Porcine vascular endothelial cells are primary targets of humoral and cellular immune responses in pig-to-primate organ xenotransplantation. Although porcine aortic endothelial cells (PAECs) are widely used to evaluate primate anti-pig immune responses, their limited proliferative capacity poses a significant obstacle to repeated and standardized experimentation. To overcome this challenge, we established immortalized PAEC lines (iPAECs) derived from WT, GTKO, and GTKO/CMAHKO/B4GALNT2KO (triple-knockout, TKO) donor pigs using stable transduction of the SV40 large T antigen. All iPAEC lines expanded stably beyond passage 20, maintained high CD31 expression, and preserved genotype-specific xenoantigen profiles. Anti-pig IgM/IgG binding and complement-dependent cytotoxicity (CDC) against these cells were measured with flow cytometry using pooled rhesus monkey sera (n=20) or human sera (n=20). Compared with WT iPAECs, GTKO iPAECs demonstrated significantly reduced IgM/IgG binding and CDC with human and rhesus sera. Additional deletion of Sda and Neu5Gc in TKO iPAECs markedly reduced human serum reactivity, whereas rhesus sera retained relatively high antibody binding and CDC against TKO iPAECs. Notably, the humoral immune responses remained consistent across primary cells and passages P5, P10, and P20, validating the long-term efficacy of iPAECs as an experimental tool. Preformed anti-pig antibodies in 30 rhesus monkeys were further evaluated using TKO iPAECs and TKO peripheral blood mononuclear cells (PBMCs). The results demonstrated a significant correlation between the two target cell types, supporting their interchangeability for humoral immune assessment. Furthermore, xenogeneic MLR assays confirmed that iPAECs could stimulate human CD4+ and CD8+ T-cell proliferation, especially following porcine IFN-γ–induced upregulation of SLA-I and SLA-II expression. Collectively, these findings establish donor-derived iPAECs as a reliable, reproducible, and genetically defined in vitro platform to comprehensively evaluate humoral and cellular xenogeneic immune responses to genetically modified porcine endothelium.

Swine leukocyte antigens (SLA) may be a new type of xenoantigen. Previous studies on SLA have primarily focused on their cross-reactivity with HLA. However, the role of SLA in stimulating xenogeneic immune responses after xenotransplantation remains unclear. In our recent kidney xenotransplantation study in rhesus monkeys using GTKO/hCD55 or GTKO/β4GalNT2KO/hCD55/hTBM pigs as donors, 5 of 13 recipients experienced early AMR accompanied by a marked increase in anti-donor pig antibodies. Flow cytometry analysis showed that the terminal sera of these recipients contained significant de novo anti-SLA antibodies, as evidenced by reduced antibody binding to GTKO/SLA-I/II KO pig PBMCs. Using GTKO/β4GalNT2KO pAECs with or without pIFN-γ stimulation as target cells, we found that the binding levels of the terminal sera to pAECs were positively correlated with SLA expression. IP-MS analysis identified multiple SLA class I and class II epitopes targeted by recipient IgG antibodies, with SLA-2 emerging as a dominant immunogenic antigen. In addition, xenogeneic MLR assays revealed that deletion of SLA, particularly SLA class II, markedly attenuated human anti-pig T-cell proliferation. These results demonstrate that induced anti-SLA antibodies can be generated in the early period after pig-to-monkey kidney xenotransplantation and may play a significant role in the development of AMR.

Background: Gene-edited pigs for xenotransplantation usually contain one or more transgenes encoding human complement regulatory proteins (CRPs). Because of species differences, human CRP(s) expressed in gene-edited pigs may have difficulty inhibiting the activation of exogenous rabbit complement added to a complement-dependent cytotoxicity (CDC) assay. The use of human complement instead of rabbit complement in CDC experiments may more accurately reflect the actual regulatory activity of human CRP(s). Methods: Peripheral blood mononuclear cells (PBMCs) were obtained from one GTKO pig and two GTKO/hCD55 pigs with a high or low level of hCD55 expression. After incubation of heat-inactivated normal human sera (HINHS) with porcine PBMCs, CDC levels were measured after the addition of commercial rabbit complement or human complement. In addition, a modified one-step CDC method was established using pooled normal human sera (NHS) without the addition of exogenous complement. Results: There was no significant difference in the binding of IgM/IgG to PBMCs from the three pigs. Both rabbit and human complement mediated a significant cytotoxic effect on GTKO pig PBMCs (98.97% vs. 82.73%). Even the high expression of hCD55 only had a very limited inhibitory effect on rabbit complement-mediated cytotoxicity (81.70% vs. 98.97%). However, regardless of whether the expression level was high or low, hCD55 had a very remarkable inhibitory effect on human complement-mediated cytotoxicity (2.94% and 23.83% vs. 82.73%; p < 0.01). Similar results were obtained using the modified one-step CDC method. In addition, the inhibitory effect of hCD55 on C3c and C5b-9 deposition on pig PBMCs was positively correlated with the expression level of hCD55. Conclusion: The use of human complement instead of rabbit complement in CDC assays can better reflect the actual cytotoxic effect of human xenoantibodies against pig PBMCs expressing human CRP(s), and thus may have potential application to gene-edited pig-to-human xenotransplantation.

