Effect of fetal growth restriction on urinary podocalyxin levels at birth in preterm neonates.

BACKGROUND: Small-for-gestational-age (SGA) neonates are at a higher risk of adult-onset metabolic disorders because of fetal programming in the presence of growth restriction. Nephrogenesis may also be affected in fetal growth restriction. This study hypothesized that urinary podocalyxin levels, a marker of nephrogenesis, would be lower among preterm SGA neonates as compared to appropriate-for-gestational-age (AGA) controls. METHODS: This cross-sectional study enrolled gestation-matched SGA (n = 90) and AGA (n = 45) neonates born at 260-366 weeks of gestation. The SGA group comprised of 45 neonates with birth weight between 3rd and 10th centile and 45 neonates with birth weight <3rd centile. The primary outcome of the study was the difference in urinary podocalyxin levels between SGA and AGA neonates. Glomerular and tubular functions were also assessed. RESULTS: Urinary podocalyxin levels were similar in SGA and AGA neonates (ng/mg of creatinine; median [interquartile range]: 28.7 [4.8-70.2] vs. 18.7 [3.1-55.9]), P value 0.14). No correlation was observed between birth weight centile and urinary podocalyxin levels (r: -0.06). Glomerular filtration rate, fractional excretion of sodium, and serum ß-2-microglobulin levels were comparable across the study groups. CONCLUSIONS: Glomerular development as assessed by urinary podocalyxin levels and renal functions are comparable in SGA and AGA preterm neonates. IMPACT: Neonates born with fetal growth restriction are at a higher risk of adult-onset metabolic disorders because of fetal programming. This cross-sectional study investigated the effect of presence and severity of fetal growth restriction on glomerular development by measuring urinary podocalyxin levels in preterm infants. This study did not observe any effect of the presence or severity of fetal growth restriction on urinary podocalyxin levels and other markers of glomerular and renal tubular functions.

The correlation of urinary podocytes and podocalyxin with histological features of lupus nephritis.

Objectives The objective of this study was to test the correlation of urinary podocyte number (U-Pod) and urinary podocalyxin levels (U-PCX) with histology of lupus nephritis. Methods This was an observational, cross-sectional study. Sixty-four patients were enrolled: 40 with lupus nephritis and 24 without lupus nephritis (12 lupus nephritis patients in complete remission and 12 systemic lupus erythematosus patients without lupus nephritis). Urine samples were collected before initiating treatment. U-Pod was determined by counting podocalyxin-positive cells, and U-PCX was measured by sandwich ELISA, normalized to urinary creatinine levels (U-Pod/Cr, U-PCX/Cr). Results Lupus nephritis patients showed significantly higher U-Pod/Cr and U-PCX/Cr compared with patients without lupus nephritis. U-Pod/Cr was high in proliferative lupus nephritis (class III±V/IV±V), especially in pure class IV (4.57 (2.02-16.75)), but low in pure class V (0.30 (0.00-0.71)). U-Pod/Cr showed a positive correlation with activity index ( r=0.50, P=0.0012) and was independently associated with cellular crescent formation. In contrast, U-PCX/Cr was high in both proliferative and membranous lupus nephritis. Receiver operating characteristic analysis revealed significant correlation of U-Pod/Cr with pure class IV, class IV±V and cellular crescent formation, and the combined values of U-Pod/Cr and U-PCX/Cr were shown to be associated with pure class V. Conclusions U-Pod/Cr and U-PCX/Cr correlate with histological features of lupus nephritis.

Urinary podocalyxin as a possible novel marker of intrauterine nephrogenesis and extrauterine podocyte injury.

