Histologically, tubulointerstitial changes can manifest in several ways:
1. Inflammation: The presence of inflammatory cells such as lymphocytes, macrophages, and sometimes neutrophils in the interstitial tissue. 2. Fibrosis: An increase in extracellular matrix components like collagen, leading to scarring and stiffening of the renal interstitium. 3. Tubular Atrophy: Shrinkage and loss of tubular cells, which can result in dilated, atrophic tubules with a flattened epithelium. 4. Interstitial Edema: Accumulation of fluid in the interstitial space, causing swelling and separation of tissue components.
