The role of iron impurities in the toxic effects exerted by short multiwalled carbon nanotubes (MWCNT) in murine alveolar macrophages.

Lung toxicity mediated by multiwalled carbon nanotubes (MWCNT) has been widely demonstrated and recently associated with induction of carcinogenic asbestos-like effects, but the chemical features that drive this toxic effect have still not been well elucidated. The presence of metals as trace contaminants during MWCNT preparation, in particular iron (Fe) impurities, plays an important role in determining a different cellular response to MWCNT. Our goal was to clarify the mechanisms underlying MWCNT-induced toxicity with correlation to the presence of Fe impurities by exposing murine alveolar macrophages to two different MWCNT samples, which differed only in the presence or absence of Fe. Data showed that only Fe-rich MWCNT were significantly cytotoxic and genotoxic and induced a potent cellular oxidative stress, while Fe-free MWCNT did not exert any of these adverse effects. These results confirm that Fe content represents an important key constituent in promoting MWCNT-induced toxicity, and this needs to be taken into consideration when planning new, safer preparation routes.

Loss of nephrin expression in glomeruli of kidney-transplanted patients under m-TOR inhibitor therapy.

The development of proteinuria has been observed in kidney-transplanted patients on m-TOR inhibitor (m-TORi) treatment. Recent studies suggest that m-TORi(s) may alter the behavior and integrity of glomerular podocytes. We analyzed renal biopsies from kidney-transplanted patients and evaluated the expression of nephrin, a critical component of the glomerular slit-diaphragm. In a group of patients on 'de novo' m-TORi-treatment, the expression of nephrin within glomeruli was significantly reduced in all cases compared to pretransplant donor biopsies. Biopsies from control transplant patients not treated with m-TORi(s) failed to present a loss of nephrin. In a group of patients subsequently converted to m-TORi-treatment, a protocol biopsy performed before introduction of m-TORi was also available. The expression of nephrin in the pre-m-TORi biopsies was similar to that observed in the pretransplant donor biopsies but was significantly reduced after introduction of m-TORi(s). Proteinuria increased after the m-TORi inititiation in this group. However, in some cases proteinuria remained normal despite reduction of nephrin. In vitro, sirolimus downregulated nephrin expression by human podocytes. Our results suggest that m-TORi(s) may affect nephrin expression in kidney-transplanted patients, consistently with the observation in vitro on cultured podocytes.

Life expectancy of women with lupus nephritis now approaches that of the general population.

Immunosuppressive treatment has changed the prognosis of Lupus nephritis over time, but improvement in prognosis is difficult to analyze in different historical periods, and should be better demonstrated in comparison with life expectancy of sex-and age-matched people. Long-term patient and renal survival of 90 patients diagnosed with Lupus nephritis at our center from 1968 to 2001 with a follow-up time of 14+/-8 years was retrospectively evaluated. Patient and kidney survival significantly increased over time. Multivariate analyses show that risks of patient and renal death decreased by 8% at each year of follow-up, and increased by more than 5 time in patients aged > 30 years at diagnosis. As only 14 patients were men, relative survival as compared to that of the sex- and age-matched general population of the Piedmont Region was calculated for the 76 women. Improvement in the survival of the cohort of women was seen at any time of follow-up: in particular, it was sharply lower in the first period (relative survival at 5, 10 and 15 years = 0.784, 0.665, and 0.620, respectively) and increased in the second (relative survival at 5, 10 and 15 years = 0.939, 0.921, and 0.850, respectively) nearly approaching that expected for the general population, i.e. 0.993, 0.983 and 0.967, respectively. Taken together, our data allow us to draw the conclusion that life expectancy in women with Lupus nephritis has improved over time, paralleling an improved awareness of the disease and a significant increase in steroid pulse therapy as induction/remission phase. Improvement in survival is for the first time demonstrated to cover the gap with life expectancy of the general population for women with Lupus nephritis.