BACKGROUND:Induction therapy is necessary to prevent acute rejection of xenografts. At present, basiliximab is rarely used as an induction therapy agent in solid organ xenotransplantation. In this study, we conducted in vitro experiments to investigate the inhibitory effect of basiliximab on human anti-porcine xenogeneic immune responses. METHODS:A xenogeneic and allogeneic mixed lymphocyte reaction (MLR) system was established using peripheral blood mononuclear cells (PBMCs) isolated from GTKO/CMAHKO/β4GalNT2KO (triple-knockout, TKO) pigs or humans as stimulator cells, and another group of human PBMCs as responder cells. Various concentrations of basiliximab were added to the MLR systems as interventions. The inhibitory effects of basiliximab on the proliferation and cytokine production of human T cells were compared. RESULTS:PBMCs from TKO pigs or humans stimulated significant proliferation of human T cells. Basiliximab inhibited human CD4+ and CD8+ T-cell proliferation in a typical dose-dependent manner in both xenogeneic and allogeneic MLR. When the concentration of basiliximab reached 1 µg/mL, the proliferation rates of xenoreactive CD4+ and CD8+ T cells decreased by more than 72%, which was quite similar to the effect in the allogeneic MLR. The inhibitory effects of basiliximab on xenogeneic T-cell responses were further confirmed by the detection of CD25 expression and supernatant cytokines (IFN-γ, TNF-α), and the results were similar to those for allogeneic MLR. CONCLUSIONS:Basiliximab can significantly reduce the xenoreactivity of human lymphocytes against TKO pig cells, and its inhibitory effect is no less than that on allogeneic T cell responses, supporting its potential as induction therapy in xenotransplantation.

Effective treatment of late antibody-mediated rejection (late AMR) is still an unmet medical need. Clearing donor-specific antibody (DSA) and preventing its rebound is the ideal goal of treatment. We have summarized the clinical data from seven patients with late or chronic active AMR after renal transplantation who received daratumumab (Dara)-based treatment first (Phase 1) and then tocilizumab (TCZ) therapy (Phase 2). Phase 1 consisted of an intensive treatment period (Dara plus PP/IVIG) and a maintenance treatment period (Dara alone). The main clinical indicators were DSA, Banff scores and renal function. After 4 to 17 weeks of intensive treatment, the MFI values of DSA in five of the seven patients fell below 5,000. During Dara maintenance treatment, only one patient’s DSA became negative, and the remaining six patients’ DSAs remained relatively stable or showed rebound. However, after TCZ treatment was begun, the DSA eventually became negative in three patients and decreased to low levels (< 3,500) in the other three patients. Also, our treatment stabilized renal function in all patients. At 24–28 months after treatment, renal biopsy showed partial remission of microvascular inflammation in four of six patients. In addition, capillary C4d deposition became negative in all patients (P = 0.001), and the mean score of i-IFTA was significantly reduced (P = 0.012). Other chronic injury scores did not change significantly. This new therapy combining Dara and TCZ achieved a good desensitization effect, providing an important reference point for designing better-optimized treatment of late or chronic active AMR in the future. This retrospectively study was approved by the Ethics Committee of Tongji Hospital, Wuhan, China (TJ-IRB20230729).

ABSTRACT Background Long‐term immunosuppressive maintenance therapy is necessary to prevent the rejection of xenografts. However, it is still unclear which oral immunosuppressant is most suitable for pig‐to‐human xenotransplantation . Methods A xenogeneic mixed lymphocyte reaction (MLR) system was established using peripheral blood mononuclear cells (PBMCs) isolated from wildtype (WT) or GTKO/CMAHKO/β4GalNT2KO (TKO) pigs as stimulator cells and human PBMCs as responder cells. Various concentrations of tacrolimus (Tac), cyclosporine (CsA), or rapamycin (Rapa) were added to the MLR system as interventions. The inhibitory effects of the three immunosuppressants on the proliferation and cytokine production of human T cells were studied and compared. The inhibitory effect of anti‐CD154 mAb alone or in combination with Tac/CsA/Rapa on xenoreactive MLR was also investigated. Results PBMCs from both WT and TKO pigs stimulated significant proliferation of human T cells. Tac had a strong inhibitory effect on human T‐cell proliferation stimulated by pig PBMCs. CsA inhibited human T‐cell proliferation in a typical dose‐dependent manner. When Tac and CsA concentrations reached 5 and 200 ng/mL, respectively, the proliferation rates of CD3 + /CD4 + /CD8 + T cells were reduced almost to a negative level. Even at high concentrations, Rapa had only a moderate inhibitory effect on xenogeneic MLR. The inhibitory effects of these three immunosuppressants on xenogeneic T‐cell responses were further confirmed by the detection of CD25 expression and supernatant cytokines (IL‐2, IL‐6, IFN‐γ, TNF‐α, IL‐4, IL‐10, and IL‐17). Although anti‐CD154 mAb monotherapy showed only moderate inhibitory effects on xenoreactive T‐cell proliferation, low‐dose anti‐CD154 mAb combined with low‐dose Tac, CSA, or Rapa could produce significant synergistic inhibitory effects. Conclusion Tac is more efficient than CsA or Rapa in inhibiting xenogeneic T‐cell responses in vitro. If used in combination with anti‐CD154 mAb, all the three immunosuppressants can achieve satisfactory synergistic inhibitory effects.

