Application of Surface Plasmon Resonance Imaging Biosensors for Determination of Fibronectin, Laminin-5, and Type IV Collagen in Plasma, Urine, and Tissue of Renal Cell Carcinoma.

Laminin, fibronectin, and collagen IV are pivotal extracellular matrix (ECM) components. The ECM environment governs the fundamental properties of tumors, including proliferation, vascularization, and invasion. Given the critical role of cell-matrix adhesion in malignant tumor progression, we hypothesize that the concentrations of these proteins may be altered in the plasma of patients with clear cell renal cell carcinoma (ccRCC). This study aimed to evaluate the serum, urine, and tissue levels of laminin-5, collagen IV, and fibronectin among a control group and ccRCC patients, with the latter divided into stages T1-T2 and T3-T4 according to the TNM classification. We included 60 patients with histopathologically confirmed ccRCC and 26 patients diagnosed with chronic cystitis or benign prostatic hyperplasia (BPH). Collagen IV, laminin-5, and fibronectin were detected using Surface Plasmon Resonance Imaging biosensors. Significant differences were observed between the control group and ccRCC patients, as well as between the T1-T2 and T3-T4 subgroups. Levels were generally higher in plasma and tissue for fibronectin and collagen IV in ccRCC patients and lower for laminin. The ROC (Receiver operating characteristic) analysis yielded satisfactory results for differentiating between ccRCC patients and controls (AUC 0.84-0.93), with statistical significance for both fibronectin and laminin in plasma and urine. Analysis between the T1-T2 and T3-T4 groups revealed interesting findings for all examined substances in plasma (AUC 0.8-0.95). The results suggest a positive correlation between fibronectin and collagen levels and ccRCC staging, while laminin shows a negative correlation, implying a potential protective role. The relationship between plasma and urine concentrations of these biomarkers may be instrumental for tumor detection and staging, thereby streamlining therapeutic decision-making.

Plasma type IV collagen levels as a potential biomarker for early detection of nephropathy in diabetes mellitus patients.

Diabetic nephropathy represents a microvascular complication related to type 2 diabetes mellitus (T2DM) that ultimately causes end-stage renal disease. Our study aimed to evaluate the association of plasma type IV collagen with albuminuria status and to assess the clinical significance of plasma type IV collagen as a potential biomarker in the early stage of diabetic nephropathy. The study comprised 75 participants diagnosed with T2DM allocated equally (n=25) into three groups: (A) normal albuminuria levels, (B) microalbuminuria, and (C) macroalbuminuria, depending on their urine albumin-to-creatinine ratio. A comparative analysis was conducted between these groups and a control group (D, n=15). The enzyme-linked immunosorbent assay (ELISA) method was employed for measuring plasma type IV collagen levels. The results revealed that plasma type IV collagen levels were significantly higher in T2DM groups than in the control group. Moreover, diabetic patients without albuminuria had significantly higher plasma type IV collagen levels than the control group (p < 0.001). Furthermore, albuminuria levels among diabetic patient groups were significantly increased as albuminuria categories increased (p < 0.001). A significant positive correlation existed between plasma type IV collagen and glycated hemoglobin (HbA1c) levels in the macroalbuminuric diabetic group. Our study employed the receiver operating characteristic (ROC) curve analysis to determine plasma type IV collagen diagnostic utility in macroalbuminuria prediction. The ROC curve analysis revealed that type IV collagen can significantly determine macroalbuminuric patients at a cutoff value of 2.25 with sensitivity, specificity, positive predictive value, and negative predictive value of 68%, 100%, 100%, and 75.8%, respectively (p < 0.001). In conclusion, plasma type IV collagen levels might serve as a valuable predictor of albuminuria onset in patients with T2DM.

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.

Urinary type IV collagen excretion is involved in the decline in estimated glomerular filtration rate in the Japanese general population without diabetes: A 5-year observational study.

Urinary type IV collagen (U-Col4) and albumin excretion is evaluated to monitor the development of diabetic kidney disease. However, U-Col4 excretion in the general population without diabetes has not yet been fully elucidated. In this study, 1067 participants without diabetes and with urinary albumin-creatinine ratio <300 mg/gCr (normo- or microalbuminuria) who underwent an annual health examination in 2004 were enrolled and observed for 5 years. They were divided according to the amount of U-Col4 or urinary albumin excreted. The decline in estimated glomerular filtration rate (eGFR) was calculated. In participants with eGFR ≥80 mL/min, abnormal U-Col4 excretion was indicated as a significant independent risk factor for 10% eGFR change per year, which is one of the prognostic factors for the development of end-stage kidney disease. Moreover, in contrast to urinary albumin excretion, U-Col4 excretion was not related to age or kidney function, suggesting that some individuals with abnormal U-Col4 excretion can have an independent hidden risk for the development of kidney dysfunction. In conclusion, it is important to measure U-Col4 excretion in the general population without diabetes to determine changes in renal features in every individual and help detect future complications such as diabetic kidney disease. If U-Col4 excretion is abnormal, kidney manifestation should be carefully followed up, even if the kidney function and urinalysis findings are normal.