[The histological picture of CRF in kidney grafts]. / Il quadro istologico dalla IRC nel rene trapiantato: tra chronic allograft nephropathy e nefropatie recidivate e ''de novo''

The most common immunological causes of delayed renal function failure in kidney grafts are recurrent glomerular disease, de novo glomerulonephritis, and chronic cellular or antibody-mediated rejection. Glomerulonephritis can recur any time in the natural history of renal allografts, with the same morphological features of the disease occurring in the native kidney. It has a frequency varying from 100% to 1% and a generally favorable prognosis with the exception of FSGS, SHU and diabetic glomerulosclerosis. The most frequent glomerular diseases to occur de novo in the kidney graft are membranous glomerulopathy, antiglomerular basement membrane disease in patients with Alport's syndrome, and nephrotic syndrome of the Finnish type with antinephrin antibodies in patients with NPHS1 gene mutations. Chronic rejection, including chronic transplant arteriopathy and chronic transplant glomerulopathy, is the cause of renal failure in up to 20% of kidney grafts and may occur as early as a few months after transplant.

Improvement in relative survival of patients with vasculitis: study of 101 cases compared to the general population.

Immunosuppressive treatment has changed the prognosis of renal vasculitis over time, but improvement in prognosis is difficult to analyze in different historical periods, and can be better demonstrated by comparison with life expectancy of sex- and age-matched people. Long-term survival of 101 patients diagnosed with systemic vasculitis at our center from 1975 to 2002 was retrospectively evaluated in comparison with that of the Region's age- and sex-matched population. Patient and kidney survival significantly increased over time. Multivariate analyses showed that risks of patient and renal death decreased by 10% and 7%, respectively, at each year of follow-up, and increased by 6.3% and 5.2% for each year of age. Relative survival significantly improved over time, approaching that of the general population for cases diagnosed after 1993, mainly in women < 60 years (from 0.671 at 5-years in the first period to 0.916 in the last period), while 5-year-relative-survival was still 0.530 and 0.682 in men and women greater than 60 years, respectively. Poisson-based multinomial analyses confirmed the significant risk of the first periods of diagnosis and of dialysis in worsening of the relative survival of patients compared to that of the general population. Life expectancy in patients with renal vasculitis has improved over time, paralleling a significant increase in steroid pulse/cyclophosphamide association therapy and an earlier diagnosis due to the introduction of the ANCA test. Relative survival has considerably improved, and now approaches that expected in the general population for women, but not for men.

Severe crescentic BK virus nephropathy with favourable outcome in a transplanted patient treated with Leflunomide.

Herein reported is a severe case of BK virus nephropathy, probably caused by an intense/overimmunosuppression and identified 17 months after transplantation. The diagnostic biopsy showed extracapillary proliferation and typical cytopathic lesions, both in tubular epithelial cells and in those of the glomerular crescents. Severe inflammatory infiltrates, tubulitis, tubular atrophy and fibrosis were also observed. Immunohistochemistry and molecular biology disclosed the presence of an AS variant of the BK virus with a high viral load, both in renal tissue and urine. Immunosuppression was reduced and Leflunomide therapy administered for a month. Although this led to an improvement in the renal function, the therapy had to be suspended due to the onset of a skin rash. A second biopsy was performed 7 months later. The cellular crescents were no longer present and there was no evidence of either histologic or immunohistochemical findings consistent with an active BK virus infection. Tubular atrophy and interstitial fibrosis were still present. In addition, fibrotic crescents, which may be interpreted as late scarring changes of previous epithelial proliferation, were found. Although molecular investigation still showed the presence of the BK virus, the viral load in renal tissue, urine and serum was greatly reduced. Indeed, serum and urine viral load was still low at the last control, five months after the second biopsy. The morphologic and clinical evolution are reported and the possible role of the therapy is discussed.

Risk management of renal biopsy: 1387 cases over 30 years in a single centre.

