Proteinuria and baseline renal function predict mortality and renal outcomes after sirolimus therapy in liver transplantation recipients

Impact of Sirolimus versus Mycophenolate Mofetil on Kidney Function after Calcineurin Inhibitor Dose Reduction in Liver Transplant Recipients

Impaired kidney function is associated with increased morbidity and mortality in patients undergoing liver transplantation. Although immunosuppressants are essential in these patients, they impair kidney function. This study aimed to compare adverse kidney outcomes between patients treated with a reduced dose of tacrolimus (calcineurin inhibitor) plus sirolimus or mycophenolate mofetil (MMF) in the liver transplant center at Kaohsiung Chang Gung Memorial Hospital between April 2011 and December 2017. Propensity score matching was used to identify 232 patients. The risk of adverse kidney outcomes was estimated using Cox proportional hazards regression, and changes in kidney function over time were analyzed using linear mixed modeling. Acute kidney disease risks in this study cohort were not significantly different for the two immunosuppressants (aHR 1.04; 95% CI: 0.70-1.55, p = 0.8328). However, sirolimus use was significantly associated with a higher risk of estimated glomerular filtration rate decline > 30% than MMF (aHR, 2.09; 95% CI: 1.33-3.28; p = 0.0014). Our results demonstrate that sirolimus use may have worsened long-term kidney outcomes compared to MMF. Close monitoring of kidney function, dose adjustment, and timely transition to MMF is necessary for LT patients receiving sirolimus.

Albuminuria post-liver transplant is a predictor of kidney disease progression and mortality

BACKGROUND: Albuminuria is a marker of chronic kidney disease (CKD) associated with an increased risk of end-stage kidney disease (ESKD) and mortality in the general population, but it is uncertain whether the same association exists in liver transplant (LT) recipients. This study examined the association between albuminuria and kidney failure and mortality in LT recipients.METHODS: Retrospective cohort study of 294 adults who received a LT between January 1, 1989, and December 31, 2011, in British Columbia, Canada. Cox multivariable regression was used to determine the association between ACR and a primary combined outcome of mortality, doubling of serum creatinine, or ESKD; and a secondary outcome of a decrease in estimated glomerular filtration rate (eGFR) ≥30%. RESULTS: At baseline, mean eGFR was 67 (SD 20.9) mL/min/1.73 m², and 10% had severe albuminuria (ACR >30 mg/mmol). The primary outcome occurred in 20.4% (60) of patients and was associated with ACR >30 mg/mmol (HR 2.77, 95% CI 1.28-6.04; P = 0.01). A decline in eGFR ≥30% occurred in 21.8% (64) of patients, and was associated with ACR >30 mg/mmol (HR 4.77, 95% CI 2.31-9.86; P < 0.0001). CONCLUSIONS: Severe albuminuria (ACR >30 mg/mmol) was associated with an increased risk of loss of kidney function and mortality after LT. Prospective studies are needed to determine if specific interventions directed at reducing albuminuria can improve long-term outcomes in LT recipients.

Acute kidney injury and chronic kidney disease after liver transplant: A retrospective observational study

BACKGROUND AND RATIONALE

Chronic kidney disease remains an important risk factor for morbidity and mortality among LT recipients, but its exact incidence and risk factors are still unclear.

MATERIAL AND METHODS

We carried out a retrospective cohort study of consecutive adults who underwent liver transplant (January 2009-December 2018) and were followed (at least 6 months) at our institution. CKD was defined following the Kidney Disease: Improving Global Outcomes (KDIGO) 2012 Clinical Practice Guidelines. Long-term kidney function was classified into 4 groups: no CKD (eGFR, ≥60mL/min/1.73m²), mild CKD (eGFR, 30-59mL/min/1.73m²), severe CKD (eGFR, 15-29mL/min/1.73m²), and end-stage renal disease (ESRD).

