CLINICAL OUTCOMES OF PATIENTS WITH LUPUS NEPHRITIS WITH EXTRACAPILLARY PROLIFERATION IN KIDNEY BIOPSY

CLINICAL OUTCOMES OF PATIENTS WITH LUPUS NEPHRITIS WITH EXTRACAPILLARY PROLIFERATION IN KIDNEY BIOPSY

Lupus nephritis occurs in approximately 40% of patients with systemic lupus erythematosus, mainly in the first 5 years after diagnosis. The association between the histopathological findings of the kidney biopsy with the clinical course of lupus nephritis has been studied, reporting that mesangial nephritis (class II) has a better prognosis, while proliferative nephritis (class III and IV) tends to have a worse prognosis, with a severe course and a deterioration in kidney function (protein loss, nephrotic syndrome, prolonged hospitalization, and chronic kidney damage). Another important histopathological change is the presence of cellular crescents (active lesions) and interstitial fibrosis (chronic damage), which are significant predictors of deterioration in renal function. The presence of extracapillary proliferation has been identified in 10.1% of biopsies from patients with lupus nephritis and from 21.7 to 51.6% in patients with class IV. The presence of extracapillary proliferation has been associated with a lower prevalence of partial or complete remission, a higher risk of relapse, and a greater requirement for renal support. The objective of the study Is to know the prevalence of extracapillary proliferation in patients with lupus nephritis and the association with a decrease in kidney function.

119 patients were included, of which 94 (79%) were women, with a median age of 32 (15-61) years, initial creatinine 1.55 (0.50-23.80) mg/dl, GFR 74 (2- 137) ml/min/1.73 m2, urinary proteinuria 5.50 (0.10-272.90) gr/24 hrs, UPC 4.38 (0.03-19.70) mg/gr, kidney biopsy report with class II 2 (1.7%), class III 8 (6.7%), class IV 51 (42.9%), class V (7.6%), class III+V 9 (7.6%) and class IV+V 40 (33.6%); In addition, 68 patients (57.14%) had extracapillary proliferative lesions in the biopsy. According to the Cox regression analysis, we identified that patients who presented extracapillary obtained significant HRs for kidney replacement therapy after diagnosis (HR 4.199, 95% CI 1.212, 14.551, p=0.024) and GFR <15 ml/min/1.73 m2 (HR 7.391, 95% CI 1.709, 31.958, p=0.007). Similarly, the outcomes of treatment change, relapse, death, GFR <60 ml/min/1.73 m2, UPC <1 mg/g, and UPC <3 mg/g were analyzed; however, they didn`t reach the level of significance.

Histological crescentic lesions have been related to a worse prognosis in patients with lupus nephritis. In our study, we observed that extracapillary is associated with some adverse outcomes such as reaching the terminal stage of chronic kidney disease (GFR < 15 ml/min/1.73 m2), the requirement for hemodialysis at the time of diagnosis and continued renal replacement therapy, which would be related to the healing process of crescents with the consequence of chronic histological lesions (fibrous crescents, glomerular sclerosis, and interstitial fibrosis).