BACKGROUND: Although renal biopsy is largely employed, even in old patients with systemic diseases, few clinical studies have addressed its risk management. We aimed to obtain a comprehensive assessment of safety/utility ratio of percutaneous renal biopsy. PATIENTS AND METHODS: Retrospective review of all the 1387 patients who consecutively underwent renal biopsy in a single centre over three decades (1973-2002) was made, with calculation of complications, multivariate logistical analyses to evaluate risk factors of complications, and rate of alteration of clinical hypotheses by pathological diagnosis. RESULTS: There were no deaths and five major complications, (0.36%). One nephrectomy (0.07%), two surgical revisions (0.1%) and two arterial-venous fistulae (0.1%). There were also 337 minor bleeding complications (24.2%) (16.4% gross haematuria and 7.8% clinically relevant haematomas needing at least prolonged bed rest). Multivariate analyses demonstrated that the risk for complications was significantly increased by systemic autoimmune diseases with odds ratio (OR) 2.06, 95% confidence interval (CI)=1.40-3.01, end-stage kidney/acute-tubular necrosis (OR 2.96, 95% CI=1.19-7.30), and prolonged bleeding time test (BTT) (OR 1.87, 95% CI=1.17-2.83). Among the 1288 cases in which a clinical hypothesis before renal biopsy was recorded, renal pathology changed previous diagnoses in 423/1,288 (32.8%) of cases. CONCLUSIONS: Risk assessment demonstrates that renal biopsy is a useful procedure with a low incidence of serious complications. Platelet function is the only modifiable factor significantly related to bleeding complications, suggesting the need for a more standardized alternative to the BTT. Platelet function should be evaluated to select low-risk patients for renal biopsy as 'a day case procedure', in order to build adequate risk management strategies.

[Antiphospholipid syndrome and kidney]. / Sindrome da anticorpi anti fosfolipidi e rene.

The diagnosis of antiphospholipid syndrome (APS) relies on clinical and laboratory criteria, which have been recently outlined in specific consensus conferences. Renal involvement in APS is not infrequent and includes different clinical patterns. For clinical purposes a distinction can be made between large vessel and microvascular involvement. Renal artery stenosis is frequent in APS. In case of microvascular involvement with an acute clinical course a differential diagnosis with other thrombotic microangiopathic diseases has to be made, taking in account thrombotic thrombocytopenic purpura, hemolytic uremic syndrome, malignant hypertension, drug nephrotoxicity (cyclosporin) and others. The disease is often chronic, with hypertension, different degrees of renal insufficiency and mild proteinuria. In patients with systemic lupus erythematosus and antiphospholipid antibodies the prognosis of kidney disease is generally poorer than in lupus alone. Finally, the kidney is almost invariably a target in catastrophic antiphospholipid syndrome. Anticoagulation is the therapy of choice, especially in arterial stenosis and acute disease, but is probably also indicated in chronic and subacute patterns. The role of immunomodulatory therapy has to be assessed.

Karyomegalic interstitial nephritis: report of 3 new cases and review of the literature.

Karyomegalic interstitial nephritis is a rare, but perhaps an "underdiagnosed" condition. Peculiar nuclear changes characterize it, involving mainly tubular cells along with glomeruli and blood vessels. Herein, 3 bioptically proven new cases of patients with chronic renal failure are discussed. The first case had a recently diagnosed karyomegalic nephritis which, to date, still does not require dialysis. The other 2 (brother and sister) required dialysis 4 and 1 years after diagnosis. Karyomegalic changes were found not only in the skin and duodenal biopsies of the male, in skin and liver biopsies of the female and in the urine cells of both patients, but also in several organs (brain, thyroid, lung, esophagus, arteries) as shown at the autopsy of the female. There was a fatal outcome for both patients. The data reported in this study emphasize the usefulness of pathologic investigation of both tissue and urine samples in the identification of this disease. Moreover, as karyomegalic interstitial nephritis is strongly suspected to have a genetic background, its identification may well not only be of clinical relevance, due to its ominous outcome, but may also bear eugenetic value.

Phenotype/genotype correlations in the ultrastructure of monogenetic glomerular diseases.

