Delayed onset lupus nephritis in the course of systemic lupus erythematosus: Relation to disease activity and therapeutic response

Background: Lupus nephritis (LN) is severe organ involvement in systemic lupus erythematosus (SLE). It could be the first presentation, commonly in the first year after diagnosis, but may arise later during the disease course. The time of LN onset can affect its clinical presentation and disease outcomes. Aim of the work: To study the differences between early and delayed onset LN during the course of SLE and the prognosis of the disease. Patients and methods: This study included 100 SLE patients with LN. They were categorized into early onset group who developed LN within one year of diagnosis and delayed onset LN if developed after one year. Renal response to treatment was compared between early and delayed-onsets LN cases after six months, one year and two years of following up. Results: This study involved 100 SLE patient, 93 females and 7 males, the mean age was 36.6 ± 8.6 years with disease duration 9.7 ± 5.03 years. Early onset LN group included 45 patients while delayed-onset group included 55. At baseline, ESR and SELENA-SLEDAI were higher (p = 0.017 and 0.016 respectively) in early onset and renal biopsy showed higher cellular and fibrous crescents in the same group (p = 0.045 and 0.012 respectively). On the other hand, delayed onset LN group after 6 months, 1 and 2 years of following up showed more frequent flares with incomplete remission (p < 0.001, p = 0.002 and p < 0.001 respectively) and higher SELENA-SLEDAI (p < 0.001). Conclusion: Early onset LN has a better treatment response and presents a valuable indicator of complete remission than delayed-onset LN.