Hematological Inflammatory Markers Across Neurodevelopmental Disorders: Preliminary Findings of an Observational Retrospective Study

<b>Background/Objectives:</b> Alterations in immunoinflammatory activation may constitute a pathogenetic mechanism in neurodevelopmental disorders (NDDs). Blood cell count (CBC) parameters and hematological inflammatory indices (neutrophil-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, platelet-to-lymphocyte ratio) are now assuming a greater role as potential biomarkers for NDDs. <b>Methods:</b> In this retrospective observational study, we gathered data on 135 medication-free individuals aged 6 to 17 years: 90 with NDDs (34 with autism spectrum disorder (ASD), 29 with attention-deficit/hyperactivity disorder, 14 with intellectual disability, and 13 with tic disorder) and 45 typically developed controls. The variables analyzed were compared using analysis of variance including Bonferroni posthoc testing for pairwise comparisons Significance was defined as <i>p</i> < 0.05. <b>Results:</b> The analysis of variance revealed statistical significance for all evaluated CBC parameters, as well as for the lymphocyte-to-monocyte ratio. Notably, subjects with ASD exhibited increased values of neutrophils, lymphocytes, monocytes, and eosinophils compared to both typically developing subjects and other NDDs. The lymphocyte-to-monocyte ratio was found to be lower in the tic disorder group compared to typically developing subjects. The elevated lymphocyte and monocyte levels in ASD subjects might reflect chronic low-grade inflammation. <b>Conclusions:</b> Consistent with the evidence in literature, statistically significant differences between the NDD group and typically developed subjects in the CBC parameters were found. The principal limitations of this investigation are the restricted sample size and the exclusion of specific NDD subtypes. Future research is needed to evaluate CBC parameters and inflammatory indices in a broader spectrum of NDDs to better understand the immunoinflammatory response specific to each disorder.