Importance of IL-6 inhibition in prevention and treatment of antibody-mediated rejection in kidney allografts

Interleukin-6 (IL-6) is a cytokine critical for innate and adaptive immune responses. However, persistent expression of high levels of IL-6 are associated with a number of pathologic conditions including autoimmune diseases and capillary leak syndrome. Importantly, in kidney transplant patients, IL-6 may play a role in mediation of cell-mediated rejection (CMR) and antibody-mediated rejection (AMR). This is likely due to the importance of IL-6 in stimulating B cell responses with pathogenic donor-specific antibody (DSA) generation and stimulation of T effector cell responses while inhibiting T regulatory cells. Data from preliminary clinical trials and clinical observations show that tocilizumab (anti-IL-6R) and clazakizumab (anti-IL-6) may have promise in treatment of CMR, AMR and chronic (cAMR). This has led to a phase 3 placebo, randomized clinical trial of clazakizumab for treatment of cAMR, a condition for which there is currently no treatment. The identification of IL-6 production in vascular endothelia cells after alloimmune activation reveals another potential pathway for vasculitis as endothelia cell IL-6 may stimulate immune cell responses that are potentially inhibitable with anti-IL-6/IL-6R treatment. Importantly, anti-IL-6/IL-6R treatments have shown the ability to induce Treg and Breg cells in vivo which may have potential importance for prevention and treatment of DSA development and allograft rejection.

Outcome and safety of a surveillance biopsy guided personalized immunosuppression program after liver transplantation

Graft survival beyond year 1 has not changed after orthotopic liver transplantation (OLT) over the last decades. Likewise, OLT causes comorbidities such as infection, renal impairment and cancer. We evaluated our single-center real-world individualized immunosuppression program after OLT, based on 211 baseline surveillance biopsies (svLbx) without any procedural complications. Patients were classified as low, intermediate and high rejection risk based on graft injury in svLbx and anti-HLA donor-specific antibodies. While 32% of patients had minimal histological inflammation, 57% showed histological inflammation and 23% advanced fibrosis (>F2), which was not predicted by lab parameters. IS was modified in 79% of patients after svLbx. After immunosuppression reduction in 69 patients, only 5 patients showed ALT elevations and three of these patients had a biopsy-proven acute rejection, two of them related to lethal comorbidities. The rate of liver enzyme elevation including rejection was not significantly increased compared to a svLbx control cohort prior to the initiation of our structured program. Immunosuppression reduction led to significantly better kidney function compared to this control cohort. In conclusion, a biopsy guided personalized immunosuppression protocol after OLT can identify patients requiring lower immunosuppression or patients with graft injury in which IS should not be further reduced.

Optimization of de novo belatacept-based immunosuppression administered to renal transplant recipients

Kidney transplant recipients administered belatacept-based maintenance immunosuppression present with a more favorable metabolic profile, reduced incidence of de novo donor-specific antibodies (DSAs), and improved renal function and long-term patient/graft survival relative to individuals receiving calcineurin inhibitor (CNI)-based immunosuppression. However, the rates and severity of acute rejection (AR) are greater with the approved belatacept-based regimen than with CNI-based immunosuppression. Although these early co-stimulation blockade-resistant rejections are typically steroid sensitive, the higher rate of cellular AR has led many transplant centers to adopt immunosuppressive regimens that differ from the approved label. This article summarizes the available data on these alternative de novo belatacept-based maintenance regimens. Steroid-sparing, belatacept-based immunosuppression (following T cell-depleting induction therapy) has been shown to yield AR rates comparable to those seen with CNI-based regimens. Concomitant treatment with belatacept plus a mammalian target of rapamycin inhibitor (mTORi; sirolimus or everolimus) has yielded AR rates ranging from 0 to 4%. Because the optimal induction agent and number of induction doses; blood levels of mTORi; and dose, duration, and use of corticosteroids have yet to be determined, larger prospective clinical trials are needed to establish the optimal alternative belatacept-based regimen for minimizing early cellular AR occurrence.

CMV high-risk status and posttransplant outcomes in kidney transplant recipients treated with belatacept

INTRODUCTION

Cytomegalovirus (CMV) remains associated with poor outcomes after kidney transplantation (kTx). The impact of belatacept on CMV infection remains understudied. In this study, we assessed the impact of belatacept on patient and graft survivals.

METHODS

CMV seronegative kTx recipients were included. Patient and graft survival were studied using Kaplan-Meier method, log-rank test. Cox models were used to compare outcomes by CMV risk and immunosuppressive regimen. Incidence and persistence of CMV viremia under belatacept vs tacrolimus were compared.

RESULTS

Among 308 CMV seronegative recipients, 168 CMV high-risk and 203 belatacept-treated patients were included. High-risk CMV status was associated with lower patient survival and graft survival. Among the CMV high-risk group, patients treated with belatacept presented a higher incidence of CMV viremia, a higher rate of first-line treatment failure and a longer time to virus clearance. They had a nonsignificant trend toward a lower graft survival.

