Frequent COL4 mutations in familial microhematuria accompanied by later-onset Alport nephropathy due to focal segmental glomerulosclerosis.

Familial microscopic hematuria (FMH) is associated with a genetically heterogeneous group of conditions including the collagen-IV nephropathies, the heritable C3/CFHR5 nephropathy and the glomerulopathy with fibronectin deposits. The clinical course varies widely, ranging from isolated benign familial hematuria to end-stage renal disease (ESRD) later in life. We investigated 24 families using next generation sequencing (NGS) for 5 genes: COL4A3, COL4A4, COL4A5, CFHR5 and FN1. In 17 families (71%), we found 15 pathogenic mutations in COL4A3/A4/A5, 9 of them novel. In 5 families patients inherited classical AS with hemizygous X-linked COL4A5 mutations. Even more patients developed later-onset Alport-related nephropathy having inherited heterozygous COL4A3/A4 mutations that cause thin basement membranes. Amongst 62 heterozygous or hemizygous patients, 8 (13%) reached ESRD, while 25% of patients with heterozygous COL4A3/A4 mutations, aged >50-years, reached ESRD. In conclusion, COL4A mutations comprise a frequent cause of FMH. Heterozygous COL4A3/A4 mutations predispose to renal function impairment, supporting that thin basement membrane nephropathy is not always benign. The molecular diagnosis is essential for differentiating the X-linked from the autosomal recessive and dominant inheritance. Finally, NGS technology is established as the gold standard for the diagnosis of FMH and associated collagen-IV glomerulopathies, frequently averting the need for invasive renal biopsies.

The Significance of Inflow Artery and Tourniquet Derived Cephalic Vein Diameters on Predicting Successful Use and Patency of Arteriovenous Fistulas for Haemodialysis.

OBJECTIVE: To investigate the significance of inflow artery and cephalic vein diameters on predicting patency of radiocephalic and brachiocephalic arteriovenous fistulas (AVFs). DESIGN: Single centre study with retrospective analysis of prospectively collected data between November 2010 and July 2015. METHODS: A detailed history and physical examination was undertaken, including age, gender, history and duration of haemodialysis, cause of chronic kidney disease, and the presence of comorbidities/risk factors. Pre-operative arterial and venous upper extremity mapping was performed and inner vessel diameter was recorded, using a tourniquet for the veins. Outcome measures included AVF use (functionality), primary, primary assisted, secondary, and functional secondary patency. RESULTS: One hundred and thirty five AVFs (57 and 78 radiocephalic and brachiocephalic AVFs, respectively) were constructed and followed up for 5 years. A cephalic vein diameter <4.3 mm (lower three quartiles) was the single independent predictor of inferior secondary and also functional secondary patency of radiocephalic AVFs (p = .02, HR 11.2, 95% CI 1.44-90.9). A brachial artery diameter ≤4.1 mm (lowest quartile) was an independent predictor of AVF functionality (57% vs. 83% for larger arteries, p = .017), and inferior primary, primary assisted, secondary, and functional secondary patency of brachiocephalic AVFs (primary assisted patency 21.9% vs. 55.9% at 3 years, p = .001/log-rank test, HR 3.1, p = .002/Cox regression). The presence of lower extremity PAD or use of dual antithrombotics was also independently associated with an inferior secondary patency. The number of risk factors (brachial artery diameter ≤4.1 mm, PAD, and use of dual antithrombotics) demonstrated risk stratification capabilities for functional secondary patency. CONCLUSIONS: Among patients undergoing radiocephalic AVFs, a tourniquet derived cephalic vein diameter <4.3 mm was the single independent predictor of inferior secondary and functional secondary patency. Among patients undergoing brachiocephalic AVFs, all patency rates were inferior in the presence of a brachial artery diameter ≤4.1 mm and secondary patency was inferior in the presence of multiple risk factors.

Outcome of transplantation in renal allograft recipients from cadaveric donors with standard and expanded criteria: a single-center experience.

