Immunotherapy following transplantation has long been a central focus in both anti-rejection strategies and the induction of immune tolerance. Regulatory B cells (Bregs) can directly suppress the immune system via the interaction between programmed cell death protein 1 (PD-1) and its ligand programmed death ligand 1 (PD-L1). Additionally, Bregs exert indirect immunosuppressive effects through the secretion of cytokines such as interleukin-10 (IL-10), transforming growth factor-β (TGF-β), and granzyme B (GrB), among which IL-10 plays a particularly critical role. This review summarizes recent progress in the classification, functional characteristics, and activation mechanisms of Bregs, as well as their potential applications in transplantation immunotherapy, aiming to provide a theoretical foundation for Breg-targeted strategies in transplant immune modulation.

Objective:To evaluate the efficacy of an etoposide (Vp16) -intensified conditioning regimen in allogeneic hematopoietic stem cell transplantation (allo-HSCT) for the treatment of relapsed/refractory acute myeloid leukemia (AML).Method:A retrospective analysis was conducted on the clinical data of 27 recipients with relapsed/refractory AML who underwent allo-HSCT using a Vp16-intensified conditioning regimen at Aerospace Center Hospital from January 2019 to January 2022. Transplantation-related complications and treatment outcomes were observed. Kaplan-Meier survival analysis was used to assess the overall survival (OS) and disease-free survival (DFS) rates.Result:Among the 27 recipients, there were 14 males and 13 females, with a median age of 41 years (range: 12~55 years). Except for one recipient who experienced primary graft failure, the remaining 26 recipients achieved hematopoietic reconstitution. The median neutrophil and platelet engraftment times were 13 days (range: 9~20 days) and 13.5 days (range: 11~33 days), respectively. Regimen-related toxicity (RRT) was mainly gastrointestinal toxicity and oral mucositis, and no deaths were attributed to RRT. A total of 12 recipients (44.44%) developed acute graft-versus-host disease (aGVHD), of whom 3 cases (11.11%) had grade III~IV aGVHD. Chronic GVHD (cGVHD) occurred in 13 recipients (48.15%), including 8 cases (29.63%) of extensive cGVHD. The median follow-up time after transplantation was 17 months (range: 1~48 months). Fifteen recipients (55.56%) survived without disease, while 12 recipients (44.44%) died— 9 due to relapse and 3 due to transplant-related complications. The 1-year overall survival and DFS rates were 74.07% and 59.26%, respectively; the 2-year overall survival and DFS rates were 59.26% and 55.56%, respectively. The 2-year relapse rate and transplant-related mortality (TRM) were 33.33% and 11.11%, respectively.Conclusion:The Vp16-intensified conditioning regimen in allo-HSCT appears to be a viable treatment option for patients with relapsed/refractory AML, offering favorable efficacy and manageable safety.

Objective:To investigate the role of calcium-binding protein S100A9 in acute lung injury induced by hepatic ischemia-reperfusion (HIR) in mice, and to explore its relationship with nuclear factor erythroid 2-related factor 2 (Nrf2).Methods:A total of 12 specific pathogen-free (SPF) male wild-type (WT) and 12 S100A9 knockout (S100A9 KO) C57BL/6J mice aged 6~8 weeks and weighing 20-25 g were randomly divided into four groups using a random number table: WT+Sham group, S100A9 KO+Sham group, WT+HIR group, and S100A9 KO+HIR group ( n=6 per group). The HIR model was established by clamping the portal vein and hepatic artery of the left and median liver lobes for 60 minutes followed by reperfusion. At 6 hours post-reperfusion, mice were anesthetized again, and blood samples were collected from the inferior vena cava. Both lungs were harvested. The lung wet-to-dry (W/D) weight ratio was measured. Hematoxylin and eosin (HE) staining was used to assess histopathological changes and calculate lung injury scores. The levels of inflammatory markers—S100A9, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) —as well as oxidative stress indicators including myeloperoxidase (MPO), reactive oxygen species (ROS), malondialdehyde (MDA), and superoxide dismutase (SOD) in serum and lung tissue were measured. Western blotting was used to assess the expression levels of nuclear and cytoplasmic Nrf2, and cytoplasmic HO-1. Results:Compared with the WT+Sham group, both the WT+HIR and S100A9 KO+HIR groups showed significantly increased lung injury scores, W/D ratio, TNF-α, IL-6, ROS, MPO, and MDA levels (all P<0.05). Compared with the WT+HIR group, the S100A9 KO+HIR group exhibited significantly reduced levels of these indicators (all P<0.05). Moreover, the S100A9 KO+HIR group showed elevated nuclear Nrf2 expression and decreased cytoplasmic Nrf2 expression, accompanied by increased expression of HO-1, Gclm, Gclc, and Nqo1 (all P<0.05). Conclusion:Upregulation of S100A9 is involved in the development of HIR-induced acute lung injury, possibly through inhibition of Nrf2 nuclear translocation.

