Urinary biopyrrins: potential biomarker for monitoring of the response to treatment with anxiolytics

Metabolomic Biomarkers in Anxiety Disorders

Anxiety disorders range among the most prevalent psychiatric disorders and belong to the leading disorders in the study of the total global burden of disease. Anxiety disorders are complex conditions, with not fully understood etiological mechanisms. Numerous factors, including psychological, genetic, biological, and chemical factors, are thought to be involved in their etiology. Although the diagnosis of anxiety disorders is constantly evolving, diagnostic manuals rely on symptom lists, not on objective biomarkers and treatment effects are small to moderate. The underlying biological factors that drive anxiety disorders may be better suited to serve as biomarkers for guiding personalized medicine, as they are objective and can be measured externally. Therefore, the incorporation of novel biomarkers into current clinical methods might help to generate a classification system for anxiety disorders that can be linked to the underlying dysfunctional pathways. The study of metabolites (metabolomics) in a large-scale manner shows potential for disease diagnosis, for stratification of patients in a heterogeneous patient population, for monitoring therapeutic efficacy and disease progression, and for defining therapeutic targets. All of these are important properties for anxiety disorders, which is a multifactorial condition not involving a single-gene mutation. This review summarizes recent investigations on metabolomics studies in anxiety disorders.

Reference urinary biopyrrin level and physiological variation in healthy young adults: relation of stress by learning

Background

Biopyrrins are end products of oxidation reactions of bilirubin with reactive oxygen, and urinary biopyrrin (UBP) levels might increase under oxidative stress. The authors examined the reference UBP level for healthy adults and its physiological variation in 40 healthy volunteers recruited from among students of our university (20 students each from third-year and fourth-year), and compared the results with data on 8-hydroxy-2-deoxyguanosine (8OHdG).

Methods

UBP and 8OHdG levels could be considered as oxidative stress markers. The UBP levels were measured with a competitive ELISA kit using biopyrrin antibody 24G7, according to the manufacturer's protocol. 8OHdG levels were measured with a Highly Sensitive 8-OHdG Check kit. UBP and 8OHdG measurements were performed in triplicate and means values calculated. For both parameters, creatinine (Cr) correction was performed using urinary creatinine levels measured by an enzymatic method.

Results

A comparison of the UBP levels between different grades revealed that the third-year students under high stress from clinical training and other course work tended to have a higher UBP level than fourth-year students. Therefore, we compared the current UBP levels in fourth-year students (samples collected in 2018) with their UBP level when they were in the third-year (samples collected in 2017) to examine the annual change. We found that the UBP level in 2017 samples was significantly higher than that in 2018 samples (P < 0.05). No difference in the 8OHdG level. Additionally, no effect of menstrual stress on the UBP level was observed.

Conclusions

These results suggest that the UBP levels may be related to school-related stress and menstruation has no effects on urinalysis results.

Pink Urine Syndrome: A Combination of Insulin Resistance and Propofol

Pink urine syndrome is mostly seen in patients treated with propofol anesthesia. The pink color is attributed to the presence of large concentrations of uric acid (and pigment), which is excreted in large amounts when propofol is given. We describe a case of propofol-induced pink urine syndrome and perform a comprehensive, evidence-based review. We discuss prior case studies already published in the literature as we speculate on the pathophysiology and how it translates to a clinically relevant entity.

Urinary Biopyrrins: A New Marker of Oxidative Stress in Psoriasis

Background:

Psoriasis is a common chronic, relapsing, immune-mediated disease involving skin and joints of genetically predisposed individuals. Oxidative stress has been found to play many important roles in cellular damage and loss of function in a number of tissues and organs and is believed to contribute to the pathogenesis of a variety of diseases. Urinary biopyrrin levels have gained attention as an indicator of oxidative stress.

Aim and Objective:

To measure urinary biopyrrins excretion as a marker of oxidative stress in psoriasis.

Patients and Methods:

This case–control study was carried out on 85 subjects; 55 cases with chronic plaque psoriasis and 30 age, gender and body mass index-matched normal subjects as a control group. Urinary biopyrrin levels were measured using enzyme immunoassay.

Results:

There was a highly significant difference between cases and controls regarding urinary biopyrrins level (P < 0.001). There was significant positive correlation between biopyrrins level and both the age of cases (r = 0.28, P = 0.01) and psoriasis area and severity index score (r = 0.99, P < 0.001).

Conclusion:

Urinary biopyrrins are increased in patients with psoriasis, and the level is correlated with disease severity. Further large-scale studies involving different ages and different clinical varieties of the disease are needed to expand and validate current findings. The clinical usefulness of antioxidants in psoriasis treatment needs to be evaluated in future research. Furthermore, the value of biopyrrins as biomarkers for monitoring response to therapy needs to be evaluated.