#5891 repeat renal biopsies in adult lupus nephritis patients

Abstract Background and Aims The role of repeat renal biopsy in lupus nephritis (LN) to guide treatment or predict prognosis has been controversial.The objective of this work is to evaluate the indications requiring the use of a second renal biopsy, as well as to describe the histological results and the therapeutic management according to the results. Method This is a descriptive retrospective study, covering 450 renal biopsy performed between January 1, 2020 and December 31, 2022 at the nephrology department of the Casablanca University Hospital. The patients were selected from the kidney biopsy register. Results Thirty patients followed for lupus nephritis had benefited from a 2nd renal biopsy. The average age of our patients was 36.4 years with a sex ratio of 0.8. The average time from first to second biopsy was 2, 1 years. The indications for a second renal biopsy was included a suspected flare (76.6%), of which had worsening proteinuria with or without rising serum creatinine (90%), or lack of treatment response (23.4%). 22 patients (73,3%) had proliferative class on their first renal biopsy. When comparing first and second renal biopsy, 26 patients (86.6%) switched histological classes .When categorized as proliferative versus non-proliferative, 21 (95.4%) patients with proliferative class on the first biopsy remained similar on the second biopsy. The mean chronicity index (CI) was significantly different for 10 consecutive biopsies with worsening CI noted with increased number of renal flares. 11 patients (36,6%) required intensification in immunosuppressive therapy after the second renal biopsy whereas 3 patients (10%) experienced a reduction in immunosuppression. 16 patients (53,3%) did not experience any change in immunosuppression. Conclusion A 2nd renal biopsy was justified in most cases, making it possible to establish a precise diagnosis, to identify the evolution of the histological lesions, and to guide the therapeutic management.