Delayed kidney transplantation in combined liver-kidney transplantation.

PURPOSE OF REVIEW: To review the impact of delayed kidney transplantation approach in combined (simultaneous) liver-kidney transplantation (CLKT). RECENT FINDINGS: CLKT offers a life-saving procedure for patients with both end-stage liver disease and chronic kidney disease or prolonged acute kidney injury. It is the most common multiorgan transplant procedure in the US accounting for 9-10% of all liver transplants performed. The number of CLKT has also been increasing in other countries with a better understanding of hepato-renal syndrome. US is the only country which implemented a national allocation policy for CLKT in 2017. Due to the different physiological needs of liver and kidney allografts immediately after transplantation, delayed kidney transplantation approach in CLKT has been introduced for the first time by the Indiana Group, naming it as 'the Indiana Approach'. Over the years, many other groups in the US and in Europe published better outcomes in CLKT using the delayed kidney transplantation approach with the support of hypothermic machine perfusion. SUMMARY: Several groups have shown that delayed kidney transplantation in CLKT is a safe procedure with better outcomes in graft(s) and patient survival.

Contrast Administration to the Deceased Kidney Donor Has No Impact on Post-Transplant Outcomes.

BACKGROUND: Contrast-induced acute kidney injury may occur in patients undergoing imaging studies. This study reviews all deceased kidney donors at a single center during a 15-y period to determine if donor contrast exposure results in contrast-induced acute kidney injury in the donor or is associated with worse outcomes in the transplant recipient. METHODS: Donor and recipient renal functions were recorded, including donor serum creatinine and recipient delayed graft function, creatinine clearance at 1 y, and early and late graft survival. Donor contrast exposure was recorded as the number of preprocurement contrasted studies. RESULTS: Donor and recipient records were available for 1394 transplants (88%). There were 51% of donors who received any contrasted study (38%, one study; 12%, two studies, and 1%, three studies). Donor contrast exposure was not associated with significant differences in preprocurement serum creatinine levels. Post-transplant, donor contrast exposure was associated with risk of neither delayed graft function (4% for all) nor early kidney graft loss. Creatinine clearance at 1 y was equivalent. Five-year Cox regression demonstrated higher graft survival for contrast-exposed grafts (P = 0.03). CONCLUSIONS: There is no negative effect of donor contrast administration on early and late kidney graft function. These findings included donor kidneys exposed to as many as three contrasted studies.

Excellent outcomes in combined liver-kidney transplantation: Impact of kidney donor profile index and delayed kidney transplantation.

The positive impact of delayed kidney transplantation (KT) on patient survival for combined liver-kidney transplantation (CLKT) has already been demonstrated by our group. The purpose of this study is to identify whether the quality of the kidneys (based on kidney donor profile index [KDPI]) or the delayed approach KT contributes to improved patient survival. In total, 130 CLKTs were performed between 2002 and 2015, 69 with simultaneous KT (group S) and 61 with delayed KT (group D) (performed as a second operation with a mean cold ischemia time [CIT] of 50 ± 15 hours). All patients were categorized according to the KDPI score: 1%-33%, 34%-66%, and 67%-99%. Recipient and donor characteristics were comparable within groups S and D. Transplant outcomes were comparable within groups S and D, including liver and kidney CIT, warm ischemia time, and delayed graft function. Lower KDPI kidneys (<34%) were associated with increased patient survival in both groups. The combination of delayed KT and KDPI 1%-33% resulted in 100% patient survival at 3 years. These results support that delayed KT in CLKT improves patient survival. The combination of delayed KT and low KDPI offers excellent patient survival up to 3 years. Improved outcomes in the delayed KT group including high KDPI kidneys supports expansion of the donor pool with the use of more extended criteria donor and donation after circulatory death kidneys. Liver Transplantation 24 222-232 2018 AASLD.

A Novel Approach in Combined Liver and Kidney Transplantation With Long-term Outcomes.

