Figure 2. Complement was extensively activated by PG immunization and intercepted by additional Efb-C treatment in the spinal bone marrow in a PG-induced AS mouse model and in AS patients detected by IHC analysis.

(A,B) PG immunization induced complement cleavage products C3b/iC3b exclusively deposited in macrophages (A) and MAC/C5b-9 deposited in various types of cells (B) compared with control treatment, which was evidently alleviated by the additional Efb-C treatment. See also Supplementary Figure S2. (C) Quantitative data of immunohistochemical analysis in (A,B). (D) The extensive complement activation was determined by C3b/iC3b and MAC deposition in most types of cells in bone marrow of facet joints collected from an ankylosing spondylitis patient with correction surgery. Lower panel shows a 10× magnification of the area outlined by the black rectangle in the upper image. Scale bars, 20 μm.