INTRODUCTION: The increasing number of patients requiring kidney transplantation and the lack of available organs has led to the utilization of kidneys from expanded criteria donors (ECD). AIM: The comparison of the clinical outcome of renal transplantation, performed in a single center, between allograft recipients from standard (SCD) and expanded criteria donors (ECD). PATIENTS AND METHODS: Data from 215 cadaveric renal transplantations performed during a 16 year period at the University Hospital of Patras were retrospectively studied. Donors' and recipients' characteristics (gender, age, history of hypertension and diabetes mellitus, cold ischemia time, post-transplant and long term graft function) were analyzed. RESULTS: Grafts from donors with expanded criteria (ECD, n = 53) were allocated to older recipients whereas grafts from donors with standard criteria (SCD, n = 162) were allocated to younger recipients. The mean cold ischemia time was 1,146 min and was similar between the two groups of patients. Patients' survival rates were similar between allograft recipients from SCD and ECD up to the 5(th) post-transplant year of follow-up. Graft survival was significantly better in allograft recipients from SCD during a 5-year follow-up period. A significantly lower eGFR was noted in allograft recipients from ECD in comparison to those from SCD throughout the observation period. Cold ischemia time was positively correlated to the development of DGF, while patients with DGF had significantly worse graft function throughout the observation period. CONCLUSION: Patient survival from ECD is comparable to that from SCD but graft survival is significantly lower. However, since renal function of recipients from ECD is adequate for long term period, grafts from ECD should be used in older patients.

Parameters influencing blood erythropoietin levels of renal transplant recipients during the early post-transplantation period.

AIM: Renal transplantation is accompanied by restoration of renal function and endogenous erythropoietin production. The purpose of this study was to investigate the time-related changes of endogenous erythropoietin secretion in the early renal post-transplant period and the influence of various parameters to this process. METHODS: Fifty-eight patients were enrolled in the study and followed up for 3 months after successful renal transplantation. Erythropoietin levels were measured at regular intervals and correlated with renal function, cold ischemia time and immunosuppressive regimen used. RESULTS: Two peaks of serum erythropoietin levels were observed: an early peak that occurred within two days after transplantation and a late one, between weeks 2 and 4, which resulted in increased blood hemoglobin levels. Factors that were found to correlate with erythropoietin levels were delayed graft function, cyclosporine use and prolonged cold ischemia time. Serum creatinine did not correlate to erythropoietin levels although the reduction of serum creatinine preceded the rise of erythropoietin levels. Normal hemoglobin values were restored about three months after successful renal transplantation. CONCLUSION: Serum erythropoietin levels increase during the early post-transplantation period resulting in correction of anemia three months after a successful renal transplantation. Restoration of allograft function is a prerequisite for erythropoietin secretion, while cold ischemia time and immunosuppressive regimen affect graft function.

Gastrointestinal disorders after renal transplantation.

BACKGROUND: Gastrointestinal disorders (GDs) are common in renal transplant recipients. The main cause of GDs seems to be the use of immunosuppressive medications, especially mycophenolic acid in the form of mycophenolate mofetil (MMF). OBJECTIVE: The aim of this study was to estimate the frequency and severity of GDs in renal allograft recipients with the use of the Gastrointestinal Symptom Rating Scale (GSRS). METHODS: Eighty-five renal allograft recipients, 50 ± 12 years old, treated with methylprednisolone, calcineurin inhibitor (cyclosporine [CsA], n = 42; tacrolimus (TAC), n = 43), and MMF were studied. RESULTS: At the time of completion of the GSRS questionnaire, 38 of the 85 patients (45%) already had their MMF dose reduced because of GDs. Only 15 patients (18%) were totally free from GDs. The most frequent and severe GDs recorded were indigestion and diarrhea who were significantly more frequent in women (P = .045). GDs were recorded in patients receiving both standard and reduced dose of MMF. MMF dose was significantly associated only with diarrhea. Although TAC-treated patients had the highest mean GSRS scores, no statistically significant differences were observed compared with CsA-treated patients. In 31 patients, MMF was replaced by enteric-coated mycophenolate sodium (EC-MPS) and new questionnaires were completed 1 month later. Significant improvement in total and all subscores of GSRS was demonstrated (P < .001). Although EC-MPS dose tolerated by the patients was higher than MMF dose, the difference was not statistically significant. CONCLUSIONS: Female sex and the use of MMF, especially in combination with TAC, are related to the occurrence of severe gastrointestinal symptoms. Substitution of MMF with EC-MPS significantly reduces the severity of symptoms and permits the use of higher doses.

Antiplatelet effects of prasugrel vs. double clopidogrel in patients on hemodialysis and with high on-treatment platelet reactivity.

