Infusion of autologous bone marrow derived mononuclear stem cells potentially reduces urinary markers in diabetic nephropathy.

BACKGROUND: Diabetic nephropathy (DN) is the leading cause of end-stage renal disease worldwide. Previous studies demonstrated safety and efficacy of autologous bone marrow-derived mononuclear cells (ABM-MNCs) in induced type-1 diabetes mellitus (T1DM) rats. However, the effect of ABM-MNCs on urinary markers of DN in humans is not well studied. We evaluated the therapeutic effect of ABM-MNCs on the urinary markers microalbuminuria (MAU), urinary type-IV collagen and urinary neutrophil gelatinase-associated lipocalin (uNGAL) in T1DM patients with and without nephropathy. METHODS: This prospective open-label pilot study included 15 patients with T1DM, who had completed 2 visits within 6 months. Patients were divided into two groups according to the presence (DN, n = 7) and absence of nephropathy (T1DM, n = 8). ABM-MNCs were injected at each visit as per study protocol. Routine laboratory data, diabetes tests (fasting serum C-peptide and insulin, glycated hemoglobin, fasting and postprandial glucose), 24-h MAU and urinary type-IV collagen were measured at each visit. uNGAL levels were studied before and after 3 days of ABM-MNCs infusion at each visit. RESULTS: Mean age of patients was 29.2 ± 10.4 years, 33% were male, and 27% of the overall group had hypertension. MAU was significantly reduced in the overall group (- 26.0%, p = 0.037), including in DN (- 83.2%, p = 0.021). A short-term significant reduction of uNGAL levels was observed 3 days after ABM-MNCs administration during the both the 1st visit (median 13.4 vs. 9.5 ng/ml, p = 0.027) and 2nd visit (median 8.8 vs. 6.4 ng/ml, p = 0.042) in both groups. However this reduction did not remain significant at the 6-month follow-up. Urinary type-IV collagen did not respond significantly to ABM-MNCs infusion. CONCLUSION: Infusion of autologous bone marrow-derived mononuclear cells significantly reduced levels of MAU in DN patients. Further studies with larger sample size are needed to confirm these observations.

Diagnostic and prognostic role of urinary collagens in primary human bladder cancer.

Collagen type 4 alpha 1 (COL4A1) and collagen type 13 alpha 1 (COL13A1) produced by urothelial cancer cells support the vital oncogenic property of tumor invasion. We investigated the diagnostic and prognostic capability of COL4A1 and COL13A1 in voided urine and compared the observed values with those of fragments of cytokeratin-19 (CYFRA21-1), nuclear matrix protein 22 (NMP-22), and voided urine cytology in bladder cancer (BCa). We collected voided urine samples from 154 patients newly diagnosed with BCa, before surgery and from 61 control subjects. Protein levels of COL4A1, COL13A1, CYFRA21-1, and NMP-22 in urine supernatants were measured using enzyme-linked immunosorbent assays. Diagnostic performance and optimal cut-off values were determined by receiver operating characteristic analysis. Urine levels of COL4A1, COL13A1, the combined values of COL4A1 and COL13A1 (COL4A1 + COL13A1), and CYFRA21-1 were significantly elevated in urine from patients with BCa compared to the controls. Among these biomarkers, the optimal cut-off value of COL4A1 + COL13A1 at 1.33 ng/mL resulted in 57.4%, 83.7%, 56.1%, 80.7%, and 91.7% sensitivity for low-grade tumors, high-grade tumors, Ta, T1, and muscle invasive disease, respectively. We evaluated the prognostic value of preoperative urine levels in 130 non-muscle invasive BCa samples after the initial transurethral surgery. A high urinary COL4A1 + COL13A1 was found to be an independent risk factor for intravesical recurrence. Although these data need to be externally validated, urinary COL4A1 and COL13A1 could be a potential diagnostic and prognostic biomarker for BCa. This easy-to-use urinary signature identifies a subgroup of patients with a high probability of recurrence and progression in non-muscle invasive and muscle invasive BCa.

New biomarkers defining a novel early stage of Fabry nephropathy: A diagnostic test study.

