Study of renal tubular glycoconjugates in tubulointerstitial damage using conjugated lectins

Changes in the glycoconjugates of renal tubules associated with tubular damage were studied by lectin histochemistry, and their possible significance was determined. The excretion of various saccharides in tubular casts may also serve as markers of renal tubular damage. Renal tissues from 55 cases with various glomerular diseases including ten controls were studied. The patients were divided into two groups: one with tubulointerstitial lesions (TILs) (30 cases), and the other without (15 cases). Our results showed a wide spectrum of changes, predominantly in the disease group with TILs. The brush border of the proximal tubules showed significantly increased staining with Triticum vulgaris (WGA) and decreased staining with Canavalia ensiformis (Con A) lectins in both disease groups. The distal tubules revealed a significant increase in the apical and a decrease in the basal staining with Arachis hypogaea (PNA) and WGA lectins, respectively, in cases with TILs. The significant decrease in the basal domain staining was also seen with WGA lectin in cortical ducts. The vulnerability of various segments of the tubules in the process of TILs was clearly demonstrable. It appeared that the distal tubules were the most vulnerable anatomical segments around which the TILs began and later spread to involve other segments of tubules.