Evolution of Proliferative Lupus Nephritis with Focal Extracapillary Proliferation in Latin American Patients with Lupus

Objectives: This study aimed to investigate the association between the extent of focal extracapillary proliferation and the likelihood of achieving complete remission at 24 months in patients with lupus nephritis (LN). Methods: A retrospective observational analysis was conducted on 124 patients with proliferative focal and diffuse LN. Patients were categorised into subgroups based on the extent of extracapillary involvement (Group 1: 5–24% crescents, Group 2: 25–50% crescents, Group 3: >50% crescents, and control group without extracapillary involvement). The primary outcome was the rate of achieving complete remission at 24 months, defined according to the 2021 Kidney Disease: Improving Global Outcomes (KDIGO) standards. Statistical analyses were performed using logistic regression. Results: A total of 107 women and 17 men participated, with mean ages of 35±10 years and 34±12 years in the study and control groups, respectively. The control group exhibited a significantly higher rate of complete remission compared to the subgroups with extracapillary proliferation. Specifically, Group 1 had an odds ratio of 7.2, (95% CI: 2.3–20.2) and a p-value of 0.001, indicating a lower probability of achieving remission. Conclusions: The presence of focal extracapillary proliferation in patients with LN was associated with a decreased likelihood of achieving complete remission at 24 months. This finding emphasises the importance of considering the extent of extracapillary proliferation in predicting treatment outcomes for LN.