BACKGROUND: Renal involvement in Fabry disease is a major determinant of overall disease prognosis and early enzyme replacement therapy seems effective in preventing progression of kidney injury. Gb3 storage, glomerular sclerosis and tubulo-interstitial fibrosis may occur with minimal or no changes on standard renal tests, hence alternative markers of renal dysfunction are crucial. In this study we compared several biomarkers with albuminuria in the identification of incipient Fabry nephropathy and their diagnostic accuracy to identify chronic kidney disease (CKD) stage≥2. METHODS: In this multicentre, prospective, cross-sectional and diagnostic test study, a cohort of 78 Fabry patients and 25 healthy controls was consecutively recruited. Patients were grouped by severity of nephropathy: 1) albuminuria<30mg/g; 2) albuminuria 30-299mg/g; 3) albuminuria>300mg/g; 4) glomerular filtration rate (GFR)<60mL/min/1.73m2. Several index tests, namely biomarkers of glomerular (transferrin and type IV collagen) and tubular (α1-microglobulin, N-acetyl-ß-glucosaminidase and alanine aminopeptidase) dysfunction were compared with the reference standard (albuminuria). RESULTS: Significant increase of all tested biomarkers in Fabry patients, even in the subgroup of patients without evidence of nephropathy. We also found inverse significant correlations between estimated GFR and collagen type IV (ρ=-0.289; p=0.003) or N-acetyl-ß-glucosaminidase (ρ=-0.448; p<0.001), which were stronger than with albumin (ρ=-0.274; p=0.019). There was also better diagnostic accuracy of N-acetyl-ß-glucosaminidase to predict CKD stage≥2. CONCLUSIONS: These results suggest that studied biomarkers may overcome the limitations of albuminuria as sensitive marker of early renal dysfunction and as marker for CKD progression risk. These biomarkers may also define novel early stages of nephropathy characterized by mesangial expansion and/or tubular damage.

Tubulointerstitial Fibrosis of Living Donor Kidneys Associates with Urinary Monocyte Chemoattractant Protein 1.

BACKGROUND: Non-invasive biomarkers that detect occult pathology in patients with normal glomerular filtration rate (GFR) and normal urine albumin excretion may help identify patients at risk for chronic kidney diseases. METHODS: Two promising biomarkers of interstitial fibrosis, urinary monocyte chemoattractant protein 1 (MCP-1) and collagen IV, were assayed among 634 living kidney donors from 2005 to 2011, who had both a frozen pre-donation spot urine sample and a core needle biopsy of their donated kidney at transplantation ('time zero biopsy'). The association of urine MCP-1 and collagen IV with kidney function (GFR and urine albumin excretion), kidney volume on computed tomographic imaging and histological findings was assessed. RESULTS: The mean ± SD age was 45 ± 12 years, 24-hour urine albumin was 4 ± 7 mg and measured GFR (mGFR) was 102 ± 18 ml/min/1.73 m2. The median (25th-75th percentile) urine level of MCP-1 was 146 (54-258) pg/ml and of collagen IV was 2.0 (1.0-3.5) µg/l. Higher urine MCP-1 associated with higher 24-hour urine albumin excretion; higher urine collagen IV associated with male gender. On kidney biopsy, any interstitial fibrosis was present in 22% and fibrosis >5% in 4% of donors. The mean MCP-1/Cr ratio was 1.49 pg/mg for 0% fibrosis, 1.80 pg/mg for 1-5% fibrosis, 2.33 pg/mg for 6-10% fibrosis and 4.33 pg/mg for >10% fibrosis. After adjustment for age, sex, mGFR and 24-hour urine albumin, higher urine MCP-1 but not collagen IV associated with interstitial fibrosis and tubular atrophy. CONCLUSION: Urine MCP-1 may detect early tubulointerstitial fibrosis in adults with normal kidney function.

Urinary angiotensinogen as a potential biomarker of intrarenal renin-angiotensin system activity in Chinese chronic kidney disease patients.

