Increased urinary orosomucoid excretion is not related to impaired renal function in patients with type 2 diabetes

A candidate panel of eight urinary proteins shows potential of early diagnosis and risk assessment for diabetic kidney disease in type 1 diabetes

Diabetic kidney disease (DKD) poses a significant health challenge for individuals with diabetes. At its initial stages, DKD often presents asymptomatically, and the standard for non-invasive diagnosis, the albumin-creatinine ratio (ACR), employs discrete categorizations (normal, microalbuminuria, macroalbuminuria) with limitations in sensitivity and specificity across diverse population cohorts. Single biomarker reliance further restricts the predictive value in clinical settings. Given the escalating prevalence of diabetes, our study uses proteomic technologies to identify novel urinary proteins as supplementary DKD biomarkers. A total of 158 T1D subjects provided urine samples, with 28 (15 DKD; 13 non-DKD) used in the discovery stage and 131 (45 DKD; 40 pDKD; 46 non-DKD) used in the confirmation. We identified eight proteins (A1BG, AMBP, AZGP1, BTD, RBP4, ORM2, GM2A, and PGCP), all of which demonstrated excellent area-under-the-curve (AUC) values (0.959 to 0.995) in distinguishing DKD from non-DKD. Furthermore, this multi-marker panel successfully segregated the most ambiguous group (microalbuminuria) into three distinct clusters, with 80% of subjects aligning either as DKD or non-DKD. The remaining 20% exhibited continued uncertainty. Overall, the use of these candidate urinary proteins allowed for the better classification of DKD and offered potential for significant improvements in the early identification of DKD in T1D populations.

Unstably controlled systolic blood pressure trajectories are associated with markers for kidney damage in prediabetic population: results from the INDEED cohort study

Background

The association between blood pressure change and kidney damage in patients with abnormal blood glucose remains unclear. The current study aimed to identify systolic blood pressure (SBP) trajectories among the prediabetic population and to determine their association with kidney damage after a long-term follow-up.

Methods

The incidence, development, and prognosis of diabetic kidney disease (INDEED) study is nested in the Kailuan cohort study with a focus on population with diabetes and prediabetes. We screened out people with prediabetes in 2006 and with more than three SBP records from 2006 to 2014 biennially. We used the latent mixture modeling to fit five groups of trajectories of SBP. In 2016, estimated glomerular filtration rate (eGFR), urinary albumin creatinine ratio (uACR), and urinary α1-microglobulin (α1MG), transferrin and α1-acid glycoprotein were measured, and the association between SBP trajectories and these markers was analyzed by linear regression and logistic regression models.

Results

Totally, 1451 participants with prediabetes and without kidney damage were identified in 2006. Five heterogeneous SBP trajectories were detected based on the longitudinal data from 2006 to 2014, as low-stable group (n = 323), moderate-stable group (n = 726), moderate-increasing group (n = 176), moderate-decreasing group (n = 181), and high-stable group (n = 45). Linear regression analysis showed that the moderate and high SBP groups had lower eGFR, higher uACR, higher urinary α1MG, higher transferrin, and higher α1-acid glycoprotein than the low-stable group. Multivariable analysis attenuated the association but did not change the statistical significance.

Conclusions

Prediabetic patients with persistent high-level SBP trajectory or gradually increased SBP trajectory had severer kidney damage during follow-up.

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 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.

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.

Pursuing type 1 diabetes mellitus and related complications through urinary proteomics

Diabetes mellitus is a chronic metabolic disease with multiple complications, and its successful management requires early diagnosis, to allow timely interventions. Here, we have comprehensively analyzed the proteome changes in urine of type 1 diabetic subjects with and without complications such as retinopathy and nephropathy. gel electrophoresis combined to liquid chromatography-tandem mass spectrometry (GeLC-MS/MS) analysis of midstream urine highlighted the mechanisms involved in disease pathogenesis as, for instance wound healing and blood coagulation in all diabetics or altered ganglioside metabolism in retinopathy, and also some urinary proteins with potential diagnosis value. From these, gelsolin and antithrombin-III appear as promising diagnosis markers for type 1 diabetes mellitus (T1DM), whereas ephrin type-B receptor 4 and vitamin K-dependent protein Z seem to be promising markers for advanced T1DM disease state presenting retinopathy and nephropathy (T1DM-R + N). Data also suggest urinary ganglioside GM2 activator and beta-hexosaminidase subunit beta as potential urinary markers of retinopathy in diabetics. Taken together, the present exploratory urinary proteomic analysis might be seen as an important starting point for studies targeting specific urinary proteins aimed at the implementation of new biomarkers for the early detection of T1DM-related microvascular complications.

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.

Proteomic identification of early biomarkers of acute kidney injury after cardiac surgery in children

BACKGROUND

Serum creatinine is a delayed marker of acute kidney injury (AKI). Our purpose is to discover and validate novel early urinary biomarkers of AKI after cardiac surgery.

STUDY DESIGN

Diagnostic test study.

SETTING & PARTICIPANTS

Children undergoing cardiopulmonary bypass surgery. The test set included 15 participants with AKI and 15 matched controls (median age, 1.5 year) of 45 participants without AKI. The validation set included 365 children (median age, 1.9 year).

INDEX TESTS

Biomarkers identified using proteomic profiling: α(1)-microglobulin, α(1)-acid glycoprotein, and albumin.

REFERENCE TEST

AKI, defined as ≥50% increase in serum creatinine level from baseline within 3 days of surgery.

RESULTS

Proteomic profiling using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) showed 3 protein peaks that appeared consistently within 2 hours in children who developed AKI after cardiopulmonary bypass surgery. The proteins were identified as α(1)-microglobulin, α(1)-acid glycoprotein, and albumin. Using clinical assays, results were confirmed in a test set and validated in an independent prospective cohort. In the validation set, 135 (37%) developed AKI, in whom there was a progressive increase in urinary biomarker concentrations with severity of AKI. Areas under the curve for urinary α(1)-microglobulin, α(1)-acid glycoprotein, and albumin at 6 hours after cardiac surgery were 0.84 (95% CI, 0.79-0.89), 0.87 (95% CI, 0.83-0.91), and 0.76 (95% CI, 0.71-0.81), respectively. Participants with increasing quartiles of biomarkers showed increasing lengths of hospital stays and durations of AKI (P < 0.001).

LIMITATIONS

Single-center study of children with normal kidney function at recruitment. The SELDI-TOF MS technique has limited sensitivity for the detection of proteins greater than the 20-kDa range.

CONCLUSIONS

Urinary α(1)-microglobulin, α(1)-acid glycoprotein, and albumin represent early, accurate, inexpensive, and widely available biomarkers of AKI after cardiac surgery. They also offer prognostic information about the duration of AKI and length of hospitalization after cardiac surgery.

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.