BACKGROUND: The number of nephrons at birth is determined during fetal development and is modulated thereafter by postnatal podocyte injury. Hyperfiltration, caused by a reduced number of nephrons, is a risk factor for chronic kidney disease. It is therefore important to monitor the formation of nephrons. METHODS: Urine samples were collected from infants within 1-2 days of birth, with follow-up sampling for preterm infants at 37-39 weeks of corrected age. Urinary levels of podocalyxin (PCX), ß2-microglobulin (ß2MG), N-acetyl-ß-D-glucosaminidase (NAG), total protein (TP), microalbumin (mAlb) and creatinine were measured and the relationship between these markers evaluated. RESULTS: Seventy-nine neonates were enrolled in this study. Urinary levels of PCX at birth were higher than normal adult reference values, with levels increasing up to a gestational age of 36 weeks (p = 0.0242). At 37-39 weeks corrected age, urinary levels of PCX decreased to adult levels. The levels of PCX in the urine at birth were not correlated to urinary levels of ß2MG, NAG, TP and mAlb. CONCLUSIONS: An increased urinary level of PCX may be a marker of both active nephron formation and podocyte injury sustained at birth. As such, changes in urinary levels of PCX are likely to reflect adaptation of renal function to the extra-uterine environment.

The Podocyte Count Detected by an Improved Immunocytochemical Method has Higher Diagnostic Efficiency than Enzyme-Linked Immunosorbent Assay and Serum Cystatin C to Evaluate the Early Stage Damage of Glomerular.

BACKGROUND: In renal diseases, earlier injury to glomerular may lead to the abscission of podocyte. The number of podocyte in urine may reflect the severity of glomerular damage. Podocalyxin (PCX) was considered as a podocyte marker. Many methods were used to detect podocyte. Applications of these methods were limited by tricky, expensive, and low accuracy. Here, we improved an immunocytochemical method to count the number of podocyte in urine. METHODS: In this study, we counted the numbers of podocyte in urine by our improved method and detected the PCX levels in urine by enzyme-linked immunosorbent assay (ELISA) in glomerulopathy patients and healthy controls. The serum levels of cystatin C (CysC), blood urea nitrogen (BUN), creatinine (CR), uric acid (URIC), and ß2-Microglobulin (ß2-MG) in all subjects were detected. Correlation analysis and diagnostic efficiencies comparisons among immuocytochemical method, ELISA, and the biochemistry index were also performed. RESULTS: The podocyte counts in patients were significantly higher than controls. Podocytes counts positively correlated with PCX concentrations and the serum CysC. The podocyte count had higher diagnostic efficiency than PCX concentrations detected by ELISA and serum CysC. CONCLUSIONS: The podocyte count detected by our improved method had higher diagnostic efficiency than ELISA and serum CysC.

Urinary podocalyxin levels were associated with urinary albumin levels among patients with diabetes.

Diabetic nephropathy has dramatically increased worldwide. In this study, we measured urinary podocalyxin in 240 patients with diabetes. The relationship between urinary podocalyxin and clinical parameters and the effects of dipeptidyl peptidase-4 inhibitors (DPP4i) and alpha-glucosidase inhibitor (a-GI) on urinary podocalyxin levels were examined. Urinary podocalyxin levels were significantly higher in patients with microalbuminuria than in those with normoalbuminuria. Urinary podocalyxin levels were also significantly related to albumin-to-creatinine ratio. Neither DPP4i nor α-GI ameliorated the increase in urinary podocalyxin levels. Our results indicated that urinary podocalyxin will be not only an early marker but also a treatment target for DN.

[Research on the Combined Detection of Urine UmAlb and Urinary Nephrin, Podocalyxin in Podocyte of MKR Mice with Diabetic Nephropathy].

OBJECTIVE: To explore the combined detection of urine UmAlb and urinary nephrin (Unephrin), podocalyxin (UPCX) in podocyte of MKR mice with diabetic nephropathy. METHODS: Thirty 8 weeks old MKR mice were randomly divided into two groups as follows: negative control group, DN model group, and another 15 wild C57 mice were used as normal control. Mice in DN model group were received unilateral nephrectomy and high-fat diet feed for 2 months. The morphological structure changes of the podocytes were observed by transmission electron microscopes. The levels of FBG were detected by electrochemical detection method, The nephrin and PCX protein expression were measured by western blotting. The levels of UmAlb, Unephrin and UPCX were detected by ELISA. RESULTS: The podocyte damage in the mice of DN model group increased significantly when compared with normal control. As compared with normal control, FBG in the model group increased significantly (P<0. 01), the expression level of nephrin and PCX in Renal Tissue and Unephrin, UPCX, and urine UmAlb were also increased significantly (P<0. 01). CONCLUSION: The level of Unephrin and UPCX were positive correlated with the level of urine UmAlb, the loss of podocyte strcture protein might be one of the mechanism in leading proteinuria in diabetic nephropathy.