BACKGROUND: Urinary angiotensinogen (AGT) mainly derives from the AGT produced in proximal tubular cells. Evidence exists that supports the correlation between urinary AGT and circulating AGT. AIM: To investigate the role of urinary AGT as a potential biomarker of intrarenal renin-angiotensin system activity in Chinese chronic kidney disease (CKD) patients. METHODS: ELISA-based method used to quantify urinary AGT. Analyzed the relationship between urinary AGT and intrarenal angiotensin II (Ang II) activity in 128 CKD patients. ELISA was applied to measure the urinary and plasma renin activity, AGT, Ang II and aldosterone. Furthermore expression levels of intrarenal renin, AGT, Ang II and Ang II receptor were examined by immunohistochemistry staining (IHCS) in 72 CKD patients undergoing renal biopsy. RESULTS: The logarithmic transformation Log(urinary AGT/UCre) levels showed a normal distribution. Therefore, Log(urinary AGT/UCre) levels were used for the analyses. Average urinary AGT was 2.02 ± 0.55 ng/(mg Cr). Hypertension, urinary protein, urinary Ang II and urinary type IV collagen (Col IV) positively correlated with urinary AGT. Estimated glomerular filtration rate (eGFR), urinary sodium and serum AGT negatively correlated with urinary AGT. Multiple regression analysis indicated that low serum AGT, high urinary protein, urinary Ang II and urinary Col IV correlated significantly with high urinary AGT. CONCLUSIONS: We observed positive correlation between urinary AGT and positive IHCS area of AGT, Ang II and Ang II type 1 receptor in renal tissue. These data suggest that urinary AGT might be a potential biomarker of intrarenal Ang II activity in CKD patients.

[Urinary excretion of fibrogenic and antifibrotic growth factors in type 1 diabetic patients: the interrelationship with diabetic nephropathy].

AIM: To assess the relation between urinary excretion of profibrotic and antifibrotic growth factors, albuminuria and glomerular fibrosis in type 1 diabetic patients. MATERIALS AND METHODS: 64 patients with diabetes were examined, including 25 ones with normal albumin excretion rate (AER), 30 microalbuminuric and 9 macroalbuminuric patients. Urinary excretion of type IV collagen, transforming growth factor-beta 1] (TGF-beta 1), tumor necrosis factor-alpha (TNF-alpha), fibroblast growth factor-2 (FGF-2), hepatocyte growth factor (HGF) and bone morphogenetic protein-7 (BMP-7) was determined by ELISA and compared to control (10 healthy subjects). Renal biopsy specimens were assessed in 7 patients with normal AER and in 14 microalbuminuric patients. RESULTS: Type IV collagen, TGF-beta1 and TNF-alpha excretion was increased significantly in patients with micro- and macroalbuminuria as compared to control (all p<0.05). Excretion of FGF-2 was increased in macroalbuminuric patients only (p=0.003). No marked changes in excretion of antifibrotic growth factors (HGF and BMP-7) were observed. TNF-alpha and FGF-2 correlated positively with urinary type IV collagen (r=0.37 and r=0.31, respectively). The presence of glomerular fibrosis in renal biopsy specimens was associated with higher excretion of TGF-beta1, TNF-alpha and FGF-2 (all p<0.05). CONCLUSION: The results suggest that unbalance between profibrotic and antifibrotic growth factors in the kidneys plays an important role in pathogenesis of diabetic nephropathy. Urinary TGF-beta1, TNF-alpha and FGF-2 may offer new possibilities for detection of renal fibrosis in diabetic patients.

Exenatide reduces urinary transforming growth factor-ß1 and type IV collagen excretion in patients with type 2 diabetes and microalbuminuria.

AIMS: It was reported that exenatide ameliorated renal injury in diabetic rats. The present study was carried out to evaluate the effect of exenatide on 24-hour urinary albumin, urinary transforming growth factor-ß(1) (TGF-ß(1)) and type IV collagen excretion in patients with type 2 diabetes and microalbuminuria. METHODS: 31 type 2 diabetic patients with microalbuminuria were randomly allocated to receive exenatide (group Exe, n = 13) or glimepiride treatment (group Glm, n = 18) for 16 weeks. Body mass index (BMI), fasting plasma glucose, 2-hour postprandial plasma glucose, glycated hemoglobin A(1c), systolic blood pressure, diastolic blood pressure, 24-hour urinary albumin, urinary TGF-ß(1) and type IV collagen concentration were analyzed between the two treatment groups. 20 age- and BMI-matched healthy subjects were chosen as the normal control group (group NC, n = 20). RESULTS: After 16 weeks of treatment, 24-hour urinary albumin, urinary TGF-ß(1) and type IV collagen in group Exe were significantly lower than those of group Glm (p < 0.01), while glycemic control had no statistical difference between the two groups. CONCLUSIONS: Our results indicate that exenatide reduces urinary TGF-ß(1) and type IV collagen excretion in patients with type 2 diabetes and microalbuminuria, which may be partly contributory to its directly renoprotective role.

