Post-transplant Recurrence Research Articles

Management and long-term outcome of recurrent idiopathic FSGS in pediatric kidney transplant recipients

Focal segmental glomerulosclerosis (FSGS) is a major cause of pediatric kidney failure. Most cases of FSGS in children are idiopathic and have a high risk of post-transplantation recurrence and graft loss. Common treatments for recurrent FSGS (rFSGS) post-transplantation include plasmapheresis, immunoadsorption, and/or immunomodulatory therapy. This study retrospectively evaluated the efficacy and safety of early plasmapheresis followed by rituximab for inducing and maintaining remission in rFSGS. Between 2014 and 2023, 8 of 65 pediatric kidney transplant recipients at our center were diagnosed with idiopathic FSGS. rFSGS was diagnosed based on nephrotic range proteinuria with no other cause and managed with plasmapheresis. Rituximab therapy was used for those who did not achieve complete remission with prolonged plasmapheresis or remained plasmapheresis dependent. 6 of 8 (75%) transplant recipients with idiopathic FSGS experienced rFSGS. All patients achieved partial or complete remission with plasmapheresis, with response times ranging from 8 to 379 days (median 13 days). Rituximab therapy was introduced for 5 plasmapheresis-dependent patients, leading to sustained remission and cessation of plasmapheresis in 3 patients, while 2 showed improved proteinuria and reduced plasmapheresis frequency. Adverse effects included rituximab-induced serum sickness in one patient and one mild allergic reaction. One patient experienced graft loss due to humoral rejection, but no grafts were lost to rFSGS, and all other grafts remained functional over an average follow-up of 50 months. Early plasmapheresis followed by rituximab therapy effectively induces remission in most post-transplantation rFSGS cases, is well tolerated, and prevents graft loss. Larger studies are needed to confirm these findings.

Analysis of treatment benefits and prognostic factors for posttransplant HCC recurrence in a large Euro-American-Asian cohort.

Posttransplant HCC recurrence significantly impacts survival, yet its management is challenging due to limited evidence. With recent advancements in HCC treatment, updated data on managing recurrent diseases are needed. In this retrospective study across 6 centers (2000-2022), we employed Cox proportional-hazards regression and log-rank tests to assess survival differences. A prognostic score model was developed to categorize patient survival. The efficacy of tyrosine kinase inhibitors was evaluated through propensity score matching. In our study, 431 of 3349 (14%) patients with HCC who underwent transplantation developed recurrence within a median interval of 18 (IQR: 9-32) months. One hundred forty-seven (34%) underwent curative-intent treatments, 207 (48%) received palliative treatments, and 77 (18%) were given best-supportive care. Patients undergoing curative-intent treatments had better survival from the time of recurrence with a median survival of 45 (95% CI: 36-63) months and 1/3/5-year survival of 90%/56%/43% compared to those receiving noncurative treatments (median: 11 [95% CI: 10-13] mo, 1/3/5-y survival of 46%/10%/7%, log-rank p < 0.001). Patients with recurrence diagnosed in the era 2018-2022 showed improved survival over the previous era (HR 0.64 [95% CI: 0.47-0.86]). Multivariable analysis identified 5 prognostic factors: ineligibility for curative-intent treatment (HR: 3.5 [95% CI: 2.7-4.6]), recurrence within 1 year (HR: 1.7 [95% CI: 1.3-2.1]), poor tumor differentiation (HR: 1.5 [95% CI: 1.1-1.9]), RETREAT score ≥3 (HR: 1.4 [95% CI: 1.1-1.8]), and alpha-fetoprotein at recurrence ≥400ng/mL (HR: 1.4 [95% CI: 1.1-1.9]). These factors contributed to a prognostic scoring system (0-9) that stratified patients into 3 prognosis groups. Both propensity score-matched analysis and multivariable regression indicated that lenvatinib was not statistically superior to sorafenib in terms of efficacy. Curative-intent treatments should be advocated for patients with posttransplant recurrence whenever possible. Prognostic factors linked to aggressive tumor biology significantly influence survival. Advancements in HCC management have improved survival outcomes over the past 5 years.

