Electron microscopy revealing subendothelial immune complex depositions with marked thickening of capillary walls is characteristic of which condition?

The presence of subendothelial immune complex depositions along with marked thickening of capillary walls is indicative of lupus nephritis. In lupus nephritis, immune complexes are deposited in the glomeruli, particularly in the subendothelial space, leading to characteristic changes observed under electron microscopy. This results in immune-mediated glomerular damage and can cause a variety of kidney issues, including nephron inflammation and impaired kidney function.

Lupus nephritis is a manifestation of systemic lupus erythematosus (SLE), an autoimmune disorder. The thickening of the capillary walls due to immune complex deposition is a hallmark of this condition, and it can lead to a range of clinical symptoms, including hematuria, proteinuria, and hypertension.

Other conditions listed, while they involve glomerular damage, do not typically present with the specific findings of subendothelial immune complex deposits and capillary wall thickening as seen in lupus nephritis. For instance, IgA nephropathy primarily shows IgA deposition in mesangial areas, while acute post-streptococcal glomerulonephritis is characterized by a different pattern of immune response, typically with subepithelial deposits, and membranous