Does JC polyomavirus cause nephropathy in renal transplant patients?

INTRODUCTION

BK polyomavirus (BKV) reactivation characterized by active viruria occurs in 23%-57% of renal allograft recipients and BKV-associated nephropathy in as many as 8% of renal allograft recipients. Only a few cases of nephritis have been attributed to JC polyomavirus (JCV) with limited information about JCV replication and its impact on graft function and survival of kidney transplant patients. We sought to determine the prevalence of BKV and JCV replication, the risk factors associated with viral reactivation, and their implications for the development of polyomavirus nephropathy (PVN) among renal transplant patients.

MATERIALS AND METHODS

The study included 186 kidney transplant recipients who were transplanted between 2005 and 2009 with a 1-year follow-up. If the urine polymerase chain reaction (PCR) was positive, we performed a PCR on blood. If this was positive or renal dysfunction was present, we performed a renal biopsy.

RESULTS

Viruria was positive in 72 cases (39%) and viremia in 12 (6.5%); including, 3 patients (1.6%) who developed PVN. In the patients with viruria, BKV was detected in 47% and JCV in 46%; both were detected in 7%, although the combination of viremia and nephropathy were caused by BKV in all cases.

CONCLUSION

In renal transplant patients, the incidence of BKV and JCV viruria was similar, although in our series the JCV serotype did not cause viremia or PVN. Our experience suggested that JCV did not have the ability to cause PVN.

Renal transplantation in old recipients from expanded criteria donors selected by kidney biopsy

BACKGROUND

In Spain, the number of ideal kidney transplant donors has fallen, with at the same time an increase in the number of older recipients on the waiting list.

AIM

To analyze the results of expanded criteria cadaveric donor kidney transplants into older recipients using grafts selected by kidney biopsy.

PATIENTS AND METHODS

We studied 360 kidney transplant recipients who had been followed to December 2009: 180 in the study group and 180 in a control group composed of younger patients who received grafts from non-expanded criteria donors between 1999 and 2006. A paraffin-embedded kidney biopsy was evaluated by the percentages of sclerosed glomeruli, arteriolar hyalinosis, intimal wall thickening, interstitial fibrosis, and tubular atrophy.

RESULTS

Significant differences were observed in donor age (63.50±5.46 vs 31.90±13.29 years; P<.001) and recipient age (58.40±8.80 vs 40.71±13.23 years; P<.001). Donor renal function was significantly worse among the expanded criteria group (90.80 vs 108.11 mL/min/1.73 m2; P=.006), remaining so over time in the recipient (at 1 year: 42.08 vs 63.71 [P<.001]; at 3 years: 41.25 vs 62.31 [P<.001], and at 7 years: 38.17 vs 64.18 [P<.001]). Censored 7-year graft survivals were 73% versus 87% (P<.001) with similar patient survivals (90.5% vs 95%; P=.39).

CONCLUSIONS

Selection of expanded criteria donors by kidney biopsy resulted in good renal function as well as graft and patient survivals at 7 years in older recipients.

Arbuscular mycorrhizal fungal propagules from tillage and no-tillage systems: possible effects on Glomeromycota diversity

Arbuscular mycorrhizal fungi (AMF) can use different types of propagules to colonize new roots. In this work we tested different types of AMF inocula obtained from a field experiment with tilled and no-tilled soils planted with wheat as well as from nondisturbed treatments with spontaneous vegetation. AMF trap cultures were carried out with soil, mycelium, segments of roots and wheat plants from the field as sources of inocula. Then after the senescence of the trap plants Glomeromycota species that had been established from each type of propagule in the substrate from the pots were identified. In field soils the proportions of Acaulosporaceae and Gigasporaceae were relatively similar to that of Glomeraceae, mainly in conventional tillage, whereas in all trap cultures investigated the percentages of members of the Glomeraceae family were higher than 90%. Because most of the trap cultures were based on intra- and/or extraradical mycelium our results show that members of Glomeraceae have advantages in the use of these propagules over Acaulosporaceae and Gigasporaceae species. We suggest that the higher contribution of Glomeraceae previously found in no-tillage systems could be related partially to the lack of disruption of the hyphal network and the composition of the soil propagules in this system.

