The Hemoglobin-to-Red Cell Distribution Width Ratio and Systemic Inflammatory Response Index in Children with Autism Spectrum Disorder

Objective: Inflammation is reported to play an important role in the etiology of autism spectrum disorder. The purpose of this study was to investigate hemoglobin-to-red blood cell distribution width ratio (HRR) and systemic inflammatory response index (SIRI) levels, which may indicate immunological mechanisms involved in the etiopathogenesis of autism spectrum disorder.

Methods: One hundred forty-eight participants (74 diagnosed with autism spectrum disorder and 74 healthy controls) aged 24-72 months were included in the study. The Childhood Autism Rating Scale was applied to measure disease severity. The Denver Developmental Screening Test-2 was applied to the children in the autism spectrum disorder group.

Results: Hemoglobin-to-red blood cell distribution width ratio and lymphocyte values were significantly low in the children with autism spectrum disorder group compared to the healthy controls (P = .031 and P = .003, respectively). No significant difference was determined between the healthy children and those with autism spectrum disorder in terms of systemic inflammatory response index. Low HRR and maternal age were determined to predict autism spectrum disorder (B = −4.963, P = .003 and B = 0.176, P = .011, respectively). Receiver-operating curve analysis showed that HRR had limited discriminative ability for autism spectrum disorder (AUC = 0.602).

Conclusion: Although HRR values were statistically lower in children with autism spectrum disorder, the observed difference was small. The small statistical difference observed in HRR may represent a preliminary finding that requires cautious interpretation and validation in larger, prospective studies.

Cite this article as: Kocaman O, Kuru T, Kara T, Avşar PA. The hemoglobin-to-red cell distribution width ratio and systemic inflammatory response index in children with autism spectrum disorder. Neuropsychiatr Invest. 2026, 64, 0065, doi: 10.5152/NeuropsychiatricInvest.2026.25065.