Focal and Segmental Glomerulosclerosis and Membranous Nephropathy overlapping in a patient with Nephrotic Syndrome: a case report

Abstract

Introduction: Some cases of membranous nephropathy (MGN) present focal segmental glomerulosclerosis (FSGS) typically associated with disease progression. However, we report a case of a patient who seemed to have MGN and FSGS, both primary. Case presentation: A 17-year-old female, Caucasian, presenting lower extremity edema associated with episodes of foamy urine and high blood pressure, had physical and laboratorial exams indicating nephrotic syndrome. A renal biopsy was performed and focal and segmental glomerulosclerosis were observed under light microscopy in some glomeruli presented as tip lesion, and in others it was accompanied by podocyte hypertrophy and podocyte detachment in urinary space, compatible with podocytopathy FSGS. Besides, there were thickened capillary loops with basement membrane irregularities due to "spikes" compatible with MGN stage II. Immunofluorescence showed finely granular IgG, IgG4, and PLA2R deposits in capillary loops and, in electron microscopy, subepithelial deposits and foot process effacement. These morphological findings are compatible with FSGS and MGN stage II. Conclusions: In the present case, clinical and morphological characteristics showed a possible overlap of primary FSGS and MGN as focal and segmental glomerulosclerosis does not seem to be related with MGN progression but with the podocytopathy FSGS.

Optimal Value for Serum Anti-PLA2R Antibody in Primary Membranous Nephropathy: A Multicenter Observational Study

“…This classification of the disease on a scale I-IV does not correlate with pathological activity or disease severity. Indeed, more advanced stages, such as III and IV, probably represent an evolution of PMN to chronicity [33]. Our results correspond to previous publications describing patients with PMN who were initially negative for serum PLA2R-Ab but showed seroconversion later.…”

“…These patients most likely have primary FSGS and PMN as overlapping diseases, such as segmental sclerosis focally as tip lesions, glomeruli with podocyte hypertrophy, and detached podocytes in the urinary space, strongly suggesting segmental sclerosis due to podocytopathy. In addition, PMN based on a second biopsy in a patient at 7 years after FSGS diagnosis has also been reported, indicating that a primary FSGS lesion may have led to the development of PMN [33]. This may be because epitopes were poorly accessible at the time of kidney biopsy, or it may reflect a technical artifact.…”