Increased urinary orosomucoid excretion: a proposed marker for inflammation and endothelial dysfunction in patients with type 2 diabetes

[Study of urinary markers of different podocytopathies by proteomic analysis]

BACKGROUND

Focal segmental glomerulosclerosis (FSGS) is a primary podocytopathy characterized by primary podocyte detection and high proteinuria. The search for biomarkers and factors associated with the progression of this disease is an important task nowdays.

AIM

To assess the proteomic profile of urine in patients with FSGS and to isolate urinary biomarkers of podocytopathies.

MATERIALS AND METHODS

The study included 41 patients diagnosed with chronic glomerulonephritis, 27 men and 14 women. According to the morphological study, 28 patients were diagnosed with FSGS, 9 with steroid-sensitive nephrotic syndrome and 14 with steroid-resistant nephrotic syndrome. The comparison group included 13 patients with membranous nephropathy. The study of the urinary proteome was carried out by targeted liquid chromatography-mass spectrometry using multiple reaction monitoring with synthetic stable isotope labelled peptide standards.

RESULTS

The main differences in the protein profile of urine were found in the subgroups of steroid-sensitive (SS) and steroid-resistant (SR) FSGS. In the FSGS SR group, at the onset of the disease, there was a high concentration of proteins reflecting damage to the glomerular filter (apo-lipoprotein A-IV, orosomucoid, cadherin, hemopexin, vitronectin), as well as proteins associated with tubulo-interstitial inflammation and accumulation of extracellular matrix (retinol- and vitamin D-binding proteins, kininogen-1, lumican and neurophilin-2). Compared with the membranous nephropathy group, FSGS patients had significantly higher urinary concentrations of carnosinase, orosomucoid, cadherin-13, tenascin X, osteopontin, and zinc-alpha-2-glycoprotein.

CONCLUSION

Thus, in patients with SR FSGS, the proteomic profile of urine includes more proteins at elevated concentrations, which reflects severe damage to various parts of the nephron compared with patients with SS FSGS and membranous nephropathy.

Associations of urinary orosomucoid, N-acetyl-β-D-glucosaminidase, and albumin with blood pressure and hypertension after 7 years. The Tromsø Study

Purpose: Subclinical chronic kidney disease is known to exacerbate hypertension and progression of kidney damage. In order to initiate timely interventions, early biomarkers for this vicious circle are needed. Our aim was to describe the cross-sectional associations of urinary orosomucoid and urinary N-acetyl-β-D-glucosaminidase (NAG) with blood pressure and the longitudinal associations of urinary orosomucoid and NAG to hypertension after 7 years, and to compare the strength of these associations to the urinary albumin excretion (UAE).Material and methods: The Tromsø Study is a population-based, prospective study of inhabitants of the municipality of Tromsø, Northern Norway. Morning spot urine samples were collected on three consecutive days in the Tromsø 6 survey (2007-2008). We assessed the cross-sectional associations of urinary orosomucoid, NAG and UAE with blood pressure in Tromsø 6. In a cohort of participants attending Tromsø 6 and Tromsø 7 (2015-2016), we studied whether urinary biomarkers were longitudinally associated with hypertension.Results: A total of 7197 participants with a mean age of 63.5 years (SD 9.2), and a mean blood pressure of 141/78 mmHg (SD 23.0/10.6), were included in the study. Orosomucoid and UAE, but not NAG, was significantly associated with systolic and diastolic blood pressure in all the crude and multivariable cross-sectional analyses. Orosomucoid had consistently, although marginally, stronger associations with blood pressure. Incident hypertension at follow-up (Tromsø 7) was consistently significantly associated with urinary orosomucoid, but not urinary NAG or UAE. However, the standardized regression coefficients for orosomucoid were only marginally stronger than the standardized regression coefficients for ACR.Conclusion: In a cohort from the general population urine orosomucoid had a stronger cross-sectional association with blood pressure than UAE. After 7 years, urine orosomucoid showed the strongest association with incident hypertension. There were varying and weak associations between U-NAG, blood pressure and hypertension.

