mg/dL, P < 0.01), and PLDH further improved the bilirubin levels in LLG donors (1.2 vs 1.6 mg/dL, P < 0.01). PLDH also afforded a low rate of early complications (Clavien-Dindo grade ≥ II, 8% vs 22%, P = 0.007) and late complications, including incisional hernia (0% vs 13.7%, P < 0.001), compared with open cases. LLG was more likely to have a single duct than a right-lobe graft (89% vs 60%, P < 0.01). Importantly, with the aggressive use of LLG in 47% of adult LDLT, favorable graft survival was achieved without any differences between the type of graft and surgical approach. CONCLUSIONS: The LLG first with PLDH approach minimizes surgical stress for donors in adult LDLT without compromising recipient outcomes. This strategy can lighten the burden for living donors, which could help expand the donor pool.

Risk factors for antibody-mediated rejection in ABO blood-type incompatible and donor-specific antibody-positive liver transplantation.

Antibody-mediated rejection (AMR) is a refractory rejection after ABO blood-type incompatible (ABOi) or donor-specific antibody (DSA)-positive liver transplantation (LT). Pretransplant rituximab desensitization dramatically reduced posttransplant AMR development; however, risk factors for AMR in the rituximab era remain unclear in both ABOi living-donor LT (ABOi-LDLT) and preformed DSA-positive LT (pDSA-LT). Of our 596 adult LDLTs (≥18 y) after rituximab introduction (2004-2019), 136 were ABOi-LDLT (22.8%). After excluding retransplants (9), acute liver failure (7), and protocol deviations (16), 104 ABOi-LDLTs were finally enrolled. Of these, 19 recipients developed AMR, 18 of which occurred within 2 weeks after transplantation (95%). ABOi-AMR significantly worsened graft and recipient survival than those without ( p =0.02 and 0.04, respectively). Model for End-stage Liver Disease (MELD) ≤13 (OR: 5.15 [1.63-16.3], p =0.005) and pre-rituximab anti-ABO IgM-titer ≥128 (OR: 3.25 [1.05-10.0], p =0.03) were identified as independent risk factors for ABOi-AMR development. Recipients fulfilling both factors showed significantly worse survival rates than those who did not ( p =0.003). Of 352 adult LTs, after introducing the LABScreen Single Ag method (2009-2019), pDSA with mean fluorescence intensity (MFI) ≥500 was detected in 50 cases (14.2%). After excluding 10 ABOi-LDLTs, 40 pDSA-LTs were finally analyzed, of which 5 developed AMR. The combination of high-titer (sum-MFI ≥10,000) and multi-loci pDSAs was a significant risk factor for pDSA-AMR development ( p <0.001); however, it did not affect the 5-year recipient survival compared with those without ( p =0.56). In conclusion, preoperative MELD ≤13 and pre-rituximab anti-ABO IgM-titer ≥128 for ABOi-LDLT, and the combination of sum-MFI ≥10,000 and multi-loci pDSAs for pDSA-LT, are risk factors for AMR in the era of rituximab desensitization. Characteristically, ABOi-AMR significantly deteriorated graft and recipient survival, whereas pDSA-AMR did not.

Association of Early Bifurcation of Hepatic Artery With Arterial Injury in Right-Sided Living-Donor Hepatectomy: Retrospective Analysis of 500 Cases.

OBJECTIVE: The aim of this study was to explore the incidence of early bifurcation of the right hepatic artery (RHA) and the right posterior hepatic artery (RPHA), which is crucial in right lobe graft (RLG) and right posterior sector graft (RPSG) procurement for living-donor liver transplantation. SUMMARY BACKGROUND DATA: Early bifurcation of the hepatic artery tends to induce oversight of one of the bifurcated arteries and its injury in RLG/RPSG procurement. Unrecognizable on conventional 3-dimensional (3-D) images, its significance is underestimated. METHODS: We enrolled 500 patients who underwent preoperative imaging for scheduled surgeries at two major transplant centers. All-in-one 3-D images consisting of the hepatic artery, portal vein, and bile duct were constructed. Early bifurcation of the RHA and the RPHA was defined as the arteries bifurcating proximal to the cutting line of the right hepatic duct and the right posterior duct, respectively. RESULTS: Early bifurcation of the RHA was seen in 11.3% of cases of an infra-portal RPHA and in 46.0% of cases of a supraportal RPHA ( P < 0.001). Early bifurcation of the RPHA was encountered in 35.3% of cases of an infra-portal RPHA, in no cases of a supra-portal RPHA, and in 100% of cases in which the arteries to segment 6/7 arose individually from the RHA. The overall incidence of early bifurcation was 19.9% for RHA and 43.6% for RPHA. CONCLUSIONS: Early bifurcation of the RHA and the RPHA is frequently encountered and requires caution for RLG/RPSG procurement. Special attention should be paid to supraportal RPHA for RLG procurement.

