Focal segmental glomerulosclerosis in renal transplants

Area of Science:

• Nephrology
• Transplantation Immunology
• Pathology

Background:

• Focal segmental glomerulosclerosis (FSG) is a significant cause of native kidney disease and can recur or arise de novo in renal allografts.
• Understanding the incidence and clinicopathological features of FSG in renal transplants is crucial for patient management.

Purpose of the Study:

• To determine the incidence and clinicopathological significance of focal segmental glomerulosclerosis (FSG) in renal allografts.
• To differentiate between recurrent and de novo FSG in renal transplant recipients.

Main Methods:

• Analysis of 154 renal allografts (biopsies, nephrectomies, necropsies) from 137 cadaveric and 17 living-related donors.
• Identification and classification of FSG as recurrent or de novo based on patient's original kidney disease.
• Histopathological examination focusing on arteriopathy and glomerular involvement patterns.
• Clinical data review, including nephrotic syndrome occurrence.

Main Results:

• FSG was identified in 11.7% of renal allografts (18/154).
• Recurrent FSG incidence was 30.8% in patients with prior FSG; de novo FSG incidence was 8.7% in patients with other original kidney diseases.
• Histological differences noted: recurrent FSG showed mild arteriopathy and juxtamedullary involvement, while de novo FSG presented with severe arteriopathy and outer cortical involvement.
• Nephrotic syndrome was more frequent and earlier in recurrent FSG cases.

Conclusions:

• FSG is a relevant complication in renal allografts, with distinct patterns for recurrent and de novo forms.
• Obliterative arteriopathy and glomerular ischemia are key in de novo FSG pathogenesis.
• While histological differences exist, clinical distinctions between recurrent and de novo FSG are less pronounced, though nephrotic syndrome is more common in recurrent cases.