BACKGROUND: High on-treatment platelet reactivity (HTPR) is frequent in patients on hemodialysis (HD) receiving clopidrogel. OBJECTIVES: The primary aim of this study was to determine the antiplatelet effects of prasugrel vs. high-dose clopidogrel in patients on HD with HTPR. PATIENTS/METHODS: We performed a prospective, single-center, single-blind, investigator-initiated, randomized, crossover study to compare platelet inhibition by prasugrel 10 mg day(-1) with that by high-dose 150 mg day(-1) clopidogrel in 21 patients on chronic HD with HTPR. Platelet function was assessed with the VerifyNow assay, and genotyping was performed for CYP2C19*2 carriage. RESULTS: The primary endpoint of platelet reactivity (PR, measured in P2Y12 reaction units [PRU]) was lower in patients receiving prasugrel (least squares [LS] estimate 156.6, 95% confidence interval [CI] 132.2-181.1) than in those receiving high-dose clopidogrel (LS 279.9, 95% CI 255.4-304.3), P < 0.001). The LS mean differences between the two treatments were - 113.4 PRU (95% CI - 152.9 to - 73.8, P < 0.001) and - 163.8 PRU (95% CI - 218.1 to - 109.2, P < 0.001) in non-carriers and carriers of at least one CYP2C19*2 allele, respectively. HTPR rates were lower for prasugrel than clopidogrel, in all patients (19% vs. 85.7%, P < 0.001) and in non-carriers (25.7% vs. 80%, P = 0.003). All carriers continued to show HTPR while receiving high-dose clopidogrel, but none showed it while receiving prasugrel. CONCLUSIONS: In HD patients exhibiting HTPR following standard clopidogrel treatment, prasugrel 10 mg day(-1) is significantly more efficient than doubling the clopidogrel dosage in achieving adequate platelet inhibition. Neither effect seems to be influenced by carriage of the loss-of-function CYP2C19*2 allele.

Urinary interleukin-6 (IL-6) and transforming growth factor (TGF-ß) levels in corticosteroidtreated patients with IgA nephropathy.

BACKGROUND: Interleukin-6 (IL-6) and transforming growth factor-ß (TGF-ß) are implicated in the progression of IgA nephropathy, which is usually treated with corticosteroids. PATIENTS AND METHODS: Urinary IL-6 and TGF-ß were measured in 21 proteinuric patients with IgA nephropathy, before and after treatment with corticosteroids, to estimate the activity of the disease after remission of proteinuria. RESULTS: Urinary IL-6 and TGF-ß levels at diagnosis were significantly higher in patients with IgA nephropathy compared to healthy subjects. TGF-ß levels, were significantly higher in patients with proteinuria > 1 g/24 h and/or severe mesangial proliferation. Although a significant reduction of proteinuria was observed with corticosteroid treatment, urinary IL-6 and TGF-ß levels remained elevated. Deterioration of renal function over a period of 5 years was observed in 3 patients. High urinary IL-6 levels at diagnosis represent a significant parameter distinguishing patients with progressive course in comparison to those with favorable clinical outcome (p = 0.01). CONCLUSION: Treatment of patients with IgA nephropathy with corticosteroids is followed by remission of proteinuria but still increased urinary IL-6 and TGF-ß excretion. This may be related to an ongoing inflammatory process within the kidney, and further research is required to estimate the value of urinary IL-6 and TGF-ß as markers of activity of the disease.

Expression of transgelin in human glomerulonephritis of various etiology.

BACKGROUND/AIMS: Activation of myofibroblasts occurs during kidney injury. Genomic and proteomic studies suggest that transgelin represents a protein that may be involved in renal injury. The purpose of this study was to estimate transgelin expression in the renal tissue of patients with glomerulonephritis. METHODS: Transgelin was identified in biopsy sections of 67 patients by immunohistochemistry and immunofluorescence. Its distribution was compared to that of α-smooth muscle actin (α-SMA), a marker of myofibroblast activation in the kidney. RESULTS: Transgelin and α-SMA expression was identified within glomeruli and interstitium. In patients with IgA nephropathy and focal segmental glomerulosclerosis, glomerular expression of transgelin was higher than that of α-SMA. The extent of transgelin immunostaining was related to mesangial proliferation (p = 0.034), glomerular sclerosis (p = 0.035), interstitial fibrosis (p = 0.047) and to the clinical course (p = 0.009). Colocalization studies showed that in some areas of kidney tissue both proteins were expressed with comparable intensity, whereas in other areas expression of either transgelin or α-SMA was predominant. CONCLUSION: Strong transgelin expression was observed in renal tissue of patients with glomerulonephritis. The observed differences in the pattern of transgelin and α-SMA expression suggest that either different subpopulations of myofibroblasts exist, or that these proteins are activated at different stages of renal injury/scarring.

