Tamm-Horsfall protein as a marker in interstitial cystitis

It has been suggested that immunohistochemical staining for Tamm-Horsfall protein in bladder epithelium may be a marker for interstitial cystitis. Of bladder biopsies from 14 interstitial cystitis patients only 3 demonstrated positive staining for Tamm-Horsfall protein within the mucosa, whereas 2 of 11 control biopsies showed positive Tamm-Horsfall protein results. In addition, staining in 4 ureteral specimens from interstitial cystitis patients and 4 controls was negative in all cases. An effort to detect this protein in enterocystoplasty specimens also showed a negative pattern. Our study does not confirm the Tamm-Horsfall protein as permeating either the bladder epithelium in interstitial cystitis or bowel mucosa in enterocystoplasty. This finding does not necessarily mean that these surfaces are not permeable to substances of smaller molecular size, nor does it define whether this is of importance in the etiology of interstitial cystitis. However, it does suggest that this technique does not allow detection of a marker for the disease.