Biomedical subjects
Publications and source records attributed to F P Schena.
Explore the source record for details and available documents.
IgA nephropathy, the most common form of primary glomerulonephritis, progresses to terminal renal failure in about 25% of patients 10 years after the apparent clinical onset. Since its description in 1968 an intense research effort in order to clarify the pathogenetic mechanisms has involved the study of animal models of the disease. In this review we analyze the experimental work reported since 1979, when the first animal model of IgA nephropathy was published by Rifai et al. We also discuss the interplay between experimental data and relevant clinical observations. Finally, we report the new insights about the role played by cytokines and growth factors.
Explore the source record for details and available documents.
BACKGROUND: Uremia produces a wide range of abnormalities of the immune system. Blood-membrane interaction in hemodialysis results in activation and severe dysfunction of peripheral blood mononuclear cells (PBMC). However, the question of whether the use of different dialytic membranes may improve PBMC dysfunctions remains unanswered. METHODS: To address this issue, the spontaneous interleukin (IL)-6, IL-8 and monocyte chemotactic peptide-1 (MCP-1) gene expression and protein release were studied in PBMC isolated from 7 healthy subjects, 8 uremic patients on conservative therapy and 8 uremic patients undergoing subsequent one month periods of hemodialysis with cuprophan (CU) and high-flux noncomplement activating membranes, polymethylmethacrylate (PMMA) and polyamide (PA). At the end of each period of treatment, PBMC were harvested at the beginning (T0) and after 180 minutes of dialysis (T180), and then were cultured in complete medium. IL-6, IL-8 and MCP-1 mRNA expression were studied by RT-PCR. In addition, MCP-1 gene expression was evaluated also by in situ hybridization. Cytokines released in the supernatant were measured by ELISA. RESULTS: Compared to the control group, PBMC from uremic patients on conservative therapy and treated by CU showed a clear reduction in the cytokine release, while PMMA and PA membranes were able to normalize IL-6, IL-8 and MCP-1 protein concentration, which had been reduced by CU treatment. Interestingly, at T0, mRNA expression for all three cytokines was increased in the patients treated by CU, when compared to the control group and the uremic patients on conservative therapy. A further up-regulation was observed at T180. PMMA and PA treatment, despite increasing the cytokine secretion, significantly reduced the dialysis-induced cytokine gene expression. CONCLUSION: PBMC exposure to CU membranes results in cytokine mRNA overexpression associated with a paradoxically reduced protein release. In contrast, long-term hemodialysis with synthetic high-flux membranes reduces IL-6, IL-8 and MCP-1 gene expression and improves the ability of PBMC to secrete these cytokines. The reduced cytokine secretion during bioincompatible dialysis may reflect a PBMC adaptation that protects uremic patients against the inflammatory effects of persistent cytokine release.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The Diagnosis Related Groups (DRGs) classification system correlates hospital performance with their relative costs and encourages more efficient productive processes. We report the following parameters: a) the distribution of hospital discharges according to the Major Diagnostic Categories (MDCs) and DRGs; b) the relationship between mean length of stay and threshold values; c) economic analysis of the cost-reimbursement pay-off. The results showed that 71.3% of DRGs belonged to nephro-urological MDC 11 and 28.7% in other internal MDCs (mainly involving cardiac and respiratory system). Of the latter, 67.7% were utilized for dialysis and transplant patients and kidney donors. In MDC 11 the most common DRGs were: the surgical DRG 315, produced by the vascular accesses for hemodialysis and by insertion of Tenckoff catheter for peritoneal dialysis, DRG 316 by cases of acute and chronic renal failure, DRG 332 by biopsy-proven glomerulonephritides. The length of stay was most commonly within range of one-third of threshold value for specific DRG; there was a low percentage of one-day stays and outlier cases. The economic analysis demonstrated that mean daily reimbursement sum was 590,714 ITL. Analysis of the overall costs yielded a mean daily cost of 455,838 ITL. In conclusion, quality indicators show that, appropriately, our specialist activity is largely devoted to the diagnosis and treatment of acute and chronic nephropathies and complications following dialysis and renal transplant.