Impact of the donor hepatectomy time on short-term outcomes in liver transplantation using donation after circulatory death: A review of the US national registry.

BACKGROUND: During the donor hepatectomy time (dHT), defined as the time from the start of cold perfusion to the end of the hepatectomy, liver grafts have a suboptimal temperature. The aim of this study was to analyze the impact of prolonged dHT on outcomes in donation after circulatory death (DCD) liver transplantation (LT). METHODS: Using the US national registry data between 2012 and 2020, DCD LT patients were separated into two groups based on their dHT: standard dHT (< 42 min) and prolonged dHT (≥42 min). RESULTS: There were 3810 DCD LTs during the study period. Median dHT was 32 min (interquartile range 25-41 min). Kaplan-Meier graft survival curves demonstrated inferior outcomes in the prolonged dHT group at 1-year after DCD LT compared to those in the standard dHT group (85.3% vs 89.9%; P < .01). Multivariate Cox proportional hazards models for 1-year graft survival identified that prolonged dHT [hazard ratio (HR) 1.46, 95% confidence interval (CI) 1.19 - 1.79], recipient age ≥ 64 years (HR 1.40, 95% CI 1.14 - 1.72), and MELD score ≥ 24 (HR 1.43, 95% CI 1.16 - 1.76) were significant predictors of 1-year graft loss. Spline analysis shows that the dHT effects on the risk for 1-year graft loss with an increase in the slope after median dHT of 32 min. CONCLUSION: Prolonged dHTs significantly reduced graft and patient survival after DCD LT. Because dHT is a modifiable factor, donor surgeons should take on cases with caution by setting the dHT target of < 32 min.

The impact of human leukocyte antigen mismatch on recipient outcomes in living-donor liver transplantation.

Donor-recipient human leukocyte antigen (HLA) compatibility has not been considered to significantly affect liver transplantation (LT) outcomes; however, its significance in living-donor LT (LDLT), which is mostly performed between blood relatives, remains unclear. This retrospective cohort study included 1954 LDLTs at our institution (1990-2020). The primary and secondary endpoints were recipient survival and the incidence of T cell-mediated rejection (TCMR) after LDLT, respectively, according to the number of HLA mismatches at all five loci: HLA-A, HLA-B, HLA-C, HLA-DR, and HLA-DQ. Subgroup analyses were also performed in between-siblings that characteristically have widely distributed 0-10 HLA mismatches. A total of 1304 cases of primary LDLTs were finally enrolled, including 631 adults (recipient age at LT ≥18 years) and 673 children (<18 years). In adult-to-adult LDLT, the more HLA mismatches at each locus, the significantly worse the recipient survival was (p = 0.03, 0.01, 0.03, 0.001, and <0.001 for HLA-A, HLA-B, HLA-C, HLA-DR, and HLA-DQ, respectively). This trend was more pronounced when multiple loci were combined (all p < 0.001 for A + B + DR, A + B + C, DR + DQ, and A + B + C + DR + DQ). Notably, a total of three or more HLA-B + DR mismatches was an independent risk factor for both TCMR (hazard ratio [HR] 2.66, 95% confidence interval [CI] 1.21-5.87; p = 0.02) and recipient survival (HR 2.44, 95% CI 1.11-5.35; p = 0.03) in between-siblings. By contrast, HLA mismatch did not affect pediatric LDLT outcomes at any locus or in any combinations; however, it should be noted that all donor-recipient relationships are parent-to-child that characteristically possesses one or less HLA mismatch at each locus and maximally five or less mismatches in total. In conclusion, HLA mismatch significantly affects not only TCMR development but also recipient survival in adult LDLT, but not in children.

Nontumor related risk score: A new tool to improve prediction of prognosis after hepatectomy for colorectal liver metastases.

