A study of cytokeratin 20 immunostaining in the urothelium of neuropathic bladder of patients with spinal cord injury.
BACKGROUND
Normal urothelium is characterised by terminally differentiated superficial cells, which express cytokeratin 20 in the cytoplasm. In contrast, cultured human stratified urothelium, which does not undergo complete terminal differentiation of its superficial cells, does not express cytokeratin 20. If spinal cord injury (SCI) affects urothelial differentiation or induces squamous or other metaplastic change undetected by histological analysis, the superficial urothelial cells of the neuropathic bladder might be expected to show absence of immunostaining for cytokeratin 20.


METHODS
We studied immunostaining for cytokeratin 20 in bladder biopsies taken from 63 consecutive SCI patients. Immunostaining was performed on paraffin-embedded tissue using a mouse monoclonal antibody (clone: Ks20.8).


RESULTS
Of 63 biopsies, the epithelium was scarce in two. Eight biopsies showed squamous metaplasia and immunostaining for cytokeratin 20 was absent in all the eight biopsies. Of the remaining 53 cases, in which the umbrella cell layer of the urothelium was intact, immunostaining for cytokeratin 20 was seen only in ten biopsies.


CONCLUSIONS
Superficial cells in the transitional epithelium showed immunostaining for cytokeratin 20 in 10 of 53 bladder biopsies taken from SCI patients. The reasons for this could be either that there is an underlying metaplasia or that changes in the neuropathic bladder affect urothelial differentiation. Taken with evidence from other systems, such as loss of cytokeratin 20 expression from static organ cultures of urothelial tissue, this might suggest that other factors, such as impairment of voluntary voiding in SCI patients, could affect expression of markers such as cytokeratin 20.
Vaidyanathan
Subramanian
S
Regional Spinal Injuries Centre, District General Hospital, Southport PR8 6PN, UK. vaidyanathansiu@hotmail.com
McDicken
Ian W
IW
Ikin
Anna J
AJ
Mansour
Paul
P
Soni
Bakul M
BM
Singh
Gurpreet
G
Sett
Pradipkumar
P
D000328:Adult; D000368:Aged; D015415:Biomarkers; D006801:Humans; D007381:Intermediate Filament Proteins / Q000032:analysis*; D053554:Keratin-20; D008875:Middle Aged; D013119:Spinal Cord Injuries / Q000150:complications*; D013194:Staining and Labeling / Q000379:methods; D001743:Urinary Bladder / Q000737:chemistry* / Q000473:pathology; D001750:Urinary Bladder, Neurogenic / Q000378:metabolism* / Q000473:pathology; D019459:Urothelium / Q000737:chemistry / Q000473:pathology
D015415:Biomarkers; D007381:Intermediate Filament Proteins; C507499:KRT20 protein, human; D053554:Keratin-20; C489975:Krt20 protein, mouse