1. Background:

    • LN is a common complication of systemic lupus erythematosus (SLE) that affects the kidneys.
    • Despite improved survival rates, LN remains associated with end-stage renal disease (ESRD) and mortality.

  2. Study Design:

    • Researchers conducted a multicenter observational study using data from the Rheumatic Disease Portuguese Registry.
    • The study aimed to analyze different LN classes (proliferative LN [PLN], membranous LN [MLN], and mixed LN) and their clinical manifestations.

  3. Patient Characteristics:

    • 260 patients with biopsy-confirmed LN were included.
    • Median follow-up was 8 years.
    • Patients were categorized based on their initial renal biopsy results.

  4. Renal Response and Predictors:

    • At 6 months, 62% achieved complete renal response, and 5% achieved partial response.
    • No response (NR) at 6 months was associated with poor long-term renal outcomes.
    • Predictors of ESRD:
      • Baseline eGFR ≤33 mL/min/1.73 m²
      • Presence of fibrous crescents
      • NR at 6 months
    • Predictors of NR at 6 months:
      • Baseline hypertension
      • SLE duration >3 months
      • Chronicity index

  5. Survival Rates:

    • Cumulative survival rates at 5, 10, 15, and 20 years were 97%, 93%, 91%, and 88%, respectively.
    • 6% of patients died during follow-up, mainly due to infection and cancer.

  6. Recommendations:

    • Consider repeated renal biopsies to differentiate ongoing active disease from irreversible damage.
    • Close monitoring is crucial to detect and treat flares promptly and prevent further loss of renal function.