Recovery from ischemic and nephrotoxic acute renal failure (ARF) requires the replacement of damaged tubular cells with new ones that restore the continuity of the renal epithelium. The repair process involves a number of growth factors produced in renal tissue that participate as autocrine or paracrine regulators in the repair process. The aim of this review is threefold: (1) to focus on the role of local growth factors such as EGF, TGF-alpha, IGF-1, HGF and TGF-beta in renal regeneration immediately after an acute renal insult. Receptors for these growth factors have been found in renal epithelial cells, medullary interstitial cells and glomeruli. These mediators play an important role in renal repair by promoting tubular cell proliferation. (2) A review the data supporting the administration of these growth factors in animal models of ARF, and the possibility of using these mediators in humans for the purpose of accelerating renal recovery and decreasing the morbidity and mortality rates, and the costs of multidisciplinary medical care, is presented. (3) Finally, the possibilities of introducing supportive therapy aimed at specific targets such as RGD peptides to reduce intratubular obstruction, atrial natriuretic factor to improve altered glomerular hemodynamics, and cell therapy such as bioartificial renal tubule in association with dialysis are discussed.
Explore the source record for details and available documents.
BACKGROUND: Recent data indicate that factors other than erythropoietin (EPO), such as insulin-like growth factor 1 (IGF-1), can promote erythropoiesis in vitro and correct the anemia of chronic renal failure in vivo. IGF-1 is produced by the liver under growth hormone control, as well as by other sources, including the kidney. The erythropoietic role of growth factors and cytokines and their possible modulation by angiotensin-converting enzyme inhibitors (ACEI) has never been explored. METHODS: This study evaluated the serum levels of EPO, IGF-1, interleukin (IL)-2, IL-3, and granulocyte macrophage-colony-stimulating factor in 40 kidney transplanted patients with or without posttransplant erythrocytosis (PTE) and in 10 living kidney donors. Then, the effect of ACEI therapy on the above pattern was examined in patients with PTE. RESULTS: EPO and IGF-1 serum levels were significantly higher in patients with PTE than in patients without PTE and in living kidney donor subjects. ACEI therapy significantly reduced hematocrit (Hct) as well as circulating IGF-1 and EPO levels. Of note, the decrease in IGF-1 was prominent mainly in those patients whose EPO levels were not significantly modified by ACEI therapy. In all of the patients Hct levels displayed a direct relationship with circulating IGF-1 levels, but not with EPO concentration. Growth hormone did not significantly differ among the groups examined, whereas it steeply increased under ACEI. Finally, no significant difference in IL-2, IL-3, and granulocyte macrophage-colony-stimulating factor serum levels was detected. CONCLUSIONS: IGF-1 seems to play a role in the ACEI-related decrease of Hct in patients with PTE, chiefly in patients without any modification of EPO serum levels.
Mononuclear cell infiltration is a common histopathological feature of acute renal transplant rejection, in which it seems to play a key role in the pathogenesis of tubulointerstitial lesions. Monocyte chemotactic peptide-1 (MCP-1) is a specific chemotactic and activating factor for monocytes. Thus, the present study was aimed at evaluating MCP-1 gene and protein expression in renal biopsies of kidney transplant recipients with acute deterioration of graft function, and to correlate it with the extent of monocyte infiltration. We studied 20 kidney transplant recipients with acute graft dysfunction (13 with acute rejection, seven with acute tubular damage). MCP-1 gene and protein expression were analyzed by in situ hybridization and immunohistochemistry, respectively. CD68-positive cells were identified as monocytes. CD68-positive cell number and MCP-1 expression were quantified by a computerized image analysis system. MCP-1 gene expression, undetectable in normal human kidneys, was strikingly increased in patients with acute rejection. The chemokine localized mainly to the proximal tubular cells and to mononuclear-infiltrating cells. In patients with acute tubular damage, the MCP-1 expression, even if higher than in controls, was significantly lower than in acute rejection. The expression of the chemokine strictly correlated with the number of infiltrating monocytes (r=0.87, P<0.05). Moreover, we measured MCP-1 urinary excretion by ELISA, in eight normal subjects (36+/-16 pg/mg urine creatinine), in 13 clinically stable transplant recipients (33+/-9 pg/mg, ns vs. normal patients), in 12 transplant recipients with acute rejection (250+/-46 pg/mg, P<0.01 vs. normal patients), and in five transplant recipients with acute tubular damage (97+/-33 pg/mg, P<0.05 vs. controls and patients with acute rejection). Urinary MCP-1 excretion directly correlated with renal MCP-1 gene expression (r=0.65, P=0.05). Finally, we observed a significant reduction in MCP-1 urine levels in patients with acute rejection, who responded to the antirejection treatment. In conclusion, our data suggest that MCP-1 may play a critical role in modulating monocyte influx and consequent tubulointerstitial damage in acute rejection. Therefore, an increase in urinary MCP-1 excretion may represent an early signal of ongoing acute graft rejection.
