Figure 2.

Complement cascade-associated proteins analyzed by ELISA. Significant differences between the bipolar II (n = 20), MDD (n = 30), and HC groups (n = 30) were observed. The expression levels of plasma C3 (A) in both the disease groups are significantly higher than the level in the HC group, and C3 expression was furthermore significantly upregulated in the MDD group compared with the bipolar II group. In contrast to C3, C4BPα (B) and CFI (C) expression levels were significantly downregulated in both disease groups compared to the HC group, the expression levels of these two proteins were significantly lower in bipolar II subjects compared to MDD subjects. *P < 0.05, **P < 0.001, and ***P = 0.000. Yellow lines highlight the differences between bipolar II and MDD subjects