Associações entre biomarcadores salivares inflamatórios e neurotróficos em crianças e adolescentes com Transtorno do Espectro Autista: estudo transversal em ambulatório de referência no Ceará

Abstract

Autism Spectrum Disorder (ASD) is a heterogeneous neurodevelopmental condition whose clinical complexity has driven the search for peripheral biomarkers capable of broadening the understanding of biological subgroups. In this context, saliva stands out as a promising matrix due to its non-invasive nature and good acceptability in pediatric populations. This study aimed to analyze the salivary profile of inflammatory cytokines (IL-1β, IL-6, and TNF-α) and neurotrophins (BDNF and β-NGF) in children and adolescents with ASD treated at a specialized outpatient clinic, as well as to investigate the associations among these biomarkers and their relationship with clinical and contextual variables. This was a translational, observational, analytical, cross-sectional study conducted with 69 participants aged 2 to 17 years. Salivary biomarkers were measured using immunoenzymatic assays, and statistical analysis included the Shapiro-Wilk test and Spearman’s correlation coefficient. All biomarkers showed non-normal distribution. In the total sample, a strong positive correlation was observed between IL-6 and TNF-α (ρ = 0.85; p < 0.001), in addition to positive associations between both cytokines and β-NGF (ρ ≥ 0.71; p < 0.001), configuring a more stable relational axis between inflammation and neurotrophic signaling. In age-stratified analyses, this pattern remained present, with greater cohesion in Group 1 (2–4 years) and maintenance of the associations among IL-6, TNF-α, and β-NGF in Group 2 (5–9 years) and Group 3 (10–17 years), whereas IL-1β and BDNF showed more variable behavior across strata. Exploratory associations were also identified between biomarkers and clinical and contextual variables, notably the negative correlation between BMI and β-NGF in Group 1, the positive correlation between family income and BDNF across different age groups, and the negative associations between food selectivity and IL-6/TNF-α in Group 3. It is concluded that salivary biomarkers revealed a consistent pattern of association between inflammation and neurotrophy, especially involving the IL-6, TNF-α, and β-NGF axis, reinforcing saliva as a promising matrix for translational research in ASD.