OBJECTIVE: The aim of this study was to compare the outcomes of simultaneous and delayed implantation of kidney grafts in combined liver-kidney transplantation (CLKT). BACKGROUND DATA: Delayed function of the renal graft (DGF), which can result from hypotension and pressor use related to the liver transplantation (LT), may cause worse outcomes in CLKT. METHODS: A total of 130 CLKTs were performed at Indiana University between 2002 and 2015 and studied in an observational cohort study. All kidneys underwent continuous hypothermic pulsatile machine perfusion until transplant: 69 with simultaneous kidney transplantation (KT) (at time of LT, group 1) and 61 with delayed KT (performed at a later time as a second operation, group 2). All patients received continuous veno-venous hemodialysis during the LT. Propensity score match analysis in a 1:1 case-match was performed. RESULTS: Mean kidney cold ischemia time was 10 ± 3 and 50 ± 15 hours, for groups 1 and 2 (P < 0.0001), respectively. The rate of DGF was 7.3% in group 1, but no DGF was seen in group 2 (P = 0.0600). Kidney function was significantly better in group 2, if the implantation of kidneys was delayed >48 hours (P < 0.01). Patient survival was greater in group 2 at 1 year (91%), and 5 year (87%) post-transplantation (P = 0.0019). On multivariate analysis, DGF [hazard ratio (HR), 165.7; 95% confidence interval (CI), 9.4-2926], extended criteria donor kidneys (HR, 15.9; 95% CI 1.8-145.2), and recipient hepatitis C (HR, 5.5; 95% CI 1.7-17.8) were significant independent risk factors for patient survival. CONCLUSIONS: Delayed KT in CLKT (especially if delayed >48 h) is associated with improved kidney function with no DGF post-KT, and improved patient and graft survival.

Native Nephrectomy with Renal Transplantation is Associated with a Decrease in Hypertension Medication Requirements for Autosomal Dominant Polycystic Kidney Disease.

PURPOSE: We assessed hypertensive control after native nephrectomy and renal transplantation in patients with autosomal dominant polycystic kidney disease. MATERIALS AND METHODS: Blood pressure control was studied retrospectively in 118 patients with autosomal dominant polycystic kidney disease who underwent renal transplantation between 2003 and 2013. Overall 54 patients underwent transplantation alone (group 1) and 64 underwent transplantation with concurrent ipsilateral nephrectomy (group 2). Of these 64 patients 32 underwent ipsilateral nephrectomy only (group 2a) and 32 underwent eventual delayed contralateral native nephrectomy (group 2b). The number of antihypertensive drugs and defined daily dose of each antihypertensive was recorded at transplantation and up to 36-month followup. RESULTS: Comparing preoperative to postoperative medications at 12, 24 and 36-month followup, transplantation with concurrent ipsilateral nephrectomy had a greater decrease in quantity (-1.2 vs -0.5 medications, p=0.008; -1.1 vs -0.3, p=0.007 and -1.2 vs -0.4, p=0.03, respectively) and defined daily dose of antihypertensive drug (-3.3 vs -1.0, p=0.0008; -2.9 vs -1.0, p=0.006 and -2.7 vs -0.6, p=0.007, respectively) than transplantation alone at each point. Native nephrectomy continued to be a predictor of hypertensive requirements on multivariable analysis (p <0.0001). The mean decrease in number of medications in group 2b from after ipsilateral nephrectomy to 12 months after contralateral nephrectomy was -0.6 (p=0.0005) and the mean decrease in defined daily dose was -0.6 (p=0.009). CONCLUSIONS: In patients with autosomal dominant polycystic kidney disease undergoing renal transplantation, concurrent ipsilateral native nephrectomy is associated with a significant decrease in the quantity and defined daily dose of antihypertensive drugs needed for hypertension control. Delayed contralateral native nephrectomy is associated with improved control of blood pressure to an even greater degree.

Recurrence of Hyperoxaluria and Kidney Disease after Combined Intestine-Kidney Transplantation for Enteric Hyperoxaluria.

BACKGROUND: Enteric hyperoxaluria (EH) occurs with a rate of 5-24% in patients with inflammatory bowel disease, ileal resection and modern bariatric surgery. The excessive absorption of calcium oxalate causes chronic kidney disease (CKD) in patients with EH. In the literature, a single experience was reported in combined intestine-kidney transplantation (CIKTx) in patients with CKD due to EH. METHODS: After a report of 2 successful cases of CIKTx in patients with EH and CKD, one was performed at our center in a 59-year-old Caucasian female who developed intestinal failure with total parenteral nutrition (TPN) dependence after a complication post-bariatric surgery. Before CIKTx, she underwent kidney transplantation alone (KTA) twice, which failed due to oxalate nephropathy. RESULTS: In July 2014, the patient underwent CIKTx and bilateral allograft nephrectomy to avoid EH and oxalate stone burden. The postoperative course was complicated with acute tubular necrosis due to the use of high pressors related to perioperative bleeding. The patient was discharged 79 days after CIKTx with a serum creatinine (sCr) of 1.2 mg/dl and free of TPN. Her sCr increased at 7 months and a renal biopsy showed oxalate nephropathy. SLC26A6 (oxalate transporter) staining was significantly diminished in native duodenum/rectum as well as in intestinal allograft compared to control. CONCLUSIONS: KTA in patients with CKD secondary to EH should not be recommended due to high risk of recurrence. Although other centers showed good long-term outcomes in CIKTx, our patient experienced recurrence of EH due to oxalate transporter defect, early kidney allograft dysfunction and prolonged antibiotic use.

