A. Zavatto

Role of BK virus infection in end-stage renal disease patients waiting for kidney transplantation – viral replication dynamics from pre- to post-transplant

We report the prevalence of BK virus (BKV) infection before renal transplantation and the dynamics of BKV viremia from pre‐ to post‐transplantation. We assessed 60 kidney transplanted patients from a single cohort in Italy, treated with identical immunosuppressive therapy, for BK viremia at pre‐transplantation, 12 h, and three and six months post‐transplantation. Polymerase chain reaction showed that the prevalence of plasma BKV replication – considered a marker of infection – was 20% in pre‐transplant patients. All pre‐transplant‐positive patients remained positive post‐transplant, whereas the majority of pre‐transplant‐negative patients remained negative. Viremia dynamics classification revealed three clusters of patients: Cluster A++, pre‐transplant‐positive patients (20%) who tested positive at least once post‐transplant; Cluster B−+, pre‐transplant‐negative patients (28%) who tested positive at least once post‐transplant; and Cluster C– –, pre‐transplant‐negative patients (52%) who remained negative throughout. These clusters presented significant differences related to the prevalence of substantially positive patients with high plasma viral load (>103 copies/mL) in cluster A, but not in donors’ or grafts’ characteristics. We suggest that pre‐transplant viral status should be considered as an additional risk factor for post‐transplant BKV replication. Therefore, pre‐transplant BKV infection screening in kidney transplant patients should be performed for improving planning of personalized immunosuppressant schemes and specific post‐transplant surveillance.

Occurrence of chronic renal failure in liver transplantation: Monitoring of pre- and posttransplantation renal function

The aim of our study was to evaluate the occurrence of middle and long-term chronic renal failure (CRF) after orthotopic liver transplantation (OLT) in relation to acute renal failure (ARF). We prospectively monitored 75 patients, studying renal function on the basis of serum creatinine and glomerular filtration rate as estimated using the Modification of Diet in Renal Disease formula before as well as 1,6, and 12 months after OLT. The prevalence of ARF was 56% classified by the Acute Kidney injury Network criteria (52% stage 1, 29% stage 2, and 19% stage 3). The occurrences of CRF were 18.6% (11/59), 11.5% (6/52), and 14% (6/43) at 1, 6, and 12 months after OLT, respectively. The occurrence of CRF before OLT was 14.7%. We did not find any association between ARF and post-OLT CRF. The most relevant result of our study was the association between CRF at 6 and 12 months after transplantation with pre-OLT CRF on univariate and multivariate analysis. We suggest that evaluation of pre-OLT renal function should always be considered in the follow-up of liver transplant patients. Pre-OLT renal dysfunction must be recognized to be a risk factor for post-OLT CRF, representing important criterion to define specific therapeutic interventions to reduce patient morbidity and mortality.

Resistive Index and MELD-Na: Nephrologic Monitoring in Cirrhotic Patients Awaiting Liver Transplantation

Renal dysfunction in cirrhotic patients is primarily related to disturbances in circulatory function. In decompensated cirrhosis, ascites and water retention are associated with development of dilutional hyponatremia. The arterial resistive index (RI) is a measure of resistance to arterial flow within the renal vascular bed. Hyponatremia is an independent predictor of mortality in patients with ascites. The aim of this study was to evaluate intrarenal RI in end-stage liver disease (ESLD) patients awaiting liver transplantation (LT) and its association with renal and hepatic function as assessed by Model for End-Stage Liver Disease (MELD) and MELD-Na scores. We evaluated 40 cirrhotic patients (23 males, 17 females) awaiting LT from January 2009 to January 2012. Twenty-six of the 40 patients (65%) showed a renal RI ≥ 0.70, the normal value according to standard reported evaluations. Patients with RI ≥ 0.70 showed significantly higher MELD and MELD-Na scores as well as greater higher serum creatinine and lower serum sodium concentrations compared with subject displaying RI <0.70. The most relevant result of our study was the strong association between elevated renal RI in ESLD patients and advanced liver dysfunction, as demonstrated by MELD and MELD-Na scores, hyponatremia, ascites, and acute renal failure episodes. In conclusion, this study suggested that intrarenal RI assessment should be considered in the clinical and nephrologic monitoring of cirrhotic patients awaiting LT.

From listing to transplant: Nephrologic monitoring in cirrhotic patients awaiting liver transplantation

Nephrologic monitoring of end-stage liver disease (ESLD) patients is part of evaluation for orthotopic liver transplantation (OLT). The numerous causes of renal dysfunction in ESLD patients sometimes relate to the extent of liver damage or sometimes more closely to organic nephropathy. The aim of this study was to evaluate renal function through a specific nephrologic form applied in our outpatient clinic to optimize nephrologic monitoring in ESLD patients awaiting OLT. We enrolled 69 cirrhotic patients (56 men, 13 women) awaiting OLT from April 2008 to January 2012. All patients were evaluated at listing and every 3 months until OLT. The most interesting result was the stable values of serum creatinine from listing to transplantation. We think that dedicated liver transplant nephrologic evaluation is important in the follow-up of ESLD patients awaiting OLT, because the presence of renal dysfunction may represent an important criterion for specific therapeutic interventions to minimize pre-OLT renal injuries that limit the effect of impaired renal function on patient outcomes.

Fluctuations of Estimated Glomerular Filtration Rate Outside Kidney Disease Improving Global Outcomes Diagnostic Criteria for Acute Kidney Injury in End-Stage Liver Disease Outpatients and Outcome Postliver Transplantation

Background Renal dysfunction in end-stage liver disease (ESLD) results from systemic conditions that affect both liver and kidney with activation of vasoconstrictor systems. In this setting, estimated glomerular filtration rate (eGFR) may undergo variations often outside Kidney Disease Improving Global Outcomes criteria for acute kidney injury (AKI) diagnosis, whose meaning is not clear. The aim of this study was to evaluate eGFR variations in ESLD outpatients listed for liver transplant (liver Tx) and the association with post-Tx outcome. Methods Fifty-one patients with ESLD were retrospectively evaluated from listing to transplant (L-Tx time), intraoperatively (Tx time), and up to 5 years post-Tx time. Variations between the highest and the lowest eGFR occurring in more than 48 hours, not satisfying Kidney Disease Improving Global Outcomes guideline, were considered as fluctuations (eGFR-F). Fluctuations of eGFR greater than 50% were defined as eGFR drops (DeGFR). Early graft dysfunction, AKI within 7 days, chronic kidney disease, and short- and long-term patient survivals were considered as outcomes. Results All patients presented eGFR-F, whereas DeGFR were observed in 18 (35.3%) of 51 (DeGFR+ group). These patients presented higher levels of Model for End-stage Liver Disease score, pre-Tx bilirubin and significantly greater incidence of post-Tx AKI stages 2 to 3 compared with patients without drops (DeGFR−). DeGFR was the only independent predictive factor of the occurrence of post-Tx AKI. The occurrence of AKI post-Tx was associated with the development of chronic kidney disease at 3 months and 5 years post-Tx. Conclusions Drops of eGFR are more frequently observed in patients with a worse degree of ESLD and are associated with a worse post-Tx kidney outcome.