Cyclosporin A in adult patients with Henoch-Schönlein purpura nephritis and nephrotic syndrome; 5 case reports.

Henoch-Schönlein purpura (HSP) is usually followed by mild renal involvement, but heavy proteinuria may also occur. Limited experience with cyclosporin A in children shows reduction of proteinuria. In this report, the use of cyclosporin A in 5 adult HSP patients with nephrotic-range proteinuria is described. Cyclosporin A in combination with prednisolone was given in 3 patients with HSP nephritis and nephrotic syndrome after a course of other immunosuppressive drugs and in 2 patients as initial treatment. All patients showed complete or partial remission of nephrotic syndrome with cyclosporin A and preserved stable renal function over a follow-up period of 5 years. We conclude that the combination of cyclosporin A with corticosteroids is effective in inducing remission of nephrotic syndrome in adult patients with HSP nephritis.

Ezetimibe is effective in the treatment of persistent hyperlipidemia of renal allograft recipients.

INTRODUCTION: Ezetimibe is a hypolipidemic agent acting via inhibition of cholesterol absorption from the small intestine. The effectiveness and safety of long-term administration of ezetimibe was evaluated in renal allograft recipients with persistent hyperlipidemia. PATIENTS AND METHODS: 67 renal allograft recipients with post-transplantation hyperlipidemia resistant to statins were included in the study; 11 were treated with ezetimibe (10 mg/day) alone and 56 with ezetimibe and statin. The effectiveness of ezetimibe was assessed by determination of total cholesterol (TC), LDL cholesterol (LDL-C), HDL cholesterol (HDL-C) and triglycerides (TR). Its safety was determined by liver enzymes (ALT, AST), LDH, CPK, serum creatinine and blood levels of immunosuppressive drugs (cyclosporine, tacrolimus, everolimus, sirolimus) over the follow-up period of 18±6 months. RESULTS: A significant reduction of TC and LDL-C blood levels by 25% and 34% respectively, was observed during the first month of treatment with ezetimibe (p<0.001). This reduction was maintained for the whole period of ezetimibe administration. Renal function remained stable over the follow-up period, while no changes of the blood levels of immunosuppressive drugs were observed. Liver enzymes, LDH and CPK remained normal in all patients except for one diabetic patient who developed rhabdomyolysis. Apart from gastrointestinal symptoms in 2 patients, no other side effects were observed. CONCLUSION: Combination of ezetimibe with statins represents an effective and safe regimen for treatment of persistent hyperlipidemia in renal allograft recipients.

Male-female differences in the risk of tuberculosis in dialysis patients.

AIM: To define any gender-related differences in the prevalence and risk for tuberculosis (TB) in hemodialysis (HD) patients. METHODS: All active TB cases were recorded during a 36-month follow-up of 272 (193 male and 79 female) HD patients. Entering the study, HD patients were tested with tuberculin and 2,4-dinitrochlorobenzene, and a cell-mediated immunity (CMI) index was estimated. Relative risks (RR) for TB were calculated considering subjects from the background general population as a reference group. The independent effect of age, BMI and tuberculin sensitivity was determined using Cox's proportional hazard model. RESULTS: Female HD patients presented significantly lower CMI indices and rates of positive Mantoux tests, but higher rates of DM, as compared to males. The male:female ratio in TB for the general and HD patients population was 1.8 and 0.6, respectively. There was a significantly lower TB prevalence in male as compared to female HD patients (7.7% vs. 11.3%), and a subsequent female predominance in risk for TB in those HD patients aged <49 and 50-69 years (M:F adjusted relative risk 0.67 and 0.53) was recorded. CONCLUSIONS: In contrast to the general population, there is a female predominance among dialysis TB patients younger than 70 years associated with the coexistence of DM. Female gender should always be considered as a risk factor when evaluating diabetic HD patients for active TB.

Microchimerism in peripheral blood and urine in renal transplant recipients: preliminary results.

