What is immune-complex deposition?

Immune complex deposition is a prominent feature of several autoimmune diseases, including rheumatoid arthritis, scleroderma and Sjögren’s syndrome. An inability to degrade immune complexes in the lysosome and subsequent accumulation on the surface of immune cells has been associated with systemic lupus erythematosus.

Where are the locations of Subepithelial autoimmune deposits?

Subepithelial deposits located at the base of the podocyte foot processes outside the GBM are found in class V disease. In this type of disease, complement-mediated injury of podocytes induces them to lay down excessive matrix material that alters the structure of the basement membrane, leading to proteinuria.

How are immune complexes deposited?

Normally, insoluble immune complexes that are formed are cleared by the phagocytic cells of the immune system, but when an excess of antigen–antibody are present, the immune complexes are often deposited in tissues, where they can elicit complement activation, localised inflammation resulting in the generation of …

How are subepithelial immune deposits formed in the body?

Subepithelial immune deposits arise mainly by local formation of immune deposits. Charge-charge interactions contribute to planting of antigens in glomeruli or to initial binding of immune complexes to glomeruli. Precipitating antigen-antibody systems are required for retention of immune deposits in glomeruli.

Where does membranous nephropathy ( MN ) deposit its cells?

Membranous nephropathy (MN) is an immune complex deposition disease. IgG and complements predominantly deposit beneath the podocytes on the sub-epithelial region of glomerular capillaries. Hence, the sub-epithelial deposits are considered to be pathognomonic for MN.

How are immune complexes deposited in renal glomeruli?

Immune deposits in renal glomeruli can arise by deposition of circulating immune complexes or by local formation of antigen-antibody complexes. Circulating immune complexes tend to form deposits in the mesangial and subendothelial areas and their size limits their passage through the lamina densa of the glomerular basement membrane.

Where does IgG deposit in the glomerular capillaries?

IgG and complements predominantly deposit beneath the podocytes on the sub-epithelial region of glomerular capillaries. Hence, the sub-epithelial deposits are considered to be pathognomonic for MN. Glomerular basement membrane (GBM) injury due to immune deposition causes podocyte structural damage which results in proteinuria.