Does alpha-1-acid glycoprotein determine for infertility in polycystic ovary syndrome?

OBJECTIVES

The underlying cause of metabolic abnormalities and ovarian dysfunction in PCOS is thought to be chronic low-grade inflammation. This study aimed to show whether alpha-1-acid glycoprotein (AGP), an inflammatory marker, predicts the risk of infertility in fertile and infertile women with PCOS. Our study had a cros-sectional case-control design.

STUDY DESIGN

A total of 20 fertile and 50 infertile patients with PCOS who wanted a child were in the early follicular phase were included in our study. Among the study groups (fertil (n = 20) and infertile (n = 50), AGP, CRP, NLR, BMI, FAI, VAI, triglyceride, HDL-cholesterol, fasting blood sugar, HOMA-IR, SHBG, testosterone values and waist circumference were measured.

RESULTS

Among the inflammatory markers compared in the fertile and infertile groups included in the study, only the difference between the AGP variable was statistically significant (p = 0.011). The mean AGP was found to be higher at a statistically significant level in the infertile group (p < 0.05). Age, BMI, waist circumference and AGP were weakly positive and CRP was moderately positive in the infertile group (p < 0.05).

CONCLUSION

AGP can be a good indicator of inflammation in PCOS, especially in infertility.Revealing the risk of infertility in PCOS with AGP measurement may contribute to the correct management of the reproductive process.

The Glomerular Endothelium Restricts Albumin Filtration

Inflammatory activation and/or dysfunction of the glomerular endothelium triggers proteinuria in many systemic and localized vascular disorders. Among them are the thrombotic microangiopathies, many forms of glomerulonephritis, and acute inflammatory episodes like sepsis and COVID-19 illness. Another example is the chronic endothelial dysfunction that develops in cardiovascular disease and in metabolic disorders like diabetes. While the glomerular endothelium is a porous sieve that filters prodigious amounts of water and small solutes, it also bars the bulk of albumin and large plasma proteins from passing into the glomerular filtrate. This endothelial barrier function is ascribed predominantly to the endothelial glycocalyx with its endothelial surface layer, that together form a relatively thick, mucinous coat composed of glycosaminoglycans, proteoglycans, glycolipids, sialomucins and other glycoproteins, as well as secreted and circulating proteins. The glycocalyx/endothelial surface layer not only covers the glomerular endothelium; it extends into the endothelial fenestrae. Some glycocalyx components span or are attached to the apical endothelial cell plasma membrane and form the formal glycocalyx. Other components, including small proteoglycans and circulating proteins like albumin and orosomucoid, form the endothelial surface layer and are bound to the glycocalyx due to weak intermolecular interactions. Indeed, bound plasma albumin is a major constituent of the endothelial surface layer and contributes to its barrier function. A role for glomerular endothelial cells in the barrier of the glomerular capillary wall to protein filtration has been demonstrated by many elegant studies. However, it can only be fully understood in the context of other components, including the glomerular basement membrane, the podocytes and reabsorption of proteins by tubule epithelial cells. Discovery of the precise mechanisms that lead to glycocalyx/endothelial surface layer disruption within glomerular capillaries will hopefully lead to pharmacological interventions that specifically target this important structure.

Alpha-1 Acid Glycoprotein and Podocin mRNA as Novel Biomarkers for Early Glomerular Injury in Obese Children

INTRODUCTION

Obesity, which is a serious problem in children, has a negative impact on many organs, including kidneys, and obesity-related glomerulopathy (ORG) is an increasingly common cause of ESKD (end-stage kidney disease) in adults. Early-detected and -treated glomerular lesions are reversible, so it is important to find a useful marker of early damage. The study aimed to evaluate the albumin-to-creatinine ratio (ACR), urinary alpha-1-acid glycoprotein (α1-AGP), and mRNA of podocyte-specific proteins as indicators of glomerular injury and their relationship with the degree of obesity and metabolic disorders.

