Dear colleagues,
It is my great pleasure to introduce to you the fifth issue of 2020 featuring original research on biomarkers in schizophrenia.
Mazza and colleagues explored the role of neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR) and monocyte/lymphocyte ratio (MLR) in non-affective psychosis. Patients with non-affective psychosis had higher NLR and MLR compared to healthy subjects while a trend was observed for PLR with patients having higher PLR. The authors conclude that the inflammatory ratios may prove useful to detect an inflammatory activation that occurs in non-affective psychosis.
Mabry et al. investigated synaptic density, neuromelanin content, glutamatergic and GABAergic inputs to the post-mortem substantia nigra in schizophrenia patients. Positive association was found between vGLUT1 with GAD67 in schizophrenia patients while a negative correlation was detected in healthy subjects. Furthermore, a decrease in inhibitory synapses was observed in patients. Their results may indicate that these factors contribute to the hyperactivity in the substantia nigra.
Cao and associates evaluated water-soluble metabolic biomarkers in schizophrenia. The composition of 11 metabolites clearly differentiated patients with schizophrenia from healthy controls. The water-soluble metabolites were mainly related to cellular bioenergetic pathways such as oxidative stress. Future research should look into pathways involving imbalance of cellular bioenergetics.
Mitelman and colleagues investigated cerebral grey matter metabolism and dopamine receptor D2/D3 availability in schizophrenia patients and healthy controls. Dopamine receptor availability was positively correlated to glucose uptake in most regions in both groups, although patients had weaker correlations and decreased receptor availability compared to controls in several regions. To conclude, the dopaminergic system is a potential modulator of grey matter metabolism and may play a role in neurometabolic coupling in schizophrenia as well as in the healthy brain.
Maes and associates assessed the association of psychomotor retardation (PMR), immune biomarkers and executive functions in schizophrenia. PMR distinguished schizophrenia patients from controls and was associated with memory and executive function impairments as well as psychotic, hostility, excitation, mannerism and negative symptoms. Cumulative effects of immune activation predicted PMR and the authors conclude that PMR may be induced by compensatory immune-regulatory system deficits and increased neurotoxic immune production.
In a brief report, Gibbons et al. determined the ATPase 13A4 mRNA expression in post-mortem schizophrenia subjects. Increased expression levels were observed in Brodmann’s area 44 in schizophrenia subjects compared to controls which was unaffected by antipsychotic treatment. The expression increase detected is contrary to genetic studies that have reported on ATP13A4 gene deletions in schizophrenia.
Dan Rujescu, MD
Chief Editor