Eleonora Francesca Pattonieri

The role of therapeutic drug monitoring in the treatment of cytomegalovirus disease in kidney transplantation

Cytomegalovirus (CMV) infection is a common complication following solid organ transplantation that may severely affect the outcome of transplantation. Ganciclovir (GCV) and its prodrug valganciclovir are successfully used to prevent and treat CMV infection; however, in a small percentage of patients, CMV gene mutations may lead to drug resistance. GCV resistance is defined as increasing CMV viremia or progressive clinical disease during prolonged antiviral therapy, due to CMV gene mutation. This has emerged as a new challenge, especially because alternative drugs such as cidofovir and foscarnet have a number of important side effects. Here we report the case of a kidney transplanted patient who experienced life-threatening CMV disease, which initially appeared to be GCV-resistant, but was instead found to be associated with inadequate antiviral drug levels. The patient was then successfully treated by monitoring plasma GCV levels. We suggest using plasma GCV monitoring in the management of all cases of critical CMV disease, in which GCV resistance is suspected.

Mesenchymal stromal cells reset the scatter factor system and cytokine network in experimental kidney transplantation

BackgroundIn former studies we showed in a rat model of renal transplantation that Mesenchymal Stromal Cells (MSC) prevent acute rejection in an independent way of their endowing in the graft. In this study we investigated whether MSC operate by resetting cytokine network and Scatter Factor systems, i.e. Hepatocyte Growth Factor (HGF), Macrophage Stimulating Protein (MSP) and their receptors Met and RON, respectively.MethodsMSC were injected into the renal artery soon after reperfusion. Controls were grafted untreated and normal rats. Rats were sacrificed 7 days after grafting. Serum and renal tissue levels of IFN-γ, IL-1, IL-2, IL-4, IL-6, IL-10, MSP/RON, HGF/Met systems, Treg lymphocytes were investigated.ResultsIn grafted untreated rats IFN-γ increased in serum and renal tissue and IL-6 rose in serum. MSC prevented both the phenomena, increased IL-10 serum levels and Treg number in the graft. Furthermore MSC increased serum and tissue HGF levels, Met tubular expression and prevented the suppression of tubular MSP/RON expression.ConclusionsOur results demonstrate that MSC modify cytokine network to a tolerogenic setting, they suppress Th1 cells, inactivate monocytes/macrophage, recruit Tregs. In addition, MSC sustain the expression of the Scatter Factor systems expression, i.e. systems that are committed to defend survival and stimulate regeneration of tubular cells.

Mesenchymal Stromal Cells Prevent Renal Fibrosis in a Rat Model of Unilateral Ureteral Obstruction by Suppressing the Renin-Angiotensin System via HuR

We studied Mesenchymal Stromal Cells (MSC) effects in experimental Unilateral Ureteral Obstruction (UUO), a fibrogenic renal disease. Rats were divided in 5 groups: sham, UUO, MSC treated-UUO, ACEi treated-UUO, MSC+ACEi treated- UUO. Data were collected at 1, 7, 21 days. UUO induced monocyte renal infiltration, tubular cell apoptosis, tubular atrophy, interstitial fibrosis and overexpression of TGFβ, Renin mRNA (RENmRNA), increase of Renin, Angiotensin II (AII) and aldosterone serum levels. Both lisinopril (ACEi) and MSC treatment prevented monocyte infiltration, reduced tubular cell apoptosis, renal fibrosis and TGFβ expression. Combined therapy provided a further suppression of monocyte infiltration and tubular injury. Lisinopril alone caused a rebound activation of Renin-Angiotensin System (RAS), while MSC suppressed RENmRNA and Renin synthesis and induced a decrease of AII and aldosterone serum levels. Furthermore, in in-vitro and in-vivo experiments, MSC inhibit Human antigen R (HuR) trascription, an enhancer of RENmRNA stability by IL10 release. In conclusion, we demonstrate that in UUO MSC prevent fibrosis, by decreasing HuR-dependent RENmRNA stability. Our findings give a clue to understand the molecular mechanism through which MSC may prevent fibrosis in a wide and heterogeneous number of diseases that share RAS activation as common upstream pathogenic mechanism.