MATERIALS AND METHODS

A total of 125 obese children and 33 healthy peers were enrolled. Patients were divided into two groups, depending on SDS BMI values. ACR, α1-AGP, mRNA expression of nephrin, synaptopodin, podocin, and C2AP protein in urine sediment were measured.

RESULTS

ACR values did not differ between groups and were within the normal range. α1-AGP and mRNA expression were significantly higher in obese children compared with controls. mRNA expression of the remaining podocyte proteins was similar in both groups. No significant differences concerning all examined parameters were found depending on the degree of obesity. There was a positive significant correlation between α1-AGP and ACR.

CONCLUSIONS

Increased α1-AGP before the onset of albuminuria suggests its usefulness as a biomarker of early glomerular damage in obese children. An increased podocin mRNA expression also indicates podocyte damage and may be linked to ORG development. The lack of increase in expression of other podocyte proteins suggests that podocin mRNA may be a more specific and sensitive biomarker. The degree of obesity has no impact on the tested parameters, but further studies are needed to confirm it.

Urinary orosomucoid: a new marker of cardiovascular risk in psoriatic patients?

Purpose

Psoriasis is one of the most common lifelong lasting dermatologic diseases. According to the latest studies, psoriatic patients have a higher risk of developing cardiovascular diseases. Psoriasis is considered as a systemic inflammatory disease. Several oxidative stress markers have been shown to be elevated in psoriasis. However, a panel of biomarkers has not been used yet. This study was aimed at exploring the connection between a panel of biomarkers (C-reactive protein, asymmetric dimethylarginine, uric acid, total antioxidant capacity, malondialdehyde, and orosomucoid [ORM]) and cardiovascular risk in psoriatic patients.

Patients and methods

The inclusion criterion was the onset of psoriasis with skin lesions. Exclusion criteria were impaired renal function (eGFR<60 mL/min/1.73 m²), acute inflammations (urinary, respiratory, skin inflammation, etc), autoimmune disorders (rheumatoid arthritis, systemic lupus erythematosus, or inflammatory bowel disease), and any kind of biological antipsoriatic treatment. Patients with a medical history of myocardial infarction, coronary heart disease, stroke, transient ischemic attack, and carotid artery stenosis were also excluded. Biomarkers were measured by routine procedures, ELISA and HPLC. QRISK®2-2017 was used to assess 10-year risk of cardiovascular disease development. Psoriasis severity was measured by the Psoriasis Area and Severity Index.

Results

One hundred and fourteen psoriatic patients were enrolled. Only urinary orosomucoid and urinary orosomucoid/urinary creatinine (u-ORM/u-CREAT) ratio showed significant correlation with QRISK score (u-ORM, r=0.245; u-ORM/u-CREAT, r=0.309). When comparing mild psoriatic patients to moderate psoriatic patients, significant differences could only be found in u-ORM and u-ORM/u-CREAT ratio.

Conclusion

There seems to be a connection between urinary ORM and cardiovascular risk. U-ORM and u-ORM/u-CREAT ratio could be used as an indicator of low-grade inflammation in mild and moderate psoriasis. However, it is the 10-year follow-up of cardiovascular events that will determine the usefulness of this biomarker panel.