RESULTS

We enrolled 410 patients followed for 53.2±32.6 months. 39 had CKD at baseline, and 95 developed de novo CKD over the observation period. There were 184 (44.9%) anti-HCV positive, 47 (11.5%) HBsAg positive, and 33 (8.1%) HBV/HDV positive recipients. Recipient risk factors for baseline CKD were advanced age (P=0.044), raised levels of serum uric acid (P<0.0001), and insulin dependent DM (P=0.0034). Early post-transplant AKI was common (n=95); logistic regression analysis found that baseline serum creatinine was an independent predictor of early post-LT AKI (P=0.0154). According to our Cox proportional hazards model, recipient risk factors for de novo CKD included aging (P<0.0001), early post-transplant AKI (P=0.007), and baseline serum creatinine (P=0.0002). At the end of follow-up, there were 116 LT recipients with CKD - 109 (93.9%) and 7 (6.1%) had stage 3 and advanced CKD, respectively. Only two of them are undergoing long-term dialysis.

CONCLUSION

The incidence of CKD was high in our cohort of LT recipients, but only a slight decline in kidney function over time was recorded. Prevention of post-transplant AKI will improve kidney function in the long run. We need more studies to analyze the function of kidneys among LT recipients over extended follow-ups and their impact on mortality.

Excellent Outcome in Living Donor Liver Transplantation: Treating Patients With Acute-on-Chronic Liver Failure

Acute-on-chronic liver failure (ACLF) is a fatal condition, and liver transplantation (LT) is a vital option for these patients. However, the result of living donor LT (LDLT) for ACLF is not well investigated. This study investigated the outcomes of LDLT in patients with ACLF compared with patients without ACLF. This was a single-center, retrospective, matched case-control study. From July 2002 to March 2017, a total of 112 patients with ACLF who underwent LDLT were enrolled according to the consensus of the Asian Pacific Association for the Study of the Liver. A total of 224 patients were selected for control comparison (non-ACLF) with demographic factors (sex, age, and body mass index) matched (1:2). Patients with ACLF were stratified into ACLF 1, 2, and 3 categories according to the number of organ failures based on the Chronic Liver Failure-Sequential Organ Failure Assessment score. Survival and surgical outcomes after LDLT were analyzed. The Model for End-Stage Liver Disease and Child-Turcotte-Pugh scores in the ACLF group were significantly higher than those in the non-ACLF group (P < 0.001). The 90-day, 3-year, and 5-year survival rates in the ACLF and non-ACLF groups were 97.3%, 95.5%, 92.9%, respectively, and 96.9%, 94.2%, and 91.1%, respectively (P = 0.58). There was more intraoperative blood loss in the ACLF group than in the non-ACLF group (P < 0.001). The other postoperative complications were not significantly different between the groups. A total of 20 patients (17.9%) in the ACLF group presented with 3 or more organ system dysfunctions (ACLF 3), and the 90-day, 3-year, and 5-year survival rates were comparable with those of ACLF 1 and ACLF 2 (P = 0.25). In carefully selected patients, LDLT gives excellent outcomes in patients with ACLF regardless of the number of organs involved. Comprehensive perioperative care and timely transplantation play crucial roles in saving the lives of patients with ACLF.

Acute kidney injury and chronic kidney disease after liver transplant: A retrospective observational study

BACKGROUND AND RATIONALE

Chronic kidney disease remains an important risk factor for morbidity and mortality among LT recipients, but its exact incidence and risk factors are still unclear.

MATERIAL AND METHODS

We carried out a retrospective cohort study of consecutive adults who underwent liver transplant (January 2009-December 2018) and were followed (at least 6 months) at our institution. CKD was defined following the Kidney Disease: Improving Global Outcomes (KDIGO) 2012 Clinical Practice Guidelines. Long-term kidney function was classified into 4 groups: no CKD (eGFR, ≥60mL/min/1.73m2), mild CKD (eGFR, 30-59mL/min/1.73m2), severe CKD (eGFR, 15-29mL/min/1.73m2), and end-stage renal disease (ESRD).