Membranoproliferative glomerulonephritis (MPGN) may be a component of a generalized vasculitis as well as a component of the clinical expression of type-II mixed cryoglobulinemia (MC). Several studies have established a striking association between hepatitis C virus (HCV) infection and MC. The potential role of HCV in the pathogenesis of MPGN, which occurs in almost half of the cases of MC patients, has not been fully investigated, and the demonstration of HCV proteins as the antigenic constituent of the glomerular immune deposits has remained elusive. Kidney biopsy specimens were obtained from 12 HCV RNA, antibody to HCV (anti-HCV)-positive patients with MPGN and type-II MC, and from 8 controls (3 HCV RNA, anti-HCV-negative patients with MPGN and MC and 5 with noncryoglobulinemic "idiopathic" MPGN). Murine monoclonal antibodies developed against c22-3, E2/NS1, c33c, c100-3, and NS5 proteins were used to detect HCV-related antigens by indirect immunohistochemistry. Acid electroelution of tissue sections was performed to enhance the sensitivity of the immunohistochemical method. Specific HCV-related proteins were detected in glomerular and tubulo-interstitial vascular structures in 8 (66.7%) HCV-positive MC patients and in none of the HCV RNA, anti-HCV-negative controls. HCV immunoreactive deposits displayed the following two major patterns: 1) a linear, homogeneous deposition along glomerular capillary walls, including endothelial cells and sub-endothelial spaces; and 2) a granular bead-like appearance with distinct deposits in mesangial and paramesangial cells. Immunoglobulin G (IgG) and M (IgM) and C3 fraction deposition in adjacent kidney sections displayed features comparable with those found for HCV deposits. Patients with granular deposits showed more pronounced renal impairment and severe proteinuria. These findings indicate that in MC patients with HCV-associated MPGN, kidney deposits consist of HCV-containing immune complexes that are likely to play a direct pathogenetic role in the renal damage.
Monocyte chemotactic peptide-1 (MCP-1) belongs to a large family of cytokines known as chemokines. It is a potent mediator of inflammatory response and is thought to play a major role in recruiting monocytes into the site of inflammation. Mixed cryoglobulinemia is a systemic vasculitis characterized in 10 to 30% of the cases by renal involvement. Monocyte infiltration into the glomerulus, and in the periglomerular and perivascular areas is a common histopathological feature of this form of glomerulonephritis. We sought to determine, by in situ hybridization and immunohistochemistry, the renal gene and protein expression of MCP-1 in cryoglobulinemic glomerulonephritis compared to normal kidney, and to correlate it with macrophage infiltration. Kidney biopsy specimens were obtained from 9 patients with cryoglobulinemic glomerulonephritis and 9 control kidneys. The distribution and intensity of MCP-1 gene and protein expression, and the macrophage infiltration (CD68 positive cells) were evaluated and quantitated by a computerized image analysis system. In normal kidneys, MCP-1 was weakly expressed, both at the gene as well as at the protein level. In diseased kidneys, a statistically significant (P < 0.001) up-regulation of MCP-1 gene and protein expression was found, particularly within the areas of tubulointerstitial damage and the glomeruli. By means of CD68 positive cells, a significant correlation (P < 0.001) was found between glomerular, tubulointerstitial macrophage infiltration and MCP-1 expression. Moreover, by combining immunohistochemistry and in situ hybridization, we observed the presence of CD68 positive cells mainly, if not exclusively, around the cells expressing MCP-1 mRNA. Interestingly, a striking increase in MCP-1 urinary concentration was found in cryoglobulinemic patients. In conclusion, our data suggest that MCP-1 may play a major role in modulating the inflammatory process observed in cryoglobulinemic glomerulonephritis.
