[Tamm-Horsfall protein].

Tamm-Horsfall protein is the most abundant protein in normal urine and the main component of urinary casts, but its precise physiological role remains to be elucidated. The interest raised by this protein has recently been boosted by the finding that its gene is identical with that of uromodulin, a glycoprotein purified from urine of pregnant women and endowed with immunosuppressive activity. In this review, are analyzed successively: the structure and physico-chemical properties of Tamm-Horsfall protein which is remarkable by its capacity for gel formation, its localization along the nephron where it is synthesized by cells of the thick ascending limb of Henle's loop, its extra-renal distribution apparently restricted to the serum and its potential physiological and pathological roles. Studies of renal biopsies with specific antibodies may provide information on the part taken by tubular obstruction in the development of renal failure.