Serial Changes of Molecular Expression of Slit Diaphragm Proteins in Post-transplant FSGS Recurrence Associated with Anti-nephrin Antibodies

Serial Changes of Molecular Expression of Slit Diaphragm Proteins in Post-transplant FSGS Recurrence Associated with Anti-nephrin Antibodies

The association between pretransplant malignancy and post-transplant survival and cancer recurrence in bilateral lung transplantation: An analysis of 23,291 recipients

BackgroundGiven the increasing need for lung transplants among older patients with a history of cancer, this study analyzed database registry to assess outcomes for BLT recipients with Pre-TM. MethodsThis study evaluated the United Network for Organ Sharing (UNOS) registry for adult BLT performed between 2005 and 2023. Patients with a history of previous or multi-organ transplants, and those with donors who had cancer history, were excluded. Propensity-score matching was used to compare patients with or without Pre-TM. Overall and Post-TM-free survival were analyzed. ResultsAmong the 23,291 recipients of BLT, 8.0%(1,870) had Pre-TM. Compared to those without Pre-TM, patients with Pre-TM had worse overall (hazard ratio[HR] 1.20, 95% confidence interval[CI] 1.12-1.29, p<0.001) and Post-TM-free survival (HR 1.32, 95% CI 1.24-1.41, p<0.001). However, after adjusting for age, sex, and race through propensity-score matching, the survival difference between the groups became non-significant (HR 1.05, 95% CI 0.97-1.13, p=0.229). While the Pre-TM group still had worse Post-TM-free survival, this difference diminished after excluding cutaneous Post-TM (HR 1.06, 95% CI 0.99-1.15, p=0.116). Additionally, the recurrence rate of Pre-TM after transplant wasn't higher than de novo cancers in patients without Pre-TM. ConclusionPatients with Pre-TM had similar overall survival rates after BLT as those without Pre-TM. Importantly, there was no increased risk of the primary Pre-TM type recurring post-transplant compared to patients without Pre-TM. If patients with PreTM are free from recurrence or metastasis for a significant amount of time, there could be some who can benefit from BLT. Further data regarding timeline between PreTM and BLT would be necessary to draw conclusion in this issue.

Anti-nephrin autoantibodies: novel predictors of post-transplant recurrence of focal segmental glomerular sclerosis.

Post-transplant recurrence of focal segmental glomerular sclerosis (FSGS) is a major challenge in the field of kidney transplantation. Currently, the most reliable predictor of FSGS recurrence is disease recurrence in a previous allograft. Recent studies suggest a possible causal role of anti-nephrin autoantibodies in the primary disease (primary FSGS and minimal change disease), as well as post-transplant recurrence of FSGS. In this issue of Kidney International, Batal etal. evaluate pretransplant anti-nephrin autoantibodies as a specific predictor of FSGS recurrence and demonstrate colocalization of nephrin and punctate IgG in anti-nephrin-positive patients with disease recurrence.

Genitourinary tumors and liver transplantation: A comprehensive review.

Liver transplantation is as a crucial therapeutic option for patients with end-stage liver disease, but the persistent organ shortage emphasizes a need to explore unconventional donor sources, including individuals with a history of malignancies. This review investigates the viability of liver donation from individuals with current or past genitourinary malignancies, focusing on renal, prostate and urinary bladder cancers. The rising incidence of urogenital malignancies among potential donors is thought to result from increasing donor age. Analysis of transmission risks reveals low rates of donor-derived cancer transmission, particularly for early-stage renal and prostate cancers. Recipients with a history of genitourinary malignancy pose complex challenges regarding post-transplant immunosuppression and cancer recurrence. Nonetheless, the evidence suggests acceptable outcomes can be achieved with careful patient selection and tailored management strategies. Recommendations for pre-transplant evaluation and post-transplant surveillance are discussed, highlighting the need for individualized approaches in this patient population. Further prospective studies are warranted to refine guidelines and optimize outcomes in liver transplantation for patients with genitourinary malignancies.

Recurrence of Hepatocellular Carcinoma after Liver Transplantation: Clinical Patterns and Hierarchy of Salvage Treatments

Introduction: The multiparametric nature of recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT) still leads to uncertainty with its practical management. This study aims to characterize the main posttransplant recurrence patterns of HCC and to explore the therapeutic modalities targeting recurrence. Methods: Consecutive patients who underwent LT for HCC at a single tertiary center were analyzed. The time from first recurrence to death was investigated for each site of presentation. The impact of each recurrence-targeted treatment on survival was studied. Results: Of 660 patients with HCC, any recurrence occurred in 96 (15.4%) patients with a median time to recurrence of 20.0 months (95% CI: 15.6–23.8). Patients recurred across different patters including solitary distant locations (30.8%, n = 28), liver only (24.2%, n = 22), lung (18.7%, n = 17), multi-organ disease (17.6%, n = 16), and bone (8.8%, n = 8). Multi-organ and bone recurrences had the poorest survival, while solitary distant lesions and pulmonary recurrences had the best outcomes. Each treatment modality carried a distinctive survival. Conclusions: Patients recurred across 3 patterns with different prognostic implications. The benefit of each treatment option on distinct recurrence patterns appears to be influenced by the biological behavior inherent in the recurrence pattern itself.

