Clinical impact of bacterial contamination of perfusion fluid in kidney transplantation.

Contamination of perfusion fluid (PF) could lead to serious infections in kidney transplant recipients. Preemptive therapy (PE-T) in case of yeast contamination of PF is mandatory. The usefulness of PE-T in presence of bacteria remains unclear. In this study we evaluated the incidence of PF bacterial contamination and the impact of PE-T on clinical outcome. Microbiological data of 290 PF and clinical data of the corresponding recipients collected in our hospital from January 2010 and December 2012 were analyzed. Recipients with bacterial contaminated PF (101) were divided in 3 groups: group 1 (n = 52) PE-T treated bacteria resistant to perioperative antibiotic prophylaxis (PAP), group 2 (n = 28) bacteria sensitive to PAP, group 3 (n = 21) PE-T-untreated bacteria resistant to PAP. Incidence of positive PF was 34.8 %, 50.4 % staphylococci, 9.9 % C. albicans. No significant differences in the rate of PF-related infections between the three groups were found. In conclusion, although PF contamination is frequent, the incidence of PF-related infections is very low. In addition, in this study PE-T did not help to reduce the rate of PF-related infection suggesting that a resonable reduction in the use of antibiotic terapy could be made. However, waiting for largest and prospective clinical trials to confirm our findings, a closely clinical and microbiologic monitoring of the recipient is highly recommended in case of PF contamination.

Cat-Scratch Disease: Case Report and Review of the Literature.

Cat-scratch disease (CSD) is caused by Bartonella henselae and characterized by self-limited fever and granulomatous lymphadenopathy. In some cases signs of a visceral, neurologic, and ocular involvement can also be encountered. In this report we describe the development of CSD in a kidney transplant patient. Immunocompromised hosts are more susceptible to infection from Bartonella compared with the standard population. Infection of Bartonella should be considered as a differential diagnosis in kidney transplant patients with lymphadenopathy of unknown origin.

Assessment of platelet function analyzer (PFA-100) in kidney transplant patients before renal allograft biopsy: a retrospective single-center analysis.

BACKGROUND: Kidney biopsy (KB) represents the criterion standard to obtain information on diagnosis and prognosis of renal allograft dysfunctions. However, it can be associated with bleeding complications (BCs). Bleeding time test (BTT), the best predictive indicator of post-biopsy BCs, is not a very reproducible test and is invasive. Therefore, the aim of this study was to evaluate whether the platelet function analyzer (PFA-100), a very reliable test to investigate primary hemostasis, could be useful in predicting the risk of bleeding complications in transplant patients undergoing KB. METHODS: We carried out a retrospective analysis of PFA-100 collagen-epinephrine (C-EPI) and collagen-adenosine diphosphate (C-ADP) closure times in 119 patients undergoing KB in our center. Data regarding BTT, age, sex, blood pressure, number of renal allograft punctures for each biopsy procedure, thromboplastin time, prothrombin time, complete blood count, and prophylactic therapy with desmopressin were also collected. Major (need for blood transfusion) or minor (no need for any intervention) BCs (hematoma and hematuria) were recorded. RESULTS: Indications for KB were: delayed graft function (n=23), allograft dysfunction (n=40), proteinuria (n=27), allograft dysfunction plus proteinuria (n=19), and protocol biopsy (n=10). Nine of the 119 patients (7.5%) developed minor BCs (6 macrohematuria, 3 hematoma), major BCs did not develop. No significant differences were found in any of the clinical and laboratory data, including BTT and PFA-100 (C-EPI and C-ADP) between patients who developed BCs compared with those who did not. In addition, there was no correlation between PFA-100 test (C-EPI and C-ADP) values and BTT data [R2=0.002; P=.6]. CONCLUSIONS: The PFA-100 test was not useful in predicting the risk of BCs in kidney transplant patients undergoing renal allograft biopsy.

A case report of AA amyloidosis associated with familial periodic fever syndrome diagnosed after kidney transplantation: never say never.