盆腔器官脱垂（POP）是中老年妇女常见的妇科疾病，严重影响患者的身心健康，且随着老龄化的加剧，POP的发生也呈上升趋势。阴道封闭术作为治疗无性生活需求的老年体弱症状性POP患者的主要手术方式之一，有着手术时间短、创伤小等优势。生活水平的提高使POP患者更关注手术治疗对其生命质量及心理状态的改善。近年来，关于阴道封闭术对老年症状性POP患者生命质量影响的研究报道渐多，本文对阴道封闭术的临床疗效、阴道封闭术对老年重度POP患者生命质量和心理健康的影响进行综述。

Background: The generation of glycoprotein galactosyltransferase α 1, 3 (GGTA1) knockout pigs has greatly contributed to the reduction of hyperacute xenograft rejection. However, it is not clear whether porcine major histocompatibility complex antigen SLA can induce significant xenoantibody production in primate recipients after kidney xenotransplantation. Methods: We have performed six renal xenotransplants in rhesus monkeys using kidneys from GTKO/hCD55 pigs. The recipient monkeys received induction therapy with anti-thymocyte globulin (thymoglobulin) and anti-CD20mAb (rituximab) and maintenance therapy with tacrolimus, mycophenolate mofetil, and low-dose corticosteroids. Two of the six recipient monkeys (17R02 and 17R05) generated high levels of circulating antibodies against non-Gal antigens and developed acute humoral xenograft rejection on days 19 and 20. To investigate the presence of anti-SLA antibodies in xenograft rejection, we used serum samples collected before transplantation (day -7) and at the time of rejection (days 19 and 20) to measure IgM/IgG antibody binding against GTKO/hCD55 or GTKO/SLA-I/II KO pig PBMCs by flow cytometry. Results: The binding of IgM and IgG antibodies to GTKO/hCD55 pig PBMCs was significantly (5 to 10 times) higher in the serum of both monkeys at the time of rejection than in serum collected before transplantation (day -7), indicating that a large proportion of the antibody against non-Gal antigens was newly generated after transplantation. In the serums of both monkeys at the time of rejection, the levels of IgM and IgG binding decreased significantly after the additional deletion of SLA-I/II (IgM decreased by 45% and 83%, IgG decreased by 54.4% and 57.7%, respectively), suggesting that anti-SLA antibodies accounted for about half or more of the non-Gal-specific antibodies generated after transplantation. Conclusions: In conclusion, we demonstrate for the first time that porcine SLA antigen can induce higher levels of anti-SLA antibodies after xenotransplantation and may play important roles in GTKO pig-to-rhesus monkey xenotransplantation. It is suggested that knockout of the SLA antigen is necessary for pig-to-rhesus xenotransplantation. Major Scientific and Technological Project of Hainan province (ZDKJ2019009), China. References: 1. Fu R, Fang M, Xu K, et al. Generation of GGTA1-/-β2M-/-CIITA-/- Pigs Using CRISPR/Cas9 Technology to Alleviate Xenogeneic Immune Reactions. Transplantation. 2020;104(8):1566-1573. doi:10.1097/TP.0000000000003205 2. Ladowski JM, Hara H, Cooper DKC. The Role of SLAs in Xenotransplantation. Transplantation. 2021;105(2):300-307. doi:10.1097/TP.0000000000003303 3. Adams AB, Lovasik BP, Faber DA, et al. Anti-C5 Antibody Tesidolumab Reduces Early Antibody-mediated Rejection and Prolongs Survival in Renal Xenotransplantation. Ann Surg. 2021;274(3):473-480. doi:10.1097/SLA.0000000000004996 4. Fischer K, Rieblinger B, Hein R, et al. Viable pigs after simultaneous inactivation of porcine MHC class I and three xenoreactive antigen genes GGTA1, CMAH and B4GALNT2. Xenotransplantation. 2020;27(1):e12560. doi:10.1111/xen.12560 5. Byrne GW. Does human leukocyte antigens sensitization matter for xenotransplantation? Xenotransplantation. 2018;25(3):e12411. doi:10.1111/xen.12411 6. Hammer SE, Ho CS, Ando A, et al. Importance of the Major Histocompatibility Complex (Swine Leukocyte Antigen) in Swine Health and Biomedical Research. Annu Rev Anim Biosci. 2020;8:171-198. doi:10.1146/annurev-animal-020518-115014 7. Mulder A, Kardol MJ, Arn JS, et al. Human monoclonal HLA antibodies reveal interspecies crossreactive swine MHC class I epitopes relevant for xenotransplantation. Mol Immunol. 2010;47(4):809-815. doi:10.1016/j.molimm.2009.10.004 8. Martens GR, Ladowski JM, Estrada J, et al. HLA Class I-sensitized Renal Transplant Patients Have Antibody Binding to SLA Class I Epitopes. Transplantation. 2019;103(8):1620-1629. doi:10.1097/TP.0000000000002739 9. Ladowski J, Martens G, Estrada J, Tector M, Tector J. The desirable donor pig to eliminate all xenoreactive antigens. Xenotransplantation. 2019;26(4):e12504. doi:10.1111/xen.12504 10. Martens GR, Reyes LM, Li P, et al. Humoral Reactivity of Renal Transplant-Waitlisted Patients to Cells From GGTA1/CMAH/B4GalNT2, and SLA Class I Knockout Pigs [published correction appears in Transplantation. 2018 Feb;102(2):e88]. Transplantation. 2017;101(4):e86-e92. doi:10.1097/TP.0000000000001646 11. Ladowski JM, Reyes LM, Martens GR, et al. Swine Leukocyte Antigen Class II Is a Xenoantigen. Transplantation. 2018;102(2):249-254. doi:10.1097/TP.0000000000001924 12. Ladowski JM, Martens GR, Reyes LM, et al. Examining the Biosynthesis and Xenoantigenicity of Class II Swine Leukocyte Antigen Proteins. J Immunol. 2018;200(8):2957-2964. doi:10.4049/jimmunol.1800022 13. Ladowski JM, Martens GR, Reyes LM, Hauptfeld-Dolejsek V, Tector M, Tector J. Examining epitope mutagenesis as a strategy to reduce and eliminate human antibody binding to class II swine leukocyte antigens. Immunogenetics. 2019;71(7):479-487. doi:10.1007/s00251-019-01123-y