Pre-transplant angiotensin receptor II type 1 antibodies and risk of post-transplant focal segmental glomerulosclerosis recurrence.

Post-kidney transplant recurrence of focal segmental glomerulosclerosis (FSGS) is a major problem. AT1R is expressed on podocyte; its expression is elevated in the proteinuric state. Using an ELISA, we tested pre-transplant sera of 28 patients with history of idiopathic FSGS for anti-AT1R levels and serum soluble urokinase-type plasminogen activator receptor (suPAR) as a biomarker for risk of recurrence of FSGS. Sera from 11 patients with polycystic kidney disease (PKD) were used as controls. Twelve patients had biopsy proven post-transplant FSGS recurrence at 1.5 months. No difference was found in the pre-transplant suPAR levels of FSGS patients (5993 ± 2292 pg/mL) vs. PKD (7334 ± 4538 pg/mL) (p = 0.23). Serum suPAR levels in patients with FSGS recurrence (5786 ± 1899 pg/mL) vs. no FSGS recurrence (6149 ± 2598 pg/mL) (p = 0.69) were not different. Anti-AT1R levels in patients with FSGS were 12.66 ± 11.85 U/mL vs. 8.69 ± 6.52 U/mL in PKD (p = 0.32); however, a difference was found in patients with and without FSGS recurrence 20.41 ± 14.36 U/mL 6.84 ± 4.181 U/mL, respectively (p < 0.01). Area under curve for suPAR and anti-AT1R to predict post-transplant FSGS recurrence was 0.51 and 0.84, respectively. Pre-transplant anti-AT1R levels appear to be a helpful biomarker in identifying patients at high risk of post-transplant FSGS recurrence.

Correlation between CT-based measured renal volumes and nuclear-renography-based split renal function in living kidney donors. Clinical diagnostic utility and practice patterns.

INTRODUCTION: Living donor evaluation involves imaging to determine the choice of kidney for nephrectomy. Our aim was to study the diagnostic accuracy and correlation between CT-based volume measurements and split renal function (SRF) as measured by nuclear renography in potential living donors and its impact on kidney selection decision. METHODS: We analyzed 190 CT-based volume measurements in healthy donors, of which 65 donors had a radionuclide study performed to determine SRF. RESULTS: There were no differences in demographics, anthropometric measurements, total volumes, eGFR, creatinine clearances between those who required a nuclear scan and those who did not. There was a significant correlation between CT-volume-measurement-based SRF and nuclear-scan-based SRF (Pearson coefficient r 0.59; p < 0.001). Furthermore, selective nuclear-based SRF allowed careful selection of donor nephrectomy, leaving the donor with the higher functioning kidney in most cases. There was also a significantly higher number of right-sided nephrectomies selected after nuclear-based SRF studies. CONCLUSION: CT-based volume measurements in living donor imaging have sufficient correlation with nuclear-based SRF. Selective use of nuclear-scan-based SRF allows careful selection for donor nephrectomy.

Efficacy and Safety of Bleselumab in Preventing the Recurrence of Primary Focal Segmental Glomerulosclerosis in Kidney Transplant Recipients: A Phase 2a, Randomized, Multicenter Study.