[Determination of urinary markers of proteolysis/fibrinolysis and fibroangiogenesis in the kidney in hypertensive patients].

AIM: To determine clinical significance of urinary biomarkers of proteolysis/fibrinolysis and fibroangiogenesis in essential hypertension (EH). MATERIAL AND METHODS: Examination of the kidneys was made in 71 patients with EH degree 1-3. Renal function was assessed by 24-h albuminuria, calculated glomerular filtration rate (GFR) by Cockroft-Golt. Early signs of renal damage were microalbuminuria--MAU (diurnal albuminuria 30-300 mg/day), reduction of GFR (< 90 ml/min/1.73 m2). EH patients with hypercreatininemia and GFR under 60 ml/min/1.73m2 corresponding to stage III of chronic kidney disease were not included in the study. An additional nephropathy marker was an elevated index of resistance of interlobular renal arteries (RI > 0.65) as shown by dopplerometry. ELISA examined urinary biomarkers of intercellular and cell-matrix interactions in the kidney in EHpatients and healthy controls (n = 12). RESULTS: MAU was detected in 54 (76%) of 71 EH patients, elevated RI > 0.65--in 37 (52%) patients. Urinary biomarkers of proteolysis/fibrinolysis and fibroangiogenesis were higher in EH patients then in the controls. Urinary excretion of PAI-1, TGF-beta1, VEGF and collagen of type IV in EH patients with MAU was significantly higher than in patients with normoalbuminuria. A strong direct correlation between MAU and the rest above urinary biomarkers was found as well as between urinary excretion of collagen IV and RI. An inverse negative relationship was seen between RI and GFR. CONCLUSION: Renal impairment in EHpatients is a progressive disorder. Each stage of this process has its own clinicodiagnostic markers. Urinary biomarkers ofproteolysis/fibrinolysis and fibroangiogenesis in the kidney are informative for monitoring of early HNP.

Urinary type IV collagen in nondiabetic kidney disease.

BACKGROUND: Type IV collagen is one of the major components of basement membrane. In diabetic nephropathy, it is already known that urinary excretion of type IV collagen increases with the disease progression. However, in nondiabetic kidney disease, urinary type IV collagen (u-IVc) levels have not been extensively investigated. The aim of this study was to evaluate u-IVc levels in various nephropathies except diabetic nephropathy. METHODS: u-IVc levels were measured cross-sectionally from 527 biopsy-proven nondiabetic renal disease patients at tertiary care hospitals by one-step sandwich enzyme immunoassay. RESULTS: On simple regression analyses, u-IVc levels had positive correlation with age, blood pressure, urinary protein (u-Prot), urinary ß(2) microglobulin, urinary N-acetyl-ß-D-glucosaminidase, HbA(1)c, and selectivity index (SI), while u-IVc had negative correlation with eGFR and serum albumin. Multiple regression analyses revealed that u-IVc was positively correlated with u-Prot, HbA(1)c and SI. Among biopsy-proven nondiabetic nephropathies, elevation of u-IVc was distinctively observed in membranous nephropathy and anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis. CONCLUSION: u-IVc levels were elevated with the increase in u-Prot, HbA(1)c and SI. In addition, among nondiabetic kidney disease, elevation of u-IVc was observed in patients with membranous nephropathy and ANCA, which might reflect the thickening of basement membrane or severe kidney damage.

Urinary biomarkers for monitoring disease progression in the Han:SPRD-cy rat model of autosomal-dominant polycystic kidney disease.

