Current aspects of renal dysfunction after liver transplantation

Risk factors for renal impairment after liver transplantation in Mongolia: a retrospective single-center study

Background

Renal impairment (RI) is a frequent complication of liver cirrhosis and is associated with increased mortality and morbidity. Liver transplantation (LT) serves as an effective treatment method for patients with cirrhosis who have impaired renal function. However, renal function often declines after LT, influenced by various factors. This study aimed to investigate the factors contributing to RI following LT in our cases.

Methods

We analyzed the demographic data, preoperative and perioperative parameters, and postoperative outcomes of patients who underwent LT at the First Central Hospital of Mongolia from September 2011 to December 2022. Renal function was assessed by measuring the glomerular filtration rate using the Cockcroft-Gault creatinine clearance formula pretransplantation and at 24 hours, 72 hours, 7 days, 14 days, and 28 days post-LT.

Results

Several factors increased the risk of RI among recipients. These included female sex (odds ratio [OR], 3.06; 95% confidence interval [CI], 1.58-5.91), Child-Turcotte-Pugh (CTP) scores of B and C (OR, 4.23; 95% CI, 0.92-19.41 and OR, 7.68; 95% CI, 1.67-35.30, respectively), preoperative continuous renal replacement therapy (CRRT; OR, 5.86; 95% CI, 1.1-31.21), and a high graft-to-recipient weight ratio (GRWR; OR, 3.45; 95% CI, 1.23-9.63). Additionally, the survival rates for recipients with RI post-LT were 93.4% at 1 year and 78.1% at 3 years.

Conclusions

Female sex, a high CTP score, preoperative CRRT, and high GRWR were identified as risk factors for RI after LT in Mongolia.

Incidence and Risk Factors Associated With Chronic Kidney Disease After Liver Transplantation: A Review of a 20-Year Experience at a Single Center

BACKGROUND

Chronic kidney disease (CKD) is one of the major complications after liver transplantation (LT), with a significant impact on patient outcomes. This study aims to investigate the incidence and risk factors of CKD in LT recipients at Siriraj Hospital over the past 20 years.

METHODS

There were 366 adult patients undergoing LT at Siriraj Hospital between January 2002 and December 2021. After excluding patients with pretransplant CKD stages 4 to 5, simultaneous liver-kidney transplantation, and patients who died after LT within 90 days, we retrospectively reviewed a total of 288 patients. Univariable and multivariable binary logistic regression analyses were used to identify the risk factors of post-transplant CKD.

RESULTS

Of the 288 patients, 171 (59.4%) developed CKD after LT. The median time to develop CKD was 5.8 months (IQR, 3.8-15.3). Univariable and multivariable analyses revealed that age ≥55 years (odds ratio [OR] = 2.44; 95% CI, 1.34-4.42; P = .003), pretransplant kidney dysfunction defined as estimated glomerular filtration rate <60 mL/min/1.73 m2 (OR = 2.23; 95% CI, 1.16-4.27; P = .016), and postoperative acute kidney injury (OR = 3.06; 95% CI, 1.73-5.42; P < .001) were significantly associated with post-transplant CKD. Patients with preexisting kidney dysfunction who received delayed calcineurin inhibitor introduction without antibody induction protocol had a significantly lower incidence of post-transplant CKD (OR = 0.28; 95% CI, 0.11-0.70; P = .007).

CONCLUSIONS

Advanced age, pre-transplant kidney dysfunction, and postoperative acute kidney injury are risk factors for CKD after LT. Importantly, delayed calcineurin inhibitor introduction can protect patients with pretransplant kidney dysfunction from developing post-transplant CKD. These results may have important clinical implications in reducing the incidence of CKD after LT.

Hereditary Transthyretin Amyloidosis and the Impact of Classic and New Treatments on Kidney Function: A Review

Hereditary transthyretin amyloidosis (ATTRv) is a rare, progressive, and life-threatening disease caused by misfolded transthyretin (TTR) proteins that aggregate as abnormal amyloid fibrils and accumulate throughout the body. The kidney is one of the main organs affected in amyloid light chain (AL) amyloidosis and ATTRv amyloidosis. The most common clinical presentation is proteinuria, which consists mainly of albumin; this is the first step in the natural history of ATTRv nephropathy. Not all TTR mutations are equal in terms of ATTRv kidney involvement. Kidney involvement in ATTRv itself is difficult to define, given the numerous associated confounding factors. There are several treatments available to treat ATTRv, including orthotopic liver transplant (OLT), which is the classic treatment for ATTRv. However, we should be careful regarding the use of calcineurin inhibitors in the setting of OLT because these can be nephrotoxic. New treatments for amyloidosis may have an impact on kidney function, including drugs that target specific pathways involved in the disease. Tafamidis and diflunisal, which are TTR stabilizers, patisiran (RNA interference agent), and inotersen (antisense oligonucleotide inhibitor) have been shown to reduce TTR amyloid. Tafamidis and patisiran are medications that have reduced the progression of kidney disease in amyloidosis, but inotersen and diflunisal may damage kidney function.

