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

The Hepatokine Orosomucoid 2 Mediates Beneficial Metabolic Effects of Bile Acids

Bile acids (BAs) are pleiotropic regulators of metabolism. Elevated levels of hepatic and circulating BAs improve energy metabolism in peripheral organs, but the precise mechanisms underlying the metabolic benefits and harm still need to be fully understood. In the current study, we identified orosomucoid 2 (ORM2) as a liver-secreted hormone (i.e., hepatokine) induced by BAs and investigated its role in BA-induced metabolic improvements in mouse models of diet-induced obesity. Contrary to our expectation, under a high-fat diet (HFD), our Orm2 knockout (Orm2-KO) exhibited a lean phenotype compared with C57BL/6J control, partly due to the increased energy expenditure. However, when challenged with a HFD supplemented with cholic acid, Orm2-KO eliminated the antiobesity effect of BAs, indicating that ORM2 governs BA-induced metabolic improvements. Moreover, hepatic ORM2 overexpression partially replicated BA effects by enhancing insulin sensitivity. Mechanistically, ORM2 suppressed interferon-γ/STAT1 activities in inguinal white adipose tissue depots, forming the basis for anti-inflammatory effects of BAs and improving glucose homeostasis. In conclusion, our study provides new insights into the molecular mechanisms of BA-induced liver-adipose cross talk through ORM2 induction.

ARTICLE HIGHLIGHTS

Urinary orosomucoid is associated with diastolic dysfunction and carotid arteriopathy in the general population. Cross-sectional data from the Tromsø study

Objectives. Urinary albumin excretion is a risk marker for cardiovascular disease (CVD). Studies suggest that urinary orosomucoid may be a more sensitive marker of general endothelial dysfunction than albuminuria. The aim of this population-based cross-sectional study was to examine the associations between urinary orosomucoid to creatinine ratio (UOCR), urinary albumin to creatinine ratio (UACR) and subclinical CVD. Design. From the Tromsø Study (2007/2008), we included all men and women who had measurements of urinary orosomucoid (n = 7181). Among these, 6963 were examined with ultrasound of the right carotid artery and 2245 with echocardiography. We assessed the associations between urinary markers and subclinical CVD measured as intima media thickness of the carotid artery, presence and area of carotid plaque and diastolic dysfunction (DD). UOCR and UACR were dichotomized as upper quartile versus the three lowest. Results. High UOCR, adjusted for UACR, age, cardiovascular risk factors and kidney function, was associated with presence of DD in men (OR: 3.18, 95% CI [1.27, 7.95], p = .013), and presence of plaque (OR: 1.20, 95% CI [1.01, 1.44], p = .038) and intima media thickness in women (OR: 1.34, 95% CI [1.09, 1.65], p = .005). Analyses showed no significant interaction between sex and UOCR for any endpoints. UACR was not significantly associated with DD, but the associations with intima media thickness and plaque were of magnitudes comparable to those observed for UOCR. Conclusions. UOCR was positively associated with subclinical CVD. We need prospective studies to confirm whether UOCR is a clinically useful biomarker and to study possible sex differences.

Urinary actin, as a potential marker of sepsis-related acute kidney injury: A pilot study

Introduction

A major complication of sepsis is the development of acute kidney injury (AKI). Recently, it was shown that intracellular actin released from damaged tissues appears in the urine of patients with multiple organ dysfunction syndrome. Our aims were to measure urinary actin (u-actin) concentrations of septic and control patients and to test if u-actin levels could predict AKI and mortality.

Methods

Blood and urine samples were collected from septic and sepsis-related AKI patients at three time points (T1-3): T1: within 24 hours after admission; T2: second day morning; T3: third day morning of follow-up. Patients with malignancies needing palliative care, end-stage renal disease or kidney transplantation were excluded. Serum and u-actin levels were determined by quantitative Western blot. Patients were categorized by the Sepsis-3 and KDIGO AKI classifications.

Results

In our study, 17 septic, 43 sepsis-induced AKI and 24 control patients were enrolled. U-actin levels were higher in septic patients compared with controls during follow-up (p<0.001). At T1, the septic and sepsis-related AKI groups also showed differences (p<0.001), yet this increase was not statistically significant at T2 and T3. We also detected significantly elevated u-actin concentrations in AKI-2 and AKI-3 septic patients compared with AKI-1 septic patients (p<0.05) at T1 and T3, along with a significant increase in AKI-2 septic patients compared with AKI-1 septic patients at T2 (p<0.01). This tendency remained the same when referring u-actin to urine creatinine. Parameters of first-day septic patient samples could discriminate AKI from non-AKI state (AUC ROC, p<0.001): u-actin: 0.876; se-creatinine: 0.875. Derived cut-off value for u-actin was 2.63 μg/L (sensitivity: 86.0%, specificity: 82.4%).

Conclusion

U-actin may be a complementary diagnostic biomarker to se-creatinine in sepsis-related AKI while higher u-actin levels also seem to reflect the severity of AKI. Further investigations may elucidate the importance of u-actin release in sepsis-related AKI.

Evaluation of serum and urinary orsomucoid protein A in psoriatic patients and their relation to severity of disease

BACKGROUND

Orsomucoid protein A (ORM) is a major acute-phase protein. Serum ORM (se-ORM) protein A elevates in infections, malignancies, and autoimmune diseases. Urinary ORM (u-ORM) protein A is more accurate and less invasive marker of inflammation. Elevated u-ORM was associated with pathomechanism factors related to psoriasis such as endothelial dysfunction; however, the clinical significance of it has not been explored yet.

AIM

To evaluate se-ORM/u-ORM protein A and urinary orsomucoid protein A/urinary creatinine (u-ORM/u-CREAT) in patient with psoriasis and their relations to severity of the disease.

