Female gender and overestimation of glomerular filtration rate: Independent predictors of acute kidney injury after liver transplantation
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Acute kidney injury (AKI) in liver transplant (LT) setting is a recognized complication and is related to increased morbidity and mortality. Pre-LT renal function is difficult to estimate, in particular for the female gender. The aim of the study was to evaluate the incidence of post-LT AKI, its relationship with survival, and related risk factors. In a single-center retrospective study of consecutive LT patients (2008 - 2015), we assessed patient characteristics and intra-LT events, and post-operative data were collected. The occurrence of AKI post-LT was also evaluated (KDIGO guidelines). Data of 145 LT patients were analyzed. 45 (31.0%) patients showed an overestimation of glomerular filtration rate (over-GFR), defined as GFR > 120 mL/min/1.73m2; 83 patients (57.2%) developed post-LT AKI. The patients (n = 145) were divided into two groups: 123 (84.8%) patients with no-AKI & AKI stage 1 and 22 (15.2%) patients with AKI stages 2 and 3. Patients with AKI stages 2 and 3 were characterized by a significantly decreased 5-year survival (p < 0.001). On the multivariable analysis, female gender and over-GFR were significantly predictive for development of AKI stages 2 and 3. Female gender has already been reported as a discriminant factor for LT candidates. Altered estimation of renal function also needs to be considered in this setting, as this could mask the presence of an unknown compromised renal function.

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 (>10(3) 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.

Possible antiviral effect of ciprofloxacin treatment on polyomavirus BK replication and analysis of non-coding control region sequences.

Acute renal dysfunction (ARD) is a common complication in renal transplant recipients. Multiple factors contribute to ARD development, including acute rejection and microbial infections. Many viral infections after kidney transplantation result from reactivation of "latent" viruses in the host or from the graft, such as the human Polyomavirus BK (BKV). We report the case of a 39 year-old recipient of a 2nd kidney graft who experienced BKV reactivation after a second episode of acute humoral rejection. A 10-day treatment with the quinolone antibiotic ciprofloxacin was administered with an increase of immunosuppressive therapy despite the active BKV replication. Real Time PCR analysis performed after treatment with ciprofloxacin, unexpectedly showed clearance of BK viremia and regression of BK viruria. During the follow-up, BK viremia persisted undetectable while viruria decreased further and disappeared after 3 months.BKV non-coding control region sequence analysis from all positive samples always showed the presence of archetypal sequences, with two single-nucleotide substitutions and one nucleotide deletion that, interestingly, were all representative of the subtype/subgroup I/b-1 we identified by the viral protein 1 sequencing analysis.We report the potential effect of the quinolone antibiotic ciprofloxacin in the decrease of the BKV load in both blood and urine.

Expected and Observed Glomerular Filtration Rates in Kidney Transplant Patients Converted to Once Daily Tacrolimus: 10 Years of Follow-up.

The decline of allograft kidney function in the long term remains a significant issue in renal transplantation, with drug nephrotoxicity and cardiovascular complications as important risk factors. Our study aimed to evaluate the estimated glomerular filtration rate (eGFR) trend and metabolic cardiovascular risk factors over 10 years in a cohort of kidney transplant (KT) recipients converted from twice-daily (TD) tacrolimus (Tac) to once-daily (OD)-Tac. We enrolled 55 consecutive KT recipients who had been at the outpatient clinic between 2009 and 2011. Thirty-seven reached the 10-year follow-up. We compared the observed eGFR with the expected eGFR trend described in KT-recipients and monitored blood pressure and metabolic cardiovascular risk factors. The observed eGFR remained stable throughout the complete follow-up (P = .188). The observed decline of eGFR was significantly lower compared with the expected decline for KT patients (P < .001). The blood pressure was maintained within target values. The monitoring of plasma glucose levels demonstrated the stability of median values (P = .686), as well as cholesterol level (P = .250), high-density lipoprotein (HDL) cholesterol (P = .294), and triglycerides (P = .592) throughout the follow-up. The monitoring of tacrolimus plasma level demonstrated that median trough levels remained constant (median values 4.4-5.5 ng/mL) throughout the entire follow-up period (P = .149). We suggest that the reasonable control of metabolic risk factors for cardiovascular disease over long-term follow-up may significantly contribute to the preservation of eGFR compared with the decline expected in KT recipients.

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.