Urinary T-Cells in Pediatric Lupus Nephritis

Lupus nephritis (LN) is a severe and frequent manifestation of systemic lupus erythematosus (SLE). Detection of initial renal manifestations and relapses during follow up is pivotal to prevent loss of renal function. Apart from renal biopsies, current urinary and serological diagnostic tests failed to accurately demonstrate the presence of active LN. Our objective is to assess the diagnostic value of urinary T-cells in comparison with traditional markers of active LN. T-cells in the urine in pediatric LN active and inactive were investigated. Twenty-five, in most cases biopsy proven, active LN patients, 25 inactive LN patients compared with 25 healthy subjects. Analysis of the urinary sediment in active and inactive renal disease showed a decrease of CD8+ T-cells as compared with healthy subjects. On the other hand, increasing of CD4+ T cells in active and inactive LN was observed when compared with healthy subjects. The expression of CD122+ on CD8+ showed an increase in active and inactive LN compared to healthy subjects. Data presented are compatible with the hypothesis that T-cells migrate from the PB to the kidney and appear in the urine of LN patients. These cells could serve as an additional marker of renal disease in patients with SLE.