Focal Segmental Glomerulosclerosis Associated with Essential Thrombocythemia

Abstract

A 72-year-old man was admitted for examination of proteinuria (9.14 g/day) and leg edema. Essential thrombocythemia (ET) was diagnosed because of thrombocytosis (platelet count, 57.9×10 4 /μL), elevated megakaryocytes in bone marrow biopsy, and JAK2 V617 mutation. Kidney biopsy led to a diagnosis of focal segmental glomerulosclerosis (FSGS) cellular variant (characterized by glomerular capillaries filled with swollen endothelial cells containing foam cells) in 6 glomeruli, FSGS tip variant in 5 glomeruli, and additional FSGS variants in other glomeruli. Affected glomeruli had anti-CD61 antibody staining-positive megakaryocyte infiltrations. ET may induce FSGS because megakaryocyte infiltration increases intraglomerular pressure, resulting in hypertension and proteinuria.

Unmasking Focal Segmental Glomerulosclerosis in a Patient With Lupus Nephritis

“…In lupus nephritis, biopsy findings include mesangial proliferation, endocapillary proliferation, and immune complex deposits identified by immunofluorescence [ 7 ]. In FSGS, biopsy shows segmental areas of sclerosis within glomeruli, often with podocyte foot process effacement seen on electron microscopy [ 8 ]. The treatment of lupus nephritis involves immunosuppressive therapy to control inflammation and prevent progression to ESRD, including induction therapy with high-dose corticosteroids combined with either cyclophosphamide or MMF, maintenance therapy with lower doses of corticosteroids along with MMF or azathioprine to maintain remission, biologics like rituximab and belimumab in refractory cases, and supportive care with blood pressure control (angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs)), lipid-lowering agents, and antimalarials like hydroxychloroquine.…”