Evaluation of the efficacy and safety of conversion to sirolimus in 85 renal transplant recipients

OBJECTIVE

Treatment with sirolimus (SRL) is a potential therapeutic option for renal transplant recipients, especially those who have developed chronic graft nephropathy (CGN) or a neoplasm. Our aim was to analyze the efficacy and safety of conversion to SRL in renal transplant recipients.

MATERIALS AND METHODS

We undertook a retrospective study of 85 patients converted to SRL, 47% for tumors, 39% for CGN, and 14% for other causes. The follow-up period was 34 months (range, 1-93 months).

RESULTS

Baseline creatinine was 1.8 +/- 0.69 mg/dL (1.6 +/- 0.59 for tumors and 2.3 +/- 0.6 for CGN). At 1 year, the creatinine was the same in both groups: 1.8 mg/dL (P = NS). Graft survival at 12 months was 89% (81% for tumors, 81% for CGN, and 100% for other causes). SRL was withdrawn in 34% of patients: 18% for severe side effects, 7% for patient death, and 9% for graft loss. The serum creatinine and proteinuria were significantly increased among those subjects who returned to dialysis because of CGN compared with those with conserved renal function. Patients who developed pneumonitis showed a lower baseline aMDRD, but no difference in SRL levels. Side effects occurred in 40% of patients, with no difference in renal function, proteinuria, or SRL levels. Renal function showed a significant improvement in the patients who continued SRL (aMDRD 45.7 vs 50.7 mL/min/1.73 m(2) at 12 months; P = .08), more marked among those who converted due to CGN. Increases were seen in levels of serum lipids, as well as in the percentage of patients treated with statins. Proteinuria increased significantly, as did the percentage of patients treated with ACE inhibitors/ARA2.

CONCLUSIONS

Conversion to SRL in patients with CGN was safe when renal function had not undergone marked worsening and there was no proteinuria. Patients who were converted experienced an improvement in renal function.

Influence of meteorological input data on backtrajectory cluster analysis – a seven-year study for southeastern Spain

Abstract. Backtrajectory differences and clustering sensitivity to the meteorological input data are studied. Trajectories arriving in Southeast Spain (Elche), at 3000, 1500 and 500 m for the 7-year period 2000–2006 have been computed employing two widely used meteorological data sets: the NCEP/NCAR Reanalysis and the FNL data sets. Differences between trajectories grow linearly at least up to 48 h, showing faster growing after 72 h. A k-means cluster analysis performed on each set of trajectories shows differences in the identified clusters (main flows), partially because the number of clusters of each clustering solution differs for the trajectories arriving at 3000 and 1500 m. Trajectory membership to the identified flows is in general more sensitive to the input meteorological data than to the initial selection of cluster centroids.

Air mass origin and its influence over the aerosol size distribution: a study in SE Spain

Abstract. A k-means cluster analysis of 96 hour trajectories arriving in Southeast (SE) Spain at 3000, 1500 and 500 m for the 7-year period 2000–2006 has been performed to identify and describe the main flows arriving at the study area. The dependence of the aerosol size distribution on the air mass origin has been studied by using non-parametric statistics. There are statistically significant differences on aerosol size distribution and meteorological variables at surface level according to the identified clusters.

Renal function in patients with cadaveric kidney transplants treated with tacrolimus or cyclosporine

INTRODUCTION

Renal function predicts graft survival in kidney transplant patients. This study compared the 2-year evolution of renal function in patients treated with cyclosporine or tacrolimus in combination with mycophenolate mofetil (MMF) and prednisone.

METHODS

We studied 1558 cadaveric renal transplant recipients from 14 Spanish hospitals between January 2000 and December 2002. Of these, 1168 were treated with tacrolimus and 390 with cyclosporine. The primary efficacy endpoint was long-term renal function. Renal function was measured by serum creatinine and glomerular filtration rate (GFR) by creatinine clearance calculated from the Cockcroft-Gault formula. This report summarizes the 2-year results.

RESULTS

At 24 months the tacrolimus group showed significantly better serum creatinine (1.5 +/- 0.7 vs 1.8 +/- 0.8 mg/dL, P < .001) and GFR (60.5 +/- 20.9 mL/min vs 47.9 +/- 10.0, P < .001) than the cyclosporine group. Additionally, recipients with ideal graft donors (23.5 +/- 2.8 vs 24.0 +/- 2.9 years) had a better serum creatinine at 2 years (1.23 +/- 0.2 vs 1.5 +/- 0.4 mg/dL, P < .05). Multivariate analysis showed that tacrolimus was an independent factor associated with better renal function: odds ratio 1.6, 95% confidence interval (1.2 to 2.2), P < .001.

