Focal segmental glomerulosclerosis in mild IgA nephropathy: a clinical-pathologic study.

Area of Science:

• Nephrology
• Pathology
• Internal Medicine

Background:

• The role of focal segmental glomerulosclerosis (FSGS) in mild IgA nephropathy remains unclear.
• IgA nephropathy is a common cause of glomerulonephritis.

Purpose of the Study:

• To investigate the clinical and pathological significance of FSGS in patients with mild IgA nephropathy.
• To determine the impact of FSGS on renal outcomes in this patient population.

Main Methods:

• Retrospective review of renal biopsies from adults with mild IgA nephropathy (Lee Grade 1 or 2) between 1996 and 2005.
• Comparison of clinical and histological features between patients with and without FSGS.
• Analysis of renal function decline (DeltaGFR) over a mean follow-up of 3 years.

Main Results:

• Seventy-five patients were analyzed; 26 had IgA nephropathy with FSGS (FSGS+ group) and 49 had IgA nephropathy without FSGS (FSGS- group).
• The FSGS+ group exhibited lower eGFR, lower serum albumin, higher mean arterial pressure, and greater proteinuria at baseline.
• Histologically, the FSGS+ group showed a higher percentage of obsolete glomeruli and more tubular atrophy/interstitial fibrosis.
• The FSGS+ group experienced a greater decline in estimated glomerular filtration rate (eGFR) over the follow-up period.

Conclusions:

• The presence of FSGS lesions in mild IgA nephropathy is associated with adverse clinical and pathological findings.
• FSGS in the context of mild IgA nephropathy appears to predict a worse renal outcome.
• These findings highlight the importance of recognizing FSGS in mild IgA nephropathy for prognostic assessment.