Massimo Gai

Neutrophil Gelatinase Associated Lipocalin Is an Early and Accurate Biomarker of Graft Function and Tissue Regeneration in Kidney Transplantation from Extended Criteria Donors

Background Delayed graft function (DGF) is an early complication of kidney transplantation (KT) associated with increased risk of early loss of graft function. DGF increases using kidneys from extended criteria donors (ECD). NGAL is a 25KDa protein proposed as biomarker of acute kidney injury. The aim of this study was to investigate the role of NGAL as an early and accurate indicator of DGF and Tacrolimus (Tac) toxicity and as a mediator of tissue regeneration in KT from ECD. Methods We evaluated plasma levels of NGAL in 50 KT patients from ECD in the first 4 days after surgery or after Tac introduction. Results Plasma levels of NGAL at day 1 were significantly higher in DGF group. In the non DGF group, NGAL discriminated between slow or immediate graft function and decreased more rapidly than serum creatinine. NGAL increased after Tac introduction, suggesting a role as marker of drug toxicity. In vitro, hypoxia and Tac induced NGAL release from tubular epithelial cells (TEC) favoring an autocrine loop that sustains proliferation and inhibits apoptosis (decrease of caspases and Bax/Bcl-2 ratio). Conclusions NGAL is an early and accurate biomarker of graft function in KT from ECD favoring TEC regeneration after ischemic and nephrotoxic injury.

Comparison between 24‐h proteinuria, urinary protein/creatinine ratio and dipstick test in patients with nephropathy: Patterns of proteinuria in dipstick‐negative patients

Objective. Three main tests are commonly employed for the measurement of proteinuria: the dipstick test, the urinary protein/creatinine ratio (P/C) and the 24‐h urine collection. The aim of this study was to evaluate the correlation between these methods, comparing linear regression and ROC curve data. Material and methods. A total of 297 consecutive outpatients with different renal diseases were included in the study. Twenty‐four‐hour proteinuria was considered the reference test. Results. A high degree of correlation was observed between all the tests (p<0.0001), the highest regression coefficient being between 24‐h proteinuria and P/C (R = 0.82), and the lowest between P/C and the dipstick test (R = 0.72). The dipstick test failed to detect pathological proteinuria in 94 patients (31.6 %). Therefore, in these subjects, the patterns of proteinuria were assessed by immunofixation and sodium dodecyl sulphate (SDS) electrophoresis. Conclusions. Our data strongly support the use of urinary P/C for the detection of proteinuria, at least in nephrology units, where the prevalence of proteinuria is likely to be high.

Microscopic Urinalysis and Automated Flow Cytometry in a Nephrology Laboratory

In their recent report, Ottiger and Huber (1) compared the UF-100 flow cytometer and the KOVA system and suggested an algorithm for the selection of samples for microscopic analysis. They found that urine samples from nephrology patients had higher microscopic review rates. We agree with them that automated systems foster rapid and standardized analysis of formed elements and offer significant labor savings (2)(3)(4), but we think that such a study may lead to different results in a laboratory of nephrology, where the prevalence of renal diseases and pathologic findings is higher. We collected 298 consecutive midstream urine samples from patients with known or suspected renal diseases. The samples were first examined with a Sysmex UF-50 (software version 0.5; TOA Medical Electronics) and then with a phase-contrast microscope (5), according to the European guidelines, at low (×100) and high (×400) magnification, by …

No recurrence of Kaposi's sarcoma in a case of renal retransplantation under a calcineurin inhibitor free immunosuppressive regimen: first report

