Proliferation cell nuclear antigen (PCNA) expression in cervical intraepithelial neoplasia (CIN). An immunohistochemical study.

We analyzed the expression of proliferating cell nuclear antigen (PCNA) in ectocervical sections fixed in formalin and embedded in paraffin using monoclonal antibody PC10, PAP and APAAP methods. A total of 156 cases was studied: 32 cases with normal epithelium, 33 cases with CIN I, 36 cases with CIN II, 55 cases with CIN III. We evaluated: 1. the index of PCNA (IPCNA), i.e. the proportion of PCNA-positive cells relative to all cells in the epithelium; 2. the IPCNA in each epithelial layer; 3. the epithelial height with PCNA-positive cells relative to the total height of the epithelium; 4. changes in the IPCNA with respect to the presence or absence of histological signs of HPV infection. We found: 1. a significant correlation between the index of PCNA and the severity of dysplasia in the whole epithelium and its individual layers; 2. a significant correlation between the epithelial height with PCNA-positive cells relative to the total height of the epithelium and the severity of dysplasia; 3. a lack of correlation between the IPCNA and HPV(+) and HPV(-) cases.