The Han:SRPD-cy rat is a well-recognized model of human autosomal-dominant polycystic kidney disease. The disease is characterized by the development of progressive renal cysts, leading to declining renal function. Disease progression typically is monitored by measurement of plasma urea concentration. Although plasma urea may be an adequate measure of overall renal function, urinary biomarkers capable of accurately monitoring disease progression may be equally useful. The goal of this study was to assess several urinary biomarkers as potential markers of disease progression in male and female Han:SPRD-cy rats. These biomarkers were compared with changes in plasma urea concentration and morphometric changes as the disease progressed. Urinary activity of N-acetyl-ß-D-glucosaminidase and concentration of α-glutathione S-transferase were measured as markers of proximal tubular dysfunction, glutathione S-transferase Yb1 as a distal tubular marker, and collagen IV as a biomarker for glomerular lesions. Urinary albumin was used as biomarker of glomerular or proximal tubular lesions. Albuminuria increased in male rats as the disease progressed, correlating with increasing plasma urea and morphologic changes. Urine concentrations of α-glutathione S-transferase decreased significantly in the male heterozygotic compared with wildtype rats in the later stages of the disease. Urinary concentrations of glutathione S-transferase Yb1 and collagen IV and activity of N-acetyl-ß-D-glucosaminidase did not change during disease progression. Measurement of urinary albumin and concentrations of α-glutathione S-transferase may be useful for monitoring disease progression in the male Han:SPRD-cy rat model in future experiments.

[Clinical usefulness of measurement of urine type IV collagen for detection of early phase of nephropathy in type 2 diabetic patients].

Urine type IV collagen concentrations in type 2 diabetic patients were measured by enzyme immunoassay which has crossreactivity with only intact type IV collagen, and the clinical usefulness for estimating the early phase of diabetic nephropathy was evaluated. Precision of the measurement system was satisfactory for clinical use and the value did not influenced by the presence of sediments in urine. In whole type 2 diabetic patients (N=132), urine type IV collagen concentration (microg/g of creatinine) increased with development of nephropathy and showed significantly increase even in normoalbuminuria when compared with that in normal control subjects (N=117). In type 2 diabetic patients (N=100) with mild microalbuminuria (less than 100 mg/g of creatinine), multiple regression analysis revealed that HbA1C was extracted as a significant valuable for urine type IV collagen, while body mass index was extracted as a significant valuable for urine albumin. In these subjects, urine type IV collagen was significantly lower in the patients with good metabolic control (HbA1C<8.0%) than those with poor control (HbA1> or =8.0%), while the urine albumin was not significantly different between those two groups. These results suggest that measurement of urine type IV collagen in type 2 diabetic patients is useful for detection of early phase of diabetic nephropathy.

Antiinflammatory and antifibrogenic effects of s-ethyl cysteine and s-methyl cysteine in the kidney of diabetic mice.

Protective effects of s-ethyl cysteine (SEC) and s-methyl cysteine (SMC) in kidney of diabetic mice were examined. SEC and SMC at 0.5, 1, 1.5, 2 g/L were added to the drinking water for 6 wk. Results showed that the intake of SEC or SMC alleviated body weight loss and urine output, as well as markedly decreased plasma blood urea nitrogen (BUN) and creatinine clearance (CCr) in diabetic mice (P < 0.05). The intake of SEC caused significantly dose-dependent increase in insulin and decrease in blood glucose, urinary albumin and type IV collagen (P < 0.05). SEC and SMC intake significantly and dose-dependently decreased malondialdehyde level and increased glutathione content in kidney (P < 0.05). The intake of these agents also increased renal GPx activity (P < 0.05), but there was no dose-dependent effect. SEC treatments dose-dependently decreased IL-6 and TNF-alpha levels, increased IL-4 and IL-10 levels, as well as upregulated IL-10 mRNA expression (P < 0.05). SMC treatments significantly suppressed renal IL-6 and TNF-alpha levels (P < 0.05), but did not affect IL-4 and IL-10 levels (P < 0.05). SEC or SMC intake significantly suppressed renal TGF-beta1 level and renal PKC activity (P < 0.05); however, only SEC treatments showed dose-dependent effect. SEC and SMC treatments significantly down-regulated mRNA expression of renal TGF-beta1 (P < 0.05), only SEC treatments had dose-dependent effects. Based on the observed antioxidative, antiinflammatory, and antifibrogenic effects, the supplement of SEC or SMC might be helpful for the prevention or treatment of diabetic kidney diseases.

