Significance of urinary albumin in patients with systemic lupus erythematosus

Objective To investigate the significance of the urinary albumin excretion for early renal involvement in systemic lupus erythematosus(SLE),and the relationship between urinary albumin excretion and disease activity.Methods The levels of 24 hour urinary albumin were measured by chemiluminescence in 104 patients with SLE,and the course of disease,disease activity and immunologic index were analyzed.Results In 104 SLE patients,72((69.2%)) patients were present of high proteinuria in 24 hour urinary albumin test.(47.5%)(29/61) of protein negative patients by routine urine test had albuminuria in 24 hour urinary albumin test.In the patients who were treated with or without corticosteroid or immuno-suppressive drugs,(45.5%)(10/22) or(48.7%)(19/39) respectively had high level of urinary albumin whereas urinary protein was negative.In the patients who were not treated with corticosteroid or immuno-suppressive drugs,there were significant difference in the SLEDAI scores((10.2)±(3.6) vs(6.6)±(2.9)) and erythrocyte sedimentation rate((62.9)±(37.1) vs(40.2)±(29.5)) mm/1 h between the patients with high level of urinary albumin and those with normal urinary albumin(P(0.05),respectively).The elevation of immunoglobulin(5/19) and the reduction of serum albumin(10/19) were more common in the patients with high urinary albumin excretion than those with normal urinary albumin(3/20 and 0/20 respectively,P(0.05)).In the patients who were treated with corticosteroid or immuno-suppressive drugs,there was significant difference in the SLEDAI scores((6.5)±(3.5) vs(3.3)±(2.7)) between the patients with high level of urinary albumin and those with normal urinary albumin.The anaemia(4/10) and the reduction of serum complement(7/10) were more common in the patients with high urinary albumin excretion than those with normal urinary albumin(0/12 and 2/12 respectively,P(0.05)).Conclusion The level of 24 hour urinary albumin could be used as a sensitive index for early renal involvement in SLE patients,and it is significant correlated to SLE activity and severity.