Recurrent or "de novo" AA amyloidosis in the renal allograft is rarely described. We describe a case of severe nephrotic syndrome in a recipient of a kidney graft with a previous diagnosis of polycystic nephropathy caused by AA amyloidosis diagnosed only after the renal transplantation. The disease was possibly a tumor necrosis factor receptor-associated periodic syndrome (TRAPS). TRAPS is a rare hereditary inflammatory disease never reported to the best of our knowledge, as a de novo diagnosis in the transplantation setting. Biopsy of the renal graft, indicated for the onset of heavy proteinuria, and genetic investigation provided the clues for diagnosis.

A newly identified mutation in the complement factor I gene not associated with early post-transplant recurrence of atypical hemolytic-uremic syndrome: a case report.

Atypical hemolytic uremic syndrome (aHUS), which can recur after renal transplantation, is associated with poor graft outcomes. The underlying genetic defect, namely, mutations in genes coding for the complement factor H, I (CFI), or membrane cofactor protein, greatly impacts the risk of aHUS recurrence. We report here the case of a patient with chronic renal failure due to aHUS in which screening for complement mutations, performed before wait-listing for kidney transplantation, showed a never described previously heterozygous mutation in the exon II of the CFI gene. Specifically, this mutation leads to a substitution of cytosine for guanosine at nucleotide 148, resulting in the change at amino acid 50 from arginine to proline. Subsequently, he received a renal allograft from deceased donor. Good graft function was established immediately, without clinical features of aHUS. Due to a lack of data on this mutation, we avoided prophylactic treatment for aHUS but closely monitored biochemical markers of aHUS to treat a possible recurrence. Immunosuppressive treatment was based on basiliximab, tacrolimus, steroids, and mycophenolic acid. At the time of discharge the serum creatinine was 1.4 mg/dL. Ten months after transplantation the patient is doing well without evidence of aHUS. Our case suggested that a heterozygous mutation in exon II of the CFI gene was not associated with a risk of early post-transplant aHUs recurrence adding new knowledge on complement mutations implicated in aHUS post-transplant recurrences.

Endothelial progenitor cell-derived microvesicles improve neovascularization in a murine model of hindlimb ischemia.

Paracrine mediators released from endothelial progenitor cells (EPCs) have been implicated in neoangiogenesis following ischemia. Recently, we demonstrated that microvesicles (MVs) derived from EPCs are able to activate an angiogenic program in quiescent endothelial cells by a horizontal transfer of RNA. In this study we aim to investigate whether EPC-derived MVs are able to induce neoangiogenesis and to enhance recovery in a murine model of hindlimb ischemia. Hindlimb ischemia was induced in severe combined immunodeficient (SCID) mice by ligation and resection of the left femoral artery and mice were treated with EPC-derived MVs (MVs), RNase-inactivated MVs (RnaseMVs), fibroblast-derived MVs or vehicle alone as control (CTL). Since MVs contained the angiogenic miR-126 and miR-296, we evaluated whether microRNAs may account for the angiogenic activities by treating mice with MVs obtained from DICER-knock-down EPC (DICER-MVs). The limb perfusion evaluated by laserdoppler analysis demonstrated that MVs significantly enhanced perfusion in respect to CTL (0.50±0.08 vs 0.39±0.03, p<0.05). After 7 days, immunohistochemical analyses on the gastrocnemius muscle of the ischemic hindlimb showed that MVs but not fibroblast-MVs significantly increased the capillary density in respect to CTL (MVs vs CTL: 24.7±10.3 vs 13.5±6, p<0.0001) and (fibroblast-MVs vs CTL: 10.2±3.4 vs 13.5±6, ns); RNaseMVs and DICER-MVs significantly reduced the effect of MVs (RNaseMVs vs CTL: 15.7±4.1 vs 13.5±6, ns) (MVs vs DICER-MVs 24.7±10.3 vs 18.1±5.8, p <0.05), suggesting a role of RNAs shuttled by MVs. Morphometric analysis confirmed that MVs enhanced limb perfusion and reduced injury. The results of the present study indicate that treatment with EPC-derived MVs improves neovascularization and favors regeneration in severe hindlimb ischemia induced in SCID mice. This suggests a possible use of EPCs-derived MVs for treatment of peripheral arterial disease.

Hepatocyte growth factor/scatter factor released during peritonitis is active on mesothelial cells.