Pre-transplant Loco-Regional Therapy for Hepatocellular Carcinoma and Post-transplant Outcomes: A National Study.

The ultimate preferred treatment for hepatocellular carcinoma (HCC) complicated with cirrhosis and portal hypertension is an orthotopic liver transplant (OLT). Loco regional therapy (LRT) has emerged to prevent tumor growth and progression of disease beyond the Milan criteria to achieve transplant. There is a paucity of data regarding safety, posttransplant survival benefits, and tumor recurrence rate achieved by these LRT modalities. We aim to assess and compare the five-year survival rate and tumor recurrence rate with or without LRT in patients after OLT with diagnosed HCC utilizing the nation's largest dataset. This is a retrospective observational study approved by Saint Louis University institutional review board. We utilized the largest dataset from the years 2003-2013 where pertaining data were gathered from Organ Procurement Transplant Network (OPTN) standard analysis and research files (STAR) through novel linkages with Medicare bills. Descriptive and comparative statistics were performed. 2412 (51.6%) patients received any form of locoregional therapy (single or combination) out of 4669 total study sample size. The overall five-year survival in the study sample was 76.1%. There was statistically no significant improvement seen in five-year posttransplant survival in the group that received one mode of LRT (adjusted hazard ratio (aHR) 0.97, P<0.64) or a combination of LRT (aHR 0.94, P<0.58) in comparison to those that received none after adjusting donor and recipient clinical characteristics. However, five-year survival trended higher among those treated with combination therapy over those treated with single LRT or none. Overall HCC recurrence was 4.8%, while no significant difference was noted when comparing above-mentioned groups. Five-year posttransplant survival and HCC recurrence rate were also found to have no difference when compared between above-mentioned groups after adjusting explant pathology. This is the largest retrospective study comparing liver transplant patients with HCC who received LRT to none. Although it did not show any statistically significant benefit of single or combination of LRT on survival or tumor recurrence after liver transplant for HCC patients, the outcomes encourage the safe and feasible use of LRT as a bridging therapy. Our study also suggests an observed pattern of improved posttransplant survival and tumor recurrence rate with combination loco-regional therapy. Larger multicenter prospective studies will be required to achieve the effect size to determine the best therapies for maximizing patient survival cost-effectively.

An inflammatory liquid fingerprint predicting tumor recurrence after liver transplantation for hepatocellular carcinoma.

Tumor recurrence is a life-threatening complication after liver transplantation (LT) for hepatocellular carcinoma (HCC). Precise recurrence risk stratification before transplantation is essential for the management of recipients. Here, we aimed to establish an inflammation-related prediction model for posttransplant HCC recurrence based on pretransplant peripheral cytokine profiling. Two hundred and ninety-three patients who underwent LT in two independent medical centers were enrolled, and their pretransplant plasma samples were sent for cytokine profiling. We identified four independent risk factors, including alpha-fetoprotein, systemic immune-inflammation index, interleukin 6, and osteocalcin in the training cohort (n=190) by COX regression analysis. A prediction model named inflammatory fingerprint (IFP) was established based on the above factors. The IFP effectively predicted posttransplant recurrence (area under the receiver operating characteristic curve [AUROC]: 0.792, C-index: 0.736). The high IFP group recipients had significantly worse 3-year recurrence-free survival rates (37.9vs. 86.9%, p<0.001). Simultaneous T-cell profiling revealed that recipients with high IFP were characterized by impaired T cell function. The IFP also performed well in the validation cohort (n=103, AUROC: 0.807, C-index: 0.681). In conclusion, the IFP efficiently predicted posttransplant HCC recurrence and helped to refine pretransplant risk stratification. Impaired T cell function might be the intrinsic mechanism for the high recurrence risk of recipients in the high IFP group.

Systematic identification of minor histocompatibility antigens predicts outcomes of allogeneic hematopoietic cell transplantation.

