Amado Andrés

Sirolimus does not exhibit nephrotoxicity compared to cyclosporine in renal transplant recipients.

Sirolimus and cyclosporine (CsA) prevent acute rejection in man when used as primary therapies in triple drug regimens. Sirolimus does not act via the calcineurin pathway and therefore is not expected to produce the same renal side‐effects. This paper presents the pooled 2‐year data analysis of renal function parameters from two open‐label, randomized, multicenter studies. Patients (18–68 years) receiving a primary renal allograft were randomized to receive concentration‐controlled sirolimus (n = 81) or CsA (n = 80), in combination with azathioprine and steroids (n = 83), or mycophenolate mofetil (MMF) and steroids (n = 78). From week 10 through year 2, calculated glomerular filtration rate (GFR) was significantly higher in sirolimus‐ than in CsA‐treated patients (69.3 vs. 56.8 mL/min, at 2 years, p = 0.004). Serum uric acid was significantly higher in the CsA‐treated patients and magnesium was significantly lower; these parameters were more likely to be within normal limits in the sirolimus group. Mean serum potassium and phosphorus were lower in sirolimus‐treated patients. In conclusion, sirolimus, when administered as primary therapy in combination with azathioprine or MMF, has a favorable safety profile compared to CsA with regards to renal function.

Effects of body-weight loss and captopril treatment on proteinuria associated with obesity.

We have identified 17 obese patients (body mass index, BMI, 37.9 +/- 4.1) with proteinuria > 1 g/day (1.3-6.4 g/24 h, mean 3.1 +/- 1.7). Their age was 34-70 years (48.3 +/- 10); 11 were females and 6 males. Six patients had only one functioning kidney and a sleep apnea syndrome had been diagnosed in 5. Renal biopsies, obtained in 5 cases, showed focal glomerulosclerosis in 2 cases, minimal changes in 2 and mesangial proliferation in 1. Nine patients (group 1) were treated with hypocaloric diets; body weight significantly decreased (BMI 37.1 +/- 3, 34 +/- 3.5 and 32.6 +/- 3.2 at 0, 6 and 12 months, respectively) as well as proteinuria (2.9 +/- 1.7, 1.2 +/- 1 and 0.4 +/- 0.6 g/24 h). There was a significant correlation between body weight loss and decrease in proteinuria (r = 0.69, p < 0.05). Eight patients (group 2) were treated with captopril, without dietary changes. BMI remained stable but proteinuria showed a dramatic decrease, similar to that in group 1 (3.4 +/- 1.7, 1.2 +/- 0.9 and 0.7 +/- 1 g/24 h, respectively). Renal function remained stable in both groups. In summary, both body weight loss and captopril treatment can induce a sharp decrease in obesity-related proteinuria.

Long-Term Beneficial Effects of Angiotensin-Converting Enzyme Inhibition in Patients With Nephrotic Proteinuria

Angiotensin-converting enzyme inhibitors (ACEI) can reduce proteinuria in diabetic and nondiabetic nephropathy. However, no studies have determined whether this antiproteinuric effect modifies the progression of renal insufficiency. We studied the evolution of 46 nondiabetic patients with nephrotic proteinuria treated with captopril for a minimum of 12 months. The follow-up period before captopril treatment was 12 to 18 months. At the end of follow-up, after captopril introduction (24.4 +/- 7.6 months), proteinuria had decreased from 6.3 +/- 2.5 to 3.9 +/- 3.1 g/24 h (P less than 0.001), with a mean decrease of 45% +/- 28%. The proteinuria decrease was higher in patients with reflux nephropathy, proteinuria associated with reduction of renal mass, inactive crescentic glomerulonephritis, nephroangiosclerosis, and IgA nephropathy, whereas patients with membranous glomerulonephritis and idiopathic focal glomerulosclerosis showed a poorer response. Patients were separated according to a proteinuria reduction greater (group A, 23 patients) or lower (group B, 23 patients) than 45% of the initial value. At the end of follow-up, renal function had not significantly changed in group A with respect to values at the start of treatment: serum creatinine (SCr) was 229 +/- 167 mumol/L (2.6 +/- 1.9 mg/dL) versus 203 +/- 97 mumol/L (2.3 +/- 1.1 mg/dL), and creatinine clearance (CrCl) was 0.80 +/- 0.52 mL/s (48 +/- 31 mL/min) versus 0.87 +/- 0.47 mL/s (52 +/- 28 mL/min). The slope of the reciprocal of Scr (1/SCr) showed a significantly beneficial change after captopril introduction.(ABSTRACT TRUNCATED AT 250 WORDS)

Membranous glomerulonephritis associated with hepatitis C virus infection in renal transplant patients