CONCLUSIONS

Patients with a renal transplant treated with tacrolimus in combination with MMF and prednisone displayed better renal function at 2 years than those who received cyclosporine.

Conversion to Sirolimus in Posttransplant Renal Neoplasms

BACKGROUND

Calcineurin inhibitors (CNIs) have been associated with the development of posttransplant malignancies, especially lymphoma and solid organ tumors. Sirolimus (SRL) has been shown to inhibit the growth of tumor cell lines in vitro and in vivo and has proven effective in clinical practice for the treatment of Kaposi's sarcoma. Organ transplant patients treated with CNIs who develop a tumor may thus benefit from conversion to SRL.

PATIENTS AND METHODS

From December 2001 to May 2006, 25 patients who developed a tumor were converted from a CNI-based immunosuppressive regimen to SRL. We analyzed the evolution of the tumor, renal function, and the adverse effects resulting from the change of immunosuppression.

RESULTS

The mean follow-up was 19 months. Creatinine clearance (Cockcroft-Gault) increased from 59.5 +/- 21.7 to 66.0 +/- 24.2 mL/min at 12 months (P = .4) and serum cholesterol from 176.7 +/- 46.8 to 216.4 +/- 40.3 mg/dL (P = .01). Proteinuria rose from 0.3 +/- 0.1 to 1.3 +/- 0.9 g/24 hours (P = .004). Adverse events included anemia, thrombocytopenia, and oral ulcers in 20% of cases, cutaneous eruption and gastrointestinal alterations in 12%, and edema in 24%. Four (16%) patients had improved blood pressure readings. Six (24%) patients died and one experienced an acute rejection episode after conversion to SRL. Nineteen (76%) patients displayed a favorable evolution with no evidence of tumor progression.

CONCLUSIONS

Conversion to SRL stabilized tumor progression in 76% of long-term renal transplant patients who developed a neoplasm over a mean follow-up of 19 months. Moreover, renal function improved. The most important adverse effects were increased cholesterol and proteinuria.

Pulmonary toxicity associated with sirolimus treatment in kidney transplantation

INTRODUCTION

An important side effect of sirolimus, a drug often used in organ transplantation, is pulmonary toxicity.

MATERIALS AND METHODS

We present five kidney transplant patients who developed this toxicity associated with sirolimus. All underwent chest radiography computed tomography, fiberoptic bronchoscopy with bronchoalveolar lavage (BAL), microbiological studies of the bronchial aspirate, blood, and sputum, and cytomegalovirus (CMV) polymerase chain reaction (PCR) in blood as well as two had transbronchial biopsies.

RESULTS

All five were men of mean age 54.8 +/- 10.3 years. In two sirolimus formed part of de novo therapy, and three were converted from calcineurin inhibitors. The mean treatment time was 16.6 +/- 13.7 months, with trough levels of 11.3 +/- 3 ng/mL. The patients presented with fever, cough, dyspnea, anemia, and dyslipidemia. The radiological pattern was diffuse alveolointerstitial (n = 2), or bilateral basal interstitial (n = 2), or bilateral basal alveolar (n = 1). The cell count in the BAL was 95% to 99% macrophages. In two patients cultures for bacteria were positive: Hemophilus and Pseudomonas. Tests for fungi, mycobacteria, pneumocystis, and legionella, as well as PCR for CMV were all negative. Transbronchial biopsy yielded insufficient material in one patient and a deposit of fibrinoid material and nonnecrotizing granuloma in the other. Antibacterial therapy was started, three with cotrimoxazole and two with ganciclovir, with no response. The respiratory symptoms improved after withdrawal of sirolimus (mean, 2.4 +/- 1.5 days). The mean hospital stay was 19.8 +/- 14.1 days.

CONCLUSION

Pulmonary toxicity due to sirolimus should be included in the differential diagnosis of kidney transplant patients who display signs of interstitial pneumonia. Its diagnosis is difficult requiring exclusion of other pulmonary diseases. Resolution of the symptoms was quick after suspension of the drug.