Peritonitis causes mesothelial detachment that may result in persistent peritoneal denudation and fibrosis. We investigated whether hepatocyte growth factor (HGF), a scatter factor that induces detachment from substrate and fibroblastic transformation of several cell types, is produced during peritonitis and is active on mesothelial cells. We studied 18 patients on peritoneal dialysis, 9 uncomplicated, 9 with peritonitis. HGF was measured in serum, peritoneal fluid, and supernatant of peripheral blood mononuclear cells and peritoneal mononuclear cells. Primary culture of human peritoneal mesothelial cells and the human mesothelial cell line MeT-5A were conditioned with recombinant HGF, serum, and peritoneal fluid. HGF levels were significantly higher in serum and peritoneal fluid of peritonitic than uncomplicated patients. Mononuclear cells of peritonitic patients produced more HGF than cells of uncomplicated patients. Recombinant HGF, serum, and peritoneal fluid of peritonitic patients caused mesothelial cell growth, detachment, transformation from epithelial to fibroblast-like shape, overexpression of vimentin, and synthesis of type I and III collagen. In conclusion, HGF released during peritonitis causes a change in mesothelial cell phenotype and function. HGF may affect the healing process facilitating repair through mesothelial cell growth, but may contribute to peritoneal fibrosis inducing cell detachment with mesothelial denudation and collagen synthesis.

Hemodialysis prevents liver disease caused by hepatitis C virus: role of hepatocyte growth factor.

UNLABELLED: Hemodialysis prevents liver disease caused by hepatitis C virus: Role of hepatocyte growth factor. BACKGROUND: Hemodialysis increases markedly the serum levels of hepatocyte growth factor (HGF) so that regular dialysis treatment (RDT) mimics the regular administration of HGF as a drug. Therefore, we have studied the effects of dialysis-associated HGF production on the severity of liver damage caused by hepatitis C virus (HCV). METHODS: Biochemical tests of liver function and liver biopsy were performed in 10 patients on RDT and in 11 patients without renal disease (WRD) converted to anti-HCV serum-positive test for the same time (48 +/- 4 months). The HGF serum concentration was measured by enzyme immunoassay. In patients on RDT, HGF was measured just before starting a dialysis session (T0), at 15 and 240 minutes of dialysis (T15 and T240), and 24 hours later (T24 hr). RESULTS: Serum HGF was similar in WRD (average 0.17 ng/ml) as in RDT at T0 (0.25 ng/ml). In RDT serum HGF increased markedly at T15 and T240 (5.51 and 2.67 ng/ml, respectively, P < 0. 001 vs. WRD and T0) and was still higher than baseline at T24 hr (0. 41 ng/ml, P < 0.05). Both grade of necroinflammatory activity and stage of fibrosis were significantly lower in RDT than in WRD (both, P < 0.001). The number of apoptotic hepatocytes was also significantly reduced in patients on RDT compared with patients WRD. CONCLUSION: These results show that HCV-related liver disease is more benign in patients on RDT. The phenomenon may depend on the marked and prolonged HGF release caused by dialysis.

Hemodialysis stimulates hepatocyte growth factor release.

Studies were performed in 26 patients on regular dialysis treatment with cuprophane (CU), polymethylmetacrilate (PMMA) or cuprammonium (CAM) dialyzers. Controls were six patients with chronic renal failure but not on regular dialysis treatment (CRF) and six healthy subjects (N). Blood was collected at the start (T0), and at 15 (T15) and 240 (T240) minutes of dialysis to measure the serum hepatocyte growth factor (HGF) concentration and to study HGF production by peripheral blood mononuclear cells (PBMC) in vitro. The form of HGF (that is, inactive/monomeric, active/dimeric) present in the serum was analyzed by immunoblotting. In addition, the ability of serum to stimulate proliferation of tubular cells (HK-2) and HGF release by PBMC and fibroblasts (MRC-5) was investigated. At T0, serum HGF levels were identical to that of the controls. In patients treated with CU, serum HGF rose from 0.24 ng/ml at T0 to 7.44 ng/ml at T15, and remained high at T240. PBMC collected at T15 and T240 released significantly more HGF in vitro than those collected at T0. Serum at T15 stimulated proliferation of HK-2 cells and the release of HGF by PBMC and MRC-5 cells. The PMMA and CAM dialyzers had similar effects as the CU. These results indicate that dialysis induces a striking rise in serum HGF and a prompt circulation of factor(s) stimulating HGF release. Dialysis-activated PBMC release HGF.