Electron microscopy defined classic patterns of hereditary glomerular disease long before genetics revealed an underlying specific mutation. Genetic analysis is now easier to perform in clinical practice but an earlier optimism that genetics would predict disease severity and phenotype is challenged. The classic paradigm is Alport nephritis in which only a subset of mutations may predict glomerular abnormalities and disease severity. Interpretation of ultrastructural pathology of monogenetic diseases like Alport nephritis is complicated when the proband is the first family member to be diagnosed or there is discrepancy between clinical presentation and ultrastructural changes. In this review the authors have selected a dozen cases representative of common monogenetic glomerular diseases as a platform to discuss the utility of diagnostic electron microscopy in the era of molecular genetics. The emphasis is on genotype/glomerular phenotype correlations.

[Polyomavirus BK nephropathy in renal transplant: 2 cases with different clinical expressions and review of the literature]. / Nefropatia da Poliomavirus BK nel trapianto renale: 2 casi con espressione clinica diversa e revisione della letteratura.

INTRODUCTION: Polyomavirus BK nephropathy is emerging as a significant cause of interstitial nephritis and allograft dysfunction (1-2). CASE REPORT: Two patients with renal transplants from cadaveric kidneys were treated with Tacrolimus plus Mycophenolate Mofetil (MMF) and Cyclosporine plus MMF, respectively. Their renal function gradually deteriorated eight to twelve months after the transplant. The renal biopsy of the first patient showed signs of significant interstitial tubulite, which necessitated the anti-rejection therapy with intravenous steroid pulses. After the pulses there was an additional dramatic increase in plasmatic creatinine, which suggested a revaluation of the kidney biopsy because of suspected Polyomavirus BK (BKV) nephropathy. In fact, after a more careful review, the suspicion of BKV infection was confirmed by the presence of intranuclear inclusions of tubular epithelium cells and marked denudation of the tubular basal membrane. The subsequent screening in both cases confirmed the presence of decoy cells in the urine, while the immunohistochemical analysis of the renal biopsy was strongly positive for the SV40 antigen. Our diagnosis was that of interstitial nephritis due to Polyomavirus BK that, in the first patient, was expressed by more aggressive clinical progress, probably due to enhanced immunosuppression from incorrect diagnosis of the interstitial rejection. The pre-transplant clinical outcome of the first patient was characterised by proteinuric nephropathy without any histological confirmation. Furthermore, we observed abundant pre-transplant residual diuresis and glucose intolerance. All these elements led us to hypothesise that native kidneys could have a fundamental role as viral reservoirs. CONCLUSION: Even though we reconfirm the decisive role of the immunosuppressive therapy and of the donor s kidney as the fundamental causes of Polyomavirus reactivation, we believe that it cannot be the result of a possible active role by the native kidney. In fact, as already noted, the SV40 genome is important in the pathogenesis of focal gomerulosclerosis. Furthermore, reports of polyoma nephropathy in not-yet-transplanted patients could accredit the role of the native kidneys as important viral reservoirs capable of inducing nephropathy in renal transplant patients.

[Renal damage in type 2 diabetes]. / Il danno renale nel diabete mellito di tipo 2.

Renal involvement in patients with type 2 diabetes will (probably) be one of the most important clinical problems for nephrologists to face during the next few years. Unlike type 1 diabetes, in type 2 diabetes the renal damage has not yet been well defined at both clinical and pathological levels. Pathological examination of renal biopsies has displayed different patterns of renal damage including diabetic glomerulosclerosis (Class 1), mostly chronic vascular changes (Class 2) and superimposed glomerular diseases (Class 3a) or unrelated to diabetic glomerulosclerosis (Class 3b). Despite the large number of papers published in this field, the actual prevalence and outcome of the different histological classes still remain to be established. Reported discrepancies are most likely caused by ethnic and geographic factors. However, as documented by a recent study carried out on a large number of patients, the prevalence of histological patterns is also greatly influenced by the policy for performing renal biopsies adopted at the various nephrological centers. Although the natural history of type 2 glomerulosclerosis (Class 1) still remains to be defined, those patients with clinical nephropathy and impairment of renal function have very poor outcome with a high rate of mortality and progression to uremia. Moreover, when diabetic glomerulosclerosis is complicated by superimposed glomerular diseases (Class 3a) the prognosis is much worse. On the contrary, when glomerular diseases are not associated with glomerulosclerosis lesions (Class 3b) the prognosis is markedly better. During the last ten years controlled studies have shown that the outcome in type 1 diabetic nephropathy has improved as a result of the use of drugs inhibiting the renin-angiotensin system. Although it is likely that this type of drug might also favourably influence the outcome of type 2 diabetic nephropathy, any conclusive evidence is presently still lacking.