Retransplantation in recipients with a previous history of post-transplant Kaposi’s sarcoma remains matter of debate. Even if a recent unique report suggests that retransplantation without recurrence is possible, the majority of authors emphasizes the high risk of relapse and therefore advices this kind of patients against retransplantation. Here we report a case of uneventful kidney retransplantation in a 31-year-old woman whose first kidney graft failed after reduction of the immunosuppressive regimen because of the onset of cutaneous and visceral Kaposi’s sarcoma. In this case, to our knowledge the first to be reported with this protocol, we adopted as immunosuppressive strategy a triple therapy with Sirolimus, Mycophenolate mofetil and steroid, with Basiliximab at induction. After 20 months the kidney function is excellent (creatinine clerance 89.3 ml/min) without evidence of Kaposi’s sarcoma recurrence. Kaposi’s sarcoma (KS) is 400-fold more frequent in kidney graft recipients than in general population with an incidence ranging from 0.5% of all renal transplants performed in Western and Northern countries to nearly 5% in the Mediterranean area. Complete remission of the cutaneous form of KS is generally achievable with reduction/discontinuation of immunosuppression with variable risk of graft failure. Indeed, if immunosuppression is reintroduced or also minimally maintained, KS generally recurs [1,2] and retransplantation is not recommended [3]. Here, we report the case of an Italian patient that lost the first kidney transplant as a consequence of the discontinuation of immunosuppression because of the onset of visceral and cutaneous KS and that has been retransplanted in our centre without recurrence of KS under an immunosuppressive regimen based on Sirolimus (SRL), Mycophenolate mofetil (MMF) and low dose of steroid. On May 1994, a 20-year-old Italian woman received a living related (father) kidney transplant for end stage renal disease caused by chronic glomerulonephritis. The initial immunosuppression consisted of Cyclosporin A (CsA) and steroid. The graft functioned immediately and attained normal serum creatinine level within 4 weeks. Thirteen months after transplantation, a biopsy of a laterocervical lymphoadenomegaly revealed the presence of KS. Endoscopy showed multiple gastric lesions as well of KS. Serology for Human Immunodeficiency Virus (HIV) type 1 and 2 and thoraco-abdominal computed tomography scan were negative. We are lacking information about Human Herpesvirus 8 (HHV8) state of both the donor and the recipient. CsA was stopped, Azathioprine was added and steroid was maintained at a lower dosage. Three months later, the graft failed for an intractable rejection. KS disappeared within 2 months from the beginning of dialysis. On February 2005, she underwent retransplantation in our centre from a HHV8 negative and CMV negative deceased donor. During the pre-transplant period (since 2000), at the moment of the surgery and after transplantation, recipient’s IgG anti-HHV8 were always positive whereas HHV8 DNA Polymerase Chain Reaction was negative. Initial immunosuppression consisted of Basiliximab, SRL 10 mg/day for 3 days tapered off on the bases of plasma levels (target plasma level 15–20 ng/ ml), MMF 1 g twice a day and prednisone 25 mg/day. Postoperative course was uneventful and renal function excellent. In the early follow up a sacral Herpes Zoster successfully treated with Acyclovir has been observed. At month 2 prednisone was tapered to 5 mg/day. From month 7, the SRL target level was 8–12 ng/ml (mean: 11.9 ± 0.5 ng/ml) and MMF was reduced to 1 g/day. At the end of follow up the regimen is SRL 2 mg/day, MMF 500 mg twice a day, and prednisone 5 mg/day. The kidney function is excellent (creatinine clearance being 89.3 ml/min). No sign of KS recurrence was observed so far. To our knowledge, only another observation of a successful retransplantation in a recipient with a previous history of KS is reported [4]. In that case a traditional triple therapy (CsA, Azathioprine and prednisone) was used. So far, this is the first report under SRL regimen. SRL is a relatively new immunosuppressant with a wellknown antitumoral activity both in vitro [5] and in vivo [6]. Recent experiences have demonstrated that SRL in

Low-protein vegetarian diet with alpha-chetoanalogues prior to pre-emptive pancreas-kidney transplantation.

BACKGROUND Pre-emptive pancreas-kidney transplantation is increasingly considered the best therapy for irreversible chronic kidney disease (CKD) in type 1 diabetics. However, the best approach in the wait for transplantation has not yet been defined. AIM To evaluate our experience with a low-protein (0.6 g/kg/day) vegetarian diet supplemented with alpha-chetoanalogues in type 1 diabetic patients in the wait for pancreas-kidney transplantation. METHODS Prospective study. Information on the progression of renal disease, compliance, metabolic control, reasons for choice and for drop-out were recorded prospectively; the data for the subset of patients who underwent the diet while awaiting a pancreas-kidney graft are analysed in this report. RESULTS From November 1998 to April 2004, 9 type 1 diabetic patients, wait-listed or performing tests for wait-listing for pancreas-kidney transplantation, started the diet. All of them were followed by nephrologists and diabetologists, in the context of integrated care. There were 4 males and 5 females; median age 38 years (range 27.9-45.5); median diabetes duration 23.8 years (range 16.6-33.1), 8/9 with widespread organ damage; median creatinine at the start of the diet: 3.2 mg/dl (1.2-7.2); 4 patients followed the diet to transplantation, 2 are presently on the diet, 2 dropped out and started dialysis after a few months, 1 started dialysis (rescue treatment). The nutritional status remained stable, glycemia control improved in 4 patients in the short term and in 2 in the long term, no hyperkalemia, acidosis or other relevant side effect was recorded. Proteinuria decreased in 5 cases, in 3 from the nephrotic range. Albumin levels remained stable; the progression rate was a loss of 0.47 ml/min of creatinine clearance per month (ranging from an increase of 0.06 to a decrease of 2.4 ml/min) during the diet period (estimated by the Cockroft-Gault formula). CONCLUSIONS Low-protein supplemented vegetarian diets may be a useful tool to slow CKD progression whilst awaiting pancreas-kidney transplantation.