Alleviation of podocyte injury: the possible pathway implicated in anti-inflammation of alpha-lipoic acid in type 2 diabetics.

BACKGROUND AND AIMS: The objective of this study is to observe the effect of alpha-lipoic acid (ALA) on Pod injury by anti-inflammation and explore its possible renal protective mechanism. METHODS: A total of 36 cases with type 2 diabetes with microalbuminuria and fasting plasma glucose (FPG) levels less than 9 mmol/L and glycated hemoglobin A1c (HbA1c) ≤9.0 % were recruited to be treated with ALA (600 mg, daily) for 6 months (group DA). Another 30 healthy individuals were chosen as normal controls (group NC). The levels of serum creatinine (Cr), FPG, and HbA1c were detected; blood pressure was recorded; and early morning urine samples (corrected for urinary Cr) were collected for the examination of urinary monocyte chemoattractant protein-1 (MCP-1), transforming growth factor-ß1 (TGF-ß1), podocalyxin (PCX), nephrin, albumin and Cr in group NC and group DA at the baseline and the sixth month. RESULTS: The excretions of urinary MCP-1, TGF-ß1, PCX, nephrin and albumin to Cr ratio (abbreviated as UMCR, UTCR, UPCR, UNCR and UACR respectively) were significantly increased in group DA compared with group NC (all P < 0.01), and after 6-month treatment, all indexes mentioned above decreased markedly (P < 0.05), while FPG and HbA1c had no obvious changes. Additionally, there was a positive correlation between UMCR, UTCR with UPCR, UNCR and UACR, respectively (all P < 0.01). CONCLUSIONS: Anti-inflammation of ALA in vivo and local kidney is implicated in the protection of glomerular Pod injury in patients with type 2 diabetes.

Urinary podocalyxin is an early marker for podocyte injury in patients with diabetes: establishment of a highly sensitive ELISA to detect urinary podocalyxin.

AIMS/OBJECTIVE: Nephropathy, a major complication of diabetes, is the leading cause of end-stage renal disease. Recent studies have demonstrated that podocyte injury is involved in the onset of and progression to renal insufficiency. Here, we describe a novel, highly sensitive ELISA for detecting urinary podocalyxin, a glycoconjugate on the podocyte apical surface that indicates podocyte injury, particularly in the early phase of diabetic nephropathy. METHODS: Urine samples from patients with glomerular diseases (n = 142) and type 2 diabetes (n = 71) were used to quantify urinary podocalyxin by ELISA. Urine samples were obtained from 69 healthy controls for whom laboratory data were within normal values. Podocalyxin was detected in urine by immunofluorescence, immunoelectron microscopy and western blotting. RESULTS: Morphologically, urinary podocalyxin was present as a vesicular structure; western blotting showed it as a positive band at 165-170 kDa. Levels of urinary podocalyxin were elevated in patients with various glomerular diseases and patients with diabetes. In patients with diabetes, urinary podocalyxin was higher than the cut-off value in 53.8% patients at the normoalbuminuric stage, 64.7% at the microalbuminuric stage and 66.7% at the macroalbuminuric stage. Positive correlations were observed between urinary podocalyxin levels and HbA(1c), urinary ß(2) microglobulin, α(1) microglobulin and urinary N-acetyl-ß-D-glucosaminidase, although urinary podocalyxin levels were not correlated with other laboratory markers such as blood pressure, lipid level, serum creatinine, estimated GFR or proteinuria. CONCLUSIONS/INTERPRETATION: Urinary podocalyxin may be a useful biomarker for detecting early podocyte injury in patients with diabetes.

Increased urinary excretion of nephrin, podocalyxin, and ßig-h3 in women with preeclampsia.