Polyomavirus BK nephropathy: the effect of an early diagnosis on renal function or graft loss

Polyomavirus BK nephropathy is a new complication among renal transplant patients. We studied 664 cadaver renal transplant recipients from February 1998 to February 2005, divided into two periods: 448 (group A, February 1998 to July 2003) and 176 (group B, August 2003 to February 2005). Twenty patients (3%) developed biopsy-confirmed polyomavirus BK nephropathy; 13 (2.9%) in group A after worsening renal function and 7 (3.9%) in group B after a prospective cytologic study in urine, examining for decoy cells, and a qualitative polymerase chain reaction (PCR) assay in urine and blood. The mean time to diagnosis was higher among group A (15.0 +/- 1.6 versus 7.2 +/- 4.0 months), as was the serum creatinine (2.5 +/- 0.7 versus 2.0 +/- 0.6 mg/dL). After 12 months the serum creatinine was 2.7 +/- 1.3 versus 1.7 +/- 0.2 mg/dL, respectively. Poor prognostic factors were a persistently positive PCR in blood and viral inclusions in the control biopsy.

Posttransplant Lymphoproliferative Disease: A Series of 23 Cases

Posttransplant lymphoproliferative disease (PTLD) is a rare but clinically important disorder due to its increasing incidence and its impact on renal function and the life of the patient. Between 1979 and 2005, this center performed 1614 kidney transplants, and 23 patients had PTLD. We undertook a retrospective study, analyzing risk factors, presentation, and evolution of the disorder. The most common clinical presentation was fever and adenopathy. All cases except one received calcineurin inhibitors, and nine were treated with monoclonal or polyclonal antibodies. Serology for Epstein Barr virus (EBV) was negative in nine patients at the time of transplant, and in five it became positive on diagnosis of PTLD. The predominant disorder was non-Hodgkin's lymphoma (NHL), either polymorphous (n = 11) or monomorphous (n = 7). The base therapy consisted of reducing or suspending calcineurin inhibitors and the addition of sirolimus and antivirals. Three patients received rituximab, and five chemotherapy. The disease progressed in 36% of the polymorphous NHL, in 67% of the monomorphous, and in 100% of the Hodgkin's lymphoma, whereas 10 patients had remission. Renal function worsened on diagnosis in eight patients, and the graft was infiltrated in five (confirmed histologically). Five patients lost the graft and 12 died; six due to infection and five due to PTLD. Survival was worse in the patients aged over 55 years. We conclude that in most cases EBV is positive on diagnosis of the PTLD, an age older than 55 years affords a poor prognosis, and lymphocyte infiltration of the graft is common, as is worsening renal function.

Anterior Uveitis Associated With Treatment With Intravenous Cidofovir in Kidney Transplant Patients With BK Virus Nephropathy

BACKGROUND

Polyomavirus-associated nephropathy (PVAN) is an important cause of kidney dysfunction and graft loss. Different treatment regimens have been used, including low-dose intravenous cidofovir. Anterior uveitis, a complication of this treatment, has been reported after its use in patients with cytomegalovirus-associated retinitis. We analyzed the incidence and associated risk factors for this disorder in patients with PVAN.

PATIENTS AND METHODS

The study included 14 kidney-transplant patients who had received low doses of cidofovir after being diagnosed with PVAN.

RESULTS

Five (35%) patients developed an episode of anterior uveitis. The mean number of cidofovir doses given was 6.8 +/- 1.6 as compared with 9.1 +/- 2.1 in patients who did not develop the disease. Creatinine clearance at diagnosis of the nephropathy and after terminating treatment was lower in the uveitis patients, who had a graft survival of 40% versus 100% in the patients who did not develop eye involvement. Treatment was suspended in the affected patients, with complete resolution in 80% after the administration of topical corticoids and cycloplegics.

CONCLUSIONS

Anterior uveitis secondary to low-dose treatment with cidofovir is a common complication in patients with PVAN and is associated with the degree of renal involvement. In the absence of larger studies, cidofovir should be used with caution in patients with creatinine clearance below 30 mL/min.

