Focal proliferative lupus nephritis. A clinicopathologic study using the W.H.O. classification

Area of Science:

• Nephrology
• Immunology
• Pathology

Background:

• Focal proliferative lupus glomerulonephritis (FPLGN) was traditionally considered less severe than diffuse proliferative lupus glomerulonephritis (DPLGN).
• Recent studies suggest no significant survival difference between focal and diffuse lupus nephritis.
• This prompted a re-evaluation using the World Health Organization (WHO) classification.

Purpose of the Study:

• To conduct a comparative clinicopathologic study of FPLGN versus DPLGN.
• To assess differences in clinical presentation, renal function, and long-term outcomes.
• To validate the WHO classification in differentiating disease severity and prognosis.

Main Methods:

• A cohort of 15 patients with FPLGN was studied and compared to patients with DPLGN.
• Clinicopathologic data were analyzed using the WHO classification criteria.
• Long-term follow-up included assessment of renal survival, renal function deterioration, and overall survival rates.

Main Results:

• Patients with FPLGN generally presented with milder renal disease, characterized by less proteinuria and renal insufficiency.
• Central nervous system involvement was more prominent in FPLGN.
• No statistically significant differences were found in cumulative five-year survival rates (FPLGN=0.751 vs. DPLGN=0.858) or renal survival rates (FPLGN=1.00 vs. DPLGN=0.846).
• Deterioration of renal function and quantitative proteinuria showed no significant differences between the groups at follow-up.

Conclusions:

• Despite qualitative differences in disease presentation, FPLGN follows a similar clinical course to DPLGN.
• The long-term renal and overall survival rates are comparable between focal and diffuse proliferative lupus glomerulonephritis.
• The distinction between focal and diffuse forms may have less prognostic significance than previously assumed.