CD107a (LAMP-1) Cytotoxic CD8 T-Cells in Lupus Nephritis Patients.

Cytotoxic CD8 T-cells play a pivotal role in the pathogenesis of systemic lupus erythematosus (SLE). The aim of this study was to investigate the role of CD107a (LAMP-1) on cytotoxic CD8 T-cells in SLE-patients in particular with lupus nephritis. Peripheral blood of SLE-patients ( = 31) and healthy controls ( = 21) was analyzed for the expression of CD314 and CD107a by flow cytometry. Kidney biopsies of lupus nephritis patients were investigated for the presence of CD8 and C107a cells by immunohistochemistry and immunofluorescence staining. The percentages of CD107a on CD8 T-cells were significantly decreased in SLE-patients as compared to healthy controls (40.2 ± 18.5% vs. 47.9 ± 15.0%, = 0.02). This was even more significant in SLE-patients with inactive disease. There was a significant correlation between the percentages of CD107aCD8 T-cells and SLEDAI. The evaluation of lupus nephritis biopsies showed a significant number of CD107aCD8 T-cells mainly located in the peritubular infiltrates. The intrarenal expression of CD107a was significantly correlated with proteinuria. These results demonstrate that CD8 T-cells of patients with systemic lupus erythematosus have an altered expression of CD107a which seems to be associated with disease activity. The proof of intrarenal CD107aCD8 suggests a role in the pathogenesis of lupus nephritis.