2284 - Late Versus Early Development of Lupus Nephritis

Tuesday, November 8, 2011: 9:00 AM-6:00 PM
Hall F2 - Poster Hall (McCormick Place West)
Debra Dye-Torrington1, Murray B. Urowitz1, Dominique Ibanez1 and Dafna D. Gladman2, 1Toronto Western Hospital and University of Toronto, Toronto, ON, 2Toronto Western Hospital, University of Toronto, Toronto, ON
Presentation Number: 2284

Background/Purpose: Renal involvement is a common complication of Systemic lupus erythematosus, occurring in 50-60% of patients. A proportion of these patients will develop lupus nephritis as an initial presentation. The remaining patients will develop lupus nephritis later in the course of the disease. A recent longitudinal observational study of an inception cohort showed that of 107 patients who developed lupus nephritis 48(45%) did so after the first three years. 9% of these patients developed lupus nephritis after 10 years. In this study we compare the baseline characteristics of patients who developed early nephritis (within 3 years of entry into the clinic) with those who developed late nephritis (after 3 years) to determine predictors of late development of lupus nephritis.

Method: Inception patients seen in clinic within one year of diagnosis of SLE were selected from a single centre cohort followed in an observational cohort study.  Lupus nephritis was defined as sterile hematuria and/or pyuria, granular casts, proteinuria (>500mg/24hr), or elevated serum creatinine (defined as greater than 120µmols/l) on two or more consecutive visits attributed to SLE, or dialysis, transplant or WHO renal biopsy ≥ class 2.  We identified patients who developed lupus nephritis after entry into the cohort.   Early lupus nephritis was defined as those developing nephritis in the first 3 years.   Patients developing lupus nephritis after three years were defined as having late lupus nephritis. The comparisons were done using t-test and chi-square test. Included in the model were sex, age at SLE diagnosis, race, SLEDAI-2K, steroids, antimalarial, immunosuppressant, complement and dsDNA at inclusion.

Result: 107 patients were identified from an inception group as having developed lupus nephritis in the course of their follow-up. This group was comprised of 89% female, 80% Caucasian. Mean (SD) age at SLE diagnosis was 34(13.9), mean (SD) SLEDAI -2K was 8.1 (7.4) and mean (SD) serum creatinine was 73.8(16.9). 51.0% had low complement and 49.5% had dsDNA antibodies. From this group, 59(55%) developed lupus nephritis within the first three years (early), while 48(45%) developed nephritis after three years. (Late). Comparison between early and late groups at first clinic visit showed  that age at SLE diagnosis was younger in the early group Mean(SD) =30.9(12.2) compared to the late group.

Conclusion: Among patients who developed Lupus Nephritis after three years, age at diagnosis was the only significant predictor. Thus ongoing observation regarding renal involvement in SLE is important in all patients.

Keywords: lupus nephritis and systemic lupus erythematosus (SLE)

Disclosure: D. Dye-Torrington, None; M. B. Urowitz, None; D. Ibanez, None; D. D. Gladman, None.