Composition of the sugar moiety of Tamm-Horsfall protein in patients with urinary diseases

The sugar moiety of Tamm-Horsfall protein (THP) is altered by pathological conditions. The aim of this study was to investigate the composition of THP glycans in urinary diseases. THP was isolated from the urine of patients w ith urinary tract infection (group A), glomerulonephritis or interstitial n ephritis (group B), and Bartter's syndrome (BS) (group C). Monosaccharides, N-glycan profile, THP reactivity with specific lectins and some other prot eins were analyzed. THP of patients from groups A, B, and C showed lower am ounts of N-acetylgalactosamine (P<0.05, P<0.005, and P<0.05, respectively) than controls; this was reflected in lower reactivity with Phaseolus vulgar is lectin (P<0.005, P<0.05, and P<0.005). Reduced amounts of N-acetylglucos amine were noticed in groups A (P<0.05) and B (P<0.05). In group A lower am ounts of galactose and alpha 2,6-linked sialic acid, as determined by react ivity with Datura stramonium lectin (P<0.005) and Sambucus nigra lectin (P< 0.005), were observed. In patients with BS there was a shift from tetrasial ylated glycans towards less-sialylated chains. We found also that THP of al l patients binds more strongly to IgC(1) (P<0.005, for all patient groups). Our results indicate that the urinary diseases examined affect the THP sug ar moiety and the binding of THP to IgG(1).