LC‑MS/MS proteomic analysis revealed novel associations of 37 proteins with T2DM and notable upregulation of immunoglobulins

Type 2 diabetes mellitus (T2DM) is a disease associated with a number of metabolic disturbances, including protein metabolism. In the present study, blood samples were obtained from Bahraini subjects, including 6 patients with T2DM and 6 age‑ and sex‑matched, non‑diabetic, healthy controls. Depleted and non‑depleted sera were prepared from the collected blood, and the global protein expression changes were evaluated by liquid chromatography tandem mass spectrometry. Only significantly and markedly differentially‑expressed proteins (P<0.05, analysis of variance; maximum fold change ≥1.5) were considered as candidate proteins for informatics analysis. Accordingly, a total of 62 proteins were identified to be differentially expressed in T2DM, compared with control subjects, and they were grouped functionally into 16 classes of proteins. The largest class was that of the immune‑associated proteins. Additionally, ~25 of these proteins (40%) had previously been associated with DM; however, the association of the other 37 proteins with T2DM was a novel observation. The majority of the identified proteins were upregulated in T2DM. The identified proteins could be involved in the pathogenesis of the disease or serve as disease biomarkers. Further validation of the identified proteins in a large study cohort is required, in order to fully access their potential clinical usefulness.

Elevated urinary orosomucoid excretion as a novel biomarker in Crohn's disease

BACKGROUND

Laboratory markers are essential tools in the follow-up of patients with Crohn's disease (CD). Our aim was to investigate urinary concentrations of orosomucoid in relation to the inflammatory activity of CD and to compare it with clinical indices and conventional laboratory parameters.

MATERIALS AND METHODS

Blood and urine samples of 86 patients (55 adults and 31 children) with CD and 68 healthy individuals (38 adults and 30 children) as controls were analysed. Patients were categorized according to their clinical scores (Harvey-Bradshaw Index [HBI] or Pediatric Crohn's Disease Activity Index [PCDAI]). Urinary orosomucoid (u-ORM) was determined by automated immune turbidimetric assay, and values were referred to urinary creatinine (u-ORM/u-CREAT, mg/mmol).

RESULTS

U-ORM/u-CREAT values were seven times higher in children with active CD (0.50 vs 0.07 mg/mmol, P < 0.001) and two times higher in adults (0.32 vs 0.14 mg/mmol, P = 0.01) compared with patients with inactive disease. U-ORM/u-CREAT showed good correlation with conventional inflammatory markers (hs-CRP, serum ORM; P < 0.01) and activity indices (HBI, P = 0.018; PCDAI, P < 0.001). U-ORM/u-CREAT had similar discriminative performance to hs-CRP and serum ORM in the differentiation of active from inactive paediatric CD patients.

CONCLUSIONS

Our findings suggest that u-ORM/u-CREAT might serve as a valuable additional marker in the follow-up of CD patients, especially in children for whom the non-invasive sampling is a further advantage.

Urinary biomarkers reporting weakness and validation failure in Type 2 diabetic nephropathy: systematic review

For better identification of novel diagnostic urinary biomarker in Type 2 diabetic nephropathy (T2DN), methodological and reporting quality is as important as validity of biomarkers. The aim of this systematic review is to find out the best-reported diagnostic urinary biomarkers study in T2DN based on STARD criteria. We also analyzed the validity of urinary markers in the selected articles those followed STARD criteria. The diagnostic accuracy of urinary biomarkers on T2DN is not conclusive because of the poor reporting quality and differences in adjustment for conventional risk factors. For a proper validation of urinary biomarkers on T2DN, in future large well-designed longitudinal studies, with specific prediction analysis and validation of the biomarkers by adjusting with possible conventional risk factors.