BACKGROUND: Focal segmental glomerulosclerosis (FSGS) is a common cause of end-stage kidney disease and frequently recurs after kidney transplantation. Recurrent FSGS (rFSGS) is associated with poor allograft and patient outcomes. Bleselumab, a fully human immunoglobulin G4 anti-CD40 antagonistic monoclonal antibody, disrupts CD40-related processes in FSGS, potentially preventing rFSGS. METHODS: A phase 2a, randomized, multicenter, open-label study of adult recipients (aged ≥18 y) of a living or deceased donor kidney transplant with a history of biopsy-proven primary FSGS. The study assessed the efficacy of bleselumab combined with tacrolimus and corticosteroids as maintenance immunosuppression in the prevention of rFSGS >12 mo posttransplantation, versus standard of care (SOC) comprising tacrolimus, mycophenolate mofetil, and corticosteroids. All patients received basiliximab induction. The primary endpoint was rFSGS, defined as proteinuria (protein-creatinine ratio ≥3.0 g/g) with death, graft loss, or loss to follow-up imputed as rFSGS, through 3 mo posttransplant. RESULTS: Sixty-three patients were followed for 12 mo posttransplantation. Relative decrease in rFSGS occurrence through 3 mo with bleselumab versus SOC was 40.7% (95% confidence interval, -89.8 to 26.8; P = 0.37; absolute decrease 12.7% [95% confidence interval, -34.5 to 9.0]). Central-blinded biopsy review found relative (absolute) decreases in rFSGS of 10.9% (3.9%), 17.0% (6.2%), and 20.5% (7.5%) at 3, 6, and 12 mo posttransplant, respectively; these differences were not statistically significant. Adverse events were similar for both treatments. No deaths occurred during the study. CONCLUSIONS: In at-risk kidney transplant recipients, bleselumab numerically reduced proteinuria occurrence versus SOC, but no notable difference in occurrence of biopsy-proven rFSGS was observed.

Comparison of donor, and early and late recipient outcomes following hand assisted and laparoscopic donor nephrectomy.

PURPOSE: While laparoscopic donor nephrectomy has encouraged living kidney donation, debate exists about the safest laparoscopic technique. We compared purely laparoscopic and hand assisted laparoscopic donor nephrectomies in terms of donor outcome, early graft function and long-term graft outcome. MATERIALS AND METHODS: We reviewed the records of consecutive laparoscopic and hand assisted laparoscopic donor nephrectomies performed by a single surgeon from 2002 to 2011. Donor operative time and perioperative morbidity were compared. Early graft function for kidneys procured by each technique was evaluated by rates of delayed graft function, need for dialysis and recipient discharge creatinine. Long-term outcomes were evaluated by graft function. RESULTS: A total of 152 laparoscopic donor nephrectomies were compared with 116 hand assisted laparoscopic donor nephrectomies. Hand assisted procedures were more often done for the right kidney (41.1% vs 17.1%, p <0.001) and in older donors (age 41.4 vs 37.5 years, p = 0.011). Warm ischemia time was shorter for hand assisted than for purely laparoscopic nephrectomy (120 seconds, IQR 50 vs 145, IQR 64, p <0.001). Median operative time was slightly shorter for the hand assisted than for the purely laparoscopic procedure (155 vs 165 minutes, p = 0.038). In each group 2 intraoperative complications required intervention (open conversion in 1 case each). Postoperatively complications developed after 5 purely laparoscopic and 5 hand assisted operations (1 Clavien 3b in each). Median length of stay was 2 days for each surgery. Postoperatively recipient outcomes were also similar. Delayed function occurred after 0% hand assisted vs 0.9% purely laparoscopic nephrectomies, dialysis was required in 0.9% vs 1.7% and rejection episodes developed in 9.7% vs 18.4% (p >0.05). At last followup the organ was nonfunctioning in 6.1% of hand assisted and 7.7% of purely laparoscopic cases (p >0.05). The recipient glomerular filtration rate at discharge home was similar in the 2 groups. CONCLUSIONS: Hand assisted laparoscopic donor nephrectomy had shorter warm ischemia time but perioperative donor morbidity and graft outcome were comparable. The choice of technique should be based on patient and surgeon preference.

Bilateral Renal Auto-Transplantation for Retroperitoneal Sarcomas: Is It Underutilized?

Sarcomas are a rare tumor of mesenchymal origin. The liposarcoma is the most common sarcoma of the retroperitoneum. Liposarcomas are typically low grade, and present at an advanced stage and a large size. We report a case of a large retroperitoneal liposarcoma, approximately 50 kg, encasing both kidneys, which was managed via a two-stage resection and staged renal auto-transplantation into the intra-peritoneal pelvis. The patient maintained normal renal function throughout, and remains disease free two years post-resection. Renal auto-transplantation with pelvic placement may facilitate improved margin-free resection. Renal relocation may allow the use of curative-intent ablative therapies such as radiofrequency ablation and radiation in cases of retroperitoneal recurrence.

Simultaneous Heart-kidney Transplant With Planned Delayed Implantation of the Kidney Graft After Ex Vivo Perfusion.