BACKGROUND: Prognostic stratification of patients with colorectal cancer liver metastasis based solely on tumor-related factors has only moderate discriminatory ability. We hypothesized that the inclusion of nontumor related factors can improve prediction of long-term prognosis of patients with colorectal cancer liver metastasis. METHODS: Nontumor related laboratory markers were assessed utilizing a training cohort from 2 U.S. institutions (n = 1,205). Factors independently associated with prognosis were used to develop a nontumor related prognostic score. The discriminatory ability, assessed by Harrell's C-statistics (C-index) and net reclassification improvement, was validated and compared with 3 commonly used tumor-related clinical risk scores: Fong clinical risk scores, m-clinical risk scores, and Genetic and Morphological Evaluation (GAME) score in an external validation cohort from 5 Asian (n = 1,307) and 3 European (n = 1,058) institutions. The discriminatory ability of nontumor related prognostic score combined with each of these 3 tumor-related prognostic scores was also estimated. RESULTS: Alkaline phosphatase (hazard ratio 1.43; 95% confidence interval, 1.11-1.84), albumin (hazard ratio 0.71; 95% confidence interval, 0.57-0.89), and mean corpuscular volume (hazard ratio 19.0, per log unit; 95% confidence interval, 4.79-75.0) were each independently associated with increased risk of death after resection of colorectal cancer liver metastasis (all P < .05). In turn, alkaline phosphatase, albumin, and mean corpuscular volume were combined to form a nontumor related prognostic score (2.942 × mean corpuscular volume + 0.399 × alkaline phosphatase-0.339 × albumin-12) × 10 (median, 16; range, 1-30). The nontumor related prognostic score had good-to-modest discriminatory ability in the external cohort (C-index = 0.58), which was comparable to the 3 established tumor-related prognostic scores (C-index: Fong clinical risk scores, 0.53, m-clinical risk scores, 0.55, GAME, 0.58). The addition of the nontumor related prognostic score to the tumor-related prognostic scores enhanced the discriminatory ability in the entire study cohort (C-index: nontumor related score+Fong, 0.60, nontumor related score+m-clinical risk scores, 0.61, nontumor related score+GAME, 0.64), as well reclassification improvement (42.5, 42.7%, and 21.2%, respectively). CONCLUSION: Nontumor related prognostic information may help improve the prognostic stratification of patients after resection of colorectal cancer liver metastasis. The nontumor related prognostic score may be combined with tumor-related prognostic tools to enhance prognostic stratification of patients with colorectal cancer liver metastasis.

Post-transplant Lymphoproliferative Disorders After Liver Transplantation: A Retrospective Cohort Study Including 1954 Transplants.

Post-transplant lymphoproliferative disorders (PTLDs) are life-threatening neoplasms after organ transplantation. Because of their rarity and multiple grades of malignancy, the incidence, outcomes, and clinicopathological features affecting patient survival after liver transplantation (LT) remain unclear. We reviewed 1954 LTs in 1849 recipients (1990-2020), including 886 pediatric (<18 years of age) and 963 adult recipients. The following clinicopathological factors were studied: age, sex, liver etiologies, malignancy grades, Epstein-Barr virus status, performance status (PS), Ann Arbor stage, international prognostic index, and histopathological diagnosis. Of 1849 recipients, 79 PTLD lesions (4.3%) were identified in 70 patients (3.8%). After excluding 3 autopsy cases incidentally found, 67 (45 pediatric [5.1%] and 22 adult [2.3%]) patients were finally enrolled. Comorbid PTLDs significantly worsened recipient survival compared with non-complicated cases (P < 0.001). The 3-year, 5-year, and 10-year overall survival rates after PTLD diagnosis were 74%, 66%, and 58%, respectively. The incidence of PTLDs after LT (LT-PTLDs) was significantly higher (P < 0.001) with earlier onset (P = 0.002) in children, whereas patient survival was significantly worse in adults (P = 0.002). Univariate and multivariate analyses identified the following 3 prognostic factors: age at PTLD diagnosis ≥18 years (hazard ratio [HR], 11.2; 95% confidence interval [CI], 2.63-47.4; P = 0.001), PS ≥2 at diagnosis (HR, 6.77; 95% CI, 1.56-29.3; P = 0.01), and monomorphic type (HR, 6.78; 95% CI, 1.40-32.9; P = 0.02). A prognostic index, the "LT-PTLD score," that consists of these 3 factors effectively stratified patient survival and progression-free survival (P = 0.003 and <0.001, respectively). In conclusion, comorbid PTLDs significantly worsened patient survival after LT. Age ≥18 years and PS ≥2 at PTLD diagnosis, and monomorphic type are independent prognostic factors, and the LT-PTLD score that consists of these 3 factors may distinguish high-risk cases and guide adequate interventions.

Complement-5 Inhibition Deters Progression of Fulminant Hepatitis to Acute Liver Failure in Murine Models.