The grafted kidney takes over: disappearance of the nephrotic syndrome after preemptive pancreas-kidney and kidney transplantation in diabetic nephropathy

This report describes the rapid and complete reversal of proteinuria after preemptive transplantation in diabetic nephropathy. Case 1 was a 42-year-old woman with type 1 diabetes (before pancreas-kidney graft: serum creatinine 1.6 mg/dL and proteinuria 9.1 g/day; 1 month after pancreas-kidney graft: proteinuria 0.3 g/day and creatinine 1.3 mg/dL). Case 2 was a 48-year-old man with type 2 diabetes (before kidney graft: creatinine 2 mg/dL and proteinuria 5.9 g/day; 1 month after: proteinuria 0.7 g/day and creatinine 1.1 mg/dL). The proteinuria pattern changed (pre: glomerular nonselective, tubular complete; post: physiologic). Renal scintiscan (99mTC-MAG3) demonstrated functional exclusion of the native kidneys, despite high pretransplant clearance (> 50 mL/min). The effect was not linked to euglycemia or readily explainable by pharmacologic effects (no difference in renal parameters after pancreas transplantation with the same protocols). These data confirm the efficacy of preemptive kidney and kidney-pancreas transplantation in diabetic nephrotic syndrome and indicate that a regulatory hemodynamic effect should be investigated.

Daily dialysis Kt/V and flexible schedules: is it possible to control efficiency, when and how?

Background Daily hemodialysis is a promising treatment schedule but uniform criteria for defining efficiency are lacking. Methods On our daily dialysis (DD) schedule, duration is flexible (2–3 hours, patients are free to add up to 30min/session), Qb 250–350 mL/min; dialyser 1.6–1.8 m2. Study was performed on 12 pts on DD for ≥2 months, with ≥4 Kt/V on subsequent days, tested in the same laboratory. Goal: To evaluate variability and identify a simple method for weekly calculation, Kt/V was assessed for 133 sessions. Results On flexible DD, variability of Kt/V-session is high (relative error 4.9%-22%). On flexible schedules, within the time range chosen (2–3 hours) variability of average hourly Kt/V is lower (standard deviation: min (0.014; max (0.052 hour, relative error 4.9%-10%) allowing calculation of weekly Kt/V (averaging 3 sessions: relative error <6%) suitable for clinical practice. Conclusions Flexible schedules, allowing patients to increase treatment time, are an interesting clinical option, but a challenge for Kt/V assessment.

A Simple Method for the Classification of Proteinuria

We read with interest the paper of Bergon et al. about the classification of renal proteinuria (1) and we agree with the authors that in the presence of proteinuria or diagnosed nephropathy it is indispensable to measure protein excretion rate in a 24-hour urine collection using a dye-binding assay with pyrogallol-red (2, 3). Otherwise, in our experience a correct evaluation of proteinuria typing is a correct and feasible method that leads to a better standardization of the results. Furthermore, the assessment in mid-stream morning second urine samples by a nephelometric analysis of urinary proteins, using urinary protein/creatinine ratios allows a reduction of pre-analytical errors linked to urine time collection and to possible protein digestion by proteases action in 24-hour-stored urine (4). Recent studies shed new light into the physiopathlogical mechanisms of urinary protein excretion: thus, in our opinion a correct method of classification of proteinuria must distinguish not only between glomerular and tubular proteinuria but, in a better way, between selective glomerular proteinuria (presence of albumin and transferrin) and not selective glomerular proteinuria (presence of proteins with MW >100 kDa), and also between incomplete tubular proteinuria (presence of proteins with MW <50 kDa) and complete tubular proteinuria (presence of proteins with MW <23 kDa) (5). Data obtained showed that complete tubular proteinuria was an index of stronger tubular pathological involvement often associated to higher levels of serum creatinine and to a worse outcome (6). In our laboratory we developed an immunofixation method using specific polyclonal antisera, for qualitative/semi-quantitative analysis of urinary proteins (retinol-binding protein: RBP; α1-microglobulin: α1m; albumin; transferrin; immunoglobulin G: IgG and α2-macroglobulin: α2m), allowing a better definition of selectivity of glomerular proteinuria and of complete or incomplete tubular proteinuria (CSI-Nefro Cinque, BIOCI, Turin, Italy) (7). The CSI (Cross Star Immunofixation) method is a gel-immunoprecipitation, characterized by a high analytical sensitivity. This is due to the characteristics of the gel itself, to the mono-specificity of the antisera and to the new type of cross-deposition of the samples and

Secondary Hyperparathyrodism in Adult Predialysis and Dialysis Patients

Following the recommendations in the Kidney Disease Improved Global Outcome (KDIGO) clinical guidelines [1], the mineral and clinical disorders related to the impact of declining renal function on calcium-phosphorus homeostasis, previously known as “renal osteodystrophy”, are today, more appropriately, renamed as chronic kidney disease-mineral and bone disorders (CKD-MBD).

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.