F. Tinti

Once Daily Tacrolimus Formulation: Monitoring of Plasma Levels, Graft Function, and Cardiovascular Risk Factors

BACKGROUND Advagraf, an extended release formulation of tacrolimus, is administered once daily during the morning fast. Tacrolimus can be safely converted from the twice daily formulation (Prograf) to the same dose (1 mg:1 mg) of once daily dosing tacrolimus (m-Tac). The adverse effects of tacrolimus play important roles in posttransplant cardiovascular risk factors (CVR): hyperglycemia, posttransplant diabetes mellitus, dyslipidemia and hypertension. It has been suggested that avoiding high tacrolimus peak levels minimizes its diabetogenic effects leading to better glycemic control. The aim of our study was to observe the effects of conversion to m-Tac therapy on graft function and CVR among stable transplant kidney recipients. METHODS We selected 2 groups of 20 patients with stable kidney transplantation, who had been treated with Prograf for >6 months with a triple regimen. Group 1 were converted to once daily tacrolimus at the same dose (1 mg:1 mg); whereas in group 2, the therapy was maintained as a twice daily regimen. Blood pressure, creatinine and glomerular filtration rate levels evaluated by the Modification of Diet in Renal Disease formula, as well as urea, total, high- and low-density lipoprotein remained stable between the 2 groups as well as inside group 1 before and after conversion. RESULTS After conversion, glycemia and triglyceride values showed significant reductions in group 1 and between the 2 groups. These results were significant, as they may be associated with better long-term graft and patient survivals.

Improvement of Graft Function after Conversion to Once Daily Tacrolimus of Stable Kidney Transplant Patients

BACKGROUND Chronic renal dysfunction is present in about one quarter of kidney transplant patients at 1 year and in about 90% by 10 years. Nephrotoxicity caused by calcineurin inhibitors is among the most common factors. Elevated tacrolimus levels have been correlated with worse control of side effects including acute and/or chronic nephrotoxicity. The aim of this study was to observe the effects on graft function of conversion from the twice daily to the once daily extended release tacrolimus formulation in stable kidney transplant recipients within 5 years of grafting. METHODS Thirty-one stable kidney transplant patients were converted at the same dosage (1 mg:1 mg). Patients served as their own controls based on results before versus after conversion. RESULTS The trough levels of tacrolimus showed a slight albeit significant reduction after the conversion. Serum creatinine and glomerular filtration rate showed a significant improvement without an association with the tacrolimus trough levels. CONCLUSION We suggest that the immunosuppression with once daily tacrolimus may be a good option for kidney transplant patients.

Early monitoring of the human polyomavirus BK replication and sequencing analysis in a cohort of adult kidney transplant patients treated with basiliximab

BackgroundNowadays, better immunosuppressors have decreased the rates of acute rejection in kidney transplantation, but have also led to the emergence of BKV-associated nephropathy (BKVAN). Therefore, we prospectively investigated BKV load in plasma and urine samples in a cohort of kidney transplants, receiving basiliximab combined with a mycophenolate mofetil-based triple immunotherapy, to evaluate the difference between BKV replication during the first 3 months post-transplantation, characterized by the non-depleting action of basiliximab, versus the second 3 months, in which the maintenance therapy acts alone. We also performed sequencing analysis to assess whether a particular BKV subtype/subgroup or transcriptional control region (TCR) variants were present.MethodsWe monitored BK viruria and viremia by quantitative polymerase chain reaction (Q-PCR) at 12 hours (Tx), 1 (T1), 3 (T2) and 6 (T3) months post-transplantation among 60 kidney transplant patients. Sequencing analysis was performed by nested-PCR with specific primers for TCR and VP1 regions. Data were statistically analyzed using χ2 test and Students t-test.ResultsBKV was detected at Tx in 4/60 urine and in 16/60 plasma, with median viral loads of 3,70 log GEq/mL and 3,79 log GEq/mL, respectively, followed by a significant increase of both BKV-positive transplants (32/60) and median values of viruria (5,78 log GEq/mL) and viremia (4,52 log GEq/mL) at T2. Conversely, a significantly decrease of patients with viruria and viremia (17/60) was observed at T3, together with a reduction of the median urinary and plasma viral loads (4,09 log GEq/mL and 4,00 log GEq/mL, respectively). BKV TCR sequence analysis always showed the presence of archetypal sequences, with a few single-nucleotide substitutions and one nucleotide insertion that, interestingly, were all representative of the particular subtypes/subgroups we identified by VP1 sequencing analysis: I/b-2 and IV/c-2.ConclusionsOur results confirm previous studies indicating that BKV replication may occur during the early hours after kidney transplantation, reaches the highest incidence in the third post-transplantation month and then decreases within the sixth month, maybe due to induction therapy. Moreover, it might become clinically useful whether specific BKV subtypes or rearrangements could be linked to a particular disease state in order to detect them before BKVAN onset.

Regression of systemic lupus erythematosus after development of an acquired Toll‐like receptor signaling defect and antibody deficiency

Toll-like receptor 9 (TLR-9) and TLR-7 may have a role in the production of anti-DNA and anti-RNA autoantibodies, respectively, but murine models do not clearly demonstrate their contribution to the development of systemic lupus erythematosus (SLE). Herein we describe a patient with SLE who had long-lasting remission of her autoimmune disease after development of an antibody deficiency resembling common variable immunodeficiency (CVID). After CVID had developed, anti-double-stranded DNA antibodies disappeared, although antinuclear antibodies remained positive for >10 years. In vitro studies revealed that the patients B cells proliferated poorly and failed to differentiate into plasmablasts after stimulation of either TLR-9 or TLR-7, providing evidence for an acquired defect of the signaling pathway downstream of these TLRs. These observations suggest, although indirectly, that signaling through TLR-9 and TLR-7 is important in the pathogenesis of human SLE, and indicate that investigation of potential treatment strategies with TLR antagonists is warranted.

