Cumulative Rejection Rates Research Articles

T Cell CEACAM1–TIM-3 Crosstalk Alleviates Liver Transplant Injury in Mice and Humans

Carcinoembryonic antigen-related cell adhesion molecule 1 (CC1) acts through homophilic and heterophilic interactions with T cell immunoglobulin domain and mucin domain-containing protein 3 (TIM-3), which regulates innate immune activation in orthotopic liver transplantation (OLT). We investigated whether cluster of differentiation (CD) 4+ T cell-dependent CC1-TIM-3 crosstalk may affect OLT outcomes in mice and humans. Wild-type (WT) and CC1-deficient (CC1 knock-out [KO]) mouse livers were transplanted into WT, CC1KO, or T-cell TIM-3 transgenic (TIM-3Tg)/CC1KO double-mutant recipients. CD4+ T cells were adoptively transferred into T/B cell-deficient recombination activating gene 2 protein (Rag2) KO recipients, followed by OLT. The perioperative liver-associated CC1 increase was analyzed in 50 OLT patients. OLT injury in WT livers deteriorated in CC1KO compared with CC1-proficient (WT) recipients. The frequency of TIM-3+CD4+ T cells was higher in WT than CC1KO hosts. Reconstitution of Rag2KO mice with CC1KO-T cells increased nuclear factor (NF)-κB phosphorylation and OLT damage compared with recipients repopulated with WT T cells. T-cell TIM-3 enhancement in CC1KO recipients (WT→ TIM3Tg/CC1KO) suppressed NF-κB phosphorylation in Kupffer cells and mitigated OLT injury. However, TIM-3-mediated protection was lost by pharmacologic TIM-3 blockade or an absence of CC1 in the donor liver (CC1KO→ TIM-3Tg/CC1KO). The perioperative CC1 increase in human OLT reduced hepatocellular injury, early allograft dysfunction, and the cumulative rejection rate. This translational study identifies T cell-specific CC1 signaling as a therapeutic means to alleviate OLT injury by promoting T cell-intrinsic TIM-3, which in turn interacts with liver-associated CC1 to suppress NF-κB in Kupffer cells. By suppressing peritransplant liver damage, promoting T-cell homeostasis, and improving OLT outcomes, recipient CC1 signaling serves as a novel cytoprotective sentinel.

350.6: The impact of circulating DSA in visceral transplant recipients without histological evidence of rejection: How should we treat or not treat?

Backgrounds: There has been accumulating evidence that donor-specific antibody (DSA) has a negative impact on the outcome of visceral allografts. Prospective DSA monitoring allows detection of circulating DSA without histological evidence of acute rejection. However, its association with acute rejection and natural course without treatment are yet to be determined. Methods: Between 2012 and 2019, 94 visceral transplantation with 25 liver-contained grafts were performed at a single institution. Induction therapy for preformed DSA included rituximab or bortezomib. DSA were monitored at 1 and 2weeks, followed by 1, 3, and 6 months, and yearly after transplant. De-novo DSA was not treated without histologically proved rejection. The characteristics and impact of DSA in terms of predictability of rejection, and its correlation of severity of acute rejection were analyzed. Results: One-year cumulative rejection rate in the entire cohort was 67%. With the protocol of anti-B cell therapy, preformed DSA did not increase the risk of rejection, regardless of the status of liver-free allografts, high titer (>4000 MFI) or persistence of DSA. Moreover, there was no difference in severity of rejection with the presence of preformed DSA (n=12) compared to that without DSA (n=36). However, 3-years graft survival was inferior in patients with preformed DSA to those without (52% vs. 64%, p=0.069), due to increased infectious complications. De-novo DSA was detected in 32 patients (35%) with an HLA-ABDR mismatch as the only predictor (Odds ratio 1.7, p=0.036). De-novo DSAs were more likely to be class II with high inclusion of anti-DQ DSA (69%). Prospective monitoring detected de-novo DSA in 25 occasions without ongoing rejection. Accordingly, it turned negative without rejection episode in 19 (76%) (Silent DSA), while subsequent rejection occurred in 6 occasions (24%) (DSA before rejection). In 10 occasions, de-novo DSA turned positive during the rejection episodes (DSA during rejection). The rejection episodes that induced DSA circulation was with a more severe grade. Conclusions: Increased immunosuppressant induction to treat preformed DSA may compensate the rejection risk, but can negatively impact the overall graft survival. With prospective monitoring and no preemptive treatment, high proportion of de-novo DSA was self-limiting, and rarely precipitated rejection episodes particularly with a severe grade.