T cell alloreactivity against minor histocompatibility antigens (mHAgs)-polymorphic peptides resulting from donor-recipient (D-R) disparity at sites of genetic polymorphisms-is at the core of the therapeutic effect of allogeneic hematopoietic cell transplantation (allo-HCT). Despite the crucial role of mHAgs in graft-versus-leukemia (GvL) and graft-versus-host disease (GvHD) reactions, it remains challenging to consistently link patient-specific mHAg repertoires to clinical outcomes. Here we devise an analytic framework to systematically identify mHAgs, including their detection on HLA class I ligandomes and functional verification of their immunogenicity. The method relies on the integration of polymorphism detection by whole-exome sequencing of germline DNA from D-R pairs with organ-specific transcriptional- and proteome-level expression. Application of this pipeline to 220 HLA-matched allo-HCT D-R pairs demonstrated that total and organ-specific mHAg load could independently predict the occurrence of acute GvHD and chronic pulmonary GvHD, respectively, and defined promising GvL targets, confirmed in a validation cohort of 58 D-R pairs, for the prevention or treatment of post-transplant disease recurrence.

Kidney transplantation in children and adolescents with C3 glomerulopathy or immune complex membranoproliferative glomerulonephritis: a real-world study within the CERTAIN research network

BackgroundComplement 3 glomerulopathy (C3G) and immune complex membranoproliferative glomerulonephritis (IC-MPGN) are ultra-rare chronic kidney diseases with an overall poor prognosis, with approximately 40–50% of patients progressing to kidney failure within 10 years of diagnosis. C3G is characterized by a high rate of disease recurrence in the transplanted kidney. However, there is a lack of published data on clinical outcomes in the pediatric population following transplantation.MethodsIn this multicenter longitudinal cohort study of the Cooperative European Paediatric Renal Transplant Initiative (CERTAIN) registry, we compared the post-transplant outcomes of pediatric patients with C3G (n = 17) or IC-MPGN (n = 3) with a matched case–control group (n = 20).ResultsEleven of 20 children (55%) with C3G or IC-MPGN experienced a recurrence within 5 years post-transplant. Patients with C3G or IC-MPGN had a 5-year graft survival of 61.4%, which was significantly (P = 0.029) lower than the 5-year graft survival of 90% in controls; five patients with C3G or IC-MPGN lost their graft due to recurrence during this observation period. Both the 1-year (20%) and the 5-year (42%) rates of biopsy-proven acute rejection episodes were comparable between patients and controls. Complement-targeted therapy with eculizumab, either as prophylaxis or treatment, did not appear to be effective.ConclusionsThese data in pediatric patients with C3G or IC-MPGN show a high risk of post-transplant disease recurrence (55%) and a significantly lower 5-year graft survival compared to matched controls with other primary kidney diseases. These data underscore the need for post-transplant patients for effective and specific therapies that target the underlying disease mechanism.Graphical abstractA higher resolution version of the Graphical abstract is available as Supplementary information

Long-term posttransplant survival outcome following bridging locoregional therapy in hepatocellular carcinoma patients: A systematic review and meta-analysis.

Liver transplantation (LT) is essential due to its curative efficacy, but liver-graft shortages have limited its widespread application. Bridging locoregional therapy (LRT) before LT has been performed to prevent tumor progression, and a recent literature review revealed that it is associated with a nonsignificant trend toward better survival outcomes. However, much more information on bridging therapy has become available since then. This meta-analysis aimed to compare the posttransplant survival and HCC recurrence between patients with and without pretransplant bridging LRT. Studies were identified in MEDLINE, SCOPUS, and the Cochrane Library. Two independent researchers screened titles and full articles, extracted relevant data, and conducted a parametric survival analysis. Out of 4794 studies, 18 cohort studies were eligible. The 1-, 3-, and 5-year overall survival (OS) rates were 93.1%, 85.0%, and 79.1% for those in the bridging LRT group, while they were 91.8%, 81.1%, and 75.5% for those who did not receive LRT, respectively. There were no differences in overall survival between these groups (HR 0.90; 0.78-1.05, P = 0.17). Interestingly, we discovered that bridging therapy helped prolong survival significantly in a high-risk population with a long waiting time (HR 0.76; 0.60-0.96, P = 0.02). Unfortunately, bridging LRT did not improve disease-free survival (HR 0.98; 0.86-1.11, P = 0.70). The results indicate that bridging LRT does not generally change post-LT outcomes. However, bridging LRT can significantly improve survival in patients with a long waiting time for LT.

Transjugular Intrahepatic Portosystemic Shunt Is Associated With Better Waitlist Management of Liver Transplant Candidates With Hepatocellular Carcinoma.