The role of microchimerism in peripheral blood and urine of renal transplant recipients remains a matter of debate, depending on the sensitivity of the methods used for detection. We studied 17 female renal transplant recipients who had received renal allografts from male donors. Polymerase chain reaction (PCR) was applied to blood and urine for the microsatellite markers D1S80, DYZ1, TH01, and kalphai SE33. Detection of DYZ1 that is present only on the Y chromosome was considered proof for microchimerism. No microchimerism was detected in peripheral blood, whereas it could be detected in the urine of 8/17 (48%) patients. There were no differences between patients with and without microchimerism regarding patient age, dialysis vintage, immunosuppression, time post-transplantation, and allograft function as measured using serum creatinine, creatinine clearance, and proteinuria. Two patients in each group showed chronic allograft dysfunction. These findings raise questions regarding the role of microchimerism in renal transplantation.

Cyclosporin-A in the treatment of nephrotic syndrome: the importance of monitoring C0 (trough) and C2 (two hours after its administration) blood levels.

Cyclosporin-A (CsA) is often used in the treatment of nephrotic syndrome. The effectiveness of CsA and the value of C2 blood levels in the treatment of nephrotic syndrome, due to various glomerular diseases, were studied. Forty-two nephrotic patients (M/F 21/21), with well-preserved renal function (creatinine clearance 87+/-20 ml/min) were included in the study. The original diagnoses were minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), membranous nephropathy (MN), IgA nephropathy (IgAN), and lupus nephritis (LN). All patients were treated with prednisolone and CsA for 24 months. Cyclosporin-A C0 and C2 blood levels were determined at regular intervals. Remission of the nephrotic syndrome was observed in all patients with MCD, IgAN and LN, in 75% with FSGS and in 83% with MN. Relapses were observed in some patients with MCD (25%) and MN (36%). The C0 levels were 93+/-15 ng/ml and the corresponding C2 levels were 498+/-110 ng/ml. However, significantly lower (340+/-83 ng/ml) or higher (680+/-127 ng/ml) to the average C2 levels were found in 6 patients (14%). No relation of C0 and C2 levels with the remission and relapse rate of the nephrotic syndrome and with renal function impairment was observed. Small doses of CsA with prednisolone are effective in the treatment of nephrotic syndrome. Although an individual variation of C2 was observed for the same target C0 levels, no relation of C2 levels was found with the remission or relapse rate of the nephrotic syndrome.

Prednisolone and azathioprine in membranous nephropathy: a 10-year follow-up study.

BACKGROUND: Idiopathic membranous nephropathy (IMN) is the most common cause of nephrotic syndrome in adults. Although its clinical course is usually benign, some patients develop chronic renal failure. Combination of corticosteroids with cytotoxic drugs and cyclosporin have been used in the treatment of the disease. Conflicting results are reported with the use ofprednisolone and azathioprine. In this study, the effect of treatment with prednisolone and azathioprine and the parameters related to a poor outcome over a follow-up period of 10 years is estimated. METHODS: 50 patients were included in this study; 33 were treated with prednisolone (initially 60 mg/day) and azathioprine (initially 2 mg/kg body weight/day) in gradually reduced doses for 26 +/- 9 months, whereas 17 patients received no immunosuppressive drugs. The clinical course was estimated using the end-points of doubling of baseline serum creatinine and/or end-stage renal failure (ESRF). The contribution of clinical and histological parameters in the clinical outcome was examined by univariate and multivariate analyses. RESULTS: Doubling of baseline serum creatinine was observed in 20 of 50 patients (40%), 14 from treated and 6 from the untreated group (42% vs. 35%, p=NS). ESRF developed in 10 of 50 patients (20%), 7 from treated and 3 from the untreated group (21% vs. 18%, p=NS). Most patients from both groups who reached the end-points had impaired renal function at presentation and persistent nephrotic syndrome during the follow-up period. Both parameters were identified as independent risk factors related to an unfavorable clinical outcome. No difference in the remission rate of nephrotic syndrome was observed between treated and untreated patients (51% vs. 58%, p=NS). CONCLUSION: Treatment with prednisolone and azathioprine seems to be of no long-term benefit in ameliorating the clinical course of nephrotic patients with membranous nephropathy. Thus, other therapeutic regimens including cyclophosphamide, chlorambucil or cyclosporin should be used in nephrotic IMN patients with poor prognostic features.

The remission of nephrotic syndrome with cyclosporin treatment does not attenuate the progression of idiopathic membranous nephropathy.