CONCLUSION

Belatacept-based maintenance immunosuppression is associated with an increased risk of CMV primary-infection and a prolonged course of viral replication in CMV high-risk patients. Further studies are needed to confirm the nonsignificant trend towards a lower graft survival in CMV high-risk patients treated with belatacept and whether it is explained by the higher risk of CMV reactivation and infection.

Novel coronavirus 2019 pneumonia in a kidney transplant recipient

The COVID-19 pandemic is spreading worldwide and the impact of the disease in transplant patients is evolving. In this case report, we presented a 63-year-old female kidney transplant recipient who presented with dyspnea and cough and was diagnosed with COVID-19 pneumonia. On the fourth day of admission, the patient's condition worsened. Therefore, the immunosuppressive medications were discontinued, and hydrocortisone was started. The patient died on the fifth day.

Late pancreatic panniculitis in a simultaneous pancreas kidney transplant patient with failed allografts

We present a rare case of pancreatic panniculitis in a 59-year-old male simultaneous pancreas-kidney (SPK) recipient with failed allografts. The patient presented with fever and painful erythematous nodules on his leg 1 month after stopping all immunosuppression. A thorough infectious and rheumatological workup was negative. He had pancreas rejection 4 years after SKP transplant and was restarted on dialysis after 14 years when his renal allograft failed due to chronic allograft nephropathy. His chronic immunosuppression (tacrolimus, azathioprine) was stopped and prednisone was weaned over 3 months at that time. A skin biopsy revealed saponification of the subcutaneous fat with inflammation pathognomonic of pancreatic panniculitis. Concurrent allograft pancreatitis confirmed with elevated lipase and a computed tomography scan finding of peripancreatic graft stranding and atrophic native pancreas. He was started on pulse steroid therapy for 3 days followed by oral taper. This resulted in dramatic resolution of all skin lesions and normalization of lipase levels within 1 week, followed by resumption of low-dose tacrolimus and azathioprine. This is an extremely rare occurrence of panniculitis in pancreas allograft after 10 years of pancreatic failure associated with stopping immunosuppression.

Posttransplant biopsy risk for stable long-term pediatric liver transplant recipients: 451 percutaneous biopsies from two multicenter immunosuppression withdrawal trials

Although liver biopsy is the gold standard for assessing allograft health, its attendant risk has deterred its use in routine monitoring of stable liver transplant recipients during long-term follow-up. We utilized prospectively collected data on adverse events from 2 clinical trials of immunosuppression withdrawal to quantify the risk of liver biopsy in pediatric liver transplant recipients. The trials included 451 liver biopsies in 179 children. No biopsies led to bleeding requiring transfusion or intervention, suggesting a clinically significant bleeding risk of <0.8%. Complications were reported in 5.5% of biopsies (95% CI 3.6%-8.1%): 5.8% (21/363) of protocol biopsies and 4.5% (4/88) of for-cause biopsies (P = .80). Mild complications occurred in 1.8% of biopsies, moderate in 1.8%, and severe in 2.0%. The majority of complications (89%) resolved within 1 week. Six of 9 (67%) severe complications were related to biliary issues; 5 were episodes of cholangitis. Biopsy-related cholangitis occurred only in children with underlying biliary strictures. Overall, biopsy-related complications were infrequent and resolved quickly. Severe complications were rare, with occult biliary stricture as the dominant driver. Our study provides evidence for clinicians who are considering the risk vs benefit of surveillance liver biopsies in pediatric liver transplant recipients.

Increasing tacrolimus time-in-therapeutic range is associated with superior one-year outcomes in lung transplant recipients

Calcineurin inhibitors (CNIs) are the backbone of traditional immunosuppressive regimens for lung transplant recipients (LTR). The CNIs are both narrow therapeutic index drugs with significant interpatient and intrapatient variability that require therapeutic drug monitoring to ensure safety and effectiveness. We hypothesized that tacrolimus time-in-therapeutic range (TTR) affects acute and chronic rejection rates in LTRs. This was a single-center, observational, cross-sectional study of 292 adult LTRs. Subjects who received tacrolimus posttransplant for the first year were included. TTR was calculated at 1 year using protocol goal ranges (12-15 mg/mL months 0-6; 10-12 mg/mL for months 7-12). The primary outcome was acute cellular rejection (ACR) burden at 1 year. Chronic lung allograft dysfunction (CLAD), mortality, and infection rate were assessed as secondary outcomes at 1 year. Primary and secondary outcomes were assessed using logistic regression. Increasing TTR by 10% was associated with a significantly lower likelihood of high-burden ACR at 1 year on univariable (OR 0.46, 95% CI 0.40-0.54, P < .001) and multivariable (OR 0.64, 95% CI 0.47-0.86, P = .003) assessment, controlling for age and induction agent. Increasing TTR by 10% was also associated with lower rates of CLAD (P < .001) and mortality (P < .001) at 1 year. Prospective studies confirming these findings appear warranted.