Objective:To investigate the impact of donor age on early postoperative liver function recovery in liver transplant recipients, as well as the incidence and risk factors for arterial complications following liver transplantation.Methods:A total of 518 patients who underwent liver transplantation at the Organ Transplantation Center of the Affiliated Hospital of Qingdao University between January 2021 and January 2024 were included in the study. Based on donor age, patients were classified into the elderly donor group (≥70 years, n=28) and the non-elderly donor group (<70 years, n=490). Liver function indicators—including aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (TBIL), and direct bilirubin (DBIL)—were measured on postoperative days 1, 3, 7, and 14. The incidence of arterial complications, including hepatic artery thrombosis and hepatic artery stenosis, was recorded. Recipients were further categorized into the arterial complication group (n=26) and the non-arterial complication group (n=492) based on postoperative outcomes, and clinical characteristics of donors and recipients were compared. Binary logistic regression analysis was conducted to identify risk factors for arterial complications.Rusults:No significant differences were observed in baseline characteristics between the elderly and non-elderly donor groups ( P>0.05). However, the elderly donor group exhibited significantly higher AST, ALT, TBIL, and DBIL levels at all postoperative time points compared to the non-elderly donor group (all P<0.05). Specifically, on postoperative day 1, AST and ALT levels were (1,024.57±256.49) U/L and (756.24±145.89) U/L in the elderly donor group, compared to (895.23±225.19) U/L and (614.85±126.51) U/L in the non-elderly donor group. On day 3, AST and ALT levels were (402.46±71.61) U/L and (423.31±87.44) U/L versus (226.37±66.54) U/L and (256.79±70.25) U/L, respectively. On day 7, AST and ALT levels were (91.78±21.84) U/L and (92.36±21.62) U/L versus (68.41±18.38) U/L and (77.47±18.16) U/L. By day 14, AST and ALT levels were (67.52±10.35) U/L and (72.17±16.28) U/L versus (35.32±9.27) U/L and (48.56±14.10) U/L, respectively ( P<0.05 for all comparisons). For bilirubin indicators, TBIL and DBIL levels in the elderly donor group were also consistently higher than in the non-elderly donor group. On day 1, TBIL and DBIL were (95.76±21.93) μmol/L and (64.22±15.07) μmol/L, compared to (77.59±20.48) μmol/L and (51.18±12.96) μmol/L. By day 14, TBIL and DBIL levels had decreased to (41.26±8.30) μmol/L and (32.45±6.21) μmol/L, compared to (28.39±7.15) μmol/L and (20.58±5.04) μmol/L in the non-elderly donor group ( P<0.05 for all comparisons). The incidence of hepatic artery complications was 10.71% (3/28) in the elderly donor group and 4.69% (23/490) in the non-elderly donor group, with no statistically significant difference between the two groups ( P>0.05). Statistical analysis employing independent t-tests and χ2 tests demonstrated significant differences between the arterial complication group and non-arterial complication group in donor quality ratio ( P<0.05) and incidence of hepatic arterial hypoperfusion ( P<0.05). Multivariate binary logistic regression analysis, after adjusting for confounding factors (e.g., recipient gender, age, body mass index [BMI], primary disease, and donor-recipient blood type compatibility), identified recipient-to-donor mass ratio ( OR=1.352, P<0.05) and insufficient hepatic arterial blood flow ( OR=1.497, P<0.05) as independent risk factors for arterial complications following liver transplantation. Conclusion:Elderly liver donors can have a certain impact on early postoperative liver function recovery in liver transplant recipients, but have no significant impact on the occurrence of arterial complications after liver transplantation. The mass ratio of recipients to donors and insufficient hepatic arterial blood flow are independent risk factors for arterial complications after liver transplantation.