Background: Xenotransplantation using genetically engineered pig organs is considered a valid potential for the human donor shortage. However, in addition to acute and chronic rejection of pig-to-human xenotransplantation by immunology barriers, the blood type incompatibility between pig and human is also one of the reasons for the failure of xenografts. Different from people, pigs only have blood types A and O. Currently, the reliable method to blood type pigs is by immunofluorescence and immunohistochemical staining of tissues (such as kidneys), but the application of this method is limited by the relative difficulty of obtaining material and the trauma associated with tissue biopsy. Although the immunofluorescence method of buccal mucosa smear is relatively simple and feasible, there is a risk of contamination with food debris and obtaining too few oral mucosal cells. In the present study, we have found a simple and reliable method for blood typing of pigs. Methods: The expression of blood group antigen on erythrocyte surface was directly detected by flow cytometry using commercial monoclonal antibodies against blood group antigen in the donor pigs (7 wild-type and 4 gene-edited pigs) undergoing allogeneic or xenogeneic kidney transplantation in our center. Clinically common methods such as slide agglutination and reverse cassette gel were used as controls, and the accuracy was verified by immunofluorescence using kidney tissue and oral buccal mucosa smears. Results: Kidney tissue and oral mucosa smear were detected in 8 cases with blood group A and 3 cases with blood group O. However, the blood type of pigs detected by slide agglutination method was O-type, and the blood type of pigs detected by reverse cassette gel method was difficult to determine. The results of blood group antigen detection on the surface of porcine red blood cells using our flow cytometry method were consistent with the immunofluorescence results of kidney tissue and oral mucosa In addition, our results also suggest that there are differences in the expression of A antigen on the surface of pig RBC and kidney, and flow cytometry can detect weak expression of A antigen on the surface of RBC. Conclusions: Although the expression of A antigen on the surface of pig RBC is weak and difficult to be detected by routine clinical blood group detection methods, flow cytometry using commercial anti-A monoclonal antibody can accurately detect the expression of A antigen on porcine red blood cells, so it is a simple and reliable method. References: 1. Wang X, Chen S, Chen G. ABO typing in experimental cynomolgus monkeys using non-invasive methods. Sci Rep. 2017 Jan 23;7:41274. doi: 10.1038/srep41274. PMID: 28112245; PMCID: PMC5256026. 2. Chen S, Wei Q, Li J, Xiang Y, Guo H, Ichim TE, Chen S, Chen G. A simple and reliable method to blood type monkeys using serum samples. Transpl Int. 2009 Oct;22(10):999-1004. doi: 10.1111/j.1432-2277.2009.00859.x. Epub 2009 Mar 9. PMID: 19298252. 3. Busch J, Specht S, Ezzelarab M, Cooper DK. Buccal mucosal cell immunohistochemistry: a simple method of determining the ABH phenotype of baboons, monkeys, and pigs. Xenotransplantation. 2006 Jan;13(1):63-8. doi: 10.1111/j.1399-3089.2005.00255.x. PMID: 16497213. 4. Smood B, Hara H, Schoel LJ, Cooper DKC. Genetically-engineered pigs as sources for clinical red blood cell transfusion: What pathobiological barriers need to be overcome? Blood Rev. 2019 May;35:7-17. doi: 10.1016/j.blre.2019.01.003. Epub 2019 Jan 28. PMID: 30711308; PMCID: PMC6467751. 5. Smith DM, Newhouse M, Naziruddin B, Kresie L. Blood groups and transfusions in pigs. Xenotransplantation. 2006 May;13(3):186-94. doi: 10.1111/j.1399-3089.2006.00299.x. PMID: 16756561. 6. Yamamoto F, Yamamoto M. Molecular genetic basis of porcine histo-blood group AO system. Blood. 2001 May 15;97(10):3308-10. doi: 10.1182/blood.v97.10.3308. PMID: 11342465.

