Urinary Tamm—Horsfall Glycoprotein in Certain Kidney Diseases and its Content in Renal and Bladder Calculi

Abstract

1. Tamm—Horsfall (T—H) glycoprotein has been measured by a specific radioimmunoassay method in the urine of patients with chronic renal failure, cadmium nephropathy and Lignac—Fanconi syndrome, and in renal and bladder calculi. 2. Total T—H glycoprotein excretion/24 h was markedly reduced in patients with chronic renal failure compared with normals. A highly significant correlation was observed between T—H excretion rate and creatinine clearance corrected for surface area, in both normals and patients with renal impairment. However, the mean T—H excretion per functioning nephron unit did not differ significantly in patients with renal failure compared with normals. 3. Total T—H excretion/24 h was in the normal range in patients with cadmium nephropathy despite reduced glomerular filtration rates, owing to a highly significant increase in T—H excretion per functioning nephron unit. Similar findings were obtained in a group of children with Lignac—Fanconi syndrome whose T—H excretion per functioning nephron unit was much higher than that of normal children in the same age range. This indicates an increased T—H glycoprotein excretion per functioning nephron unit in both these conditions. 4. T—H glycoprotein content of bladder and renal calculi ranged from 0002 to 5.07 mg/g of calculus. There was no correlation between T—H glycoprotein content and either the total protein content or the qualitative inorganic composition of the stones.

Glycosaminoglycans, proteins, and stone formation: adult themes and child’s play

“…However, recent years have seen rapid progress in the study of several stone proteins, and the remainder of this section will be devoted to a discussion of what is currently known about them. The intriguing and contradictory properties of THG have contributed greatly to the general confusion surrounding its function in stone formation, and this is reflected in the fact that the excretion of THG does not seem to differ between stone formers and healthy subjects [65,97,98]. One notable exception to this is the study of Baggio et al [18] which, in addition to urinary GAG excretion, compared that of THG in pediatric stone patients and healthy children.…”

Intact protein core structure is essential for protein-binding, mononuclear cell proliferating, and neutrophil phagocytosis-enhancing activities of normal human urinary Tamm–Horsfall glycoprotein

“…Functionally, THP can stimulate resting polymorphonuclear neutrophils (PMN), lymphocytes and monocytes [17][18][19], but inversely suppress mitogen-activated lymphocyte proliferation [20,21]. In certain pathological conditions, urinary THP involves in the pathogenesis of distal nephrons and the urinary tract disorders such as cast nephropathy [22], urolithiasis [23], and tubulointerstitial nephritis [24]. Despite intensive studies in this field, the inter-relationships among glycomoiety, protein core, and biological functions of THP remain to be elucidated.…”

Interactions between Stone-Forming Calcific Crystals and Macromolecules

“…Recent studies have shown differ ences in sialic acid contents and surface charge between THP from stone formers and normal individuals. Isoelec tric focussing (IEF) studies have shown that THP from healthy individuals has a pi value of approximately 3.5, while THP from recurrent stone formers has pi values between 4.5 and 6 and the two exhibit completely differ ent IEF patterns [90], Despite its abundance in the urine, only minor amounts of THP are found in the stone matrix, 0.002-5.07 mg/g (w/w) of stone [39], In addition, THP was not detected in matrices of CaOx crystals induced in human urine in vitro [31], However, a recent investigation de tected the presence of THP in matrices of both the CaOx and CaP crystals induced in human urine but discovered that it can be easily removed by washing with sodium hydroxide solution [12], indicating that THP interacts with crystal surfaces. Ultrastructural investigations of CaOx human urinary stones [unpubl.…”