BACKGROUND Hepatitis C virus (HCV) infection has been described in association with various types of glomerular diseases, usually type I membranoproliferative glomerulonephritis and rarely membranous glomerulonephritis (MGN). In this article, we describe the first series of MGN exhibited in renal transplant patients and associated with HCV infection. METHODS From January 1980 to December 1994, 2045 kidney transplantations were performed in our renal transplant units. A retrospective analysis demonstrated an overall 20% prevalence of HCV virus-positive patients; 409 transplanted patients were HCV positive (ELISA and RIBA). RESULTS Fifteen patients developed an allograft MGN (3.66%) 24 months after renal transplantation. MGN appeared in the form of significant proteinuria (>1.5 g/24 h) with stable renal function. In all cases, graft biopsy demonstrated a thickening of the capillary wall, subepithelial electron-dense deposits, and IgG and C3 diffuse granular deposits along the basal membrane. Ten cases were considered de novo, two cases were considered recurrent MGN, and three cases were considered undetermined because the primary renal disease was chronic glomerulonephritis. All patients showed negative antinuclear antibodies and cryoglobulins, normal complement, and negative rheumatoid factors. During follow-up (an average of 2 years), 12 patients developed a progressive worsening of renal function, with increased serum creatinine and persistent proteinuria; 8 of the 12 patients returned to dialysis. Of the remaining three cases, two patients showed partial remission of nephrotic syndrome after high doses of steroids, and one patient persisted with stable renal function and proteinuria (<2 g/24 h.). CONCLUSIONS In summary, HCV is preferentially associated with MGN in renal transplant patients, rather than with membranoproliferative glomerulonephritis as in the normal adult population. MGN associated with HCV infection has a similar clinical picture and outcome to posttransplant idiopathic de novo MGN, with persistent massive proteinuria and progressive deterioration of renal function.

Double versus single renal allografts from aged donors

BACKGROUND The age limit of the cadaver kidney donors is increasing in response to the growing demand for renal transplantation. Simultaneous double kidney transplantation (SDKT) with kidneys obtained from elderly adults has been proposed to increase the transplantation number and improve its results. However, if SDKT is performed when there are no clear indications, a negative effect could be produced on the total number of transplanted patients as both kidneys would be used for only one recipient. MATERIAL AND METHODS In December 1996 we designed a transplantation protocol to be able to extend the selection of cadaver kidney donors with normal serum creatinine levels without establishing any age limit. A pregraft renal biopsy was always performed to analyze the glomerulosclerosis (GE) percentage whenever the donors were 60 years of age or older. A SDKT was performed in a single recipient when the donor age was 75 years or older or when the donors between 60 and 74 years old had a GE rate of more than 15%. On the contrary, a single kidney transplantation was performed in two different recipients for kidneys from donors between 60 and 74 years of age with a GE rate of less than 15%. Kidneys having GE rates of more than 50% were discarded for transplantation. Donor kidneys from subjects younger than 60 years of age were always used for a single kidney transplantation. RESULTS Based on the above mentioned protocol, from December 1996 to May 1998, 181 patients received a kidney transplantation in our hospital. These patients were divided into three groups: group I which included the SDKT recipients (n=21), group II or single kidney recipients from 60- to 74-year-old donors (n=40), and group III or recipients from <60-year-old donors (n=120). The mean follow-up time was 15+/-5 months (range 6-24). Mean donor age was 75+/-7 years in group I, this was significantly higher than in group II (67+/-4, P<0.001) and group III (37+/-15, P<0.001). The primary nonfunction rate was low in the three groups, there being no statistically significant differences (5, 5, and 4%, respectively). A significantly greater percentage of patients from group I (76%) presented immediate renal graft function as compared with group II (43%, P<0.01) and III (50%, P<0.05). The acute rejections rate was very low in all three groups (9.5, 7.5, and 22%, respectively) with significant differences between groups II and III (P<0.05). No significant differences between the different groups were observed for one year actuarial patient survival (100, 95, and 98%, respectively) or graft survival rates (95, 90, and 93%, respectively). The 6-month serum creatinine levels were excellent in the three groups, although there were significant differences between groups I and II (1.6+/-0.3 vs. 1.9+/-0.6 mg/dl, P<0.05), II and III (1.9+/-0.6 vs. 1.4+/-0.4 mg/dl, P<0.001), and I and III (P<0.05). CONCLUSIONS Simultaneous double kidney transplantations make it possible to use kidneys from extremely elderly donors (>75 years) or those whose GE>15%. In addition, kidneys from donor 60-74 years old in which the GE<15% can be used for single kidney transplantations in two different recipients with excellent results.

Clinical Significance of Donor-Unrecognized Bacteremia in the Outcome of Solid-Organ Transplant Recipients

We evaluated the clinical significance of unrecognized bacteremia in the organ donor (i.e., blood culture results that were reported to be positive after transplantation) on the outcome of transplant recipients. Twenty-nine of 569 liver and heart donors (5%) had bacteremia at the time of organ procurement, but there were no documented instances of transmission of the isolated bacteria from the donor to the recipient. Unrecognized bacteremia in the donor does not have a negative clinical impact on the outcome of organ transplant recipients.