Objective:To evaluate the efficacy of modified splenic arteriovenous shunt surgery at the distal pancreatic tail in combined pancreas-kidney transplantation.Methods:A retrospective analysis was conducted on 24 recipients who underwent combined pancreas-kidney transplantation with the modified splenic arteriovenous shunt at the pancreatic tail from November 2023 to October 2024 (shunt group) and 231 recipients who received conventional splenic artery and vein ligation since 2016 (ligation group). The incidence of perioperative thrombosis and severe adverse events was compared between the two groups using the chi-square test or Fisher's exact test. Independent sample t-tests were performed to assess postoperative pancreatic and renal function recovery as well as blood perfusion in 15 recipients from the shunt group and 20 from the ligation group who underwent CT perfusion imaging (CTP).Results:The incidence of perioperative splenic arteriovenous thrombosis was lower in the shunt group (0) compared to the ligation group (4.76%, 11/231), though the difference was not statistically significant ( P=0.606). One month postoperatively, the shunt group demonstrated significantly lower serum amylase levels than the ligation group (99.61±19.62 vs. 148.20±70.67 U/L, P=0.018). However, at the time of CTP examination, serum lipase (67.87±32.35 vs. 45.11±17.94 U/L, P=0.014) and creatinine levels (131.79±26.41 vs. 112.1±24.98 μmol/L, P=0.034) were significantly higher in the shunt group. Urea nitrogen levels were also significantly higher in the shunt group both one month postoperatively (11.24±4.64 vs. 8.51±3.01 mmol/L, P=0.043) and at the CTP examination (10.41±1.78 vs. 6.87±1.91 mmol/L, P=0.001). Regarding pancreatic perfusion, blood volume in both the pancreatic head (15.99 ± 3.51 vs. 20.67 ± 5.47 ml/100 g, P = 0.024) and tail (17.19±4.24 vs. 27.40±19.80 ml/100 g, P=0.039) was significantly lower in the shunt group. After one minute of splenic artery perfusion, the shunt group exhibited significantly higher splenic artery blood flow (755.85±101.50 vs. 574.00 ± 142.06 ml·min -1· (100 g) -1, P<0.001) and blood volume (58.90 ±19.93 vs. 23.21±17.02 ml/100 g, P=0.007) compared to the ligation group. These differences persisted after two minutes of perfusion (blood flow: 793.83±68.57 vs. 503.78 ± 130.80 ml·min -1· (100 g) -1, P<0.001; blood volume: 64.22±15.74 vs. 34.32±20.39 ml/100 g, P=0.002). For the transplanted kidney, the shunt group had significantly lower blood flow (113.10±28.55 vs. 232.76±113.37 ml·min -1· (100 g) -1, P<0.001), blood volume (28.95±10.79 vs. 38.36±12.38 ml/100 g, P=0.047), and capillary surface permeability (PS) (26.49±16.57 vs. 43.02±20.37, P = 0.042) in the upper pole. Similar reductions in blood flow, blood volume, and PS were observed in the middle dorsal region ( P=0.018, 0.021, and 0.048, respectively) and lower pole ( P<0.001, P=0.048, and P=0.012, respectively). Conclusion:The modified splenic arteriovenous shunt at the pancreatic tail appears to be a safe and effective approach to reducing the risk of pancreatic graft thrombosis. This technique facilitates effective diversion of pancreatic parenchymal blood flow into the splenic vein, alleviating hyperperfusion of the transplanted pancreas. While renal blood perfusion was reduced postoperatively, it did not adversely affect renal function.

The shortage of donor organs is the primary factor limiting the availability of liver transplantation (LT) and is a leading cause of death among patients on the waiting list. The reuse of liver allografts, while rare, represents a significant and unconventional donor resource, offering a promising strategy to expand the donor pool. This approach has been documented in international literature, demonstrating favorable surgical outcomes and long-term follow-up results. Here, we report the first case of liver allograft reuse in the Liver Transplantation Center, Department of General Surgery, Huashan Hospital, Fudan University. In this case, the first recipient underwent orthotopic LT for acute liver failure and hepatic encephalopathy. However, their condition deteriorated on the seventh postoperative day, culminating in brain death. Following evaluation and maintenance, the liver allograft was successfully re-transplanted into a second recipient, who had undergone LT six days earlier but experienced acute hepatic artery embolism leading to rapid liver function deterioration. The second recipient's liver function recovered smoothly after surgery, and they were discharged on the 28th postoperative day. This case highlights the significant value of liver allograft reuse in expanding the donor pool and providing life-saving options for critically ill patients requiring urgent LT.

