Evaluation of oxLDL and LOX-1 levels in obsessive-compulsive disorder

Oxidative stress and inflammatory dysregulation are increasingly implicated in the pathophysiology of obsessive-compulsive disorder (OCD). The oxidized low-density lipoprotein (oxLDL)/lectin-like oxidized LDL receptor-1 (LOX-1) axis is involved in oxidative-inflammatory signaling but has not previously been investigated in OCD. In this cross-sectional case-control study, serum LOX-1 and oxLDL levels were measured by enzyme-linked immunosorbent assay in 67 patients with OCD and 37 healthy controls, together with neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and mean platelet volume (MPV). Contrary to the directional hypothesis, serum LOX-1 and oxLDL levels were significantly lower in patients with OCD than in controls (both p < .001; rank-biserial r=.461 and .568, respectively). NLR was higher in the OCD group in the unadjusted comparison (p=.030), whereas PLR and MPV did not differ significantly between groups. After adjustment for age, sex, body mass index, smoking pack-years, LDL, and HDL using analysis of covariance, group differences in LOX-1, oxLDL, and NLR remained significant. The direction of the LOX-1 and oxLDL findings was consistent across sensitivity analyses addressing values above the assay range. Neither LOX-1 nor oxLDL was significantly associated with OCD symptom severity or illness duration. These preliminary findings represent the first characterization of the oxLDL/LOX-1 axis in OCD and indicate an unexpected peripheral biomarker pattern characterized by lower serum LOX-1 and oxLDL alongside higher NLR. However, because most patients were receiving psychotropic medication, disorder-related and treatment-related contributions cannot be disentangled. Prospective studies in drug-naive samples are needed to clarify the temporal dynamics and clinical relevance of these findings.