Objective: To describe and analyze the clinical and immunological characteristics of a large series of patients with delayed lupus nephritis (LN).
Methods: This was a cross-sectional study. Patients with systemic lupus erythematosus (SLE) who developed renal involvement five or more years after the first manifestation(s) of the disease (delayed LN, N=48) were compared to SLE patients in whom LN developed within five years or less after SLE appeared (early-onset LN, N=187). A control group, the no LN (NLN) group, consisted of long-standing SLE patients (duration of disease > 10 years) who have never shown signs of renal involvement (N=164).
Results: The delayed LN group was positively associated with Sjögren’s syndrome, lung involvement, and antiphospholipid syndrome as compared with early LN. However, its renal clinical expression and histopathological patterns were similar to those of early-onset LN. The frequency of anti-dsDNA, anti-Sm and anti-RNP antibodies was higher in patients with LN than in the NLN group, as was the frequency of low complement levels. Jaccoud’s arthropathy was a protective factor for nephritis.
Conclusions: Delayed LN is not uncommon in SLE patients. The identified risk factors might aid in its diagnosis and enhance ability to identify patients at risk for this complication of SLE.