Kidney nontumor / medical renal
Tubulointerstitial disease
Other tubular and interstitial disease
Tamm-Horsfall protein
Author: Monika Roychowdhury, M.D.
Last author update: 1 March 2015
Last staff update: 20 July 2022
Copyright: 2003-2025, PathologyOutlines.com, Inc.
PubMed Search: Bladder Tamm-Horsfall protein
Table of Contents
Definition / general | Terminology | Epidemiology | Pathophysiology | Etiology | Diagrams / tables | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Electron microscopy description | Electron microscopy imagesCite this page: Roychowdhury M. Tamm-Horsfall protein. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/bladdertamm.html. Accessed January 10th, 2025.
Definition / general
- Tamm-Horsfall protein (THP) is a high molecular weight glycoprotein discovered by Tamm and Horsfall (J Exp Med 1952;95:71)
- Normally synthesized by thick ascending limb of loop of Henle, possibly distal convoluted tubules
- Most abundant protein in urine of healthy individuals
- May accumulate in renal parenchyma, perirenal soft tissue, renal hilar lymph nodes or bladder with pathologic conditions
Terminology
- Also known as uromodulin, from UMOD gene on #16 (Wikipedia)
Epidemiology
- THP deposits are present in 60% of cystectomy specimens, 4% of bladder biopsies
- In bladder specimens with THP deposits, mean age is 61 years, range 45-78 years, 85% are men (Am J Surg Pathol 1994;18:615)
Pathophysiology
- Inserted into luminal cell surface of renal tubules by glycosyl-phosphatidylinositol (GPI)-anchor, then excreted in urine at a rate of 50 - 100 mg/day
- Stones may form due to defective urinary Tamm Horsfall protein, due to lack of sialic acid (Int J Biol Sci 2008;4:215)
- Has a strong tendency to form macroaggregates of several million Daltons, particularly in highly tonic solutions
- Forms the matrix of urinary casts and stones
Etiology
- Deposited in areas of necrosis, inflammation, fibrinous exudates, ulcer, crystalline material
- May be host defense factor against Proteus mirabilis urinary tract infections (J Urol 2009;181:2332)
- May have role in pathophysiology of interstitial cystitis (BJU Int 2009;103:1085)
- Comprises matrix of urinary casts formed during acute kidney injury (Webpath tutorial) and matrix of urinary stones
- Also present in deposits associated with interstitial kidney disease
- Also associated with urothelial carcinoma, nephrogenic adenoma
Diagrams / tables
Images hosted on other servers:
Diagram of Tamm-Horsfall protein secretion (green dots), forming a hyaline cast in the collecting duct
Gross description
- Large, waxy, pale or weakly eosinophilic mass
Microscopic (histologic) description
- Glassy, PAS+ acellular material
- May also appear as strands of eosinophilic material obscured by fibrinous exudates or necrotic tissue
Microscopic (histologic) images
Images hosted on other servers:
Nephronophthisis: end stage renal disease
Lymphatics
Pyelonephritis - protein cylinder
Pyelonephritis immunostain
Positive stains
- PAS, trichrome (pale blue)
- Anti Tamm-Horsfall protein antibody
Electron microscopy description
- Nonbranching 4 nm wide parallel fibrils
Electron microscopy images
Images hosted on other servers:
In lymphatics