After continuous efforts from generations of transplant surgeons, kidney transplantation (KT) has become an optimal treatment for end-stage renal disease.However, an imbalance between supply and demand of organs has always restricted the development of KT.For this clinical dilemma, xenotransplantation is expected to become one practical alternative for alleviating organ shortage.This review summarized recent literature reports of kidney xenotransplantation and the latest cases of pig-to-human kidney and heart transplantations.Also clinical transformations and applications of kidney xenotransplantation were discussed.

Objective:To summarize the incidence of acute rejection (AR) after pediatric kidney transplantation (KT) at a single center and examine its impact on graft/patient survival and risk factors for AR.Methods:This is a retrospective cohort study including pediatric recipients who underwent kidney transplantation in past 8 years.After excluding recipients of graft thrombosis within a week post-transplant and lost to follow-ups, a total of 143 cases were ultimately recruited and assigned into two groups of AR (n=29) and non-AR (n=114).Basic profiles of both donors and recipients and graft/patient survival rate were compared between two groups.Relative risk factors for AR episodes were also examined by Logistic regression.Results:Renal grafts for 130/143 cases (90.9%) were harvested from deceased donors and 120(83.9%) cases from children.Twenty-seven transplants (18.9%) were performed in infants and young recipients aged < 3 years.During a median follow-up of 33 months, 34 AR episodes occurred in 29(20.3%) patients.Rate of re-transplantation (27.6% vs. 7.9%), pediatric donor (96.5% vs. 80.7%) and rabbit anti-human thymocyte globulin (rATG) induction (79.3% vs. 36%) were significantly higher in AR group than non-AR group ( P=0.007, P=0.046, P<0.001).Multivariate regression analysis indicated that basiliximab induction caused a significant reduction in the risk of AR incidence as compared with rATG induction (odds ratio 0.13, 95% confidence interval 0.04-0.43, P<0.001).The median time of AR incidence was 1.3 months post-transplantation and 23 episodes (67.6%) were confirmed by biopsy.After anti-rejection treatment, 52.9%(n=18) of the cases achieved a full recovery and 38.3% (n=13) had improved graft function.However, 3 cases (8.8%) developed irreversible graft failure.The 1/3-year graft survival rates were significantly lower in AR group than those in non-AR group (75.3% vs. 95.2%, 68.4% vs. 90.4%, P=0.01), and there was no significant difference in 1-and 3-year patient survival rates between two groups. Conclusions:The incidence of AR is relatively high in pediatric renal transplantation, which has an impact on graft survival.Basiliximab induction can effectively reduce the risk of AR.

Objective This study investigated the composition of pathogenic microorganisms, clinical features, and therapeutic strategies of infective artery rupture of renal allografts in recipients receiving deceased donor (DD) kidneys. Methods We retrospectively studied the clinical data of the DD kidney transplant recipients with donor-associated infection at Tongji Hospital, Wuhan, China from January 1, 2015 to December 31, 2018, related recipients and corresponding donors. We collected the entire results of pathogenic microorganisms cultured from these related ruptured kidneys and then analyzed their distribution and differences. Results A total of 1440 kidney transplants from DD were performed in our center. The total incidence of infective artery rupture in kidney transplants was about 0.76% (11/1440), and the annual incidence ranged from 0.25% to 1.03%. The microbial culture results revealed that 11 recipients suffered from infective artery rupture and 3 recipients who accepted the kidney from same donor had the donor-associated pathogens, including 9 fungal strains (28.1%) and 23 bacterial strains (71.9%). There were 4 recipients infected with multi-drug-resistant Staphylococcus and Klebsiella pneumoniae from the above 11 recipients, of which, 10 recipients underwent graft loss, and one died of septic shock. The microbial cultures of the remaining 3 recipients who received appropriate anti-infective regimens turned negative eventually, and the patients were discharged successfully without significant complications. Conclusion Renal recipients with infections derived from DDs were at high risk of artery rupture, graft loss, or even death. Appropriate anti-infective treatment is essential to reduce the incidence of artery rupture and mortality.

Sda, produced by the B4GALNT2 enzyme, has been recognized as an important xenoantigen for pig-to-nonhuman primate xenotransplantation. However, little is known about Sda expression in pigs and its immunogenicity in xenotransplantation. In this study, peripheral blood mononuclear cells (PBMCs) were isolated from wildtype, GTKO (with high, moderate, and low Sda expression), GTKO/β4GalNT2KO, GTKO/CMAHKO, or GTKO/CMAHKO/β4GalNT2KO pigs. Anti-pig IgM/IgG binding and complement-dependent cytotoxicity (CDC) to pig PBMCs was measured by flow cytometry using pooled rhesus monkey sera (n=20) or human sera (n=20). As compared to wild-type pigs (n=12), GTKO pigs (n=17) had a significantly higher mean level of Sda expression on PBMCs and showed a greater individual difference in expression. Both the overall binding of monkey serum IgM/IgG antibody to GTKO pig PBMCs and CDC against these PBMCs decreased significantly with a progressive reduction in Sda expression, showing a clear dose-effect relationship. Both the monkey serum antibody binding and CDC decreased significantly after the additional deletion of Sda, whereas the binding of human serum antibody and CDC against the GTKO pig PBMCs were markedly reduced after the deletion of Neu5Gc in the pigs. In addition, anti-Sda antibody accounted for > 50% of the induced anti-non-Gal antibody at the time of rejection in two rhesus monkeys that received GTKO/hCD55 pig kidney xenotransplantation, and the anti-Sda antibody showed significant cytotoxic activity against GTKO pig cells. We conclude that both natural and induced anti-Sda antibodies play important roles in GTKO pig-to-rhesus monkey xenotransplantation, thus providing further evidence for GTKO/β4GalNT2KO pigs as the preferred organ source for rhesus monkeys as a preclinical model of xenotransplantation.