Impact of antiretroviral regimen on renal transplant outcomes in HIV-infected recipients.

Protease inhibitors (PI) pose a challenge post-transplant due to significant drug interactions with calcineurin inhibitors, prompting many clinicians to convert patients to non-interacting regimens prior to transplant. The purpose of this study was to examine the impact of PI-based regimens on graft outcomes in HIV-infected renal transplant recipients. In this retrospective cohort study, 50 HIV-infected renal allograft recipients (27 receiving a PI regimen, 23 receiving a non-PI regimen) transplanted between 2003-2015 were analyzed. Cumulative rejection rates at 12 and 36months were 41% and 54% in the PI group vs 52% and 86% in the non-PI group. At last follow-up, the overall risk of acute rejection in the PI group was 46% lower compared with the non-PI cohort (P=0.12). Patients who received a PI-based regimen had significantly reduced graft failure rates (P=0.027). There was no difference between groups in the degree of interstitial fibrosis/tubular atrophy, arteriolar hyalinosis, arterial sclerosis, or glomerular sclerosis on available biopsies, despite longer follow-up time in the PI group. Our study suggests that PI-based antiretroviral therapy regimens are associated with improved graft survival and that patients can achieve adequate outcomes on a PI-based regimen when necessary. Due to study limitations, further studies are needed to determine the optimal immunosuppression/antiretroviral therapy regimen post-transplant.

Early Conversion to Prednisolone/Everolimus as an Alternative Weaning Regimen Associates With Beneficial Renal Transplant Histology and Function: The Randomized-Controlled MECANO Trial.

In renal transplantation, use of calcineurin inhibitors (CNIs) is associated with nephrotoxicity and immunosuppression with malignancies and infections. This trial aimed to minimize CNI exposure and total immunosuppression while maintaining efficacy. We performed a randomized controlled, open-label multicenter trial with early cyclosporine A (CsA) elimination. Patients started with basiliximab, prednisolone (P), mycophenolate sodium (MPS), and CsA. At 6 months, immunosuppression was tapered to P/CsA, P/MPS, or P/everolimus (EVL). Primary outcomes were renal fibrosis and inflammation. Secondary outcomes were estimated glomerular filtration rate (eGFR) and incidence of rejection at 24 months. The P/MPS arm was prematurely halted. The trial continued with P/CsA (N = 89) and P/EVL (N = 96). Interstitial fibrosis and inflammation were significantly decreased and the eGFR was significantly higher in the P/EVL arm. Cumulative rejection rates were 13% (P/EVL) and 19% (P/CsA), (p = 0.08). A post hoc analysis of HLA and donor-specific antibodies at 1 year after transplantation revealed no differences. An individualized immunosuppressive strategy of early CNI elimination to dual therapy with everolimus was associated with decreased allograft fibrosis, preserved allograft function, and good efficacy, but also with more serious adverse events and discontinuation. This can be a valuable alternative regimen in patients suffering from CNI toxicity.

Kidney Transplantation in HIV-Infected Recipients: Therapeutic Strategy and Outcomes in Monocentric Experience

BackgroundIn Human immunodeficiency virus (HIV)-positive patients undergoing kidney transplantation, outcomes and immunosuppression (IS) protocol are not yet established due to infectious and neoplastic risks as well as to pharmacokinetic interactions with antiretroviral therapy (TARV). MethodsWe report a retrospective, 1-center study on 18 HIV+ patients undergoing, between October 2007 and September 2015, kidney transplantation (13 cases) or combined kidney-liver transplant (5 cases). Inclusion criteria for transplant were based on the Italian National Transplant Center protocol. IS regimen was based on quick tapering of steroids and the use of mTOR inhibitors (mTORi) with low dose of calcineurin inhibitors (CNI). In the early post-transplant period, TARV was based on enfuvirtide, raltegravir, plus 1 or more nucleoside analogues. ResultsIn a mean follow-up of 3.1 years, patient survival rate at 1 and 3 years was, respectively, 86.6% and 84.6%, whereas graft survival was 81.2% and 78.6%. Cumulative rejection rate was 20.0% and 26.6% (1- and 3-year results). Median eGFR (MDRD) was 58.8 mL/min and 51.9 mL/min at 1 and 3 years. We had 9 cases of clinically relevant infections (2 Pneumocystis jirovecii pneumonia, 1 pulmonary aspergillosis, 2 severe sepsis, and 4 HCV reactivation) as well as 1 case (5.5%) of HIV reactivation. ConclusionsIS therapy based on mTORi and low CNI dose ensures good graft survival, low rate of acute rejection, limited drug toxicity, and control of HIV disease. TARV has no significant interaction with IS therapy.