Median arcuate ligament compression syndrome (MALS) presents with atypical clinical manifestations. MALS is rarely reported in pediatric patients but is recognized as an independent risk factor for postoperative hepatic artery thrombosis in liver transplant recipients. We report a case of a pediatric liver transplant recipient with hepatolenticular degeneration, cirrhosis, and acute liver failure. Despite undergoing artificial liver support therapy, the patient showed no significant improvement in liver function and subsequently underwent liver transplantation. Intraoperatively, weak arterial pulsation and the absence of a pulsatile waveform in the hepatic artery anastomosis raised suspicion of MALS. The condition was successfully managed by releasing and transecting the median arcuate ligament, along with ligation of the splenic and left gastric arteries. To optimize transplantation outcomes, meticulous preoperative imaging assessment, particularly focusing on characteristic findings in CT angiography, is essential. Additionally, individualized surgical planning and intraoperative adjustments based on ultrasound monitoring and arterial pulsation assessments are critical for ensuring successful transplantation.

Objective:To investigate the predictive value of elevated calprotectin S100A9 (S100A9) concentration during living-donor liver transplantation (LDLT) for early acute lung injury (ALI) in children with biliary atresia.Method:A retrospective analysis was conducted on 280 pediatric patients with biliary atresia who underwent LDLT using hyperreduced left lateral segment grafts at Tianjin First Central Hospital between January 2019 and January 2021. Based on intraoperative serum S100A9 levels at 30 minutes after graft reperfusion, patients were divided into the high S100A9 group (≥9.05 μg/L, 141 cases) and the low S100A9 group (<9.05 μg/L, 139 cases). General clinical characteristics were compared between the two groups. Univariate and multivariate logistic regression analyses were performed to examine the correlation between S100A9 levels and early postoperative ALI. The predictive value of risk factors was assessed using receiver operating characteristic (ROC) curve analysis with calculation of the area under the curve (AUC) .Result:A total of 280 eligible children were included in the study, with 141 in the high S100A9 group and 139 in the low S100A9 group. The incidence of ALI was significantly higher in the high S100A9 group (31.2%) compared to the low S100A9 group (10.8%). Multivariate regression analysis identified elevated preoperative creatinine levels ( OR=1.191, 95% CI: 1.069~1.321, P=0.002), increased intraoperative S100A9 concentrations ( OR=1.426, 95% CI: 1.272~1.599, P=0.021), and higher intraoperative blood transfusion volume ( OR=0.985, 95% CI: 0.973~0.997, P=0.017) as independent risk factors for postoperative ALI in pediatric LDLT. The predictive value of intraoperative S100A9 levels for ALI was significant, with an AUC of 0.816 (95% CI: 0.758~0.874), a sensitivity of 80.5%, a specificity of 73.7%, and an optimal cutoff value of 9.49 μg/L. Furthermore, preoperative albumin and creatinine levels were found to be correlated with increased intraoperative S100A9 levels. Conclusion:Elevated intraoperative S100A9 levels, increased preoperative creatinine levels, and higher intraoperative blood transfusion volumes are independent risk factors for early ALI following pediatric LDLT. S100A9 levels have strong predictive value for ALI occurrence, highlighting the need for perioperative monitoring and intervention strategies to improve postoperative outcomes.