RESULTS

We enrolled 410 patients followed for 53.2±32.6 months. 39 had CKD at baseline, and 95 developed de novo CKD over the observation period. There were 184 (44.9%) anti-HCV positive, 47 (11.5%) HBsAg positive, and 33 (8.1%) HBV/HDV positive recipients. Recipient risk factors for baseline CKD were advanced age (P=0.044), raised levels of serum uric acid (P<0.0001), and insulin dependent DM (P=0.0034). Early post-transplant AKI was common (n=95); logistic regression analysis found that baseline serum creatinine was an independent predictor of early post-LT AKI (P=0.0154). According to our Cox proportional hazards model, recipient risk factors for de novo CKD included aging (P<0.0001), early post-transplant AKI (P=0.007), and baseline serum creatinine (P=0.0002). At the end of follow-up, there were 116 LT recipients with CKD - 109 (93.9%) and 7 (6.1%) had stage 3 and advanced CKD, respectively. Only two of them are undergoing long-term dialysis.

CONCLUSION

The incidence of CKD was high in our cohort of LT recipients, but only a slight decline in kidney function over time was recorded. Prevention of post-transplant AKI will improve kidney function in the long run. We need more studies to analyze the function of kidneys among LT recipients over extended follow-ups and their impact on mortality.

Acute and chronic kidney disease after pediatric liver transplantation: An underestimated problem

Acute and chronic kidney injuries represent critical issues after liver transplantation (LTx), but whereas renal dysfunction in adult transplant patients is well documented, little is known about its prevalence in childhood. It is a challenge to accurately evaluate renal function in patients with liver disease, due to several confounding factors. Creatinine-based equations estimating glomerular filtration rate, validated in nephropathic patients without hepatic issues, are frequently inaccurate in end-stage liver disease, underestimating the real impact of renal disease. Moreover, whereas renal issues observed within 1 year from LTx were often related to acute injuries, kidney damage observed after 5-7 years from LTx, is due to chronic, irreversible mechanisms. Most immunosuppression protocols are based on calcineurin inhibitors (CNIs) and corticosteroids, but mycophenolate mofetil or sirolimus could play significant roles, also in children. Early diagnosis and personalized treatment represent the bases of kidney disease management, in order to minimize its close relation with increased mortality. This review analyzed acute and chronic kidney damage after pediatric LTx, also discussing the impact of pre-existent renal disease. The main immunosuppressant strategies have been reviewed, highlighting their impact on kidney function. Different methods assessing renal function were reported, with the potential application of new renal biomarkers.

Everolimus and long-term decline in renal function after liver transplantation: real-life experience with measured GFR

Switching from calcineurin-inhibitors (CNI) to everolimus >6-12-months after liver transplantation (LT) seems inefficient in improving renal function, but whether everolimus halts further renal-function decline compared to low-dose CNI remains unclear. In a retrospective single-center study of everolimus after LT (2008-2016) with routine measured glomerular filtration rates (mGFR; ⁵¹Cr-EDTA- or iohexol clearance), we compared by propensity-score matching everolimus therapy to low-dose CNI therapy. The study comprised 36 patients with everolimus introduced on average 22 months post-LT (range 2-105 months, median follow-up 3.4 years), and 36 matched controls. Everolimus introduction was associated with a mean improvement in mGFR of 7 mL/min up to 1 year (p = .003), restricted to patients switched <1-year post-transplant and at tacrolimus trough levels >5 ng/mL. The differences between the everolimus group and controls in delta-mGFR from baseline to 1 year (7.3 vs 4.3 mL/min, p = .25) or 1-year to last follow-up (-0.8 vs -0.2 mL/min/year, p = .71) were non-significant. Proportions with mGFR decline >3 mL/min/year were similar between groups (11% and 14%, p = 1.00). Everolimus was stopped in three patients (8%), and acute rejection occurred in 17%. In conclusion, despite an early improvement in renal function after everolimus introduction, we found no evidence that everolimus halts the long-term mGFR decline compared to continued low-dose CNI therapy. Due to retrospective design, small sample size and heterogenous characteristics, definite conclusions require prospective studies.

Clinical Outcomes of Tuberculosis in Recipients After Living Donor Liver Transplantation

Background

This study aimed to determine clinical outcomes using various drugs during tuberculosis (TB) treatment among living donor liver transplant (LDLT) recipients with TB and to assess the impact of performing LDLT in patients with active TB at the time of LDLT.

Material/Methods

Out of 1313 LDLT performed from June 1994 to May 2016, 26 (2%) adult patients diagnosed with active TB were included in this study. Active TB was diagnosed using either TB culture, PCR, and/or tissue biopsy.