BACKGROUND: Simultaneous heart-kidney transplant (SHK) is an established option for patients with severe heart failure and chronic kidney disease. Recent studies in simultaneous liver-kidney transplantation demonstrate favorable outcomes achieved by delaying implantation of the kidney for over 24 h. This report describes a case series of consecutive patients listed for SHK who had planned delayed implantation of the kidney graft. METHODS: This case series represents a retrospective analysis of SHK patients extracted from the transplant database at a single center. RESULTS: There were 7 patients who underwent SHK during the study period. In all cases, kidney grafts were maintained on hypothermic ex vivo pulsatile perfusion for delayed implantation (mean cold ischemia 53 h [range, 31-69]). The first 5 patients had 100% 1-y heart and kidney graft survival with good function. Patient 6 was unstable on extracorporeal membrane oxygenation post-heart transplant. The kidney was implanted at 69 h, and the patient died soon thereafter. Patient 7 was also unstable on extracorporeal membrane oxygenation after heart transplant. The decision was made to implant the kidney into a backup kidney recipient. The heart transplant recipient subsequently died several days later, whereas the kidney was successfully transplanted in the alternate candidate. CONCLUSIONS: This case series highlights the potential utility of delayed kidney implantation in SHK patients. SHK with delayed renal transplant may provide an improved physiologic environment for renal transplant, which may result in improved early renal graft function. Delayed kidney transplant also provides the opportunity to transplant the kidney graft into an alternate candidate.

Vascular catastrophes following pancreas transplantation: an evolution in strategy at a single center.

INTRODUCTION: Complications of pancreas transplantation involving the arterial anastomosis are potentially life threatening. In this report, we review our experience with such vascular catastrophes. METHODS: Pancreas transplants performed between January 2003 and December 2009 were reviewed. All cases of pseudoaneurysm (PA) or arterioenteric fistula (AEF) were included. RESULTS: Of 346 pancreas transplants, 10 vascular catastrophes in nine recipients were identified. There were five PAs, one involving the pancreas allograft, one involving the donor iliac artery Y-graft stump following allograft pancreatectomy, two involving the kidney allograft, and one involving the bifurcation of the Y-graft. The latter was treated with coil embolization, but subsequently developed into an AEF. There were five AEFs including the recipient mentioned above. Four had a failed allograft and three had discontinued immunosuppression. The final case had a clamp injury to the proximal common iliac artery that fistulized to the donor duodenum. The management, course and outcome of all nine recipients are described in detail. CONCLUSION: Vascular catastrophes such as PA and AEF are potentially life-threatening complications of pancreas transplantation. Immediate treatment at the time of bleeding is essential and covered stenting of the involved artery may provide immediate vascular control in these situations.

Vasopressin for Post-kidney Transplant Hypotension.

Introduction: Hypotension after deceased donor kidney transplant (DDKT) is a risk factor for delayed graft function (DGF) and poor graft survival (GS). We hypothesize that vasopressin use in hypotensive DDKT recipients (DDKTRs) to increase blood pressure (BP) reduces DGF rates and is safe without increasing mortality. Methods: Group with vasopressin "study group" (n = 45) was defined as DDKTRs between 2012 and 2017 who required vasopressin for hypotension systolic BP (SBP) <120 mm Hg or diastolic BP (DBP) <60 mm Hg. DDKTRs with no-vasopressin "comparison group" (n = 90) were propensity score-matched DDKTRs between 2012 and 2017 without vasopressin use. Primary outcomes were GS, creatinine and allograft biopsy rate at 1 year, DGF rate, and death during transplant hospitalization. Results: Vasopressin group had lower mean maximum and minimum SBP and DBP in the operating room (OR). Median vasopressin start time post-DDKT was 2 hours (interquartile range [IQR] 1-6), and duration of use was 42 hours (IQR 24-63). DGF, creatinine at 1 year, and allograft biopsy rates were comparable. No deaths occurred during transplant hospitalization. Multivariable analysis did not find an effect of vasopressin use on GS. Conclusion: Treatment of hypotensive DDKTRs with vasopressin is safe and facilitated similar graft function and survival with that of nonhypotensive patients. In the absence of a randomized control trial, our study supports the safety of vasopressin therapy to prevent the adverse effects of hypotension.

Procedure: Laparoscopic Donor Nephrectomy.