Perfusion of isolated rat kidney with Mesenchymal Stromal Cells/Extracellular Vesicles prevents ischaemic injury

Kidney donation after circulatory death (DCD) is a less than ideal option to meet organ shortages. Hypothermic machine perfusion (HMP) with Belzer solution (BS) improves the viability of DCD kidneys, although the graft clinical course remains critical. Mesenchymal stromal cells (MSC) promote tissue repair by releasing extracellular vesicles (EV). We evaluated whether delivering MSC‐/MSC‐derived EV during HMP protects rat DCD kidneys from ischaemic injury and investigated the underlying pathogenic mechanisms. Warm ischaemic isolated kidneys were cold‐perfused (4 hrs) with BS, BS supplemented with MSC or EV. Renal damage was evaluated by histology and renal gene expression by microarray analysis, RT‐PCR. Malondialdehyde, lactate, LDH, glucose and pyruvate were measured in the effluent fluid. MSC‐/EV‐treated kidneys showed significantly less global ischaemic damage. In the MSC/EV groups, there was up‐regulation of three genes encoding enzymes known to improve cell energy metabolism and three genes encoding proteins involved in ion membrane transport. In the effluent fluid, lactate, LDH, MDA and glucose were significantly lower and pyruvate higher in MSC/EV kidneys as compared with BS, suggesting the larger use of energy substrates by MSC/EV kidneys. The addition of MSC/EV to BS during HMP protects the kidney from ischaemic injury by preserving the enzymatic machinery essential for cell viability and protects the kidney from reperfusion damage.

Multiple electrolyte disorders in a neurosurgical patient: solving the rebus

BackgroundIt is important to ensure an adequate sodium and volume balance in neurosurgical patients in order to avoid the worsening of brain injury.Indeed, hyponatremia and polyuria, that are frequent in this patient population, are potentially harmful, especially if not promptly recognized.Differential diagnosis is often challenging, including disorders, which, in view of similar clinical pictures, present very different pathophysiological bases, such as syndrome of inappropriate antidiuresis, cerebral/renal salt wasting syndrome and diabetes insipidus.Case presentationHere we present the clinical report of a 67-year-old man with a recent episode of acute subarachnoid haemorrhage, admitted to our ward because of severe hyponatremia, hypokalemia and huge polyuria.We performed a complete workup to identify the underlying causes of these alterations and found a complex picture of salt wasting syndrome associated to primary polydipsia. The appropriate diagnosis allowed us to correct the patient hydro-electrolyte balance.ConclusionThe comprehension of the pathophysiological mechanisms is essential to adequately recognize and treat hydro-electrolyte disorders, also solving the most complex clinical problems.

Global Performance Status Score: A New Tool to Assess Physical Performance in Kidney Transplant Patients

BACKGROUND Information on physical performance in renal transplantation is limited because of the shortage of specifically designed evaluation instruments. Therefore, we elaborated and validated the Global Performance Status (GloPerSta) score to provide a new and comprehensive tool, exploring the different components of physical performance in kidney transplant patients. METHODS We elaborated the GloPerSta score on the basis of the data obtained from a cross-sectional study, in which we evaluated the physical performance of a cohort of kidney transplant patients. The results of these analyses were weighted to describe the different contribution of any single test, via the generation of a structural equation model, resulting in the definition of the GloPerSta. Then, to internally validate this score, we studied its correlation with clinical parameters and quality of life (evaluated as KDQOL-SF, Kidney Disease Quality of Life-Short Form) in the same patient population. RESULTS We enrolled 132 patients in whom the functional tests revealed a great heterogeneity. GloPerSta allowed the stratification of the patients in 3 different physical performance categories (low: score 0-11; medium: 12-22; high: 23-33). Internal validation showed that GloPerSta was directly and significantly correlated with the quality of life and allograft function, independent of the time from transplantation. CONCLUSIONS The GloPerSta is a reliable tool to assess physical performance in a kidney transplant population. Its application might be of help in identifying patients needing intensive and personalized rehabilitation programs.

Chronic pyelonephritis: a misunderstood cause of renal allograft loss

Chronic pyelonephritis: a misunderstood cause of renal allograft loss Although urinary tract infections (UTI) are the most frequent infections in kidney transplant patients, there are no sufficient data about the prevalence of acute and chronic pyelonephritis and organ or patient survival. We present the clinical case of a young woman with a kidney transplant admitted to our Nephrology Clinic because of an acute worsening of renal function and a history of recurrent UTI. The renal biopsy showed medullary tissue with a severe tubule-interstitial damage, suggestive for acute rejection, insomuch that steroids were prescribed. Due to the lack of any clinical improvement, a second biopsy was performed, showing a histological picture of chronic pyelonephritis with a severe and advanced damage. Subsequently, because of the severe renal failure the patient underwent peritoneal dialysis and transplant nephrectomy. This clinical case is exemplificative of the possible adverse outcomes of recurrent UTI that might lead in a short time to organ failure, highlighting the importance of a definitive histologic diagnosis.