ABO blood group antibodies have not been generated or are at low titer during early infancy. Therefore, in theory, ABO-incompatible kidney transplantation (ABOi KT) may be successfully achieved in small infants without any pre-transplant treatment. We report here the first ABO-incompatible deceased donor kidney transplantation (ABOi DDKT) in an infant. The recipient infant was ABO blood group O, and the donor group A. The recipient was diagnosed with a Wilms tumor gene 1 (WT1) mutation and had received peritoneal dialysis for 4 months prior to transplant. At 7 months and 27 days of age, the infant underwent bilateral native nephrectomy and single-kidney transplantation from a 3-year-old brain-dead donor. No pre- or post-transplantation antibody removal treatment was performed, since the recipient's anti-iso-hemagglutinin-A Ig-M/G antibody titers were both low (1:2) before transplantation and have remained at low levels or undetectable to date. At 11 months post-transplant, the recipient is at home, thriving, with normal development and graft function. This outcome suggests that ABOi DDKT without antibody removal preparatory treatment is feasible in small infants, providing a new option for kidney transplantation in this age range.

目的总结5例婴幼儿肾移植的围手术期护理经验.方法术前成立特护小组,术后给予患儿严密的生命体征监护、细致入微的病情观察、出入液量平衡管理、抗凝治疗、抗排斥及抗感染治疗、并发症的观察和护理.结果2例患儿术后早期移植肾恢复不良,其中1例发生排斥反应,移植肾功能恢复延迟,行二次肾移植后痊愈出院;另1例行血液透析后移植肾功能恢复.2例患儿移植术后出现不同程度的排斥反应,通过抗排斥治疗后痊愈出院.1例患儿术后移植肾恢复顺利.结论婴幼儿病情变化快、并发症多,专业化的诊疗护理能提高肾移植成功率,促进患儿早日康复.

Liraglutide, a glucagon-like peptide-1 receptor (GLP-1R) agonist, has been reported to exert protective effects against myocardial, hepatic, and gastric ischemia-reperfusion injury (IRI), but whether it can protect against renal IRI remains unknown. Here, a lethal renal IRI model was established with a 100% mortality rate in untreated mice. Treatment with liraglutide involving a regimen of multiple doses resulted in 100% survival, remarkable preservation of renal function, a significant reduction in pathological damage, and blunted upregulation of TNF-alpha, IL-1 beta, IL-6, MCP-1, TLR-2, TLR-4, and RAGE mRNA. We found that liraglutide treatment dramatically inhibited ischemia-induced nucleocytoplasmic translocation and release of HMGB1. This inhibition was associated with a marked decrease (similar to 60%) in nuclear histone acetyltransferase activity. In addition, the protective effects of liraglutide on renal IRI were largely abolished by the administration of exogenous HMGB1. When the GLP-1R antagonist exendin (9-39) was given to mice before each liraglutide administration, or GLP-1R(-/-) mice were used for the renal IRI experiments, the protective effect of liraglutide on renal IRI was partially reversed. Moreover, liraglutide pretreatment significantly inhibited HMGB1 nucleocytoplasmic translocation during hypoxic culture of HK-2 cells in vitro, but the addition of exendin (9-39) significantly eliminated this inhibition. We demonstrate here that liraglutide can exert a strong protective effect on lethal renal IRI in mice. This protection appears to be related to the inhibition of HMGB1 nuclear-cytoplasmic translocation and release and partially depends on GLP-1R. Thus, liraglutide may be therapeutically useful for the clinical prevention and treatment of organ IRI.