Minimally invasive approaches for laparoscopic donor nephrectomy are necessary to limit surgical morbidity, and technical challenges differ from those encountered during other laparoscopic renal surgeries. Presented here is a step-by-step guide for laparoscopic donor nephrectomy-focusing on pure laparoscopic and hand-assisted techniques. Both straight laparoscopic and hand-assisted nephrectomies were performed in healthy donors who met transplantation criteria in terms of global health and psychologic well-being. Patient positioning, trocar placement, surgical steps, incision closure, and postoperative care are reviewed. Standard equipment used to complete this procedure is itemized. This guide outlines indications, preoperative preparation, and procedural steps for laparoscopic donor nephrectomy. The techniques and the evolution thereof represent our experience since 2002 for 510 cases. The attached videos demonstrate a high-volume surgeon's typical approach while factoring in anatomical variation. In both cases, the donor nephrectomies were without incident and the patient's postoperative courses were without complication. A basic framework for donor nephrectomy is presented highlighting surgical steps we believe to be essential for graft preservation and ultimately effective transplantation. Although no two cases are the same, systematic approaches will allow for timely case completion, fewer complications, and better donor/recipient outcomes.

Combined liver-kidney transplantation with positive crossmatch: Role of delayed kidney transplantation.

BACKGROUND: Positive crossmatch (XM+) combined liver-kidney transplantation due to preformed donor-specific human leukocyte antigen antibodies has produced mixed results. We sought to understand the role of delayed kidney transplant approach in XM+ combined liver-kidney transplantations. METHODS: XM+ combined liver-kidney transplantations were retrospectively reviewed. T- and B-cell XM, complement-dependent cytotoxic crossmatch, and flow cytometric crossmatch were performed prospectively. RESULTS: Of 183 combined liver-kidney transplantations performed (2002-2019), 114 (62%) were with "delayed" kidney transplant approach and 19 (19 of 183, 10%) were XM+. Of 19 XM+ combined liver-kidney transplantations, kidney transplant was "delayed" in 14 by an average of 47 hours (range 24-64 hours) from liver transplant. There was a significant reduction in both class I (mean pre-liver transplant mean fluorescence intensity (MFI) 26,230 versus mean post-liver transplant and pre-delayed kidney transplant MFI 3,272, P = .01) and total MFI (mean pre-liver transplant MFI 27,233 vs mean post liver transplant and predelayed kidney transplant MFI 11,469, P = .01). However, there was no significant change in the MFI of class II donor-specific antibodies (mean pre-liver transplant MFI 17,899 versus post-liver transplant and pre-delayed kidney transplant MFI 14,341, P = .19). None of XM+ delayed kidney transplants had delayed graft function, and there was no antibody-mediated rejection. One-year patient survival for the XM+ combined liver-kidney transplantation with delayed kidney transplant approach was 92.9%, which is comparable to patient survival of XM- combined liver-kidney transplantation. Whereas patient survival in recipients before "delayed" approach ("simultaneous"; n = 5) was 40% when liver-kidney transplants were performed simultaneously (P = .06). CONCLUSION: In sensitized combined liver-kidney transplantation recipients, the "delayed" kidney transplant approach is associated with a significant reduction in total and class I donor-specific antibodies after liver transplant before kidney transplant, enabling therapeutic interventions such as plasmapheresis, if needed, providing optimal outcomes similar to crossmatch recipients.

Genetic engineering of porcine endothelial cell lines for evaluation of human-to-pig xenoreactive immune responses.

Xenotransplantation (cross-species transplantation) using genetically-engineered pig organs offers a potential solution to address persistent organ shortage. Current evaluation of porcine genetic modifications is to monitor the nonhuman primate immune response and survival after pig organ xenotransplantation. This measure is an essential step before clinical xenotransplantation trials, but it is time-consuming, costly, and inefficient with many variables. We developed an efficient approach to quickly examine human-to-pig xeno-immune responses in vitro. A porcine endothelial cell was characterized and immortalized for genetic modification. Five genes including GGTA1, CMAH, ß4galNT2, SLA-I α chain, and ß2-microglobulin that are responsible for the production of major xenoantigens (αGal, Neu5Gc, Sda, and SLA-I) were sequentially disrupted in immortalized porcine endothelial cells using CRISPR/Cas9 technology. The elimination of αGal, Neu5Gc, Sda, and SLA-I dramatically reduced the antigenicity of the porcine cells, though the cells still retained their ability to provoke human natural killer cell activation. In summary, evaluation of human immune responses to genetically modified porcine cells in vitro provides an efficient method to identify ideal combinations of genetic modifications for improving pig-to-human compatibility, which should accelerate the application of xenotransplantation to humans.