Results

The median age was 56 years and the male/female ratio was 1.6: 1. Most patients had pulmonary TB (69.2%), followed by extrapulmonary and disseminated TB (15.4% each). Fourteen (53.8%) patients underwent LDLT even with the presence of active TB. All patients concurrently received anti-TB [Rifampicin-based: 13 (50%); Rifabutin-based: 12 (46.2%); INH-based: 1 (3.8%)] and immunosuppressive drugs [Tacrolimus-based: 6 (23%); Sirolimus/Everolimus-based: 20 (77%)]. During treatment, adverse drug reactions (ADR) occurred in 34.6% of patients: acute rejection in 6 (23.1%), hepatotoxicity in 2 (7.7%), and blurred vision in 1 (3.8%). Twenty-three (88%) patients completed their TB treatment. Neither TB recurrence nor TB-specific mortality were observed. Three (11.5%) patients died of non-TB-related causes. The overall 5-year survival rate was 86.2%. Patients with ADRs had a higher incidence of incomplete TB treatment (log-rank: p=0.012). Furthermore, patients with incomplete treatment were significantly associated with decreased overall survival (log-rank: p<0.001). Immunosuppressive and anti-TB drugs used during TB treatment and performing LDLT in patients with active TB at the time of LDLT were not associated with ADRs and overall survival.

Conclusions

Outcomes are generally favorable with intensive peri-operative evaluation and surveillance. ADRs and incomplete TB treatment may result in poor prognosis and increased mortality rates.

The role of sirolimus in proteinuria in diabetic nephropathy rats

Objective(s):

The aim of this study was to observe the impact of sirolimus on proteinuria in streptozotocin (STZ) induced diabetic rats.

Materials and Methods:

Rats were given a single injection of STZ to induce diabetic rat model. Rats’ 24 hr urine was collected to test, urinary and the kidney tissues were harvested at the 8^th and 20^th weeks, respectively. Podocyte morphological changes were examined by electron microscopy and the ZO-1, podocin expressions in kidneys were detected by immunohistochemistry; the protein levels of Raptor and pS6 were measured by Western blot assay.

Results:

In the early stage of diabetic nephropathy (DN), sirolimus reduced the proteinuria significantly (P<0.05); but in the advanced stage of DN, sirolimus worsened proteinuria (P<0.05). Electron microscopy test suggested that sirolimus could reduce the injury of podocyte at the early DN, but increased the injury at the late DN podocyte. Immunohistochemistry results indicated that sirolimus increased the expressions of podocin and ZO-1 at the early DN (P<0.05), but reduced the expressions of ZO-1 and podocin (P<0.05) at the advanced DN. In the different periods of DN, the expression levels of Raptor and pS6 in sirolimus-treated groups were significantly lower than in the DN control groups (P<0.05).

Conclusion:

Sirolimus can reduce proteinuria and alleviate the early DN podocyte injury in diabetic rat model by inhibiting the activity of mTORC1; but in the advanced stage of DN, sirolimus can increase podocyte injury and urine protein level.

Sirolimus induces depletion of intracellular calcium stores and mitochondrial dysfunction in pancreatic beta cells

Sirolimus (rapamycin) is an immunosuppressive drug used in transplantation. One of its major side effects is the increased risk of diabetes mellitus; however, the exact mechanisms underlying such association have not been elucidated. Here we show that sirolimus impairs glucose-stimulated insulin secretion both in human and murine pancreatic islets and in clonal β cells in a dose- and time-dependent manner. Importantly, we demonstrate that sirolimus markedly depletes calcium (Ca²⁺) content in the endoplasmic reticulum and significantly decreases glucose-stimulated mitochondrial Ca²⁺ uptake. Crucially, the reduced mitochondrial Ca²⁺ uptake is mirrored by a significant impairment in mitochondrial respiration. Taken together, our findings indicate that sirolimus causes depletion of intracellular Ca²⁺ stores and alters mitochondrial fitness, eventually leading to decreased insulin release. Our results provide a novel molecular mechanism underlying the increased incidence of diabetes mellitus in patients treated with this drug.