Molecular characterization and sequence analysis of polyomavirus strains isolated from needle biopsy specimens of kidney allograft recipients.

We retrospectively examined 29 renal allograft biopsy specimens from 42 kidney transplant recipients by means of molecular biologic techniques (nested polymerase chain reaction), immunohistochemical analysis (anti-SV40 antibody), and histologic examination to evaluate the presence of polyomaviruses (PVs), viral genotypes, genomic mutations, and their pathologic significance. PV genomes were found in six cases (21%); restriction fragment length polymorphism analysis characterized 4 as JC virus (JCV) and 2 as BK virus (BKV). The latter also were positively stained immunohistochemically and showed histologically typical intranuclear viral inclusions; JCV cases were negative. DNA sequence analysis revealed only minor changes in the 4 JCV cases (3 archetypes and 1 JCV type 3, not associated with a known pathogenic genotype) but identified 2 specific variants in the BKV isolates (AS and WW strains). Given the different histologic findings (mixed inflammatory infiltration in the AS and no inflammation in the WW strain), we speculate that different BKV strains may cause differential damage in transplanted kidneys. Finally, the negative histologic and immunohistochemical JCV results, as well as the absence of viral mutations, indicate that JCV renal infection is latent in transplant recipients.

[Biopsy experience at the G. Bosco Hospital from 1996 to 1999]. / Esperienza bioptica dell'Ospedale G. Bosco dal 1996 al 1999.

BACKGROUND: Aim of this study was a retrospective analysis of the renal biopsies performed in our Division. METHODS: Since January 1, 1996 to September 30, 1999 289 biopsies were performed on native kidneys, 90 patients were older than 65. RESULTS: The most frequent nephropathy was IgA glomerulonephritis (IgAGN) (28%), followed by membranous glomerulonephritis (MGN) (11%). In patients older than 65, the most frequent was MGN (20%), followed by IgAGN (12.2%). The total complications were 84 (29.1%) (hematomas >3 cm 1%; blood transfusion: 1.4%). Complications were not related to age, blood pressure, renal function, clinical presentation, number of shots. In 217 patients, the results obtained with two different modalities were compared: manual system (needle size=15 gauge) and automatic system (18 gauge). No statistically significant differences were found as regards the number of shots for single biopsy, number of glomeruli and major complications (1.6% vs 1.3%), while minor complications were more frequent in the second group. CONCLUSIONS: In conclusion, the number of renal biopsies performed in our Division has been increasing year after year. This trend can be partially explained by our wider indications to renal biopsy in elderly population (the data related to resident population showed the greatest prevalence of biopsies in patients 70 to 79 years old). Renal biopsy actually represents a safe examination even in elderly patients. From a technical point of view, on the basis of personal experience, 18 gauge acecut automatic needles seem to be preferred to other kind of devices.

Molecular characterization and sequence analysis of polyomavirus BKV-strain in a renal-allograft recipient.

The significance of polyomavirus (PV) infection was investigated in a 53-year-old patient who underwent renal transplantation and was treated with triple immunosuppressive therapy (tacrolimus, prednisone, and azathioprine). A renal biopsy taken because of the suspicion of acute rejection showed focal inflammatory interstitial infiltration, tubulitis, and tubular cell nuclear changes consistent with the hypothesis of viral infection. Both the tubular and decoy cells identified by means of urinalysis positively stained for anti-SV40 antibody. Polymerase chain reaction performed on the DNA extracted from renal tissue and isolated from urine showed the presence of an antigenic variant (AS) of the BKV archetype after sequence analysis of the transcription control region (TCR). On the basis of the diagnosis of BKV infection, immunosuppressive therapy was reduced. The patient's renal function improved and was still stable 8 months later when urinalysis showed only a few decoy cells, which were found to be infected by JC but not BK virus. These data suggest that only the BKV, probably favoured by immunosuppressive therapy (tacrolimus), causes renal damage. It is worth underlining that even small and sporadic viral genome mutations may lead to pathologic effects.

