Background/Objectives: It has been suggested that chronic inflammatory diseases may be associated with an increased risk of cardiovascular disease. In this study, we investigated plasma soluble CD40 ligand (sCD40L) levels and their association with carotid intima–media thickness (cIMT) in children with Familial Mediterranean fever (FMF). Methods: The study was designed as a prospective cross-sectional study. The study included 68 asymptomatic children aged 5–18 years with FMF, diagnosed according to Tel Hashomer criteria, who were followed up regularly for at least one year, receiving regular colchicine treatment and not in an acute exacerbation period, along with 65 healthy children with similar demographic characteristics. cIMT was assessed by ultrasound and plasma sCD40L levels were measured by sandwich ELISA in all children. Results: Erythrocyte sedimentation rate, high-sensitivity C-reactive protein and serum amyloid A levels were not significantly different between patients and controls. However, sCD40L (p = 0.004) and fibrinogen (p = 0.011) levels were significantly higher in the FMF group compared to the control group. No significant difference was found between the patient and control groups in terms of carotid intima–media thickness (p = 0.517). Multivariate logistic regression was performed to assess the independent associations of fibrinogen and sCD40L with FMF. The results of this analysis indicated that sCD40L, but not fibrinogen, demonstrated a significant association with FMF (odds ratio [OR]: 1.003, 95% confidence interval [CI]: 1.001–1.006, p = 0.011). To determine the diagnostic performance of sCD40L, a receiver operating characteristic (ROC) curve was generated. This analysis demonstrated that sCD40L levels exceeding 100 pg/mL were predictive of FMF, yielding a sensitivity of 70.6% and a specificity of 62.3%. The positive predictive value and negative predictive value were 55.4% and 64.3%, respectively. The area under the curve for sCD40L was 0.644 (95% CI: 0.549–0.738, p = 0.004), signifying a statistically significant predictive capacity. Plasma sCD40L levels were significantly higher in FMF children with the M694V mutation (p = 0.013). Conclusions: The results of this study suggest that the high plasma sCD40L levels found in children with FMF may be related to the inflammatory activation of the disease rather than to atherosclerosis.

Background: The objective of this study was to evaluate serum soluble lectin-like oxidized low-density lipoprotein receptor-1 (sLOX-1) levels in children with type-1 diabetes mellitus (T1DM) without any atherosclerotic complications and to investigate whether there was an association with early atherosclerotic processes in these children. Methods: The study’s design entailed a prospective cross-sectional observational study methodology. The patient group consisted of 80 consecutive children aged 8–18 years who had been diagnosed with T1DM for at least ten years and had not developed any chronic clinical complications related to T1DM. The control group consisted of 72 completely healthy children with similar demographic characteristics. Serum levels of sLOX-1 were measured, and carotid intima-media thickness (cIMT) was evaluated using ultrasonography in all subjects. Results: A statistical analysis of the results was conducted. The serum sLOX-1 level was found to be significantly higher in the patient group than in the control group (0.49 ± 0.11 vs. 0.82 ± 0.35; p < 0.001). The statistical significance observed was maintained in the multivariable logistic regression analysis (p < 0.001). A significant correlation was identified between cIMT and serum sLOX-1 levels (r = 0.669, p < 0.001). The receiver operating characteristic curve for sLOX-1 indicated that a cutoff value greater than 0.65 ng/mL was associated with T1DM. Conclusions: Serum sLOX-1 levels were markedly elevated in children with T1DM who had not yet manifested chronic complications. These findings suggest that elevated serum sLOX-1 levels may be associated with the progression of atherosclerosis in children with T1DM.