Serum Galectin-3 and IL-6 as Inflammatory Markers in Bipolar Disorder: Insights from Manic and Euthymic Episodes

Objectives: This study aimed to assess serum Galectin-3 (Gal-3) and IL-6 levels, along with other inflammatory markers, in type-1 bipolar disorder (BD) patients and explore their relationship with clinical features, metabolic parameters, and symptom severity. Background: The study included 38 manic, 35 euthymic BD patients, and 40 healthy controls. Sociodemographic data, such as age, gender, alcohol and smoking habits, and body mass index (BMI), were recorded. Methods: The Young Mania Rating Scale (YMRS) and Hamilton Depression Rating Scale (HAM-D) were administered to patients. Biochemical measurements included Gal-3, IL-6, CRP, neutrophil, lymphocyte, platelet counts, and inflammatory indices like NLR, PLR, SII, and SIRI. Results: Gal-3 levels significantly differed among the groups (F = 52.251, p < 0.001), with the highest levels in euthymic patients. IL-6 levels were elevated in both manic and euthymic patients compared to controls (F = 7.379, p = 0.001). Manic patients had significantly higher levels of neutrophils, monocytes, CRP, NLR, PLR, SII, and SIRI. A positive correlation was found between Gal-3 levels, the total number of episodes, and YMRS scores in manic patients. In euthymic patients, Gal-3 levels correlated positively with disease duration and episode count. Conclusions: Elevated Gal-3 levels, particularly in the euthymic phase, may serve as a biomarker for BD and indicate ongoing inflammation. These findings suggest Gal-3 could help identify BD and differentiate the euthymic phase.