Objective:To investigate the treatment approaches and outcomes of early hepatic artery thrombosis (E-HAT) in adult recipients following orthotopic liver transplantation (OLT).Methods:A retrospective analysis was conducted on clinical data of E-HAT cases after adult OLT at the First Affiliated Hospital of Xi'an Jiaotong University from January 2010 to June 2022. Clinical characteristics, treatment methods, therapeutic outcomes, long-term survival of recipients and grafts, and the incidence of long-term complications were summarized. The Kaplan-Meier method was utilized to calculate recipient survival rates.Results:Among 1 016 OLT recipients, 22 cases (2.2%) developed postoperative E-HAT. There were 19 males and 3 females, with a age of 44.81±9.98 years. E-HAT was diagnosed via angiography at a median of 3.5 (1.0, 7.0) days post-OLT. Twenty recipients underwent vascular intervention therapy, achieving clinical success in 14 cases (70.0%) with a mean thrombolysis duration of 5.1±3.2 days. Twelve cases (60.0%) experienced complications, including abdominal bleeding (10 cases), gastrointestinal bleeding (1 case), catheter-related infection (1 case), subcutaneous bleeding (1 case), and hepatic artery dissection (1 case). Five recipients underwent hepatic artery re-anastomosis, including two initial cases and three following failed interventional therapy. Surgery was performed at a median of 5.0 (1.0, 15.3) days post OLT, with 4 successful cases. Through combined interventional and surgical treatment, 81.8% (18/22) of grafts were salvaged. However, the success rate was significantly lower in cases with marked transaminase (AST, ALT) and total bilirubin elevation (16/18 vs 2/4). Nineteen E-HAT survivors were followed for a median of 22 (5, 52) months. During follow-up, 2 cases experienced thrombus recurrence, and 12 cases developed biliary complications, including ischemic biliary stenosis (11 cases), extensive liver necrosis (1 case), localized liver abscess (1 case), and biliary anastomotic stenosis (1 case). Seven recipients died due to graft failure. The 1-year, 3-year and 5-year cumulative survival rates were 67.2%, 60.5% and 34.5%, respectively.Conclusions:Combined interventional and surgical treatment demonstrates a high success rate for managing E-HAT, particularly when addressed before significant graft damage. Ischemic biliary stenosis remains the most common long-term complication.

Objective:To investigate the current application status of prophylactic anti-infective drugs during the perioperative period in liver transplantation centers and provide data references for further standardizing prophylactic regimens.Methods:A questionnaire comprising 53 questions across 5 dimensions was designed and released using the WJX platform. The dimensions included basic information about medical institutions, perioperative pathogenic microorganisms, current status of empirical antibacterial prophylaxis, adjustments to prophylactic anti-infective strategies, and an overview of prophylactic measures against other pathogens. Based on the survey results, the types of common perioperative pathogens in liver transplantation, types of prophylactic antibacterial drugs, timing and duration of administration, upgraded prophylaxis strategies (such as escalation of antibiotic classes or extension of drug application duration), and prevention strategies for other pathogens were summarized.Results:A total of 13 completed questionnaires from pharmacists at liver transplantation centers were collected. The most common pathogens during the perioperative period were Gram-negative bacilli, including Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii. The most frequently used prophylactic antibacterial drugs were cefoperazone/sulbactam and piperacillin/tazobactam. Regarding the timing of administration, 9 centers administered drugs 0.5 to 1.0 hour before surgery, 3 within 0.5 hour, and 1 within 1 hour preoperatively. The prophylactic duration was within 7 days postoperatively for living donor liver transplantation in 10 centers, while for cadaveric donor liver transplantation, only 6 centers adhered to the 7-day duration. When donors had infections with sensitive bacteria, 9 centers upgraded prevention strategies: 2 centers escalated the antibiotic class or adjusted regimens, 5 centers extended the duration of prophylaxis, 2 centers implemented donor-specific susceptibility-guided antibacterial treatments regardless of colonization or infection, and 5 centers administered prophylaxis only in cases of colonization based on donor susceptibility results. When donors had multi-drug resistance bacterial infections, 11 centers upgraded prevention strategies: 7 escalated the antibiotic class or adjusted regimens, 4 extended prophylaxis duration, 6 implemented susceptibility-guided treatments irrespective of colonization or infection, 1 administered prophylaxis only for colonization based on donor susceptibility results, and 2 abandoned transplantations. 7 centers routinely applied antifungal prophylactic measures, including 1 for preoperative prophylaxis and 6 for postoperative prophylaxis, using caspofungin (4 centers), fluconazole (2 centers), posaconazole (1 center), and micafungin (1 center). 6 centers initiated antifungal prophylaxis in cases with donor or recipient fungal infection history or active fungal infections detected during liver procurement. Most antifungal prophylaxis was administered within 72 hours postoperative (11 centers), with durations mostly within 14 days (12 centers). For viral infections, 6 centers adopted routine postoperative prophylactic measures. Conclusions:Currently, the perioperative prophylactic anti-infective strategies in 13 liver transplantation centers are not standardized. High-quality multicenter clinical studies are needed to compare the effectiveness of different prophylactic regimens, aiming to further standardize the types and durations of prophylactic drug use.