Raised plasma concentrations of 3-methoxy-4-hydroxyphenylethyleneglycol in cirrhotic patients with or without hepatic encephalopathy

Metabolome analyses of skin dialysate: Insights into skin interstitial fluid biomarkers

BACKGROUND

Metabolites in biofluids can serve as biomarkers for diagnosing diseases and monitoring body conditions. Among the available biofluids, interstitial fluid (ISF) in the skin has garnered considerable attention owing to its advantages, which include inability to clot, easy access to the skin, and possibility of incorporating wearable devices. However, the scientific understanding of skin ISF composition is limited.

OBJECTIVE

In this study, we aimed to compare metabolites between skin dialysate containing metabolites from the skin ISF and venous blood (plasma) samples, both collected under resting states.

METHODS

We collected forearm skin dialysate using intradermal microdialysis alongside venous blood (plasma) samples from 12 healthy young adults. We analyzed these samples using capillary electrophoresis-fourier transform mass spectrometry-based metabolomics (CE-FTMS).

RESULTS

Significant positive correlations were observed in 39 metabolites between the skin dialysate and plasma, including creatine (a mitochondrial disease biomarker), 1-methyladenosine (an early detection of cancer biomarker), and trimethylamine N-oxide (a posterior predictor of heart failure biomarker). Based on the Human Metabolome Technologies database, we identified 12 metabolites unique to forearm skin dialysate including nucleic acids, benzoate acids, fatty acids, amino acids, ascorbic acid, 3-methoxy-4-hydroxyphenylethyleneglycol (an Alzheimer's disease biomarker), and cysteic acid (an acute myocardial infarction biomarker).

CONCLUSION

We show that some venous blood biomarkers may be predicted from skin dialysate or skin ISF, and that these fluids may serve as diagnostic and monitoring tools for health and clinical conditions.

Hashimoto encephalopathy with high plasma monoamine metabolite levels: a case report

Hashimoto encephalopathy (HE) is believed to be an immune-mediated disorder associated with Hashimoto's thyroiditis. It was suggested that neuropsychiatric symptoms, the presence of antithyroid antibody, and good response to steroids were important for the diagnosis of HE. It has been reported that homovanillic acid (HVA) and 3-methoxy-4-hydroxyphenylglycol (MHPG), which are monoamine metabolites of dopamine and noradrenaline, respectively, are the possible biomarkers of neuropsychiatric diseases. We report a case of Hashimoto encephalopathy, in which we longitudinally measured the plasma levels of monoamine metabolites. A 52-year-old woman developed acute psychosis, and was admitted to the psychiatric ward of our hospital due to psychotic state, 6 days after a traffic accident. An extensive evaluation showed no remarkable findings, except an increase in antithyroglobulin antibodies. Plasma levels of HVA and MHPG were extremely high at 66.5 and 41.8 ng/mL, respectively. On day 16, 50 mg/day oral prednisolone was administered, which improved her psychotic symptoms. Plasma levels of HVA and MHPG decreased to 7.2 and 9.9 ng/mL, respectively, on day 19. After the temporary worsening of psychosis and increase in plasma levels of HVA and MHPG, the dosage of prednisolone was tapered and low-dose risperidone was started. Her psychiatric symptoms gradually improved and plasma monoamine metabolite levels decreased again (HVA: 17.9 ng/mL; MHPG: 7.7 ng/mL). Although autoimmune mechanism has been suggested to be involved in HE, neural mechanism and pathogenesis of HE remain unknown. Our findings suggest that monoaminergic neural activity might be associated with psychotic symptoms in patients with HE and plasma levels of monoamine metabolites might be useful as state markers.

Schizophrenia and liver dysfunction

It is suggested that a non-hepatocellular liver dysfunction, caused by the presence of a congenital or acquired portal-systemic shunt, constitutes a major predisposing factor in the pathogenesis of schizophrenia. In addition to the common occurrence of schizophrenic reactions observed in liver disease, this suggestion is supported by autoptic findings in addition to the fact that a considerable number of abnormal biochemical and biological phenomena are shared by patients suffering from schizophrenia and portal-systemic shunting. The frequency of abnormal portal-systemic shunts in schizophrenia is unknown. Recent advances in non-invasive Doppler-sonographic techniques should enable an elucidation of this question.