Recent advances in pathophysiology and biomarkers of sepsis-induced acute kidney injury

Sepsis is a complex clinical syndrome characterized by a systemic inflammatory response to an infective insult. This process often leads to widespread tissue injury and multiple organ dysfunction. In particular, the development of acute kidney injury (AKI) is one of the most frequent complications, which increases the complexity and cost of care, and is an independent risk factor for mortality. Previous suggestions highlighting systemic hypotension, renal vasoconstriction and ischaemia-reperfusion injury as the primary pathophysiological mechanisms involved in sepsis-induced AKI have been challenged. Recently it has been shown that sepsis-induced AKI occurs in the setting of microvascular dysfunction with release of microparticles, inflammation and energetic adaptation of highly metabolic organs to cellular stress. The intolerable high mortality rate associated with sepsis-induced AKI is partially explained by an incomplete understanding of its pathophysiology and a delay in diagnosis. The aim of this review is to focus on advances in understanding the sepsis pathophysiology, with particular attention to the fundamental mechanisms of sepsis-induced AKI and the potential diagnostic and prognostic markers involved.

Model for end-stage liver disease score versus simplified acute physiology score criteria in acute renal failure after liver transplantation

Hepatic function and renal failure are closely related among patients with end-stage liver disease (ESLD) due to splanchnic hemodynamic mechanisms that characterize advanced decompensated cirrhosis. Acute renal failure (ARF) is a frequent complication that occurs immediately post-orthotopic liver transplantation (OLT). The Model for End-stage Liver Disease (MELD) score describes the survival of patients with ESLD awaiting OLT related to the severity of liver disease. The Simplified Acute Physiology Score (SAPS II) is a mortality prediction model that scores the severity of illness among intensive care unit patients. In a previous study we observed an association between ARF post-OLT and a higher MELD score, but it was not clear whether this association depends on the grade of ESLD or on the critical condition of liver transplant patients. The aim of this study was to evaluate the association of ARF with MELD score and/or SAPS II criteria among liver transplant patients. We analyzed 46 patients with ESLD who underwent deceased donor OLT. All patients were evaluated at baseline and in the first 7 days post-OLT. According to the RIFLE classification, the incidence of the worst grade of ARF post-OLT was 19.2%. These patients showed significantly higher MELD scores, while there was no association with systemic parameters related to the critical patients condition or with the mortality score as evaluated by SAPS II criteria. We confirmed the association between renal failure and hepatic function among liver transplant patients. A more severe degree of hepatic dysfunction before OLT was associated with a greater incidence of ARF that can adversely affect patient survival.

Meaning of early polyomavirus-BK replication post kidney transplant.

Polyomavirus BK (BKV) infection is ubiquitous in the human population. Under immunosuppression, BKV can undergo reactivation resulting in viral replication. What really happens in the early hours posttransplantation is not clearly defined; the meaning of early viremia and viruria is not clear. BKV viremia is considered a marker of infection. The aim of our study was to investigate the prevalence of early BKV infection in kidney transplant patients, to evaluate the relationship to infections at 3 and 6 months and the association with recipient, donor, and graft features. We enrolled 36 kidney transplanted patients from May 2006 to April 2007. BKV load was measured on plasma and urine samples by Q-PCR at 12 hours (T(0)/early) as well as 3 (T(3)) and 6 (T(6)) months thereafter. A high percentage of BKV infections were detectable in the first hours after transplantation (33.3%), which remained unchanged to month 6 post transplantation. Moreover, patients who were positive at T(0) had a high probability of remaining positive thereafter. The number of copies in plasma samples tended to increase at 3 months and to decrease thereafter, whereas the urine viral load tended to steadily increase. Among BKV-positive patients, we identified 2 groups according to viremic state at T(0): 9 patients (group A); who were already positive and remained so to T(6) 5 and 3 patients who turned positive at 3 or at 6 months, respectively (group B). Group A included 75% of positive patients at T(0) and 90% of positive patients at either T(3) or T(6) (P = .007). The most important contribution of our study was to highlight the presence of BKV infection in renal transplant recipients from the first hours posttransplantation. This condition seemed to be the most important risk factor for persistent infection in the first 6 months.

Acute Renal Failure in Liver Transplant Recipients: Role of Pretransplantation Renal Function and 1-Year Follow-Up

Chronic renal failure and acute renal failure (CRF and ARF) are common complications after orthotopic liver transplantation (OLT) that adversely affect patient survival. Many factors influence the development of ARF in the OLT setting. In a previous study we reported an association between ARF and the development of CRF at 1 month after OLT. The aims of our study were to evaluate the influence of ARF on short-, middle-, and long-term renal function after OLT and its influence on 1-year survival of patients and grafts. Fourty-four patients who underwent deceased donor OLT between August 2008 and August 2010 were evaluated pretransplantation, in the perioperative period, and at 1, 6, and 12 months posttransplantation. ARF was associated with CRF at 1 month post-OLT, whereas no association was observed at 6 and 12 months post-OLT. The development of CRF at 6 months post-OLT was associated with pre-OLT renal dysfunction and 1 month post-OLT CRF. Four patients died in the ARF group, whereas 3 patients died in the group without ARF. We confirmed ARF to be a predictive event for short-term renal dysfunction. The majority of patients recovered renal function after the first month. Although many pre-, peri-, and post-OLT factors may contribute to the development of posttransplantation CRF, pre-OLT CRF seemed to be the most important risk factor.

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.