Renal Outcome and Predictors of Clinical Renal Involvement in Patients with Silent Lupus Nephritis

Objectives: We investigated the development of clinically overt nephritis in patients with silent lupus nephritis in an effort to determine predictors of onset.

Methods: We selected 31 patients with systemic lupus erythematosus (SLE) who were diagnosed as having silent lupus nephritis between 1985 and 1995. Urinalysis, blood cell count, serum creatinine, complement levels, and anti-double-stranded DNA antibody (anti-dsDNA antibody) levels were followed retrospectively for at least 60 months in each patient.

Results: During the follow-up period, 8 patients developed clinical renal disease and 23 had no renal impairment. The mean time of overt nephritis onset was 58 months and renal function deteriorated mildly in 3 patients. Although clinical and laboratory findings were not significantly different at SLE onset, patients with overt nephritis showed both persistent elevation of anti-dsDNA antibodies and persistently low levels of serum C3 and CH50 for at least 24 months before the onset of overt nephritis.

Conclusions: Although the renal prognosis was relatively favorable, 25.8% of patients developed overt nephritis during the follow-up period. Elevation of anti-dsDNA antibodies with hypocomplementemia was persisted in these patients, suggesting the utility of these factors as predictors of clinical renal involvement in silent lupus nephritis.