Urinary Orosomucoid A Potential Marker Of Inflammation In Psoriasis

Background: Psoriasis is one of the most common chronic, life-long dermatologic diseases, which has considerable negative effects on quality of life. Psoriasis is considered as a systemic inflammatory disease, thus acute phase proteins such as C-reactive protein (CRP) and orosomucoid (ORM) have been shown to play a role in its pathophysiology. This study was aimed to compare CRP, serum ORM (se-ORM) and urinary ORM (u-ORM) levels of psoriatic patients to healthy individuals. Methods: 87 psoriatic patients and 41 healthy individuals were enrolled. Simultaneously obtained venous blood and spot urine samples were analysed. High sensitivity CRP and se-ORM levels were determined by routine procedures on automated analyzers. Urinary ORM was measured by a novel automated turbidimetric assay. U-ORM was referred to urinary creatinine (u-ORM/u-CREAT, mg/mmol). Results: Significantly higher hsCRP (p<0.001) and u-ORM/u-CREAT (p=0.001) levels were found among psoriatic patients compared to controls. No significant differences were found between the groups regarding se-ORM levels. HsCRP, se-ORM and u-ORM/u-CREAT levels were significantly higher in patients with severe psoriasis than in mild and moderate cases (p<0.05). Conclusion: As a highly sensitive, easily available biomarker u-ORM shows itself capable of becoming a new inflammatory marker in psoriasis providing clinically useful information on disease severity.

Urinary orosomucoid: a novel, early biomarker of sepsis with promising diagnostic performance

Background:

In order to help clinical decision making, we investigated the diagnostic and prognostic ability of urinary orosomucoid (u-ORM) as a new sepsis biomarker, and compared its performance to classical inflammatory parameters.

Methods:

We monitored u-ORM in septic (n=43) and SIRS (n=13) patients in a 5-day follow-up study vs. control patients (n=30). U-ORM was measured by a newly developed turbidimetric assay. U-ORM values were referred to urinary creatinine and expressed as u-ORM/u-CREAT (mg/mmol).

Results:

Significantly higher (p<0.001) u-ORM/u-CREAT levels were found in sepsis than in SIRS. Both intensive care unit (ICU) groups showed strongly elevated values compared to controls (p<0.001). The medians of admission u-ORM/u-CREAT levels were 19.2 in sepsis, 2.1 in SIRS and 0.2 mg/mmol in controls. The area under the receiver operating characteristic curve for distinguishing SIRS from sepsis was found to be 0.954 for u-ORM/u-CREAT, superior to serum ORM and hsCRP. U-ORM levels did not change during the 5-day follow-up and were independent of the severity of sepsis however, we found extremely elevated u-ORM/u-CREAT values in dialyzed septic patients (52.2 mg/mmol as median).

Conclusions:

The early and relevant increase of u-ORM in sepsis suggests that it might be a promising novel marker of sepsis and could be a valuable part of routine laboratory and clinical practice.

Urinary orosomucoid: validation of an automated immune turbidimetric test and its possible clinical use

INTRODUCTION

Besides routine serum markers of inflammatory diseases, the diagnostic potential of selected urinary proteins has not been fully exploited yet. Former studies revealed that urinary orosomucoid (u-ORM) might have complementary information in inflammatory disorders. Our aim was to develop and validate a fully automated method for u-ORM measurements and to evaluate its potential clinical impact on systemic inflammatory diseases.

MATERIALS AND METHODS

A particle-enhanced immune turbidimetric assay was validated for a Cobas 8000/c502 analyzer to determine u-ORM levels. Spot urine samples from 72 healthy individuals, 28 patients with Crohn's disease and 30 septic patients were studied.

RESULTS

Our assay time was 10 minutes and the detection limit of u-ORM was 0.02 mg/L. The intra- and inter-assay imprecision expressed as CV was less than 5%, and the recovery ranged between 95-103%. Within 10 to 60 years of age, a preliminary reference range for urinary orosomucoid/creatinine ratio (u-ORM/u-CREAT) was found to be 0.08 (0.01-0.24) mg/mmol [median (2.5-97.5 percentiles)]. Compared to controls, a five-fold increase of u-ORM/u-CREAT values in Crohn's disease and approximately a 240-fold increase in sepsis were observed.

CONCLUSIONS

We set up a fast, sensitive and precise turbidimetric approach for automated u-ORM determination. Our highly sensitive assay is ideal for routine u-ORM measurements and might be a potential novel laboratory test in the management of systemic inflammatory processes.