Evidence linking glycated albumin to altered glomerular nephrin and VEGF expression, proteinuria, and diabetic nephropathy.

BACKGROUND: Albumin modified by Amadori-glucose adducts has been linked to the development of diabetic nephropathy through its ability, independent of hyperglycemia, to activate protein kinase C-beta (PKC-beta), up-regulate the transforming growth factor-beta (TGF-beta) system, and stimulate expression of extracellular matrix proteins in glomerular cells, and by the demonstration that reducing the burden of glycated albumin ameliorates renal structural and functional abnormalities in the db/db mouse. METHODS: To probe whether the salutary effects consequent to lowering glycated albumin, which include reduction of albuminuria, relate to an influence of the Amadori-modified protein on nephrin, the podocyte protein critical to regulation of protein excretion, and on the angiogenic vascular endothelial growth factor (VEGF), which induces microvascular permeability, diabetic db/db mice were treated with a small molecule that inhibits the nonenzymatic glycation of albumin. RESULTS: Compared to nondiabetic db/m mice, diabetic controls exhibited increased urinary excretion of albumin and type IV collagen, elevated renal TGF-beta1 protein levels, reduced glomerular nephrin immunofluorescence and nephrin protein by immunoblotting, and increased glomerular VEGF immunostaining and renal VEGF protein content. Diabetic animals receiving test compound showed significant lowering of proteinuria, normalization of renal TGF-beta1 protein, and significant restoration of altered glomerular nephrin and VEGF expression. CONCLUSION: The findings causally implicate the increased glycated albumin associated with the diabetic state in the abnormal renal nephrin and VEGF expression found in diabetes, thereby promoting proteinuria and glomerulosclerosis.

Cigarette smoking exacerbates and its cessation ameliorates renal injury in type 2 diabetes.

BACKGROUND: Patients with type 2 diabetes and macroalbuminuria generally experience progressive glomerular filtration rate (GFR) decline despite angiotensin-converting enzyme inhibition (ACEI) and blood pressure (BP) control but this therapy generally stabilizes GFR in those without macroalbuminuria. Cigarette smoking exacerbates GFR decline in patients with type 2 diabetes and macroalbuminuria despite ACEI and BP control; whether this therapy prevents nephropathy progression in nonmacroalbuminuric type 2 diabetic smokers is unknown. METHODS: We determined the course of urine excretion of indices of renal injury that distinguished patients with type 2 diabetes with and without macroalbuminuria but with normal plasma creatinine who were prospectively followed 6 months while receiving ACEI and BP control. We compared this course in nonsmokers and smokers with normo-, micro-, and macroalbuminuria (n = 157) and in response to smoking cessation in a separate cohort (n = 80) with microalbuminuria. RESULTS: Urine excretion of transforming growth factor beta-1 (UTGFbetaV) increased in macroalbuminuric but not in nonmacroalbuminuric nonsmokers and UTGFbetaV rate was higher in smokers than nonsmokers within each albuminuria group. In the separate microalbuminuric cohort, the rate of UTGFbetaV change for quitting smokers was not different from nonsmokers (0.093 versus -0.123 ng/g of creatine/week, P = not significant) but that for nonquitting smokers (0.970) was higher than nonsmokers (P = 0.017). CONCLUSIONS: Patients with type 2 diabetes who are at high risk compared with low risk for nephropathy progression have progressive renal injury as measured by increasing UTGFbetaV. Cigarette smoking exacerbates renal injury in type 2 diabetes despite BP control and ACEI, but its cessation in those with microalbuminuria ameliorates the progressive renal injury caused by continued smoking.

Relationship between levels of urinary type IV collagen and renal injuries in patients with IgA nephropathy.