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by a newly discovered coronavirus and has rapidly spread to most of the world and resulted in a global pandemic. However, there is a paucity of information available to characterize the immunodeficient population in the COVID-19 pandemic, especially information that focuses on patients after renal transplantation as the typical representative of this population. Understanding the susceptibility, clinic characteristics, treatment strategy, and prognosis of this population is of substantial importance for the management of immunodeficient patients in the pandemic. This is a retrospective, multicenter, observational cohort study, and conducted in all the transplant centers within Hubei province, China. All renal allograft recipients who lived in Hubei province and were performing their follow-up within these hospitals were enrolled. We obtained the medical records and compiled the data of recipients who were infected with COVID-19 between December 11, 2019 and May 1, 2020. The study was approved by the Institutional Review Board of Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (No. TJ-C20200166), written informed consent was obtained from the participants for the publication of their individual details in this manuscript. Hubei province has a population of 59.17 million. As of May 1, 2020, 68,128 cases of COVID-19 had been diagnosed, in accompaniment with 4512 deaths. The overall incidence of infection is 0.12%, with a mortality of 6.60%.[1] Currently, there are 4468 renal allograft recipients located in Hubei province participating in follow-up at these hospitals. Until May 1, 2020, 31 recipients had been diagnosed with COVID-19 [Supplementary Table 1, https://links.lww.com/CM9/A576]. The diagnosis period was from January 17 to March 16, 2020. Both the cumulative number and incidence of confirmed infected cases of COVID-19 in the Hubei general population and renal allograft recipients are shown in Figure 1. The incidence of COVID-19 in renal allograft recipients in Hubei was 0.69%, which was nearly six times more than the incidence among the general population of Hubei (0.69% vs. 0.12%, P < 0.001) [Supplementary Figure 1A, https://links.lww.com/CM9/A577]. The patients were divided into two groups, not severe (n = 16) and severe (n = 15), based on their clinical manifestations. The basic characteristics of the recipients are shown in Supplementary Table 2, https://links.lww.com/CM9/A576.Figure 1: (A) Red line: the cumulative number of confirmed infected cases of COVID-19 in Hubei from January 11, 2020 to April 26, 2020. A total of 68,128 people were infected. As of April 26, a total of 63,616 patients were cured, 4512 patients died, and the number of existing infected patients is 0.[1] Blue line: 31 renal allograft recipients had been diagnosed as having COVID-19 from January 17 to March 16, three recipients died, and 29 recipients were discharged. (B) The cumulative incidence of confirmed infected cases of COVID-19. COVID-19: Coronavirus disease 2019.All of the patients had abnormal findings upon chest computed tomography (CT) examination. In patients presenting with severe manifestations, the incidence of ground-glass opacity and interstitial abnormalities in the CT were higher than the not severe group (13/15 vs. 6/16, P = 0.005; 6/15 vs. 0, P = 0.005; respectively). The number of patients with lymphocyte counts <1000 per mm3 was statistically different (15/15 vs. 10/16, P = 0.008). The incidence of acute respiratory distress syndrome (ARDS) was also significantly higher in the severe than in the not severe group (6/15 vs. 0, P = 0.007). The overall incidence of acute kidney injury (AKI) was 9/31 (29%) among all recipients, and the incidence in the severe group was significantly higher than in the not severe group (7/15 vs. 2/16, P = 0.030) [Supplementary Table 3, https://links.lww.com/CM9/A576]. Once diagnosed, maintenance of immunosuppressant regimens were adjusted immediately for all but one patient. In 25/31 (81%) cases, withdrawal involved mycophenolic acid and calcineurin inhibitors (CNI), while the maintenance immunosuppressants were simply oral or bolus steroids; 12/31 (39%) patients received oral steroids only, 12/31 (39%) received low doses of 40 to 80 mg/day methylprednisolone, and one received a high dose of >250 mg/day methylprednisolone. In the severe group, 13/15 patients needed some means of mechanical ventilation. In the not severe group, none required mechanical ventilation (13/15 vs. 0, P < 0.001). As to the outcomes, 28/31 (90%) patients recovered and were finally discharged from the hospital. In the severe group, 3/31 (10%) patients died, of whom one had chronic obstructive pulmonary disease as an underlying disease, one was accompanied with gastrointestinal hemorrhage, and the other case was accompanied with severe renal allograft dysfunction that required dialysis. This mortality was slightly higher than that of the general population of Hubei (4512 out of 68,128, 6.60%, P = 0.490) [Supplementary Table 4, https://links.lww.com/CM9/A576]. We compared these data with those of the general population published by Guan et al,[2] and found that COVID-19 in renal allograft recipients was significantly more severe (48% vs. 16%, P < 0.001), required more mechanical ventilation (42% vs. 6%, P < 0.001), needed more intensive care unit (ICU) admission (13% vs. 5%, P = 0.050), and had greater incidence of AKI (29% vs. 0.5%, P < 0.001). The mortality rate in the recipient group was higher than that in the general population, but there was no statistical significance (10% vs. 7%, P = 0.490) [Supplementary Figure 1B–F, https://links.lww.com/CM9/A577]. Our data indicated that an immunocompromised person does have higher susceptibility for COVID-19 infection. The incidence of COVID-19 disease in this cohort was 0.69%, which was nearly six times the overall incidence of 0.12% in Hubei. Currently, it is well accepted that the immunocompromised population has higher susceptibility to transmitted diseases.[3] Despite this, it is very difficult to assess the exact differences when comparing the immunocompromised with the general population. The lockdown of Hubei province not only helped to control the transmission of the virus, but also provided us an opportunity to know the epidemiology of a special herd. These data suggested that COVID-19, like most viruses, is more likely to be transmitted to the immunosuppressed population. Thus, in a high risk area, stricter self-protection strategies should be adopted to avoid infection. The most common symptoms of COVID-19 include cough, fatigue, fever, dyspnea, muscle aches, and gastrointestinal symptoms.[4] Unlike the general population, renal allograft recipients had lower incidence of fever as an initial symptom. Of the recipients, six had never had a fever until discharge. This is consistent with a recent report from New York, in which only 30.7% patients had a fever as a presenting symptom. This diminishing of the fever is due to the use of antimetabolites as immunosuppressants, which can result in the absence of fever in up to 40% of infections. Once infected, an immunocompromised person is at higher risk of developing a severe case.[5] In this cohort, almost half (48%) of cases included were severe, much higher than that in the general population (16%). When compared with the general population, more cases needed mechanical ventilation, developed ARDS, and were admitted into the ICU. It is obvious that, in the immunocompromised population, antivirus ability is impaired significantly. This finding is consistent with an influenza study, in which the authors found that patients receiving immunosuppressive therapy are at risk for more severe or complicated influenza-induced disease. Furthermore, lymphocyte count has been associated with increased disease severity in COVID-19. Patients who died from COVID-19 are reported to have had significantly lower lymphocyte counts than survivors. The high incidence of lymphopenia in this cohort might explain why they were more prone to develop the severe syndrome. Our data also shows that hospitalized COVID-19 infection is correlated with a high incidence of AKI in renal allograft recipients. Although the COVID-19 virus nucleic acid can be detected in the urine, it is not certain that this virus can damage the kidneys directly. The incidence of AKI in the general population varies from 0 to 23% among hospitalized patients and 19% to 29% in critical care patients. In a large cohort reported by Guan et al, the incidence of AKI was only 0.5%. Our data reported an incidence of 29% among all the patients and 47% among severe patients, and these numbers are the highest among current publications. A single renal allograft within the body, facing immunological rejection and CNI renal toxicity every day, has a low capacity to endure the inflammatory environment and anti-infection medicines. Our opinion is that the high incidence of AKI is not caused by rejection, since renal allograft function could recover without anti-rejection therapy. Thus, treating COVID-19 infection among renal allograft recipients should involve the consideration of more strategies to protect renal allograft function. Our data showed that, although they face more severe clinical manifestations, immunocompromised patients do not have to have a worse outcome. In this cohort, 28 (90%) patients recovered and were discharged from the hospital. Only three out of 31 (10%) patients died of COVID-19 pneumonia, and this is significantly lower than the report from New York, which indicated a figure of 28%[6] and only slightly higher than the mortality of the general population in Hubei (6.6%). Early admission to the hospital, lower dose of maintenance immunosuppressants following transplantation, and early reduction of immunosuppressants might account for the relatively lower incidence of death. Moreover, although the use of corticosteroids in treating COVID-19 pneumonia remains controversial, a low dose of bolus corticosteroid (methylprednisolone 40–80 mg/day) was widely used in replacement of maintenance immunosuppressants in this cohort. According to experience from the management of cytomegalovirus infection, which is a common infectious complication after renal transplantation, a low dose of corticosteroid is a well-tolerable selection for the reduction of inflammation and cytokine release. The effect of a low-dose bolus steroid should not be excluded for achieving a relatively benign outcome. We found during the COVID-19 breakout in Hubei province, China, the immunocompromised population, as represented by renal allograft recipients, had higher susceptibility for virus infection, more severe clinical manifestations, longer lengths of hospital stay, and more AKI complications. However, these patients did not have to have a worse outcome if disease management was carefully handled. Funding This work is funded by a Key Project of Health and Family Planning Commission of Hubei Province of China (No. WJ2019Z007), the National Key Research & Development Program of China (2018YFA0108804), the National Natural Science Foundation of China (Nos. 81970650 and 81770753), the Youth Program of National Natural Science Foundation of China (No. 81800661), the Fundamental Research Funds for the Central Universities (No. 20ykpy34), and the China Postdoctoral Science Foundation Funded Project (No. 2020M683083). Conflicts of interest None.