BACKGROUND: Idiopathic membranous nephropathy (IMN), a common cause of nephrotic syndrome in adults, is usually treated by combination of corticosteroids with cytotoxic drugs. In cases resistant to this regimen, the use of cyclosporin A (CsA) is followed by frequent remissions of the nephrotic syndrome. AIM: The purpose of this study was to estimate the effectiveness of prednisolone and small doses of CsA as first-line treatment of nephrotic patients with IMN, in relation to the progression of the disease, based on functional and histological changes. PATIENTS AND METHODS: Sixteen patients, with nephrotic syndrome due to IMN and well-preserved renal function, were treated with prednisolone (starting dose: 0.5 mg/kg bw/day) and CsA (starting dose: 3 mg/kg bw/day) for 24 months. A repeat renal biopsy was performed after 18 months of treatment in 10 patients with remission of nephrotic syndrome, to estimate the activity of the disease and to identify any features of CsA toxicity. RESULTS: Remission of the nephrotic syndrome was observed in 14 out of 16 patients after 5 +/- 2 months of treatment. Complete remission was observed in 8 and partial remission in 6 patients (urinary protein was reduced from 6.9 +/- 3.4-0.2 +/- 0.06 g/24 h and 1.2 +/- 1.0 g/24 h, respectively, p < 0.01). The renal function was well preserved in 13 out of 16 patients over a 24-month period of treatment. Deterioration of renal function was observed in 3 patients (creatinine clearance reduced from 86 +/- 21-37 +/- 17 ml/min, p < 0.05) who had either persistent nephrotic syndrome or frequent relapses. Relapses of the nephrotic syndrome were observed in 5 of 14 patients. Repeat renal biopsies showed that glomerular sclerosis, tubulointerstitial injury, vascular hyalinosis and stage of the disease were deteriorated in most patients. Isometric vacuolization of tubular epithelial cells was observed in 2 of 10 patients. CONCLUSION: IMN nephrotic patients treated with prednisolone and low doses of cyclosporin A showed a high remission rate of nephrotic syndrome. However, progression of chronic histological lesions was found in repeat renal biopsies. This suggests that cyclosporin can frequently induce remission of nephrotic syndrome in IMN patients, but even low doses of the drug are not free of potential renal toxicity.

Endothelin-1 in the kidney and urine of patients with glomerular disease and proteinuria.

BACKGROUND: Endothelin-1 (ET-1) is a strong vasoconstrictive peptide that is involved in the pathogenesis of arterial hypertension. There is increasing evidence, based on studies in experimental animals, that endothelin-1 is produced by tubular epithelial cells in response to activation by filtered protein and is involved in the development of renal scarring. The aim of this study is to examine the distribution of ET-1 in the renal tissue of patients with heavy proteinuria and to estimate the changes in its urinary excretion after immunosuppressive therapy. PATIENTS AND METHODS: Twenty-four patients with severe proteinuria (7.5 +/- 6.5 g/24 h) due to different types of glomerular disease and normal renal function (creatinine clearance 91 +/- 14 ml/ min) were investigated. All patients underwent a renal biopsy and commenced on immunosuppressive therapy with corticosteroids and cyclosporin A. The localization of ET-1 in the renal tissue was examined by immunohistochemistry and compared to control renal tissue from 9 patients who underwent nephrectomies because of hypernephroma. In patients with proteinuria, endothelin-1 excretion in the urine at diagnosis was determined by radioimmunoassay and compared to that of 14 healthy subjects. A second measurement of urinary ET-1 excretion was performed after remission of proteinuria or 6 months after the initiation of treatment in patients with persistent nephrotic syndrome. RESULTS: ET-1 in renal tissue of patients and controls was localized within the cytoplasm of endothelial cells. In nephrotic patients, it was also localized within the cytoplasm of tubular epithelial cells. Urinary ET-1 levels were higher in nephrotic patients compared to healthy subjects (746 +/- 180 ng/24 h vs 410 +/- 112 ng/ml, p < 0.001). In 17 of 24 patients who showed remission of proteinuria with immunosuppressive therapy, the urinary ET-1 levels decreased (from 803 +/- 168 ng/24 h to 511 +/- 80 ng/24 h, p < 0.001) whereas in 7 patients with persistent proteinuria, urinary ET-1 excretion remained elevated. CONCLUSIONS: The increased urinary excretion of ET-1 in patients with severe proteinuria followed by a significant decrease after remission ofproteinuria with immunosuppressive treatment, along with its expression within tubular epithelial cells, suggests a possible relationship between proteinuria and renal ET-1 production.