METHODS

This case-control study was conducted at Dermatology and Andrology Department; 35 psoriasis patients and 35 age- and sex-matched healthy controls were included. They were subjected to history taking and general and dermatological examination. Psoriasis severity was assessed by Psoriasis Area and Severity Index (PASI) score. Measurement of se-ORM/u-ORM protein A using ELISA and u-ORM/u-CREAT using colorimetric method.

RESULTS

Highly significant difference between psoriasis patients and controls regarding u-ORM protein A level (p value = 0.01). It was also higher in severe cases than moderate and mild ones and higher in moderate than mild cases (p value 0.001, 0.001, and 0.004, respectively). There were significantly higher u-ORM/u-CREAT (p ˂ 0.001) levels in psoriasis patients than in controls. Also, significantly higher U-ORM/u-CREAT levels were found in severe psoriasis cases than in mild and moderate cases (p = 0.003 and 0.006, respectively). While the se-ORM levels showed no significant differences between the studied groups.

CONCLUSION

u-ORM/u-CREAT is a highly sensitive, easily available, and new inflammatory biomarker of psoriasis which correlates to the disease severity.

Urinary Proteomics Identifying Novel Biomarkers for the Diagnosis of Adult-Onset Still's Disease

Adult-onset Still’s disease (AOSD) is a systemic, multigenic autoinflammatory disease, and the diagnosis of AOSD must rule out neoplasms, infections, and other autoimmune diseases. Development of a rapid and efficient but non-invasive diagnosis method is urgently needed for improving AOSD therapy. In this study, we first performed a urinary proteomic study using isobaric tags for relative and absolute quantification (iTRAQ) labeling combined with liquid chromatography–tandem mass spectrometry analysis in patients with AOSD and healthy control (HC) subjects. The urinary proteins were enriched in pathways of the innate immune system and neutrophil degranulation, and we identified that the α-1-acid glycoprotein 1 (LRG1), orosomucoid 1 (ORM1), and ORM2 proteins were highly expressed in patients with AOSD. The elevated urine levels of LRG1, ORM1, and ORM2 were further validated by enzyme-linked immunosorbent assay in active patients with AOSD, disease controls, and HC subjects. Receiver operating characteristic curves showed that the areas under the curve of LRG1, ORM1, and ORM2 were 0.700, 0.837, and 0.736, respectively (all p < 0.05). Furthermore, we found that the urine levels of LRG1, ORM1, and ORM2 were positively correlated with the systemic score and erythrocyte sedimentation rate and that the urine levels of LRG1 were positively correlated with interleukin 1β (IL-1β), IL-6, and IL-18 levels, whereas the urine levels of ORM1 were positively correlated with the IL-1β level. Together, our study identified novel urinary markers for non-invasive and simple screening of AOSD.

Hypoxia is not the primary mechanism contributing to exercise-induced proteinuria

Introduction

Proteinuria increases at altitude and with exercise, potentially as a result of hypoxia. Using urinary alpha-1 acid glycoprotein (α1-AGP) levels as a sensitive marker of proteinuria, we examined the impact of relative hypoxia due to high altitude and blood pressure-lowering medication on post-exercise proteinuria.

Methods

Twenty individuals were pair-matched for sex, age and ACE genotype. They completed maximal exercise tests once at sea level and twice at altitude (5035 m). Losartan (100 mg/day; angiotensin-receptor blocker) and placebo were randomly assigned within each pair 21 days before ascent. The first altitude exercise test was completed within 24–48 hours of arrival (each pair within ~1 hour). Acetazolamide (125 mg two times per day) was administrated immediately after this test for 48 hours until the second altitude exercise test.

Results

With placebo, post-exercise α1-AGP levels were similar at sea level and altitude. Odds ratio (OR) for increased resting α1-AGP at altitude versus sea level was greater without losartan (2.16 times greater). At altitude, OR for reduced post-exercise α1-AGP (58% lower) was higher with losartan than placebo (2.25 times greater, p=0.059) despite similar pulse oximetry (SpO₂) (p=0.95) between groups. Acetazolamide reduced post-exercise proteinuria by approximately threefold (9.3±9.7 vs 3.6±6.0 μg/min; p=0.025) although changes were not correlated (r=−0.10) with significant improvements in SpO₂ (69.1%±4.5% vs 75.8%±3.8%; p=0.001).

Discussion

Profound systemic hypoxia imposed by altitude does not result in greater post-exercise proteinuria than sea level. Losartan and acetazolamide may attenuate post-exercise proteinuria, however further research is warranted.

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.

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 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.

Nonconventional Markers of Sepsis

Sepsis still remains a challenging healthcare problem with high mortality rate. To improve outcome, early diagnosis and monitoring of sepsis is of utmost importance. In this process objective laboratory parameters are the most helpful. Procalcitonin and C-reactive protein are the most commonly used and recommended markers of sepsis however, more than 200 sepsis biomarkers have already been published. This mini review focuses on nonconventional novel possibilities for the recognition of sepsis severity. Presepsin, actin and actin scavenger proteins (gelsolin and Gc-globulin) and orosomucoid are discussed. Besides serum parameters, the urinary levels of these markers are also elaborated, since urinary biomarkers of sepsis provide new diagnostic implications and are helpful for monitoring both the kidney function and the septic process. Increasing serum actin levels and decreasing levels of actin binding proteins seem to be associated with sepsis severity and outcome. Actin can be detected in the urine samples of septic patients as well, and strongly elevated levels of it were found in sepsis-related acute kidney injury. Both serum and urinary orosomucoid might be able to indicate sepsis, however urinary orosomucoid is a more sensitive inflammatory marker. Novel laboratory tests can provide rapid help for clinical decision making because the key point in successful treatment lies in the early diagnosis of sepsis.