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.

[Kidney injury molecules (KIM-1, MCP-1) and type IV collagen in the assessment of activity of antineutrophil cytoplasmic antibody-associated glomerulonephritis]. / Molekuly povrezhdeniia pochechnoi tkani (KIM-1, MCP-1) i kollagen IV tipa v otsenke aktivnosti assotsiirovannogo s antineitrofil'nymi tsitoplazmaticheskimi antitelami glomerulonefrita.

AIM: To assess the significance of determining the serum and urinary concentrations of monocyte chemotactic protein-1 (MCP-1), kidney injury molecule-1 (KIM-1), and type IV collagen in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) to estimate the activity of renal involvement in AAV. SUBJECTS AND METHODS: 78 patients (32 men and 46 women) (median age 55 (45; 61) years) with AAV were examined. The patients were divided into 3 groups according to the AAV activity estimated using the Birmingham vasculitis activity Score (BVAS): 1) 25 patients with active ANCA-associated glomerulonephritis (GN); 2) 26 patients with active AAV without renal involvement; 3) 27 patients in sustained AAV remission. The serum and urinary concentrations of the markers were measured by enzyme immunoassay. RESULTS: The urinary concentration of all 3 biomarkers was higher in patients with renal involvement (Group 1); the differences in the levels of MCP-1 and type IV collagen were statistically significant as compared to Groups 2 and 3 (p<0.01), while that in KIM-1 level was only in Group 2. There were statistically significant correlations between the urinary concentration of these biomarkers and the traditional GN activity indices (erythrocyturia, daily proteinuria (DPU), total BVAS scores that reflect renal involvement, as well as serum creatinine levels and estimated glomerular filtration rate (p<0.05). ROC curve analysis showed that the urinary MCP-1 excretion of ≥159 pg/ml had the highest (92%) sensitivity and urinary type IV collagen excretion of ≥3.09 µg/l had the highest (86%) specificity in assessing the activity of ANCA-associated GN. At the same time, their diagnostic value increased in terms of a combination of DPU and ESR (96% sensitivity, 84.9% specificity). CONCLUSION: The urinary excretion of MCP-1, KIM-1, and type IV collagen reflects the severity of local renal inflammation in AAV patients and a study of these indicators is a promising diagnostic tool for assessing the activity of ANCA-associated GN.

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.

Camel milk attenuates the biochemical and morphological features of diabetic nephropathy: inhibition of Smad1 and collagen type IV synthesis.

Diabetic nephropathy (DN) is a common microvascular complication of diabetes mellitus (DM) that worsens its morbidity and mortality. There is evidence that camel milk (CM) improves the glycemic control in DM but its effect on the renal complications especially the DN remains unclear. Thus the current study aimed to characterize the effects of CM treatment on streptozotocin (STZ)-induced DN. Using STZ-induced diabetes, we investigated the effect of CM treatment on kidney function, proteinuria, renal Smad1, collagen type IV (Col4), blood glucose, insulin resistance (IR), lipid peroxidation, the antioxidant superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH). In addition renal morphology was also examined. The current results showed that rats with untreated diabetes exhibited marked hyperglycemia, IR, high serum urea and creatinine levels, excessive proteinuria, increased renal Smad1 and Col4, glomerular expansion, and extracellular matrix deposition. There was also increased lipid peroxidation products, decreased antioxidant enzyme activity and GSH levels. Camel milk treatment decreased blood glucose, IR, and lipid peroxidation. Superoxide dismutase and CAT expression, CAT activity, and GSH levels were increased. The renoprotective effects of CM were demonstrated by the decreased serum urea and creatinine, proteinuria, Smad1, Col4, and preserved normal tubulo-glomerular morphology. In conclusion, beside its hypoglycemic action, CM attenuates the early changes of DN, decreased renal Smad1 and Col4. This could be attributed to a primary action on the glomerular mesangial cells, or secondarily to the hypoglycemic and antioxidant effects of CM. The protective effects of CM against DN support its use as an adjuvant anti-diabetes therapy.

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 type IV collagen is related to left ventricular diastolic function and brain natriuretic peptide in hypertensive patients with prediabetes.

