Renal biopsy findings in new-onset systemic lupus erythematosus with clinical renal disease.

OBJECTIVES: Renal biopsy has been used extensively in systemic lupus erythematosus (SLE) with renal involvement. However, there is no complete agreement about the need for renal biopsy at presentation. The goal of this study is to define the role of renal biopsy as a therapeutic guide in new-onset SLE with renal involvement.
METHODS: We retrospectively analyzed renal biopsy findings in 131 SLE patients who received renal biopsy within 3 months from the diagnosis of SLE.
RESULTS: In patients presenting with acute renal failure, 91% of patients had proliferative lupus nephritis (LN) (class IV, mixed class V + III) and 9% had non-proliferative lupus nephropathy (pure class V). In patients presenting with nephrotic range proteinuria, proliferative LN (class III, IV, mixed class V + III) and non-proliferative lupus nephropathy (class II, pure class V) accounted for 55% and 36% of patients, respectively, whereas 9% had non-lupus nephropathy. With the exception of anti-double-stranded DNA, no clinical findings correlated with pathology. In patients presenting with sub-nephrotic proteinuria, 49% of patients had proliferative LN (class III, IV, mixed class V + III) and 51% had non-proliferative lupus nephropathy (class II, pure class V). Decreased C4 levels were more common in patients with proliferative LN (P = 0.031). In patients presenting with isolated hematuria, all were not active form nephropathy.
CONCLUSIONS: Our data suggested that similar clinical features may be observed despite very different classes of LN. Therefore, in new-onset SLE patients with clinical renal disease, early renal biopsy may be helpful in planning the treatment.