Explore the source record for details and available documents.
BACKGROUND: The aim of this multicentre collaborative study was to compare the progression of renal disease in children and adults with Henoch-Schönlein purpura (HPS) nephritis selected on the basis of IgA-dominant renal deposits and biopsy material available for review. METHODS: The analysis was performed in 152 patients (95 adults and 57 children < 16 years old at diagnosis) with a follow-up (> or = 1 year up to 20 years (4.9 +/- 3.4 years in adults and 4.8 +/- 3.9 years in children). RESULTS: Renal histology and clinical presentation were similar in both age groups: crescents were found in 36% of adults and 34.6% of children (in only 2.7% of adults and 1.9% of children involving > 50% of glomeruli), nephrotic-range proteinuria in 29.5% of adults and 28.1% of children and functional impairment in 24.1% of adults and 36.9% of children. The outcome was similar for both age groups (remission, 32.5% of adults and 31.6% of children; renal function impairment, 31.6% of adults and 24.5% of children). Endstage renal disease was observed in 15.8% of adults and in 7% of children. Renal function survival at 5 years was not significantly different in the two groups (85% in adults and 95% in children) and at 10 years it was approximately 75% in both groups. None of the children died and adult survival was 97% at 5 years. In adults at presentation, renal function impairment (P < 0.02) as well as proteinuria higher than 1.5 g/day (P < 0.02) and hypertension (P < 0.001) were negative prognostic factors. Multivariate analysis stressed the main statistical relevance of proteinuria (relative risk 2.37, P < 0.02). Conversely, in children no definite level of proteinuria, hypertension or other data were found to be associated with poor prognosis. CONCLUSIONS: Among patients with a clinical presentation which warrants renal biopsy, HSP nephritis has a similar prognosis in children and adults. The evolution is more predictable in adults than in children.
BACKGROUND: Despite marked improvements in the success of solid organ transplantation, a significant percentage of transplanted organs is lost due to recurrent episodes of acute cellular rejection. The mechanisms that govern allograft rejection likely include a complex regulatory network of multiple cytokines and growth factors. DESIGN AND METHOD: This study investigated the kidney gene (in situ hybridization) and protein (immunohistochemistry) expression and the urinary excretion rate of IL-6 and EGF in 29 renal transplant recipients: 16 with acute cellular rejection (AR) and 13 with acute tubular damage/cyclosporine toxicity (ATD). RESULTS: AR patients displayed a 4-fold increase of renal IL-6 expression, which localized chiefly to proximal tubular cells and monocytes/macrophages, whereas EGF signal was extremely weak or even absent. In ATD patients, EGF expression was markedly reduced, while IL-6 specific signal was unchanged. In all the patients examined the renal expression of IL-6 and EGF strictly correlated with their urinary excretion rate (r:0.459, P:0.001). Thus, urinary IL-6/EGF ratio was markedly increased in the former group (> 20-fold at day 1), where it paralleled the modifications of plasma creatinine over time (r:0.603, P < 0.0001), and was only slightly increased in the latter group (< 3-fold). CONCLUSION: Kidney transplanted patients with acute cellular rejection or acute tubular damage/CyA nephrotoxicity exhibit a distinctly different pattern of intragraft expression of IL-6 and EGF, which is closely reflected by their rate of urinary excretion.