Orosomucoid is an independent predictor of prognosis in chronic heart failure

BACKGROUND

Heart failure is associated with low-grade inflammation. In the present study we sought to assess the prognostic impact of orosomucoid, a marker of inflammation, in outpatients with heart failure.

METHODS

In outpatients with chronic heart failure (no change in clinical status and/or therapy >3 months prior to inclusion), baseline levels of orosomucoid were determined. Clinical follow-up was obtained and the rate of heart failure-related deaths and hospitalisations recorded.

RESULTS

A total of 134 patients (median age 71, 33.3 % female, mean left ventricular ejection fraction [LVEF] 36 %) were included. During a median follow-up of 695 (456-811) days, 54 patients (40.1 %) experienced an event. On Cox multivariate analysis, orosomucoid levels above the median (>497 mg/l) emerged as an independent predictor of prognosis (hazard ratio = 2.86, 95 % confidence interval 1.48-5.52 after adjusting for age, gender, ischaemic vs. non-ischaemic aetiology, LVEF, NT-proBNP and NYHA class).

CONCLUSION

Orosomucoid levels are an independent predictor of heart failure-related mortality and hospitalisations in patients with chronic heart failure.

Excretion of urinary orosomucoid 1 protein is elevated in patients with chronic heart failure

Easily screening markers for early detection of chronic heart failure (CHF) are lacking. We identified twenty differently expressed proteins including orosomucoid 1(ORM1) in urine between patients with CHF and normal controls by proteomic methods. Bioinformatics analyses suggested ORM1 could be used for further analysis. After verification by western blotting, the urinary levels of ORM1 were quantified with enzyme-linked immunosorbent assay (ELISA) by correcting for creatinine expression. The ORM1-Cr was significantly elevated in CHF patients than normal controls (6498.83±4300.21 versus 2102.26±1069.24 ng/mg). Furthermore, a Spearman analysis indicated that the urinary ORM1 levels had a high positive correlation with the classification of CHF, and the multivariate analysis suggested that the urinary ORM1 content was associated with the plasma amino-terminal pro- brain natriuretic peptide (NT-proBNP) (OR: 2.106, 95% CI: 1.213–3.524, P = 0.002) and the New York Heart Association (NYHA) classification (OR: 3.019, 95% CI: 1.329–4.721, P<0.001). In addition, receiving operating curve (ROC) analyses suggested that an optimum cut-off value of 2484.98 ng/mg with 90.91% sensitivity and 85.48% specificity, respectively, could be used for the diagnosis of CHF. To sum up, our findings indicate that ORM1 could be a potential novel urinary biomarker for the early detection of CHF.

The novel diagnostic biomarkers for focal segmental glomerulosclerosis

Background. Focal segmental glomerulosclerosis (FSGS) is a glomerular injury with various pathogenic mechanisms. Urine proteome panel might help in noninvasive diagnosis and better understanding of pathogenesis of FSGS. Method. We have analyzed the urine sample of 11 biopsy-proven FSGS subjects, 8 healthy controls, and 6 patients with biopsy-proven IgA nephropathy (disease controls) by means of liquid chromatography tandem mass spectrometry (nLC-MS/MS). Multivariate analysis of quantified proteins was performed by principal component analysis (PCA) and partial least squares (PLS). Results. Of the total number of 389 proteins, after multivariate analysis and additional filter criterion and comparing FSGS versus IgA nephropathy and healthy subjects, 77 proteins were considered as putative biomarkers of FSGS. CD59, CD44, IBP7, Robo4, and DPEP1 were the most significant differentially expressed proteins. These proteins are involved in pathogenic pathways: complement pathway, sclerosis, cell proliferation, actin cytoskeleton remodeling, and activity of TRPC6.There was complete absence of DPEP1 in urine proteome of FSGS subjects compared with healthy and disease controls. DPEP1 acts via leukotrienes on TRPC6 and results in increased podocyte motility and proteinuria. Conclusion. The results suggest a panel of candidate biomarkers for noninvasive diagnosis of FSGS, while complete absence of DPEP1 might represent a novel marker of FSGS.

