A 2 year old child with leukemia develops nephrotic syndrome. Light microscopic studies are normal. Electron microscopic studies demonstrate fusion of epithelial foot processes. The current hypothesis for the pathogenesis of this change is that it is secondary to which of the following?
The child is suffering from minimal change or nil disease (lipoid nephrosis), which has a peak incidence at 2-3 years of age. Minimal change disease can be associated with food allergies, medications, or hematologic malignancies, or it can occur idiopathically. The pathology does not appear to involve complement, immunoglobulins, or immune complex deposition. Rather, an altered cell-mediated immunologic response with abnormal secretion of lymphokines by T cells is thought to reduce the production of anions in the glomerular basement membrane, thereby increasing the glomerular permeability to plasma albumin through a reduction of electrostatic repulsion. The loss of anionic charges is also thought to or foot process fusion. Some authors have noted that other conditions associated with T-cell abnormalities, such as Hodgkin's disease and T-cell lymphoma, are sometimes associated with minimal change disease. Consumption of complement factors is observed in many conditions in which complement activation occurs, for example, membranoproliferative glomerulonephritis. IgG directed against renal and pulmonary basement membranes is found in Goodpasture's syndrome, a cause of rapidly progressive glomerulonephritis and hemoptysis. Immune complex deposition is associated with type III hypersensitivity reactions,including postinfectious glomerulonephritis, lupus nephritis, Henoch-Schonlein purpura, cryoglobulinemia, and bacterial endocarditis. Ref: Wyatt C., Butterwoh IV J.F., Moos P.J., Mackey D.C., Brown T.G. (2008). Chapter 16. Pathology of the Kidney and Bladder. In C. Wyatt, J.F. Butterwoh IV, P.J. Moos, D.C. Mackey, T.G. Brown (Eds), Pathology: The Big Picture.
Consumption of complement factors
IgG directed against basement membrane
Immune complex deposition
Lymphokine production by T cells