The short-term impact of protocol biopsies in a live-related renal transplant program using tacrolimus based immunosuppression

The aim of the study was to assess the impact of protocol biopsies in a live-related renal transplant program using tacrolimus-based immunosuppression in the short term. Eighty-three live-related transplant recipients were randomly allocated to protocol biopsy group (Group I, n = 40) and a control group (Group II, n = 43). Other immunosuppressants in these groups consisted of either mycophenolate mofetil or azathioprine and steroids. Protocol biopsies were conducted in biopsy group at 1, 6, and 12 months post-transplant. The non-biopsy group was followed by serial serum creatinine and biopsies in them were conducted as and when clinically indicated. Both groups were analyzed at 12 months with respect to graft function and survival. The two groups were similar with respect to age, number of dialysis pre-operatively, tacrolimus levels, induction therapy, donor age, and donor glomerular filtration rate. Forty protocol biopsies were conducted at 1 month, 31 at 6 months, and 26 at 12 months. The prevalence of sub-clinical rejection at 1, 6, and 12 months in these biopsies was 17.5%, 11.2%, and 10.3%, respectively. The prevalence of calcineurin inhibitor toxicity during same period was 15%, 15.5%, and 14.4%, respectively. The cumulative rejection rate in Group I and Group II at 12-month follow-up was 10.3% and 11.3% (P = 0.78), respectively, and cumulative calcineurin inhibitor toxicity at 12 months was 14.4% and 9.3% (P = 0.59), respectively, were not statistically significant. There was no difference in graft survival and function at 1 year. Protocol biopsies have a limited role in a well-matched renal transplant program with tacrolimus-based immunosuppression in the short term. However, the long-term impact of protocol biopsies needs further evaluation.

Evaluation of biological specimen acceptability in a complex clinical laboratory before and after implementing automated grading serum indices

ABSTRACTContinuous monitoring of specimen acceptability, collection and transport can result in the prompt identification and correction of problems, leading to improved patient care and a reduction in unnecessary redraws and delays in reporting results. This study aims to identify unacceptable blood specimens and to calculate the specimen rejection rate (SRR) before and after the implementation of automated checks of serum indices. This study was conducted between January 2009 and December 2010. The number of rejected specimens, location and reason for rejection were recorded. The Architect c8000 analyser (Abbott, Illinois, USA) was used to assess serum indices based on characteristic spectral patterns and mathematical manipulations of absorbance values measured at several wavelengths. The SRR was calculated, and the target cut-off value for the SRR was <0.5%, as established by the College of American Pathologists (CAP). The SRR values were 0.13% and 0.21% for the years 2009 and 2010, respectively. Haemolysis was the most significant reason for sample rejection, with cumulative rejection rates (CRR) of 49.3% and 61.4% for 2009 and 2010, respectively. Adult intensive care units (ICUs) had the most sample rejections (23.5%), followed by neonatal ICUs (13.8%), cardiac ICUs (13%), paediatric ICUs (10.8%) and long-term wards (10.5%), of which 60%, 79%, 84.9%, 36.6 % and 75%, respectively, of the rejected samples were haemolysed. The increase in rejected samples may be due to an improvement in staff awareness of sample rejection, aided by automatic sample integrity grading by automated chemistry analysis systems.

Integrin Antagonists for Transplant Immunosuppression: Panacea or Peril?

Integrin Antagonists for Transplant Immunosuppression: Panacea or Peril?

TREATMENT OF CORNEAL ALLOGRAFT REJECTION WITH THE CYTOTOXIN IL-2-PE40

IL-2-PE40 is a recombinant chimeric protein composed of IL-2, fused to a modified pseudomonas exotoxin. This molecule is extremely toxic to activated T cells expressing high-affinity IL-2R. We used this new molecule for selective immunosuppression to treat corneal allograft rejection in the rat, using Fisher and Lewis rats, a strain combination differing only in medial and minor histocompatibility antigens. The effect of IL-2-PE40 on the immunologic response was studied using both a heterotopic corneal graft model and orthotopic grafts. At the dose of 0.31 micrograms/g given intraperitoneally every 12 hr, IL-2-PE40 produced a significant reduction of both total lymph node cells and cytotoxic-T-cell (CTL) activity in draining lymph nodes (DLN) of heterotopically grafted animals. IL-2-PE40 treatment also significantly reduced the clinical rejection score and cumulative rejection rate (CRR) in orthotopic grafts and appears to be a very effective immunosuppressive agent.