Increased orosomucoid in urine is an independent predictor of cardiovascular and all-cause mortality in patients with type 2 diabetes at 10 years of follow-up

AIMS

To evaluate whether increased urinary orosomucoid excretion rate (UOER) is an independent predictor of cardiovascular and all-cause mortality in type 2 diabetes (T2DM) and type 1 diabetes (T1DM) at 10years of follow-up.

METHOD

We followed 430 patients with T2DM and 148 patients with T1DM until emigration, death or November 2011. We measured UOER levels in overnight urine samples.

RESULTS

Descriptive data are given in the article. In patients with T2DM and T1DM, all-cause mortality (log-rank test, p<0.01 for both types) and cardiovascular mortality (log-rank test, p<0.01 for T2DM and p=0.04 for T1DM) were significantly higher in patients with increased UOER. Normoalbuminuric patients with T2DM and increased UOER levels had higher all-cause and cardiovascular mortality (log-rank test, p<0.01 for both types). UOER was independently predictive of all-cause (HR 1.52; 95% CI 1.10-2.09; p=0.01) and cardiovascular (HR 2.31; 95% CI 1.46-3.66; p<0.01) mortality in patients with T2DM, but not in patients with T1DM.

CONCLUSION

UOER is an independent predictor of all-cause and cardiovascular mortality even in normoalbuminuric patients with T2DM at 10years of follow-up. Further studies are needed in order to evaluate the prognostic and clinical relevance.

Urinary fetuin-A is a novel marker for diabetic nephropathy in type 2 diabetes identified by lectin microarray

We analyzed the urine samples of patients with type 2 diabetes at various stages of diabetic nephropathy by lectin microarray to identify a biomarker to predict the progression of diabetic nephropathy. Japanese patients with type 2 diabetes at various stages of nephropathy were enrolled and we performed lectin microarray analyses (n = 17) and measured urinary excretion of fetuin-A (n = 85). The increased signals of urine samples were observed in Siaα2-6Gal/GalNAc-binding lectins (SNA, SSA, TJA-I) during the progression of diabetic nephropathy. We next isolated sialylated glycoproteins by using SSA-lectin affinity chromatography and identified fetuin-A by liquid chromatography–tandem mass spectrometer. Urinary excretion of fetuin-A significantly increased during the progression of albuminuria (A1, 0.40±0.43; A2, 0.60±0.53; A3 1.57±1.13 ng/gCr; p = 7.29×10⁻⁸) and of GFR stages (G1, 0.39±0.39; G2, 0.49±0.45; G3, 1.25±1.18; G4, 1.34±0.80 ng/gCr; p = 3.89×10⁻⁴). Multivariate logistic regression analysis was employed to assess fetuin-A as a risk for diabetic nephropathy with microalbuminuria or GFR<60 mL/min. Fetuin-A is demonstrated as a risk factor for both microalbuminuria and reduction of GFR in diabetic nephropathy with the odds ratio of 4.721 (1.881–11.844) and 3.739 (1.785–7.841), respectively. Collectively, the glycan profiling analysis is useful method to identify the urine biomarkers and fetuin-A is a candidate to predict the progression of diabetic nephropathy.

Increased urinary orosomucoid excretion predicts preeclampsia in pregnant women with pregestational type 1 diabetes

AIMS

We evaluated the urinary orosomucoid excretion (UOE) as a biomarker of preeclampsia and preterm delivery in pregnant women with type 1 diabetes.

METHODS

Singleton pregnant women with pregestational type 1 diabetes were included provided one urine sample had been collected before 17 gestational weeks. Serum and urinary orosomucoid were analysed by immunoturbidimetry. Primary outcome measurements were development of preeclampsia (blood pressure>140/90mmHg and proteinuria) and preterm delivery before 37 weeks.