Objective:To explore the efficacy and safety of a novel Tripterygium preparation (Kunxian Capsules)in kidney transplant recipients developing refractory proteinuria after transplantation.Methods:A total of 59 kidney transplant recipients received regular follow-ups from August 2018 to July 2021.Severity of proteinuria, kidney graft function and adverse effects were retrospectively recorded before and at Month 1/2/3/6 months after Kunxian treatment.They were divided into two groups of effective and void to explore the potential effect-related factors.Results:Six-month treatment was completed in 57 patients except for 2 cases of discontinued treatment due to severe adverse effects.A significant reduction in amount of proteinuria was observed at Month 1 [1.09(0.42, 2.59 g/24 h)vs 1.82(1, 2.7 g/24 h, P<0.01)]and the trend continued during subsequent follow-ups.Twenty-nine patients(50.9%)responded remarkably.Eighteen patients(31.6%)showed no response.The overall effective rate was 68.4%.Inter-group comparison revealed strong correlations between treatment efficacy and baseline serum creatinine levels, early initiation of treatment and symptom duration from onset to treatment.Kidney graft IgA nephropathy demonstrated the highest effective rate(11/13, 84.6%). Furthermore, elevated blood concentration of tacrolimus hinted at a potential drug interaction. Conclusions:Kunxian Capsules is efficacious and safe for renal transplant recipients developing moderate-severe proteinuria and not responding to traditional medications.Early initiation of treatment before graft function decline is recommended.Reducing tacrolimus dose cautiously in advance and monitoring adverse events are also essential.