Emerging evidence has shown that podocyte injury and reduced specific podocyte protein expressions contribute to proteinuria in preeclampsia. We collected urine specimens from women with preeclampsia to study whether podocyte-specific protein shedding is associated with renal barrier dysfunction. Urine specimens from women with normal pregnancies and from pregnant women complicated by chronic hypertension were used for comparison. We determined soluble podocyte slit protein nephrin levels in the urine specimens. Podocalyxin, ßig-h3, and VEGF concentrations were also measured. We found that nephrin and podocalyxin were barely detectable in the urine specimens from normal pregnant women and from women with chronic hypertension. In preeclampsia, urinary nephrin and podocalyxin concentrations were significantly increased and highly correlated to each other, r(2) = 0.595. Nephrin and podocalyxin were also correlated with urine protein concentrations. ßig-h3 was detected in the urine specimens from women with preeclampsia, and it is highly correlated with nephrin and podocalyxin concentrations in preeclampsia. ßig-h3 was undetectable in normal pregnancy and pregnancy complicated by chronic hypertension. Elevated VEGF levels were also found in women with preeclampsia compared with those of normal pregnancy and pregnancy complicated by chronic hypertension. These results provide strong evidence that podocyte protein shedding occurs in preeclampsia, and their levels are associated with proteinuria. The finding of urinary ßig-h3 excretion in preeclampsia suggests that increased transforming growth factor activity might also be involved in the kidney lesion in this pregnancy disorder.

Novel flow cytometric method for the detection of podocalyxin-positive elements in urine of patients with glomerulonephritides - first promising results.

Glomerulonephritides together create a heterogenic group of supposedly immunologically mediated diseases of glomeruli. They still belong among the most frequent causes of chronic renal failure. Detection of podocytes in urine might serve as an important marker of glomerulonephritides activity. The aim of this study was to develop a novel flow cytometric method for the detection of podocyte fragments and podocytes in urine and assess its possible use in clinical practice. We placed emphasis on the improvement of pre-analytic phase. To suppress the autofluorescence of the background, blocking solutions and magnetic separation were used. An additional surface marker CD10 (nephrilysin) was used together with routinely used podocalyxin (PCX) in order to achieve better identification of podocytes. Based on the surface marker expression, three different element types were identified in the urine samples: PCX+/CD10+ elements (EL) (supposedly podocytes), PCX-/CD10+ EL (supposedly parietal epithelial cells) and PCX+ EL. We examined a total of 36 patients who underwent renal biopsy (non-glomerular nephropathy, MGN, FSGS, IgAN, AAV and MPGN) and 27 healthy controls. Negative results were found in non-glomerular nephropathy and in MGN. In patients with FSGS and IgAN, the levels of urine elements were slightly increased. The highest levels of all elements were found in AAV and MPGN. Our first results suggest that flow cytometric detection may distinguish between glomerular and nonglomerular diseases and that the levels of urine elements might correlate with the degree of glomerular destruction.

Evaluation of renal clinicopathological changes in IgA nephropathy by urinary podocytes excretion and podocalyxin expression.

OBJECTIVE: To explore the association of urinary podocyte excretion and renal expression of podocyte-specific marker podocalyxin (PCX) with clinicopathological changes in immunoglobulin A nephropathy (IgAN). METHODS: Morning urine samples from IgAN patients and healthy controls were collected. The expression of glomerular PCX was quantified in 50 IgAN patients diagnosed by renal biopsy. IgAN was classified based on the Lee's Grading system and scored according to the Katafuchi semiquantitative criteria. Morphological evaluation of podocyte was determined by electron microscopy. RESULTS: The amount of urinary podocytes in the IgAN patients was significantly higher than that in the healthy controls (p < 0.01). Pairwise comparison among Lee's grades of IgAN showed that the median of urinary podocytes in Lee's I-II group was lower than that in Lee's III, IV, and V groups (p < 0.05); group III lower than group V (p < 0.05). The positive rate of urinary podocytes was the highest in Lee's IV and V groups (100%), and lowest in Lee's I-II group (55%). Multiple comparison among groups of Lee's grades of IgAN showed that the glomerular PCX expression in Lee's I-II group was higher than that in Lee's III, IV, and V groups (p < 0.05); groups III and IV higher than group V (p < 0.05). The amount of urinary podocytes in IgAN patients was negatively correlated with PCX expression (r = -0.702, p < 0.01), but positively correlated with 24-h urinary protein (r = 0.465, p < 0.01) and glomerular (r = 0.233, p < 0.01) and renal tubular pathological scores (r = 0.307, p < 0.05). The glomerular PCX expression was negatively correlated with 24-h urinary protein (r = -0.367, p < 0.05) and glomerular (r = -0.560, p < 0.05) and tubular pathological scores (r = -0.377, p < 0.05). Electron microscopy showed significant changes in podocytes of IgAN, especially in the foot process. CONCLUSION: The amount of urinary podocyte can reflect the loss of podocytes in renal tissue, which may be a marker of IgAN progression.