Because type IV collagen is synthesized by podocytes and mesangial cells, we investigated the relationship between levels of urinary type IV collagen (uIV) and renal injuries in patients with IgA nephropathy. uIV was measured by a highly sensitive one-step sandwich enzyme immunoassay prior to renal biopsy. Patients with IgA nephropathy were classified into four grades (grade 1 = good prognosis, grade 2 = relatively good prognosis, grade 3 = relatively poor prognosis, and grade 4 = poor prognosis) by the prognostic criteria of the Ministry of Health, Labor, and Welfare of Japan. Levels of uIV in grade 4 were significantly higher than those in grades 1-3. These levels tended to increase gradually due to progression of renal injuries. The grades were further divided into two groups: group I (good or relatively good prognoses) and group II (relatively poor or poor prognoses). Patients with proteinuria of <1.0 g/day were defined as groups Ip and IIp. The levels of uIV in group II were significantly higher than those in group I, and those in group IIp were significantly higher than those in group Ip. It appears that the level of uIV can be a useful marker for detection of renal injuries in IgA nephropathy.

[Additive antiproteinuric effect of angiotensin II receptor antagonist and angiotensin-converting enzyme inhibitor in patients with chronic glomerulonephritis].

Angiotensin II type-1 receptor blocker (ARB) and angiotensin-converting enzyme inhibitor (ACEI) have been thought to be effective for reducing proteinuria in patients with chronic glomerulonephritis. Recently, an additive effect of these two types of angiotensin blockers has been reported in patients with IgA nephropathy, but the mechanism responsible for the effect has not yet been determined. In this study, we examined additive effect of these two drugs in chronic glomerulonephritis patients. Ten patients with biopsy-proven primary glomerulonephritis (eight IgA nephropathy patients, two membranous nephropathy patients), non-nephrotic proteinuria (protein, 0.5 to 3.5 g/day) received candesartan cilexetil (2 or 4 mg) for 8 weeks. After the 8 weeks, a combination of perindopril erbumine (1 or 2 mg) and candesartan cilexetil was administered to the patients. Perindopril was stopped after the 8-week administration of the two drugs. Candesartan alone reduced proteinuria by 13%. Combination of these two drugs induced a more remarkable reduction of proteinuria (48%; p < 0.05 vs other periods). The decrease in mean blood pressure by the combination therapy was significantly correlated with the decrease in proteinuria. The combination of drugs also reduced the amount of urinary type-IV collagen excretion. An additive effect of ACEI and ARB on proteinuria and urinary type-IV collagen excretion was recognized in patients with chronic glomerulonephritis.

Matrix metalloproteinase activity in urine of patients with renal cell carcinoma leads to degradation of extracellular matrix proteins: possible use as a screening assay.

PURPOSE: Localized renal cell carcinoma is usually curable by nephrectomy. However, a large fraction of patients already present with metastatic disease, which results in a poor outcome. Currently no clinically relevant screening assay is available to detect early stage renal cell carcinoma. We investigated whether urinary extracellular matrix (ECM) proteins and/or matrix metalloproteinase (MMP) activity may be valuable as a noninvasive indicator of early stage renal cell carcinoma. MATERIALS AND METHODS: Urine specimens from preoperative patients with renal cell carcinoma and healthy controls were collected. The urinary excretion of the ECM proteins collagen IV, laminin and fibronectin was investigated by immunoblotting. MMP activity was assessed by gelatin zymography and by a fluorescence based microtiter plate activity assay. RESULTS: The full-length forms of all 3 ECM proteins investigated were significantly decreased or absent in renal cell carcinoma urine. Based on criteria established in this study this finding would lead to the correct detection of 95% of patients with renal cell carcinoma (21 of 22) with a false-positive rate of 4.5% (1 of 22 controls). All 11 nonmetastatic cases of the lowest clinical stage (T1N0M0) were correctly identified. The absence of urinary ECM proteins was due to significantly increased urinary MMP activity. CONCLUSIONS: Analysis of decreased urinary ECM proteins and analysis of increased MMP activity may have value for the development of a sensitive, high throughput molecular screening assay to detect early stage renal cell carcinoma.

Analysis of collagen IV and fibronectin in blood and urine in evaluation of nephrotic fibrosis in children with chronic glomerulonephritis.