Systematic screening and treatment of asymptomatic bacteriuria in renal transplant recipients

We sought to examine the impact of asymptomatic bacteriuria on renal transplant outcome by retrospectively analyzing 189 renal transplant recipients for whom systematic screening uncovered 298 episodes of asymptomatic bacteriuria in 96 recipients. These patients were treated and all were followed for 36 months. Significant risk factors included female gender, glomerulonephritis as the disease that led to transplantation, and double renal transplant. There were no differences in serum creatinine, creatinine clearance, or proteinuria between patients with and without bacteriuria. The incidence of pyelonephritis in these patients was 7.6 episodes per 100 patient-years compared with 1.07 in those without asymptomatic bacteriuria. Between two to five and more than five bacteriuria episodes were significant independent factors associated with pyelonephritis whereas more than five episodes was a significant independent factor associated with rejection. Thus, we found no differences in renal function prognosis between patients who do not develop asymptomatic bacteriuria and those uncovered by systematic screening and who received treatment following kidney transplantation. Despite this treatment, the incidence of pyelonephritis was much higher in the group of patients with detected asymptomatic bacteriuria.

Successful treatment of mucor infection after liver or pancreas-kidney transplantation.

BACKGROUND Mucormycosis is a rare and opportunistic infection usually associated with hematologic diseases, diabetes mellitus, renal failure, solid tumors, and organ transplantation. METHODS We present five cases of mucor infection after transplantation (three after a series of 750 orthotopic liver transplantation and two after a series of 13 simultaneous pancreas-kidney transplantation in patients with type 1 diabetes) subjected to medical and surgical treatment and analyze the factors related to the development of this infection. RESULTS The clinical forms were two cutaneous (laparotomy wound or prior surgical drain site), two rhino-maxillary, and one pulmonary. As risk factors for mucormycosis all patients had pre- or posttransplantation diabetes, and showed at least one episode of acute rejection that required aggressive immunosuppression (2-7 g of methylprednisolone; also three patients were treated with antithymocyte globulin [ATG] monoclonal antibody [orthoclone and/or OKT3]). We also found renal failure, acidosis, malnutrition, and Candida and cytomegalovirus infections as factors related to mucor infection. Diagnosis of fungal infection was confirmed by exudate or fluid culture in three cases and by biopsy in two. All patients were treated with liposomal amphotericin B (from 3.5 to 5.6 g of total dose) and resection until the surgical margins were free of infection. All patients survived after this severe infection. CONCLUSIONS With an early diagnosis of mucormycosis by clinical findings, culture, or tissue biopsy, and aggressive treatment consisting of administration of liposomal amphotericin B and surgical resection of all infected tissue, excellent results are achieved.

Long-term experience with kidney transplantation from hepatitis C-positive donors into hepatitis C-positive recipients.

Kidney transplantation from hepatitis C virus (HCV) antibody positive donors (HCVD+) into HCV antibody positive recipients (HCVR+) is controversial. We implemented this policy in our units in 1990. Herein, we report the long‐term safety of this strategy. From March 1990 to March 2007, 162 HCVR+ received a kidney from HCVD+ (group 1) and 306 from HCVD− (group 2) in our units. Mean follow‐up was 74.5 months. Five‐and 10‐year patient survival was 84.8% and 72.7% in group 1 vs. 86.6% and 76.5% in group 2 (p = 0.250). Three deaths in group 1 and two in group 2 were liver‐disease related. Five‐ and 10‐year graft survival was 58.9% and 34.4% versus 65.5% and 47.6% respectively (p = 0.006) while death‐censored graft survival was 69% and 47% versus 72.7% and 58.5% (p = 0.055). Decompensated chronic liver disease was similar: 10.3% versus 6.2%. Cox‐regression analysis could not identify the donors HCV serology as a significant risk factor for death, graft failure and severe liver disease in HCVR+. In conclusion, long‐term outcome of HCVR+ transplanted with kidneys from HCVD+ seems good in terms of patient survival, graft survival and liver disease. HCVD+ was not a significant risk factor for mortality, graft failure and liver disease among HCVR+. These data strongly suggest that the use of kidneys from HCVD+ in HCVR+ is a safe long‐term strategy that helps to prevent kidney loss.

mTOR inhibitor–associated proteinuria in kidney transplant recipients

The use of mammalian target of rapamycin inhibitor (mTOR-I) after kidney transplantation has been associated with a higher incidence of proteinuria compared with calcineurin inhibitors (CNIs). This review will focus on mTOR-I-associated proteinuria in different settings after kidney transplantation: de novo mTOR-I treatment in combination with CNI, de novo mTOR-I-containing and CNI-free treatment, early conversion from a CNI-based regimen to an mTOR-I-based regimen, and late conversion. Some possible mechanisms of mTOR-I-induced proteinuria will also be reviewed.