[Clinical significance of determining urinary podocalyxin level in children with primary nephrotic syndrome].

OBJECTIVE: To study the clinical significance of urinary podocyte marker protein podocalyxin (PCX) in the diagnosis of primary nephrotic syndrome (PNS) in children and the evaluation of disease severity. METHODS: PCX levels in the first morning urine were measured by turbidimetric immunoassay (TIA) in 175 children, including 53 children with acute PNS [36 cases of simple nephrotic syndrome (NS) and 17 cases of nephritic NS], 56 children with PNS in the remission stage (relapsed: 42 cases) and 66 healthy children (control group). Twenty-four hour urinary protein was measured in the 53 children with acute PNS. The optimal operating points for the diagnosis of acute PNS and nephritic NS were determined using the receiver-operating characteristic curve (ROC curve). RESULTS: Significant increasd levels of urinary PCX were found in children with acute PNS compared with those in the remission stage and the control group (P<0.01). A positive correlation was found between urinary PCX and 24 hour urinary protein in children with acute PNS (r=0.39, P<0.01). In children with acute PNS, urinary PCX levels were significantly higher in the nephritic NS group than in the simple NS group (P<0.05). In children in the remission stage, a significant increase in levels of urinary PCX was found in children who had relapsed compared with those who had not (P<0.05). The area under the ROC curve for the diagnosis of acute PNS and nephritic NS was 0.915 and 0.784 respectively. The optimal operating point for the diagnosis of acute PNS and nephritic NS was 7.97 and 10.28 ng/mL respectively, with a sensitivity and specificity of 81.1% and 93.4% respectively for acute PNS and of 94.1% and 52.8% respectively for nephritic NS. CONCLUSIONS: The quantitative detection of urinary PCX is useful in the evaluation of podocyte dynamic changes. It is helpful in the diagnosis of acute PNS and in the differentiation of nephritic NS and simple NS.

Clinical significance of tubular and podocyte biomarkers in acute kidney injury.

BACKGROUND: Acute kidney injury (AKI) is a common complication in critically ill patients. Urinary excretion of liver-type fatty acid-binding protein (L-FABP), which is expressed in the proximal tubules, reflects the presence of tubular injury. Urinary excretion of podocalyxin (PCX), a glycoprotein prominently expressed on podocytes, is associated with podocyte injury. Our aims were to evaluate the utility of urinary L-FABP for the early detection of AKI and to examine whether podocyte injury is present in AKI patients using the biomarker of urinary PCX. METHODS: Patients admitted to the intensive care unit (ICU) were divided into the AKI group (n = 14) and non-AKI group (n = 11), according to the occurrence of AKI during hospitalization in the ICU. Changes in various biomarkers were evaluated. RESULTS: In the AKI group, elevation of urinary L-FABP level [maximum value of L-FABP, 199.0 (92.5-433.6) µg/g creatinine, median (25-75% interquartile range)], which reflects tubular injury (area under the curve 0.95, cut-off value 44.1 µg/g Cr), occurred between -30 and 0 h before the occurrence of AKI (i.e., the time at which serum creatinine peaked), and elevation of urinary PCX level [maximum value of PCX, 389.5 (267.0-501.0) µg/g creatinine; upper limit of reference value, 160 µg/g creatinine] occurred during the time of recovery from AKI when serum creatinine levels were decreasing between 34.0 and 72.0 h after the occurrence of AKI. Furthermore, a parameter with the primary large AUC for predicting the onset of AKI was urinary L-FABP. CONCLUSIONS: Our study suggests that L-FABP is a useful biomarker for early detection of AKI and that podocyte injury was induced during the recovery phase of AKI.