Transjugular intrahepatic portosystemic shunt (TIPS) reduces portal hypertension complications. Its impact on hepatocellular carcinoma (HCC) remains unclear. We evaluated 42,843 liver transplant candidates with HCC from the Scientific Registry of Transplant Recipients (2002-2022). 4,484 patients with and without TIPS were propensity score-matched 1:3. Analysing wait-list changes in total tumor volume, HCC count, and alpha-fetoprotein levels, and assessing survival from listing and transplantation; TIPS correlated with a decreased nodule count (-0.24 vs. 0.04, p = 0.028) over a median wait period of 284 days (IQR 195-493) and better overall survival from listing (95.6% vs. 91.5% at 1year, p < 0.0001). It was not associated with changes in tumor volume (0.28 vs. 0.11cm³/month, p = 0.58) and AFP (14.37 vs. 20.67ng/mL, p = 0.42). Post-transplant survival rates (91.8% vs. 91.7% at 1year, p = 0.25) and HCC recurrence (5.1% vs. 5.9% at 5 years, p = 0.14) were similar, with a median follow-up of 4.98 years (IQR 2.5-8.08). While TIPS was associated with a reduced nodule count and improved waitlist survival, it did not significantly impact HCC growth or aggressiveness. These findings suggest potential benefits of TIPS in HCC management, but further studies need to confirm TIPS safety.

Clinical Course of Nonresponders With Recurrent Focal Segmental Glomerulosclerosis After Pediatric Kidney Transplantation: A Retrospective Multicenter Study.

Primary focal segmental glomerulosclerosis (FSGS) frequently recurs after kidney transplantation and is associated with poor graft survival. Patients who do not achieve remission (nonresponders) have an especially poor graft survival. However, the characteristics that may affect graft survival in nonresponders are unknown. This study aimed to determine the clinical characteristics associated with graft survival in nonresponders. We retrospectively collected the clinical records of patients with FSGS and an age at onset <16 years who experienced posttransplant recurrence of FSGS at six hospitals in Japan from 1993 to 2018. Eight nonresponders with recurrent FSGS were enrolled in this study. The median time to recurrence after kidney transplantation was 1 day (interquartile range, 1-2 days). All patients received therapeutic plasma exchange and methylprednisolone pulse therapy. Rituximab was used as an add-on therapy in three patients. Five patients lost their graft within 2 years after kidney transplantation (rapid group). In contrast, three patients had much longer graft survival (nonrapid group). We compared the clinical characteristics of the rapid and nonrapid groups. Proteinuria tended to be lower in the nonrapid group at the third and subsequent months of therapy. The rapid group had persistent nephrotic syndrome. The rate of reduction in proteinuria was lower in the rapid group than in the nonrapid group. Our study suggests that persistent nephrotic syndrome and a low rate of reduction in proteinuria may predict rapid progression to graft failure in nonresponders.

Novel engineered regulatory macrophages combined with ICIs for post-transplant recurrence after liver transplantation for HCC.

e14582 Background: Liver transplantation is the most effective treatment for early-stage hepatocellular carcinoma (HCC), but post-transplant recurrence limits the efficacy of surgery and affects the patient prognosis. Most of the current attempts to apply immune checkpoint inhibitors (ICIs) to posttransplant recurrence have resulted in either acute allograft rejection or tumor progression, which may be related to the disruption of the immune balance that maintains immune tolerance and enhances immune activation. Methods: Therefore, we constructed an engineered regulatory macrophages (Mregs) with anti-tumor capacity in the transplant setting using reprogrammed liposomes to precisely regulate the immune microenvironment of post-transplant recurrence, in order to create suitable conditions for the safe use of ICIs. Results: Experimentally, Mregs were shown to prolonged allograft survival without promoting tumor development. Through fusing with the Mregs membrane, reprogrammed liposomes insert an anti-CD47 lipid shell onto the surface, enhancing phagocytosis against tumor. The drug-loaded inner core entered into the cytoplasm to reprogram Mregs. Tomivosertib downregulated the expression of PD-L1 and attenuated the immunosuppressive effect. Pexidartinib inhibited the polarization of the M2 pathway and upregulated the expression of CD80, CD86, and MHC II, enhancing the ability of antigen presentation. Combination with anti-PD-L1 antibodies can enhance anti-tumor effect without accelerating allograft rejection. Both in vivo and in vitro results demonstrate that engineered Mregs provide conditions for the safe use of anti-PD-L1 antibodies in the context of transplantation. Conclusions: Engineered Mregs combined with ICIs enhances immunotherapeutic efficacy and provides a viable therapeutic approach for posttransplant recurrence after liver transplantation for HCC.

