Urinary CD4 T cells identify SLE patients with proliferative lupus nephritis and can be used to monitor treatment response.

Objectives: Proliferative lupus nephritis (LN) is one of the major concerns in the treatment of systemic lupus erythematosus (SLE). Here we evaluate urinary CD4 T cells as a biomarker of active LN and indicator of treatment response.

Methods: Urinary CD3CD4 T cells were quantified using flow cytometry in 186 urine samples from 147 patients with SLE.