Comparison of three methods for isolation of urinary microvesicles to identify biomarkers of nephrotic syndrome.

Urinary microvesicles, such as 40-100 nm exosomes and 100-1000 nm microparticles, contain many proteins that may serve as biomarkers of renal disease. Microvesicles have been isolated by ultracentrifugation or nanomembrane ultrafiltration from normal urine; however, little is known about the efficiency of these methods in isolating microvesicles from patients with nephrotic-range proteinuria. Here we compared three techniques to isolate microvesicles from nephrotic urine: nanomembrane ultrafiltration, ultracentrifugation, and ultracentrifugation followed by size-exclusion chromatography (UC-SEC). Highly abundant urinary proteins were still present in sufficient quantity after ultrafiltration or ultracentrifugation to blunt detection of less abundant microvesicular proteins by MALDI-TOF-TOF mass spectrometry. The microvesicular markers neprilysin, aquaporin-2, and podocalyxin were highly enriched following UC-SEC compared with preparations by ultrafiltration or ultracentrifugation alone. Electron microscopy of the UC-SEC fractions found microvesicles of varying size, compatible with the presence of both exosomes and microparticles. Thus, UC-SEC following ultracentrifugation to further enrich and purify microparticles facilitates the search for prognostic biomarkers that might be used to predict the clinical course of nephrotic syndrome.

Kidney transplant monitoring by urinary flow cytometry: Biomarker combination of T cells, renal tubular epithelial cells, and podocalyxin-positive cells detects rejection.

Creatinine and proteinuria are used to monitor kidney transplant patients. However, renal biopsies are needed to diagnose renal graft rejection. Here, we assessed whether the quantification of different urinary cells would allow non-invasive detection of rejection. Urinary cell numbers of CD4+ and CD8+ T cells, monocytes/macrophages, tubular epithelial cells (TEC), and podocalyxin(PDX)-positive cells were determined using flow cytometry and were compared to biopsy results. Urine samples of 63 renal transplant patients were analyzed. Patients with transplant rejection had higher amounts of urinary T cells than controls; however, patients who showed worsening graft function without rejection had similar numbers of T cells. T cells correlated with histological findings (interstitial inflammation p = 0.0005, r = 0.70; tubulitis p = 0.006, r = 0.58). Combining the amount of urinary T cells and TEC, or T cells and PDX+ cells, yielded a significant segregation of patients with rejection from patients without rejection (all p < 0.01, area under the curve 0.89-0.91). Urinary cell populations analyzed by flow cytometry have the potential to introduce new monitoring methods for kidney transplant patients. The combination of urinary T cells, TEC, and PDX-positive cells may allow non-invasive detection of transplant rejection.

Urinary podocalyxin: Is it a real index of disease activity in egyptian patients lupus nephritis?

Systemic lupus erythematosus (SLE) is an inflammatory autoimmune disease characterized by production of a number of antinuclear antibodies. Podocyte injury is an important feature and can be detected by several markers including podocalyxin. We aimed to evaluate the impact of SLE on urinary levels of podocalyxin and to determine its relationship to renal biopsy, proteinuria, and disease activity in lupus nephritis (LN) patients. Sixty individuals were recruited; 30 SLE patients with LN as well as 30 healthy volunteers and they were subjected to full history, clinical examination, kidney function, protein/creatinine ratio, urinary podocalyxin, and kidney biopsy. Patients with LN had higher level of urinary podocalyxin (3.96 ± 2.24) than the other group (0 ± 0), (P <0.001). Class IV LN was the most common class found among LN patients [18 cases (60%)]. There was a statistically significant positive correlation between SLE disease activity index score, protein/creatinine ratio, and urinary podocalyxin (P <0.001, r = 0.98) (P <0.001, r = 0.765). There was a statistically significant negative correlation between serum albumin, serum calcium, and urinary podocalyxin (P = 0.001, r = -0.589) (P = 0.025, r = -0.407). Urinary podocalyxin level significantly predicts the pathological impact of SLE on the kidney and could be used as a noninvasive marker for such effect and its progression.

Role of urinary podocalyxin in early diagnosis of diabetic nephropathy.