#277 Update to the long-term safety and efficacy of iptacopan in C3G: 33-month extension study data from patients enrolled in a phase 2 study

Abstract Background and Aims Complement 3 glomerulopathy (C3G), due to dysregulation of the alternative complement pathway (AP), is an ultra-rare primary glomerulonephritis. Iptacopan (LNP023) is an oral, proximal complement inhibitor that specifically binds factor B and inhibits the AP. We previously reported the primary endpoint data from the Phase (Ph) 2 extension study (NCT03955445), showing proteinuria reduction (57% [p &amp;lt; 0.0001]) and estimated glomerular filtration rate (eGFR) improvement (by +6.83 mL/min/1.73 m2 [p = 0.0174]) from baseline, following 12 months (M) of treatment with iptacopan in patients with C3G. Here we present further long-term efficacy and safety data from patients with C3G and recurrent C3G (post-kidney transplantation), who completed 33M of treatment with iptacopan (NCT03955445). Method Adults with C3G disease (Cohort A) or C3G recurrence post-transplantation (Cohort B) received iptacopan 200 mg twice-daily (bid) for at least 12 weeks in the Ph2 study (NCT03832114) before entering the open label extension study (NCT03955445). Long-term efficacy was assessed by a number of renal endpoints, including a 2-component composite renal endpoint (eGFR stability [≤10% reduction] and ≥50% proteinuria reduction). Long-term safety and tolerability of iptacopan was continually monitored. Results Of 27 patients completing the Ph2 study (NCT03832114), 26 (16 Cohort A, 10 Cohort B) entered the extension study treatment with iptacopan 200 mg bid; 22 patients (14 Cohort A, 8 Cohort B) completed the 33M visit (i.e., 3M in the Ph2 study and 30M in the extension study). In Cohort A, 42.9% of patients met the 2-component composite renal endpoint criteria at 33M. Proteinuria (first morning void [FMV] urine protein–creatinine ratio [UPCR]) was reduced by 41% (p = 0.0097) compared to baseline. eGFR stabilized or improved in most patients (13/16) over time and change from baseline at the 33M time-point was −3.18 mL/min/1.73 m2 (p = 0.3512). C3 levels increased by 275% (p &amp;lt; 0.0001) from baseline. In Cohort B, eGFR change from baseline at the 33M time-point was −6.34 mL/min/1.73 m2 (p = 0.0571), and C3 levels increased by 102%. Baseline proteinuria values (FMV UPCR) were within the normal range for most participants in Cohort B and remained so during iptacopan treatment. Iptacopan was generally well-tolerated, and most adverse events were of mild severity in both cohorts. Biomarkers demonstrated substantial AP inhibition. Conclusion Long-term treatment with iptacopan was associated with sustained reduction in proteinuria in patients with C3G (Cohort A), and preservation of eGFR. These improvements in kidney function were associated with substantial inhibition of the AP leading to normalization of serum C3. Iptacopan was well-tolerated with no new safety findings in the long term, in patients with C3G, including those with recurrence post-transplantation on top of broad triple immunosuppression. The ongoing Ph3 APPEAR-C3G study (NCT04817618) is evaluating the efficacy and safety of iptacopan in patients with C3G.

#1450 Polygenic risk score of native IgA nephropathy predicts risk of post-transplant disease recurrence

