Study design: A comparative study of immunostaining for parathyroid hormone-related protein (1-34) (PTHrP (1-34)) in the vesical epithelium of biopsies obtained from patients with non-neuropathic bladder and those with neuropathic bladder.
Objectives: To investigate the immunostaining for PTHrP (1-34) in the control cases and in neuropathic bladders showing (1) normal transitional epithelium, (2) hyperplastic transitional epithelium, and (3) squamous metaplasia.
Setting: Regional Spinal Injuries Centre, and Department of Cellular Pathology, Southport & Ormskirk Hospitals NHS Trust, Southport, Department of Pathology, Royal Liverpool University Hospital and the Departments of Clinical Chemistry and Cell Biology, The University of Liverpool, Liverpool, England.
Methods: Cold cup biopsies of bladder mucosa were taken from patients suffering from neuropathic urinary bladder when they were undergoing a therapeutic procedure in the urinary tract. Immunohistochemistry was performed on these biopsy specimens using a rabbit polyclonal antibody raised to a synthetic peptide corresponding to human PTHrP (1-34). Control group (n=10) consisted of archival biopsies taken from non-neuropathic bladders.
Results: In the control group, the transitional epithelium showed no immunostaining, or at the most, very faint positive staining was seen in the transitional epithelium of non-neuropathic bladder. Positive immunostaining to PTHrP (1-34) was seen in the normal transitional epithelium of neuropathic bladder in nine of 13 cases. Hyperplastic transitional epithelium showed positive immunostaining for PTHrP (1-34) in 11 of 13 biopsies from patients with neuropathic bladder. Immunostaining for PTHrP (1-34) was observed in the metaplastic squamous epithelium in 14 of 17 cases with neuropathic bladder.
Conclusion: The transitional epithelium of non-neuropathic bladder showed no immunostaining, or at the most, very faint positive staining for PTHrP (1-34). In contrast to this, positive immunostaining for PTHrP (1-34) was observed more frequently in the vesical epithelium of neuropathic bladder. This observation opens up avenues for innovative therapy with PTHrP or its analogues for possible modulation of urothelial differentiation in the neuropathic bladder.