Fig. 9

Immunohistochemistry of key immune checkpoint proteins. (A) Immunohistochemistry for HLA-DMB in 3 control and 3 ankylosing spondylitis (AS) ligaments samples. Scale bar: 1 mm on the left image, and 250 μm on the right image. (B) Quantification and statistical analysis of HLA-DMB immunohistochemistry results. (C) Immunohistochemistry for HLA-DPA1 in 3 control and 3 AS ligaments samples. Scale bar: 1 mm on the left image, and 250 μm on the right image. (D) Quantification and statistical analysis of HLA-DPA1 immunohistochemistry results