Abstract Background and Aims IgA nephropathy (IgAN) is a polygenic immune-mediated progressive glomerular disease. Recent GWAS reported that high genome-wide polygenic risk score (IgAN GPS), including 1 249 077 variants mapping to systemic immune pathways, was associated with risk of end stage kidney disease (ESKD). Post transplant (KTx) IgAN recurrence occurs in 30% of cases and it is a major cause of graft loss. Pathogenesis and predictors of IgAN recurrence are still not well defined. Herein, we studied the role of native IgAN GPS and clinical factors in predicting post-KTx IgAN recurrence and graft failure in a large cohort of KTx recipients. Method Four thousand one hundred eighty six KTx recipients from 6 sites were genome wide genotyped and imputed against multi-ancestry reference panels, retrieving &amp;gt;10 million variants. In each recipient, native IgAN GPS was computed and standard-normalized (i.e. expressed in units of standard deviations from the mean distribution in matched controls). Native kidney disease diagnosis, clinical parameters, and post-KTx outcome data were retrieved retrospectively from clinical charts. The IgAN GPS was tested as predictor of native IgAN in the entire KTx cohort in a logistic regression model adjusted for sex, age, recruitment site, and first 5 PCs. IgAN GPS was tested as predictor of age at transplantation (proxy for age at ESKD) among KTx recipients with native IgAN in a linear regression model adjusted for sex, recruitment site, and first 5 PCs. In recipients with native IgAN, recipient and donor parameters were individually tested as predictors for time to IgAN recurrence and time to graft failure in Cox proportional hazards models adjusted for recruitment site and first 5 PCs. Predictors with P-value &amp;lt; .1 were included in the multivariable models. Recipient IgAN GPS was added to the clinical models and tested for prediction of time-to IgAN recurrence, and, among KTx recipients with IgAN recurrence, of time-to subsequent graft failure. Results Three hundred sixty nine KTx recipients were affected by native IgAN, 271 were of male sex, median age at transplantation was 45 years, and 149 received a living donor KTx. Over a median follow-up time of 46 months, 96 IgAN recurrence events occurred, and, among KTx recipients with recurrent IgAN, 27 subsequent graft failure events occurred after 100 months post KTx. IgAN GPS significantly predicted native IgAN cases among all KTx recipients (OR [95% CI]: 1.95 [1.76,2.16], p = 5.60E-07, AUROC 0.73), and lower age at transplantation among recipients with native IgAN (beta [s.e.]: −1.11[0.55], p = 0.04). Clinical model for IgAN recurrence included age, sex, year of transplant, HLA mismatch, recruitment site, and first 5 PCs; clinical model for graft failure included age, sex, year of transplant, HLA mismatch, type of donation, donor age, sex, rejection events, recruitment site, and first 5 PCs. At the multivariable analysis, IgAN GPS, lower age at transplantation, lower HLA mismatch, and higher year of transplant were independently associated with time to IgAN recurrence (Fig. 1a). Among KTx recipients with recurrent IgAN, higher IgAN GPS predicted time-to graft failure independently from clinical factors (Fig. 1b), but not in non-recurrent cases. Conclusion In the KTx setting, IgAN GPS was an independent predictor of IgAN recurrence, suggesting shared genetic susceptibility between native and recurrent IgAN. In addition, associations of IgAN GPS with lower age at transplantation, and with graft failure among recurrent IgAN cases, suggest that IgAN GPS may be predictive of a more aggressive native as well as recurrent disease. Associations with lower HLA mismatch advocate donor-recipient genetic similarities as potential additional predictors of IgAN recurrence. These data, which need external validation, may provide potential new insights into the pathobiology and prediction of recurrent IgAN.

#2811 Factor B inhibition with iptacopan in C3 glomerulopathy recurrence after transplantation: a case presentation

Abstract Background and Aims C3 glomerulopathy (C3G) is a clinical-pathological entity resulting from dysregulation of the alternative pathway of the complement system (APC) in the fluid phase. The recurrence risk of C3G after kidney transplantation is about 70% with high risk of graft loss. Standard treatment relies on nephroprotection and unspecific immunosuppression but there are currently new molecules that target specifically APC under development. A novel factor B inhibitor, iptacopan, has shown promising results both in native kidney and transplant recurrence cases in a phase II trial. Method We present a real-world clinical case of early C3G recurrence after kidney transplantation treated with iptacopan (Novartis MAPs program). Patient was vaccinated for encapsulated bacteria. Iptacopan was initiated 200 mg BID. We also present histological response. Results 38-year-old male with chronic kidney disease secondary to C3G initially presented with nephrotic syndrome and hematuria at the age of 31y following a respiratory infection. Blood test showed low serum C3 levels and the presence of C3 nephritic factor without pathological genetic alterations. Kidney biopsy confirmed membranoproliferative glomerulonephritis (MPGN) with predominant C3 deposition. He progressed to CKD stage G5 requiring hemodialysis instead of nephroprotection and immunosuppression with corticosteroids and mycophenolate; and addition with cyclophosphamide and rituximab after 19 months from onset. Five years later, the patient was admitted as first kidney transplant recipient from deceases donor Maastricht-III. Induction therapy included thymoglobulin, and tacrolimus, mycophenolate, and corticosteroids. He experienced delayed graft function requiring hemodialysis. An early biopsy proved C3G recurrence with endocapillary proliferation without C4d deposit and absence of donor specific antibodies. Despite conventional immunosuppression and addition of rituximab and plasma exchange; hemodialysis requirement still be present. So, because C3G pathophysiological base, iptacopan was begun with successful clinical response as he reached hemodialysis discontinuation; and kidney function stabilized after one year of treatment with an estimated glomerular filtration rate about 30 mL/min/1.73 m2. In the follow-up biopsy 5 months later, deposit of C3 in the glomerulus disappeared compared to the post-transplant recurrence but with persistence of endocapillary and mesangial proliferation (see Fig. 1). However, interestingly, he experienced a clinical recurrence with acute kidney injury and hematuria after unintentional iptacopan discontinuation, which was resolver after reinitiating and recovering its previous graft function. No infectious complications were observed after one year of treatment with factor B inhibitor. Conclusion New molecules under development that specifically target APC (fluid phase) may change the treatment scenario of C3G and its recurrence in kidney transplantation. We expose a real-practice early C3G recurrence after kidney transplantation successfully treated with iptacopan. The patient reached kidney function stabilization and disappearance of C3 deposits on immunofluorescence of the follow-up biopsy, identical results as the phase II clinical trial of iptacopan in C3G. So, we might conclude that iptacopan is an effective and safe option for C3G recurrence after kidney transplantation. But, data from randomized studies are needed in order to confirm the efficacy and safety of new inhibitors of the APC as iptacopan.