AIM: Urinary type IV collagen is an early biomarker of diabetic nephropathy. Concomitant prediabetes (the early stage of diabetes) was associated with left ventricular (LV) diastolic dysfunction and increased brain natriuretic peptide (BNP) in hypertensive patients. We hypothesized that urinary type IV collagen may be related to these cardiac dysfunctions. METHODS: We studied hypertensive patients with early prediabetes (HbA1c <5.7% and fasting glucose >110, n=18), those with prediabetes (HbA1c 5.7-6.4, n=98), and those with diabetes (HbA1c>6.5 or on diabetes medications, n=92). The participants underwent echocardiography to assess left atrial volume/body surface area (BSA) and the ratio of early mitral flow velocity to mitral annular velocity (E/e'). Left ventricular diastolic dysfunction (LVDD) was defined if patients had E/e'≥15, or E/e'=9-14 accompanied by left atrial volume/BSA≥32ml/mm(2). Urinary samples were collected for type IV collagen and albumin, and blood samples were taken for BNP and HbA1c. RESULTS: Urinary type IV collagen and albumin increased in parallel with the deterioration of glycemic status. In hypertensive patients with prediabetes, subjects with LVDD had higher levels of BNP and urinary type IV collagen than those without LVDD. In contrast, in hypertensive patients with diabetes, subjects with LVDD had higher urinary albumin and BNP than those without LVDD. Urinary type IV collagen correlated positively with BNP in hypertensive patients with prediabetes, whereas it correlated with HbA1c in those with diabetes. CONCLUSIONS: In hypertensive patients with prediabetes, urinary type IV collagen was associated with LV diastolic dysfunction and BNP.

Urinary type IV collagen as a predictor for the incidence of microalbuminuria in young patients with Type 1 diabetes.

AIMS: To clarify whether urinary type IV collagen-to-creatinine ratio is a predictor for the incidence of microalbuminuria in patients with Type 1 diabetes. METHODS: A longitudinal observational cohort study was conducted; the subjects included normoalbuminuric patients diagnosed with Type 1 diabetes before the age of 30 years and who were less than 40 years old at the start of the observation. In total, 225 patients were enrolled (age, mean ± SD: 25 ± 5 years; male: 32.9%). The endpoint was the incidence of microalbuminuria, defined as 30 mg/g Cr ≤ urinary albumin-to-creatinine ratio < 300 mg/g Cr. Patients were divided into two groups based on the median of urinary type IV collagen-to-creatinine ratio levels. RESULTS: During the median follow-up period of 8.8 years (range 1.0-12.8 years), 13 patients with high urinary type IV collagen-to-creatinine ratio progressed to microalbuminuria. Meanwhile, only one patient with low urinary type IV collagen-to-creatinine ratio reached the endpoint. Kaplan-Meier estimates for the time to reach the endpoint were significantly faster for patients with a high ratio than for those with a low ratio (log-rank test, P < 0.001). In the multivariate Cox hazard analysis, the hazard ratio for patients with high vs. low urinary type IV collagen-to-creatinine ratio was 13.51 (95% CI 1.59-115.02, P = 0.017). When urinary type IV collagen-to-creatinine ratio was treated as a continuous variable, logarithmically transformed urinary type IV collagen-to-creatinine ratio, but not baseline albumin-to-creatinine ratio, was independently associated with reaching the endpoint (hazard ratio 19.23, 95% CI 1.53-242.30, P = 0.022). CONCLUSIONS: Urinary type IV collagen may be an important predictor for the incidence of microalbuminuria in young patients with Type 1 diabetes.

The angiotensin II type 1 receptor blocker olmesartan preferentially improves nocturnal hypertension and proteinuria in chronic kidney disease.

Accumulated evidence suggests that an altered ambulatory blood pressure (BP) profile, particularly elevated nighttime BP, reflects target organ injury and is a better predictor of further cardiorenal risk than the clinic BP or daytime BP in hypertensive patients complicated by chronic kidney disease (CKD). In this study, we examined the beneficial effects of olmesartan, an angiotensin II type 1 receptor blocker (ARB), on ambulatory BP profiles and renal function in hypertensive CKD patients. Forty-six patients were randomly assigned to the olmesartan add-on group (n=23) or the non-ARB group (n=23). At baseline and after the 16-week treatment period, ambulatory BP monitoring was performed and renal function parameter measurements were collected. Although the baseline clinic BP levels and the after-treatment/baseline (A/B) ratios of clinic BP levels were similar in the olmesartan add-on and non-ARB groups, the A/B ratios of ambulatory 24-h and nighttime BP levels in the olmesartan add-on group were significantly lower. Furthermore, the A/B ratios of urinary protein, albumin and type IV collagen excretion in the olmesartan add-on group were significantly lower than those in the non-ARB group (urinary protein excretion, 0.72±0.41 vs. 1.45±1.48, P=0.030; urinary albumin excretion, 0.73±0.37 vs. 1.50±1.37, P=0.005; urinary type IV collagen excretion, 0.87±0.42 vs. 1.48±0.87, P=0.014) despite comparable A/B ratios for the estimated glomerular filtration rate in the two groups. These results indicate that in hypertensive patients with CKD, olmesartan add-on therapy improves the ambulatory BP profile via a preferential reduction in nighttime BP with concomitant renal injury inhibition.

