Plasma biomarkers in adolescents with schizophrenia‐spectrum disorder

Abstract

AimSchizophrenia onset in the developmental age has a strong neurodevelopmental burden and is associated with a poorer prognosis. The approach to diagnosis is still based on symptomatic description without objective validation. In this study, we aimed to compare the peripheral blood levels of hypothesized biomarker proteins: brain‐derived neurotrophic factor (BDNF), proBDNF, p75 neurotrophin receptor (p75NTR) and S100B between early‐onset schizophrenia‐spectrum adolescents (n = 45) and healthy controls (n = 34).MethodsClinical assessment of the participants encompassed symptomatic description with the use of structured interviews and executive function objective measurement. Plasma levels of BDNF protein were significantly lower in schizophrenia patients than in controls both at admission (p = .003) and 6–8 weeks follow‐up (p = .007).ResultsWe observed significant correlations between BDNF, proBDNF and p75NTR levels and positive and negative symptoms scale (PANSS) scores, p75NTR and S100B levels and suicidal parameters, as well as a correlation of BDNF plasma level with the risky decision‐making style in Iowa Gambling Task (IGT).ConclusionsThe results indicate a potential value of studied proteins as a biomarker in the diagnosis and monitoring of the disease's course.

Peripheral S100B Protein Levels in Five Major Psychiatric Disorders: A Systematic Review

“…Changes in S100B levels during antipsychotic treatment were widely studied, with contrary results. No differences [ 13 , 23 , 39 , 41 , 42 , 43 , 44 , 45 , 46 ] or decreases [ 12 , 19 , 45 , 47 , 48 , 49 ] in S100B concentrations were reported during antipsychotic treatment. Elevation in S100B levels in the patient group with predominant negative symptoms were also found [ 39 ].…”

“…Most studies reported the absence of correlation of S100B levels with age [ 10 , 13 , 15 , 30 , 33 , 35 , 36 , 40 , 50 ], but positive [ 32 ], as well as negative [ 43 ], correlations with age were discovered, also. There were no correlations of circulating S100B with gender in most of the studies published [ 10 , 13 , 15 , 22 , 27 , 30 , 33 , 40 , 50 , 52 ], although higher S100B levels were found in schizophrenic males compared to females [ 32 ], contrary to higher S100B in female SCH compared to male SCH [ 36 ].…”

“…No correlation of S100B levels with schizophrenia symptoms severity measured using Positive and Negative Symptoms Scale (PANSS) total score was detected in the majority of the studies [ 20 , 27 , 28 , 30 , 31 , 39 , 40 , 41 , 43 , 45 , 47 , 48 , 50 , 51 ]. In contrast, others reported a positive [ 17 , 19 , 21 , 23 ] or negative [ 22 ] correlation with total PANSS score.…”

“…A negative correlation between age and the number of suicidal attempts was detected. A lack of correlation with symptom severity measured with PANSS, either at baseline or after treatment, was found [ 43 ]. Another study compared S100B levels between 60 children SCH patients treated with risperidone for 12 weeks, with 60 matched healthy controls.…”

The potential role of the p75 receptor in schizophrenia: neuroimmunomodulation and making life or death decisions

“…Increased plasma levels of p75 receptor protein are reported in first-episode psychosis patients compared to clinical high-risk individuals and controls ( He et al, 2019 ), with higher ratios of p75/TrkB protein found in serum of first-episode psychosis patients compared to unaffected siblings and controls ( Yesilkaya et al, 2022 ), reflecting a trophic imbalance preceding diagnosis and treatment that may favour apoptotic functions of the receptor. Whilst plasma p75 protein levels were found to positively correlate with positive and negative symptom scores in schizophrenia ( Zakowicz et al, 2023 ), other studies report no changes in p75 protein in the plasma of schizophrenia patients compared to controls ( Haack et al, 1999 ; Yesilkaya et al, 2022 ), with some reporting lower serum levels of p75 receptor protein ( Zakharyan et al, 2014 ; Chen et al, 2017 ; Turhan et al, 2016 ). A potential contributor to the heterogeneous results of studies assessing peripheral p75 receptor expression in schizophrenia is the prevalence of single nucleotide polymorphisms (SNPs) of the p75 receptor evident in patients.…”