Glomerular hypertrophy in preeclamptic patients with focal segmental glomerulosclerosis - A morphometric analysis

Background: Focal segmental glomerulosclerotic lesion (FSGS lesion) is frequently observed in preeclamptic patients with nephrotic syndrome. Patients and methods: We performed a morphometric analysis of renal biopsies from 20 patients with severe preeclampsia to evaluate the pathogenetic role of glomerular hypertrophy in preeclamptic nephropathy associated with FSGS lesion. We also analyzed biopsies obtained from 6 preeclamptic patients without FSGS lesion and 10 patients with isolated hematuria. Nonsclerotic glomeruli were examined. Results: The mean glomerular tuft area (GTA), the whole glomerular area (WGA), and the extracellular matrix area (EMA) were significantly and negatively correlated with the postpartum day at biopsy in preeclamptic patients with FSGS lesion who underwent renal biopsy within 40 days after delivery. The mean GTA, WGA, EMA and number of mesangial cells (MN) were significantly increased in preeclamptic patients with FSGS lesion compared with patients with isolated hematuria and compared with those without FSGS lesion when the biopsy time was matched between patients with and without FSGS lesion. The GTA and WGA were not different between preeclamptic patients without FSGS lesion and patients with isolated hematuria. Conclusion:These results support the assumption that glomerular hypertrophy that develops during severe toxemic pregnancy plays an important role in the pathogenesis of FSGS lesion and is reversible about 40 days after delivery.