Post Liver Transplant Renal Dysfunction-Evaluation, Management and Immunosuppressive Practice

Liver transplantation (LT) is an effective and lifesaving treatment for patients with end-stage liver disease and hepatocellular carcinoma. Significant improvement in intermediate and long-term survival has been possible due to advancements in immunosuppressive therapy, perioperative care, and surgical techniques. Despite these advances, metabolic complications, including diabetes mellitus, cardiovascular diseases, malignancies, and renal dysfunction, are challenging issues after LT. Acute kidney injury (AKI) and chronic kidney disease (CKD) after LT are common and result in significant morbidity and mortality. Early diagnosis of kidney injury after LT is challenging, and no technique has yet proven effective in prediction of renal dysfunction. The methods for assessing renal function range from formulas that predict glomerular filtration rate to non-invasive biomarkers. The universal adoption of the model for end-stage liver disease has a direct impact on the incidence of peri-transplant AKI and development of CKD in the long-term. Post-LT renal dysfunction is multifactorial and is usually a result of pre-transplantation comorbidities, occurrence of renal dysfunction on the waiting list, perioperative events, and post-transplant nephrotoxic immunosuppressive medication use. Early identification of patients at risk for renal dysfunction and adoption of preventive measures are crucial in the pre-transplant period. No data are currently available to suggest a surgical technique that reliably demonstrates renal protection. Nephroprotective strategies during LT follow accepted surgical practice guidelines, such as maintenance of intravascular volume and mean arterial pressure. The management of kidney disease following LT is challenging, as by the time the serum creatinine is significantly elevated, few interventions impact the course of progression. Early nephroprotective measures are strongly advised and they mostly center on delaying the administration of calcineurin inhibitors (CNIs) during the initial postoperative period, lowering CNI dosage and combining CNI with mycophenolate mofetil and everolimus. The reasons for renal failure following LT, the techniques used to diagnose it, and the therapies designed to preserve renal function both immediately and late after LT are all critically evaluated in this review.

Long Term Complications of Immunosuppression Post Liver Transplant

Improvement in immunosuppression has led to a remarkable improvement in short-term and long-term outcomes post-liver transplant (LT). However, with improvements in long-term survival, complications related to immunosuppressive drugs, either directly or indirectly, have also increased. The adverse events could be drug-specific, class-specific, or generic. Calcineurin inhibitors (cyclosporine and tacrolimus) are the backbone of the immunosuppression after LT and the main culprit associated with most of the complications, including renal failure, post-transplant diabetes mellitus (PTDM), and metabolic syndrome. Steroids are also implicated in the development of diabetes, osteoporosis, and metabolic syndrome post-LT. The development of infections and de novo malignancies (DNMs) is a generic effect linked to the overall cumulative immunosuppression. The development of these complications significantly hampers the quality of life and leads to increased morbidity and mortality post-LT. Thus, it is important to minimize the cumulative immunosuppression dose while simultaneously preventing allograft rejection. This review provides up-to-date, comprehensive knowledge of the complications of long-term immunosuppression post-LT along with associated risk factors and strategies to minimize the risk of complications.

Role of the Nephrologist in Non-Kidney Solid Organ Transplant (NKSOT)

BACKGROUND

Chronic kidney disease (CKD) is a common complication of a non-kidney solid organ transplant (NKSOT). Identifying predisposing factors is crucial for an early approach and correct referral to nephrology.

METHODS

This is a single-center retrospective observational study of a cohort of CKD patients under follow-up in the Nephrology Department between 2010 to 2020. Statistical analysis was performed between all the risk factors and four dependent variables: end-stage renal disease (ESKD); increased serum creatinine ≥50%; renal replacement therapy (RRT); and death in the pre-transplant, peri-transplant, and post-transplant periods.

RESULTS

74 patients were studied (7 heart transplants, 34 liver transplants, and 33 lung transplants). Patients who were not followed-up by a nephrologist in the pre-transplant (p < 0.027) or peri-transplant (p < 0.046) periods and those who had the longest time until an outpatient clinic follow-up (HR 1.032) were associated with a higher risk of creatinine increase ≥50%. Receiving a lung transplant conferred a higher risk than a liver or heart transplant for developing a creatinine increase ≥50% and ESKD. Peri-transplant mechanical ventilation, peri-transplant and post-transplant anticalcineurin overdose, nephrotoxicity, and the number of hospital admissions were significantly associated with a creatinine increase ≥50% and developing ESKD.

CONCLUSIONS

Early and close follow-up by a nephrologist was associated with a decrease in the worsening of renal function.