RESULTS

In total 173 women were included. The UOE increased during pregnancy. Preeclampsia developed in 20 women and 65 women delivered preterm. Using logistic regression analysis we found that UOE>1.37mg/l (OR: 6.85 (95% CI: 1.97-23.88; p<0.003)), nulliparity (3.88 (1.10-13.72); p<0.04), systolic blood pressure>120mmHg (4.12 (1.35-12.59); p<0.02) and duration of diabetes>20 years (3.69 (1.18-11.52); p<0.03) independently predicted the development of preeclampsia. Independent predictors of preterm delivery were duration of diabetes and HbA1c>7%. The remaining covariates included in the regression models were BMI, serum creatinine, smoking and microalbuminuria.

CONCLUSIONS

Increased UOE early in pregnancy predicted preeclampsia in women with pregestational type 1 diabetes independently of albuminuria and other known risk factors. No association to preterm delivery was found.

Urinary biomarkers involved in type 2 diabetes: a review

Diabetes mellitus is one of the most challenging health concerns of the 21st century. With at least 30% of the diabetic population remaining undiagnosed, effective and early diagnosis is of critical concern. Development of a diagnostic test, more convenient and reliable than those currently used, would therefore be highly beneficial. Urine as a diagnostic medium allows for non-invasive detection of biomarkers, including some associated with type 2 diabetes and its complications. This review provides a synopsis of those urinary biomarkers that potentially may provide a basis for the development of improved diagnostic tests. Three main pathways for the sourcing of potential makers are identified: kidney damage, oxidative stress and low-grade inflammation including atherosclerosis/vascular damage. This review briefly presents each pathway and some of the most relevant urinary biomarkers that may be used to monitor the development or progression of diabetes and its complications. In particular, biomarkers of renal dysfunction such as transferrin, type IV collagen and N-acetyl-beta-D-glucosaminidase might prove to be more sensitive than urinary albumin, the current gold standard, in the detection of incipient nephropathy and risk assessment of cardiovascular disease. Inflammatory markers including orosomucoid, tumour necrosis factor-alpha, transforming growth factor-beta, vascular endothelial growth factor and monocyte chemoattractant protein-1, as well as oxidative stress markers such as 8-hydroxy-2'deoxyguanosine may also be useful biomarkers for diagnosis or monitoring of diabetic complications, particularly kidney disease. However, the sensitivity of these markers compared with albumin requires further investigation.

Two-dimensional differential in-gel electrophoresis proteomic approaches reveal urine candidate biomarkers in pediatric obstructive sleep apnea

RATIONALE

Sleep studies are laborious, expensive, inaccessible, and inconvenient for diagnosing obstructive sleep apnea (OSA) in children.

OBJECTIVES

To examine whether the urinary proteome uncovers specific clusters that are differentially expressed in the urine of children with OSA.

METHODS

Two-dimensional differential in-gel electrophoresis (2D-DIGE) and mass spectrometry proteomics followed by validation with western blot of ELISA.

MEASUREMENTS AND MAIN RESULTS

Morning urine proteins from 60 children with polysomnographically confirmed OSA and from matched children with primary snoring (n = 30) and control subjects (n = 30) were assessed. A total of 16 proteins that are differentially expressed in OSA were identified, and 7 were confirmed by either immunoblots or ELISA. Among the latter, receiver-operator curve analyses of urinary concentrations of uromodulin, urocortin-3, orosomucoid-1, and kallikrein assigned favorable predictive properties to these proteins. Furthermore, combinatorial approaches indicated that the presence of values beyond the calculated cutoff concentrations for three or more of the proteins yielded a sensitivity of 95% and a specificity of 100%.

CONCLUSIONS

Proteomic approaches reveal that pediatric OSA is associated with specific and consistent alterations in urinary concentrations of specific protein clusters. Future studies aiming to validate this approach as a screening method of habitually snoring children appears warranted.