EFFECTS OF CYCLOSPORINE-A ON SERUM AND URINARY SOLUBLE INTERLEUKIN-2 RECEPTOR IN PATIENTS WITH LUPUS NEPHRITIS

Objective To evaluate the association cf the level oi urine and serum soluble interleukin-2 receptor (sIL-2R) with disease activity and resp onse to cyclosporine A (CsA) therapy in patients with lupus nephritis (LN). Methods Sixteen hospitalized patients with LN were studied. At a dmission, fifteen patients had type IV-LN and one had type V-LN. All p atients received CsA 6 mg/kg per day for 6-8 weeks, then tapered off g radually to 2 mg/kg per day. The levels of urinary and serum sIL-2R we re determined by enzyme-linked immunosorbent assay (ELISA). Serum anti nuclear antibody (ANA), anti-dsDNA antibody (A-ds-DNA), complement C3 and C4, total IgG, creatinine, urinary red blood cells and protein exc retion, and lympocyte subpopulations in the peripheral blood were also measured before and after CsA treatment. Results In LN patients, both urinary (534 +/- 101 U/ml) and serum SIL-2R levels (326 +/- 148 U/ml) were higher than those in normal controls. These findings were associ ated with higher levels of peripheral bood CD4+ and CD8+ lymphocytes ( 29.3 +/- 4.24 and 28.6 +/- 9.12%), higher titer of serum anti-ds-DNA l ower levels of serum complement C3 and C4 (0.98 +/- 0.23 and 0.24 +/- 0.12 g/L), as well as more proteinuria (Upro 2.99 +/- 0.76 g/24 hrs) a nd hematuria (URBC 83.9 +/- 95.2 10(4)/ml). These abnormalities were g radually ameliorated by CSA therapy. the changes in the levels of both serum (116 +/- 58.6 U/ml) and urine (136 +/- 43. 2 U/ml) SIL-2R induc ed by CsA (at 8 weeks) were correlated with the changes in the levels of CD4+ and CD8+ cells (23.2 +/- 3.30 and 26.7 +/- 3.54%), degrees of immune abnormalities (serum C3 and C4 1.28 +/- 0.14 and 0.42 +/- 0.06 g/L), and renal injuries (Upro 1.07 +/- 0.46 g/24 hrs, URBC 5.82 +/- 3 .15 10(4)/ml). Conclusions These results suggest that serum and urinar y sIL-2R are sensitive markers for the disease activity in patients wi th LN. CsA, a powerful immunosuppressive agent, significantly improves both immunologic disorders and renal functional impairments, the mech anism of which on patients with LN appears to inhibit the lymphocyte a ctivation in the peripheral blood and renal tissues as indicated by th e decrease in sIL-2R levels.