Distribution of alpha-chains of type IV collagen in glomerular basement membranes with ultrastructural alterations suggestive of Alport syndrome.

BACKGROUND: In Alport syndrome (AS) impaired production and/or assembly of col IV alpha-chain isoforms results in abnormal structure of glomerular basement membrane (GBM), haematuria and, frequently, progressive renal disease. We investigated the relationship between col IV alpha-chains expression and morphology of GBM, as a possible key to the better understanding of the pathogenesis of renal disease in AS. METHODS: GBM distribution of col IV alpha1-, alpha3-, and alpha5-chain was investigated by immunohistochemistry in 32 patients (21 males and 11 females, mean age at biopsy of 11.5 years) with ultrastructural findings suggestive of AS. Ten patients had a proven COL4A5 mutation. Based on the severity of ultrastructural findings, the biopsies were grouped in three (I-III) electron microscopy (EM) classes. Significant EM changes of GBM (thinning, thickening, splitting, basket weaving of the lamina densa) were singularly evaluated using a semiquantitative scale (0-3). RESULTS: Col IV alpha1-chain was demonstrated in GBM of all patients. Three patterns of staining for col IValpha3- and alpha5-chains were observed: positive, negative, and alpha3(IV)-positive/alpha5(IV)-negative. By chi(2)-test, EM class III lesions and complete loss of alpha3(IV)- and alpha5(IV)-antigen were significantly more frequent (P<0.05 and P<0.01) in male patients, but no significant relation was observed between EM classes and immunohistochemical patterns. GBM alterations did not correlate with staining for alpha5(IV)-chain. Intensity of alpha3(IV)-chain staining, however, had a negative correlation (P<0.05) with the severity of GBM basket weaving. CONCLUSIONS: Our results suggest that the alpha3(IV)-chain-containing col IV-network plays a fundamental role in structural and, possibly, functional organization of GBM. Absence of alpha3(IV)-chain in GBM could indicate a more severe renal disease in AS.

The concept of 'glomerulonephritis'. the fascinating history of evolution and emergence of a specialist's nosology focus on Italy and Torino.

Though the term 'nephritis' first appeared in the 19th century, this word did not bear the same meaning as it does today; indeed, for many years it was used to indicate 'renal diseases' (in the sense of Bright's disease) in a larger sense. This review summarizes the long gestation of the concept of 'glomerulonephritis' from the prehistory of medicine up to the beginning of the second half of the 20th century with emphasis on Italy and, in particular, on Torino, which was the capital of the Kingdom of Italy from 1861 to 1865. To the best of our kowledge, this is the first study reporting an epidemiology survey of Bright's disease in Italy from 1880 up to 1960. Towards the end of the 19th century, Bright's disease accounted for 26 deaths/year/10(5) population (in comparison with more than 200 from tuberculosis) in Italy, roughly paralleling that reported in the USA. At the beginning of the 20th century, Bright's disease was the seventh cause of death (almost 1% of total deaths) in Italy. Furthermore, in Italy, as elsewhere, autopsy studies showed a higher percentage of deaths attributed to Bright's disease (5-7%) in comparison with those obtained from vital statistics. In 1960, just before the beginning of renal replacement therapy, Bright's disease accounted for 15.7 deaths/year/10(5) population (= 1.46% of all deaths), roughly paralleling that reported in the United Kingdom (13.8/10(5) population = 1.25% of deaths). Probably, it was difficult to recognize the real incidence of chronic renal diseases leading to death in the 1960s, and vital statistics were able to furnish only approximate estimates. However, noteworthy is the fact that these values were very close to those estimated as being the annual need for renal replacement therapy (10-20 cases/year/10(5) population).