Affect DCT
Mechanism: Free light chains (Bence Jones proteins) produced by malignant plasma cells in multiple myeloma are filtered by the glomeruli and then reabsorbed by the renal tubules. When the capacity of the proximal tubules to reabsorb these proteins is exceeded, they precipitate and form casts within the distal tubules.
Pathophysiology: These casts can obstruct the tubules, leading to tubular injury, interstitial inflammation, and fibrosis. This is the most common renal manifestation of multiple myeloma and is often referred to as "myeloma kidney."
