Lower ANXA3 Levels May Be Related to Major Depressive Disorder.

Annexin A3 (ANXA3) is a calcium-binding protein that plays a role in membrane phospholipid metabolism and inflammation, and significant alterations have been shown in some psychotic disorders. Because its association with major depressive disorder (MDD) is unclear, we aimed to compare serum ANXA3 levels in patients with MDD and healthy controls and to investigate their relationship with depression severity. Serum ANXA3 concentrations in 90 patients diagnosed with MDD and 90 healthy controls were measured by ELISA. Depression severity was assessed using the Beck Depression Inventory (BDI). Serum ANXA3 levels were significantly lower in patients with MDD compared to controls (p < 0.001). ANXA3 showed negative correlations with neutrophil count, platelet count, neutrophil-to-lymphocyte ratio (NLR), glucose, creatinine, and ALT levels, and positive correlations with lymphocyte and red blood cell counts. We found that low ANXA3 levels, high NLR, and glucose dysregulation predicted greater depression severity. Using ROC analysis, we demonstrated that ANXA3 has high discriminatory power in distinguishing moderate to severe cases of MDD (AUC > 0.90). ANXA3 may serve as a biomarker of depression severity. Further studies are needed to clarify its clinical utility and confirm whether ANXA3 alterations represent state or trait markers of depression.