Transforming growth factor-beta(1) and myofibroblasts: a potential pathway towards renal scarring in human glomerular disease.

BACKGROUND/AIMS: The cellular and humoral factors involved in the development and progression of renal scarring have not been fully investigated. Transforming growth factor-beta (TGF-beta(1)) is considered to be the main fibrogenic growth factor and it is implicated in the pathogenesis of renal fibrosis in experimental and clinical nephropathies. On the other hand, collagen III is an important component of the extracellular matrix. In this study we attempted to identify any possible links between TGF-beta(1) and collagen III synthesis and expression with the expression of myofibroblasts in the evolution of renal scarring in human glomerular diseases. METHODS: We studied retrospectively 40 patients with various types of primary and secondary glomerulonephritis (GN), with either proliferative or nonproliferative pattern, with emphasis on the renal synthesis of TGF-beta(1) and collagen III (detected by in situ hybridization) and their expression (detected by immunohistochemistry) as well as myofibroblast expression. The possible links of TGF-beta(1) expression with myofibroblast distribution (alpha-smooth muscle actin, alpha-SMA(+) cells) and with conventional histopathology and renal function was also examined. RESULTS: TGF-beta(1) protein and mRNA were detected in the renal tubular epithelial cells and interstitium and to a lesser extent within glomeruli of patients with GN. Collagen III was mainly detected in the interstitium (peritubular and periglomerular areas) and to a lesser extent in the glomeruli. Messenger RNA for collagen III followed a similar peritubular and periglomerular distribution to that of TGF-beta(1) and alpha-SMA(+) interstitial cells. The intensity of interstitial TGF-beta(1) protein expression was significantly related to the degree of interstitial fibrosis (r = 0.628, p < 0.01), tubular atrophy (r = 0.612, p < 0.01), interstitial collagen III expression (r = 0.478, p < 0.05), and serum creatinine values (r = 0.722, p < 0.001). Also there was a close positive correlation between the severity of interstitial myofibroblast expression and interstitial TGF-beta(1) (r = 0.412, p < 0.05), as well as collagen III (r = 0.409, p < 0.05). In addition, a significant correlation was found between glomerular TGF-beta(1) expression and severity of glomerulosclerosis (r = 0.620, p < 0.01). CONCLUSION: The results of this study suggest that TGF-beta(1) plays an important role in the pathogenesis of fibrosis developing in human kidney, during the evolution of glomerular disease. Interstitial myofibroblasts may contribute to interstitial fibrosis through the synthesis and release of both TGF-beta1 and collagen III.

Polymorphonuclear leukocyte rigidity is defective in patients with chronic renal failure.

BACKGROUND: The purpose of the study was to investigate the rigidity of polymorphonuclear leukocytes (PMNs) in non-dialysed chronic renal failure (CRF) and haemodialysis (HD) patients. METHODS: PMN rigidity as well as tumour necrosis factor alpha (TNF-alpha) and interleukin 1beta (IL-1beta) plasma levels were assessed in 10 early-stage CRF, 10 late-stage non-HD, and 10 HD patients, before and during dialysis. In HD patients both cellulose acetate and polysulphone membranes were used. Ten healthy subjects served as controls. Rigidity was tested by counting the deformability in morphologically passive PMNs by the micropipette method. Cytokine levels were measured by enzyme-linked immunosorbent assay. RESULTS: PMN rigidity was significantly increased in end-stage CRF patients regardless of HD but not in early-stage CRF. In HD patients PMN rigidity increased significantly 60 min after initiation of HD. There was an increase of TNF-alpha and IL-1beta levels in end-stage non-HD and HD patients and a further increase at 60 min after initiation of HD. The percentage of morphologically activated PMNs was increased only during dialysis. The nature of the HD membrane had no influence on rigidity, PMN activation, or cytokine production. CONCLUSIONS: The results indicate that PMN rigidity is defective in end-stage chronic CRF patients and is further increased 60 min after initiation of HD, regardless of the nature of the HD membrane used. PMN activation, increased TNF-alpha and IL-1beta levels, or a direct PMN impairment may cause the observed cell rigidity.