Figure 6
Cathepsin S in human SLE and lupus nephritis. (A) Cat-S plasma levels were determined in patients with systemic lupus erythematosus (SLE) and healthy controls by ELISA. The patient characteristics are listed in Table 1. ***p < 0.001 versus healthy controls. (B,C) In SLE patients Cat-S plasma levels were not correlated with the respective SLE disease activity index (SLEDAI). (D) Dual immunostaining for Cat-S and the macrophage marker CD68 of human kidney biopsies showed double positivity in single cells within the glomerular tuft. Cat-S positivity was also noted in CD68 negative tubular epithelial cells. Representative images of two different renal biopsies (class IV lupus nephritis) are shown at the indicated scale 100 µm. (E) Dual fluoresence staining for Mac-2 and Cat-S in kidneys of MRL-(Fas)lpr mice of different age groups compared to MRL-wt (scale 25 µm).