[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.

Relationship between renal hemodynamics and urinary type IV collagen in patients with essential hypertension.

Urinary type IV collagen excretion (uT4C) in diabetic patients is higher than in normal subjects. In this study, we investigated the relationship between uT4C and renal hemodynamics in 42 patients with essential hypertension. The renal resistive index (RI) is calculated from blood flow velocities measured using pulsed-wave in interlobar arteries. There was a significant correlation between uT4C to creatinine ratio (uT4C/uCr) and age, hemoglobin A1c (HbA1c), and RI. A stepwise regression analysis showed that RI was independently associated with uT4C/uCr. These results indicated that uT4C may be a marker of renovascular stiffness due to glomerulosclerosis in patients with essential hypertension.

Association of urinary type IV collagen with GFR decline in young patients with type 1 diabetes.

BACKGROUND: Some patients with diabetes have advanced diabetic glomerular lesions and progressive kidney function decline even if urinary albumin levels are in the normal range. Therefore, another prognostic marker for diabetic kidney disease needs to be identified. We aimed to clarify whether urinary type IV collagen is associated with the progression of kidney function decline in patients with type 1 diabetes. STUDY DESIGN: Hospital-based observational cohort study. SETTING & PARTICIPANTS: 231 normo- and microalbuminuric patients with type 1 diabetes who were younger than 40 years at the start of the study. PREDICTOR & MEASUREMENTS: Urinary type IV collagen, determined using a 1-step sandwich enzyme immunoassay. OUTCOME: The primary outcome measurement was rate of change in estimated glomerular filtration rate (eGFR). RESULTS: Mean follow-up was 7.4 ± 1.3 (standard deviation) years. Urinary type IV collagen-creatinine ratio (T4C) was associated significantly with rate of change in eGFR in both univariate (r = -0.169; P = 0.01) and multivariate regression analyses (standardized estimate = -0.131; P = 0.03). In the sensitivity analysis limited to patients with normoalbuminuria (n = 213), T4C, but not urinary albumin-creatinine ratio (ACR), was associated significantly with rate of change in eGFR (standardized estimate = -0.12; P = 0.03). The interaction between logarithmically transformed ACR and logarithmically transformed T4C on eGFR decline was not significant (P for interaction = 0.2). We compared the adjusted rate of change in eGFR among 4 groups classified according to normal or increased T4C and ACR values and found that the rate of decline in eGFR in patients with increased T4C and normal ACR values was significantly faster than that in patients with normal T4C and ACR values (-4.3 and -3.0 mL/min/1.73 m(2)/y; P = 0.004, analysis of covariance). LIMITATIONS: Study size was relatively small. CONCLUSIONS: T4C is associated with progression of kidney function decline in young patients with type 1 diabetes.

[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.

Diabetic nephropathy in humans: pathologic diversity.

PURPOSE OF REVIEW: Both type 1 and type 2 diabetes are associated with severe complications including diabetic nephropathy. With the rapidly rising number of patients with diabetes worldwide, diabetic nephropathy is becoming one of the most common causes of renal disease. Much research effort is being put into how to identify diabetic nephropathy in patients with diabetes. A considerable number of biomarker studies were recently published on markers in plasma or urine, either with the aim to distinguish patients with or without diabetic nephropathy, or with the aim to predict renal outcome in those patients with diabetic nephropathy. We review the most recent findings on this subject and discuss the lack of histologically proven diabetic nephropathy in the majority of these studies. RECENT FINDINGS: Most conspicuous in the field of diabetic nephropathy was the recent identification of a number of biomarkers used either in the diagnosis of diabetic nephropathy or in the evaluation of therapies meant to prevent, slow down, or reverse the processes causing diabetic nephropathy. For the histopathology of diabetic nephropathy, a new classification system was launched in 2010, which will be discussed together with future perspectives. SUMMARY: Combining histopathological grading of and biomarkers for diabetic nephropathy will further our understanding of this complex disease manifestation.