#1315 Management and long-term outcome of recurrent idiopathic FSGS in pediatric renal transplant recipients

Abstract Background and Aims Focal segmental glomerulosclerosis (FSGS) is a leading cause of pediatric end-stage renal disease (ESRD). While approximately 30% of pediatric FSGS is attributed to monogenic disorders, most cases are idiopathic, carrying a high risk of post-transplantation recurrence and graft loss. Commonly used protocols for recurrent FSGS (rFSGS) include plasmapheresis or immunoadsorption, and/or immunomodulatory therapy. We retrospectively evaluated the efficacy and safety of early plasmapheresis followed by rituximab therapy for induction of remission in rFSGS. Method Between 2014-2023, 8/65 pediatric renal transplant recipients at our center were diagnosed with idiopathic FSGS. Five patients underwent preventive plasmapheresis initiated between day 7 pre-transplantation to day 1 post-transplantation, depending on donor source (living/deceased). rFSGS, was diagnosed based on nephrotic range proteinuria of no other cause, and managed with daily plasmapheresis, followed by frequency tapering. Failure to achieve complete remission while on prolonged plasmapheresis was managed with Rituximab therapy. Results 6/8 patients (75%) experienced rFSGS. All achieved partial or complete remission with plasmapheresis therapy. Nevertheless, 5/6 patients exhibited plasmapheresis-dependence, thereby necessitating rituximab therapy. Of these, 3/5 patients achieved sustained remission enabling plasmapheresis cessation, while in 2/5 showed markedly improved proteinuria, enabling reduction of plasmapheresis frequency to once weekly. Adverse effects included rituximab-induced serum sickness in one patient, requiring therapy discontinuation. While one patient suffered from graft loss due to humoral rejection, no graft was lost to rFSGS, and all other grafts remained functional over an average follow-up period of 50 months. Conclusion We suggest that early introduction of plasmapheresis and rituximab therapy effectively induces remission in most post-transplantation rFSGS, is well tolerated, and prevents graft loss. Additional, large scale studies are needed to establish our observation.

Cancer Surveillance in Solid Organ Transplant Recipients With a Pretransplant History of Malignancy: Multidisciplinary Collaborative Expert Opinion.

With improved medical treatments, the prognosis for many malignancies has improved, and more patients are presenting for transplant evaluation with a history of treated cancer. Solid organ transplant (SOT) recipients with a prior malignancy are at higher risk of posttransplant recurrence or de novo malignancy, and they may require a cancer surveillance program that is individualized to their specific needs. There is a dearth of literature on optimal surveillance strategies specific to SOT recipients. A working group of transplant physicians and cancer-specific specialists met to provide expert opinion recommendations on optimal cancer surveillance after transplantation for patients with a history of malignancy. Surveillance strategies provided are mainly based on general population recurrence risk data, immunosuppression effects, and limited transplant-specific data and should be considered expert opinion based on current knowledge. Prospective studies of cancer-specific surveillance models in SOT recipients should be supported to inform posttransplant management of this high-risk population.