An unusual association between focal segmental sclerosis and lupus nephritis: a distinct concept from lupus podocytopathy?

Abstract

Lupus nephritis (LN) is usually associated with immune deposition in the glomerular capillary wall. On the other hand, focal segmental glomerulosclerosis (FSGS) is not typically associated with immune deposition, and its pathogenesis includes podocyte damage and loss. The definition of lupus podocytopathy (LP) excludes patients with electron-dense glomerular basement membrane deposits. Here, we report the case of an LN patient with nephrotic proteinuria. Renal pathology demonstrated focal endocapillary hypercellularity superimposed on foam cells. Immunofluorescence revealed diffuse global subepithelial immune deposits, and electron microscopy showed electron-dense glomerular basement membrane deposits and diffuse foot process effacement. Treatment with steroid and cyclosporine improved her proteinuria. Post-treatment renal re-biopsy revealed focal segmental sclerotic lesions closely resembling FSGS. These results indicate that the pathogenesis of this case may involve an FSGS-like condition or podocytopathic change. It is possible that careful examination would reveal podocytopathic changes other than LP in patients previously diagnosed as LN class III + V. Further investigations are needed to understand FSGS-like pathological changes accompanied with capillary immune deposits in LN.