Introduction. Podocyte injury has been reported as an early feature of DN therefore, the assessment of podocyte injury can be accomplished by estimation of podocalyxin in urine. This study aimed to estimate the urinary podocalyxin levels and to determine the sensitivity and specificity of this biomarker for early detection of DN.Materials and methods. A total of 90 patients with type 2 diabetes mellitus (T2DM) were included in this cross-sectional study. Sixty of them were without diagnosed DN, and 30 with diagnosed DN. A control group consisted of 30 healthy subjects. All patients with T2DM were divided into three subgroups according to urinary microalbumin/creatinine ratio (UM/CR): normoalbuminuric, microalbuminuric and macroalbuminuric patients. Urine samples, were used for measurement of podocalyxin by ELISA, creatinine and microalbumin. Fasting venous blood samples was collected for biochemical analyses.Results. The levels of urinary podocalyxin (u-PDX) were higher in patients with T2DM compared to control subjects and a statistically significant difference among studied subgroups regarding u-PDX was found (p < 0.05). Levels of u-PDX are increasing gradually with the degree of DN (p < 0.029). u-PDX levels were positively correlated with UM/CR (r = 0.227, p = 0.002). A cut-off level of 43.8 ng/ml u-PDX showed 73.3% sensitivity and 93.3% specificity to detect DN in early stage. A cut-off level of 30 mg/g UM/CR showed 41.5% sensitivity and 90% specificity in predicting DN. u-PDX was elevated in 48,2% of normoalbuminuric patients.Conclusion. Urinary podocalyxin be useful and more sensitive and specific marker in early detection of DN than microalbuminuria.

Association between Renal Podocalyxin Expression and Renal Dysfunction in Patients with Diabetic Nephropathy: A Single-Center, Retrospective Case-Control Study.

This retrospective study investigated whether podocalyxin expression in renal biopsies and urine of patients with diabetic nephropathy (DN) is associated with renal function. This retrospective study included 32 patients with nephropathy, secondary to type 2 diabetes treated at the First Hospital of Lanzhou University (January 2010 to January 2015). Compared with the control group, the DN group had a significantly lower renal expression of podocalyxin and higher urinary podocalyxin/creatinine ratio. Patients with DN were divided into the high and low expression groups according to podocalyxin expression in renal tissues. Patients in the low expression group had longer diabetes duration, lower plasma albumin and eGFR, higher glycated hemoglobin (HbA1c), 24 h urinary protein, serum creatinine, and urinary podocalyxin/creatinine ratio, and more severe glomerular, tubulointerstitial, and renal interstitial inflammation than patients in the high expression group (all P < 0.01). The renal survival rate was significantly lower in the low expression group than in the high expression group (P < 0.01). Single-factor Cox regression analysis showed that reduced podocalyxin expression and increased urinary podocalyxin excretion were associated with poor renal outcome. Measuring podocalyxin levels in renal tissues and urine could help evaluate the progression of DN.

Evaluation of the urinary podocalyxin and nephrin excretion levels to determine a safe time interval between two sessions of SWL for renal stones: a non randomized exploratory study.

OBJECTIVES: We aimed to evaluate the role of nephrin and podocalyxin in determining the intervals between shock wave lithotripsy (SWL) sessions and how soon the kidney damage was recovered. METHODS: This work was a prospective study that included 30 patients with unilateral kidney stones. The patients' midflow urine samples were collected before SWL and 1 h, 1 day and 1 week after the procedure. Nephrin and podocalyxin levels in the urine samples were measured by the enzyme-linked immunosorbent assay method. RESULTS: Among the 30 patients who underwent SWL, 19 were males and 11 were females. The mean age of the SWL group was 34.7 ± 13.2. Both biomarkers did not correlate with age, creatinine values, body mass index, stone side, stone size, energy, frequency and shock numbers. Nephrin and podocalyxin levels were significantly higher at the pre-SWL point (p < 0.05). After the procedure, a significant decrease was observed in both biomarker levels (p < 0.05). At the end of first day, these levels started to increase progressively up to the end of the first week (p > 0.05). CONCLUSIONS: Nephrin and podocalyxin may help to determine early period kidney damage associated with SWL. Post-SWL podocalyxin and nephrin values may be used to determine the interval between SWL sessions.