BACKGROUND & AIMS: Acute liver failure (ALF) is a life-threatening condition with limited treatment alternatives. ALF pathogenesis seemingly involves the complement system. However, no complement-targeted intervention has been clinically applied. In this study, we aimed to investigate the potential of Complement-5 (C5)-targeted ALF treatment. METHODS: ALF was induced in C5-knockout (KO, B10D2/oSn) mice and their wild-type (WT) counterparts (B10D2/nSn) through intraperitoneal lipopolysaccharide (LPS) and d-galactosamine (D-GalN) administration. Thereafter, monoclonal anti-C5 antibody (Ab) or control immunoglobulin was administered intravenously. Furthermore, a selective C5a-receptor (C5aR) antagonist was administered to WT mice to compare its efficacy with that of anti-C5-Ab-mediated total C5 inhibition. We clarified the therapeutic effect of delayed anti-C5-Ab administration after LPS/D-GalN challenge. We also assessed the efficacy of anti-C5-Ab in another ALF model, using concanavalin-A. RESULTS: Liver injury was evident 6 hours after LPS/D-GalN administration. C5-KO and anti-C5-Ab treatment significantly improved overall animal survival and significantly reduced serum transaminase and high-mobility group box-1 release with decreased histological tissue damage. This improvement was characterized by significantly reduced CD41+ platelet aggregation, maintained F4/80+ cells, and less infiltration of CD11+/Ly6-G+ cells with lower cytokine/chemokine expression. Furthermore, C5-KO and anti-C5-Ab downregulated tumor necrosis factor-α production by macrophages before inducing marked liver injury. Moreover, single-stranded-DNA cells and caspase activation were reduced, indicating significant attenuation of apoptosis. Anti-C5-Ab treatment protected the liver more effectively than the C5aR antagonist, and its delayed doses were hepatoprotective. In addition, anti-C5-Ab treatment was effective against concanavalin-A-induced ALF. CONCLUSIONS: C5 inhibition effectively suppresses progression to ALF in mice models of fulminant hepatitis, serving as a new potential treatment strategy for ALF.

Is 0.6% Reasonable as the Minimum Requirement of the Graft-to-recipient Weight Ratio Regardless of Lobe Selection in Adult Living-donor Liver Transplantation?

BACKGROUND: Several studies reported favorable outcomes of small-for-size grafts with graft-to-recipient weight ratio (GRWR) <0.8% in living-donor liver transplantation (LDLT). However, their indications should be carefully determined because they must have been indicated for low-risk cases over larger grafts with 0.8% ≤ GRWR. Furthermore, evidence for minimum requirements of GRWR remains inconclusive. We investigated the safety of small-for-size grafts against larger grafts by adjusting for confounding risk factors, and minimum requirement of graft volume in adult LDLT. METHODS: We enrolled 417 cases of primary adult-to-adult LDLT in our center between 2006 and 2019. The outcomes of small grafts (0.6% ≤ GRWR < 0.8%, n = 113) and large grafts (0.8% ≤ GRWR, n = 289) were mainly compared using a multivariate analysis and Kaplan-Meier estimates. RESULTS: The multivariate analysis showed that small grafts were not a significant risk factor for overall graft survival (GS). In the Kaplan-Meier analysis, small grafts did not significantly affect overall GS regardless of lobe selection (versus large grafts). However, GRWR < 0.6% was associated with poor overall GS. Although there were no significant differences between the 2 groups, unadjusted Kaplan-Meier curves of small grafts were inferior to those of large grafts in subcohorts with ABO incompatibility, and donor age ≥50 years. CONCLUSIONS: Similar outcomes were observed for small and large graft use regardless of lobe selection. 0.6% in GRWR was reasonable as the minimum requirement of graft volume in LDLT. However, small grafts should be indicated carefully for high-risk cases.

Complement 5 Inhibition Ameliorates Hepatic Ischemia/reperfusion Injury in Mice, Dominantly via the C5a-mediated Cascade.

BACKGROUND: Hepatic ischemia/reperfusion injury (IRI) is a serious complication in liver surgeries, including transplantation. Complement activation seems to be closely involved in hepatic IRI; however, no complement-targeted intervention has been clinically applied. We investigated the therapeutic potential of Complement 5 (C5)-targeted regulation in hepatic IRI. METHODS: C5-knockout (B10D2/oSn) and their corresponding wild-type mice (WT, B10D2/nSn) were exposed to 90-minute partial (70%) hepatic ischemia/reperfusion with either anti-mouse-C5 monoclonal antibody (BB5.1) or corresponding control immunoglobulin administration 30 minutes before ischemia. C5a receptor 1 antagonist was also given to WT to identify which cascade, C5a or C5b-9, is dominant. RESULTS: C5-knockout and anti-C5-Ab administration to WT both significantly reduced serum transaminase release and histopathological damages from 2 hours after reperfusion. This improvement was characterized by significantly reduced CD41+ platelet aggregation, maintained F4/80+ cells, and decreased high-mobility group box 1 release. After 6 hours of reperfusion, the infiltration of CD11+ and Ly6-G+ cells, cytokine/chemokine expression, single-stranded DNA+ cells, and cleaved caspase-3 expression were all significantly alleviated by anti-C5-Ab. C5a receptor 1 antagonist was as effective as anti-C5-Ab for reducing transaminases. CONCLUSIONS: Anti-C5 antibody significantly ameliorated hepatic IRI, predominantly via the C5a-mediated cascade, not only by inhibiting platelet aggregation during the early phase but also by attenuating the activation of infiltrating macrophages/neutrophils and hepatocyte apoptosis in the late phase of reperfusion. Given its efficacy, clinical availability, and controllability, C5-targeted intervention may provide a novel therapeutic strategy against hepatic IRI.