PURPOSE: This report describes data collected by the Italian Registry of Renal Biopsies (IRRB) (E mail http://www.teseo.it/nephrology/irrb), which includes 15461 renal biopsies (RB) performed over a period of 7 years (1987-1993). METHODS: From 1987 to 1988, the Registry recorded only the histological diagnosis of 3686 RB, whereas beginning in 1989, additional records (sex, age, clinical symptoms and renal function) were obtained from 11,775 patients undergoing RB. This is the first report on such a large number of RB containing data from 96% of Italian renal units which routinely perform RB. RESULTS: In 13,835 RB performed in native kidneys, two groups of renal diseases, primary (59.9%) and secondary (25.4%) glomerulonephritis (gn), were more frequent than others. Among primary gn, the frequency of cases of IgAN, membranous gn, and focal and segmental glomerulosclerosis were 36.9, 21.7 and 10.4% respectively. Renal disease due to immune-mediated causes (51%) and dysgammaglobulinaemia (26.9%) were the most frequent among secondary gn. In the former group, the frequency of cases with lupus nephritis and vasculitis were 51.6 and 25.9% respectively. Renal amyloidosis (39.3%), essential mixed cryoglobulinaemia (30.9%), and multiple myeloma were the most frequent forms in the latter group. In 1993 the incidence of the following groups of renal disease was: primary gn (22.7 p.m.p.), secondary gn (11.1 p.m.p.) of which immune-mediated gn (5.8 p.m.p.), dysgammaglobulinaemias associated with nephritis (2.4 p.m.p.). IgAN and membranous gn, as primary gn, had an incidence of 8.4 and 4.9 p.m.p, respectively, while lupus nephritis (2.6 p.m.p.) and renal vasculitis (1.6 p.m.p.) were the most frequent forms of secondary gn. Clinical data regarding 10357 RB collected during 5 years (1989-1993), showed that the most common indications to perform RB were urinary abnormalities (30.8%) and nephrotic syndrome (27.1%), followed by recurrent episodes of macrohaematuria (8.7%) and nephritic syndrome (5.4%). Acute renal failure was present in 9.2% of patients and chronic renal insufficiency in 18.8% of cases. Membranous gn (32.9%), focal and segmental glomerulosclerosis (12.3%), and minimal-change disease (12.0%) were the most frequent diagnoses in patients with nephrotic syndrome, while post-streptococcal gn (16.1%) and IgAN (14.0%) were frequent in the nephritic syndrome. IgAN was frequently found in patients with urinary abnormalities (29.8%) and recurrent episodes of macrohematuria (71.4%). Twenty per cent of the acute renal insufficiency cases were secondary to necrotizing vasculitis, while chronic renal failure was present in 16.6% of the IgAN patients. FUTURE TRENDS: The IRRB is considering to extend its programme to include (i) paediatric section regarding RB from patients aged less than 18 years; (ii) annual review of clinical data concerning the kidney function of selected groups of patients recorded in IRRB, and (iii) the listing of IRRB records on the INTERNET, to facilitate the distribution of information throughout the scientific community.
Glomerular C3 deposits are commonly found in immunoglobulin A (IgA) nephropathy. Renal gene expression and protein synthesis of complement components have been shown in settings of tissue inflammation. In this study, the pathogenetic involvement of locally produced C3 in IgA nephropathy was analyzed. C3 gene expression was analyzed by reverse transcription, polymerase chain reaction, and in situ hybridization techniques. C3 mRNA was detected in 56% of cases, with a significantly higher percentage in patients with moderate-to-severe lesions than in those with mild lesions (P < 0.01). By in situ hybridization, C3 transcript was predominantly expressed by tubular cells and some interstitial cells. C3 mRNA was also observed on glomerular parietal epithelial cells. Immunoreactive native C3 was detected on cortical tubuli by an anti-C3c immunoalkaline-phosphatase technique. A significant correlation was found between renal C3 transcription and glomerulosclerosis, intracapillary proliferation (both P < 0.005) and markers of interstitial damage, including tubular atrophy (P < 0.05), interstitial infiltration (P < 0.05), and fibrosis (P < 0.005). Proteinuria (P < 0.05), but not serum creatinine, at the time of renal biopsy correlated with C3 mRNA. In conclusion, it was demonstrated that the C3 gene was expressed primarily in proximal tubular cells and occasionally in glomerular crescents, and that its expression correlated with clinical and histologic markers of severity and poor outcome of IgA nephropathy. Thus, a pathogenetic involvement of the local transcription and translation of the C3 gene in IgA nephropathy was suggested.