BACKGROUND: Changes in the concentration of extracellular matrix components in body fluids may reflect the degree of kidney fibrosis. The aim of our study was to evaluate fibronectin (FN) and type IV collagen (COL IV) concentrations in blood serum and urine, and to refer these values to immunoreactivity in renal biopsy material. MATERIAL/METHODS: Our research involved 37 children with glomerulonephritis (GN) aged 4-15 and 18 healthy children. The patients were divided into 3 groups according to the histopathological diagnosis of GN: I - minimal change GN (MCGN, n=17), II - lupus nephritis (LN, n=7), III - other types of GN (n=13). RESULTS: Significantly higher COL IV concentrations in serum and urine were noted in the patient group in comparison to the controls, but no differences in FN concentrations. The highest values of serum and urine COL IV were observed in the LN patients. Positive correlation was found between serum and urine COL IV and its renal content in the LN group. CONCLUSIONS: The results indicate that serum and urine COL IV rises in children with GN, above all in the course of LN. This also reflects changes in renal COL IV content.

Tranilast slows the progression of advanced diabetic nephropathy.

BACKGROUND: Tranilast, N-(3,4-dimethoxycinnamoyl) anthranilic acid, suppresses collagen synthesis by various cells, including macrophages and fibroblasts, by interfering with the actions of transforming growth factor-beta 1. We investigated the effect of tranilast on progression of diabetic nephropathy (DN), since this process is associated with accumulation of collagens in the glomerulus and interstitium. METHODS: Tranilast (100 mg, 3 times daily) was administered to 9 outpatients with advanced DN who were receiving an angiotensin-converting enzyme inhibitor or an angiotensin II receptor antagonist and who exhibited a progressive decline in renal function. The decline in renal function before and during tranilast treatment was evaluated for each patient on the basis of the slope in reciprocal serum creatinine (1/S(Cr)) over time. Urinary type IV collagen (U-IV.C) and protein (U-P) excretions were measured just before commencement of tranilast treatment and every 2 months during the treatment. RESULTS: One male patient dropped out soon after commencement of tranilast treatment due to development of lung cancer, and hemodialysis was introduced in one female patient 6 months after the start of treatment. In the 8 patients who did not drop out, 1/S(Cr) was significantly less steep during tranilast treatment than before treatment (-0.00748 +/- 0.00700 vs. -0.01348 +/- 0.00636 dl/mg/month, respectively; p = 0.0374). U-IV.C and U-P tended to decrease with time, although the decrease was statistically insignificant. CONCLUSIONS: Our data suggest that tranilast treatment may suppress accumulation of collagens in renal tissue and may be therapeutically useful for reducing the progression of advanced DN.

Urinary type IV collagen: a specific indicator of incipient diabetic nephropathy.

OBJECTIVE: To determine whether urinary type IV collagen can serve as an indicator specific for diabetic nephropathy. METHODS: Using a novel sandwich ABC-ELISA to measure type IV collagen directly, the 24-hour urinary type IV collagen excretion rate was determined in 120 diabetic patients and some groups of controls. Urinary albumin determinations were made with a RIA kit at the same time. A total of 13 diabetic patients with microalbuminuria underwent percutaneous renal biopsy for definitive diagnosis of diabetic nephropathy. Type IV collagen and TGF-beta 1 immunoreactivities were detected with ABC methods in renal biopsies. RESULTS: Urinary type IV collagen excretion was significantly increased in diabetic patients with microalbuminuria, especially those with albumin excretion above 200 mg/24 h. By comparison, collagen excretion was equivalent to that in healthy controls when measured in diabetics with normalbuminuria and in patients with primary glomerular disease, primary hypertension, or coronary heart disease. Urinary type IV collagen excretion in diabetics was negatively correlated with creatinine clearance. In renal biopsies from subjects with elevated collagen excretion, the glomeruli showed pathological changes typical of diabetic nephropathy. Also, excessive type IV collagen and TGF-beta 1 immunoreactivity were detected in the glomeruli, Bowman's capsule and interstitium. CONCLUSIONS: Excretion of type IV collagen, possibly reflecting increased production or decreased degradation of this protein, may be a clinically useful indicator of incipient diabetic nephropathy.