Vesical urothelium proliferation in spinal cord injured persons: an immunohistochemical study of PCNA and MIB.1 labelling.

Urinary tract infection occurs more commonly, is more virulent and proves more difficult to eradicate in spinal cord injury persons than in the neurologically intact. In order to find out the peculiarities of the neuropathic bladder which make it vulnerable to recurrent cystitis, we studied the proliferation status of the urothelium in spinal cord injured persons. Eleven consecutive, unselected male spinal cord injury patients (aged 18-73 years) were included in the study. Those with, or undergoing treatment for acute urinary tract infection were excluded. All patients underwent cystoscopy and cold cup bladder biopsy from the trigone and bladder dome. Immunocytochemical analysis was performed using defined, commercially available antibodies for PCNA (PCNA 10, DAKO) and MIB-1 (raised against recombinant DNA defined segment of Ki-67 antigen DAKO) streptavidin/biotin and alkaline phosphatase immunocytochemistry (for MIB-1 with microwave-enhanced antigen retrieval) were used to demonstrate the presence of cell cycling-associated nuclear proteins. Foci of lymphocytic aggregations present in the sections served as in-section controls for antigen preservation. Ten patients showed labelling of 20-70% of cells for PCNA in basal cell layers of dome lining. Higher urothelial layers showed a variable, but generally reduced degree of labelling. Of these 10 patients, three showed complete absence of MIB-1 activity in the basal and other layers of dome urothelium and two demonstrated only a very occasional positive nucleus. MIB-1 labelling was < 5% in four others and it was between 5% and 10% in one.(ABSTRACT TRUNCATED AT 250 WORDS)