Outcome and morbidity of pancreas transplantation in a single Spanish institution

BACKGROUND

Pancreas transplantation is nowadays the only treatment to reestablish normal blood glucose in diabetic patients. Moreover, transplantation may also prevent and possibly even revert diabetes-related complications. We present our results with the first 4 years of a pancreas transplantation program.

MATERIALS AND METHODS

From February 2000 to June 2004, we performed 43 pancreas transplants in 42 recipients. In all cases the technique was enteric drainage of the exocrine secretions and systemic venous derivation to the inferior vena cava for endocrine secretions.

RESULTS

A simultaneous pancreas-kidney transplant was performed in 37 (88.1%) patients, a pancreas after kidney in 4 (9.5%) patients, and a retransplant in 1 (2.4%) patient. Glycosylated hemoglobin and C peptide returned to normal values in all cases. Patient and graft survivals were 91% and 84%, respectively, after a median follow-up of 19 months. The rate of reoperations was 31% with an overall 16% graft loss.

CONCLUSIONS

Our results were comparable to those of larger series.

Fungal spore diversity of arbuscular mycorrhizal fungi associated with spring wheat: effects of tillage

We investigated the influence of tilling, N fertilization and crop stage on arbuscular mycorrhizae (AM) fungal species diversity in a wheat monoculture in the Pampa region of Argentina. Glomalean spores were isolated by wet sieving and decanting from conventionally tilled and nontilled soils cropped with wheat with or without N fertilization, at three phenological stages of the crop (tilling, flowering and grain filling) and fallow. Morphological characterization yielded at least 24 AM fungi taxa in the field samples, belonging to six genera of AMF: Acaulospora Archaeospora, Entrophospora, Gigaspora, Glomus and Scutellospora. Tilling and fertilization treatments did not result in decreased spore biodiversity. Wheat phenology influenced AM communities, with highest spore biodiversity during grain filling.

Pancreas Islet Transplantation in Patients With Type 1 Diabetes Mellitus After Kidney Transplantation

Diabetic patients with end-stage renal disease have a high mortality rate. A combined kidney-pancreas transplant is associated with greater life expectancy. Pancreas islet transplantation is an alternative involving a lower degree of morbidity. We present two patients, of 41 and 37 years of age, with a long history of diabetes mellitus (C-peptide negative), both with a previous kidney transplant, who had been treated with 22 and 28 U of insulin/d, respectively. Both patients had frequent episodes of unawareness hypoglycemia. Pancreatic islets were infused to a total of 7809 and 19,180 IE/kg, respectively. Basal posttransplant C peptide levels were 2.9 and 1.3 ng/mL. After the implant, one patient required occasional doses of insulin, and the other patient more than 50% reduced dose. After the first implant neither patient had any episodes of unawareness hypoglycemia. HbA1c at 4 months were 6.2% and 6.9%. There were no transplant-related complications.

[De novo hemolytic uremic syndrome in a kidney-pancreas recipient in the postoperative period]

Among the numeruos adverse side effects of tacrolimus (TAC), de novo thrombotic microangiopathy stands out as an infrecuente but severe complication. Renal dysfunction is the only alteration that should lead to suspicion of thrombotic microangiopathy, because the clinical features of intravascular hemolysis are not always found. The definitive diagnosis can usually be made with kidney biopsy. Patientes with TAC induced thrombotic microangiopathy usually promptly recover after treatment withdrawal or reduction in the dose of TAC and a short course of plasma therapy, but the risk of rejection increases. Switching from TAC to cyclosporine has also been tried with resolution of the hemolysis but thrombotic microangiopathy has been noted with both and this condition may later recur. We present a 29-year-old man who received a kidney-pancreas transplant for end-stage diabetic nephropathy. After initial induction with basiliximab, the immunosuppression consisted of prednisone, tacrolimus and mycophenolate mofetil. Twenty four days posttransplantation his renal function declined with a peak creatine level of 2.35 mg/dl. Laboratory studies showed thrombocytopenia and features of intravascular hemolysis. TAC associated hemolytic uremic syndrome was suspected and drug was immediately stopped and converted to sirolimus. Also he was treated with plasma infusion. The allograft biopsy showed focal glomerular and arteriolar acute thrombosis without evidence of rejection. Our experience demostrate that switching from tacrolimus to sirolimus could be an adecuate strategy for patients who develop FK506-associated de novo thrombotic microangiopathy without increase risk of acute rejection.