The use of Ag-NOR stain to determine the proliferative activity of cervical intraepithelial neoplasia

Objective : To determine the proliferative activity of cervical intraepithelial lesions to assist in the diagnosis and treatment of these lesions through the use of silver stained nucleolar organizer region (Ag +– NOR). Nucleolar organizer regions (NOR) are loops of ribosomal DNA (rDNA) occurring in the nuclei of cells.Cell proliferation under normal physiological conditions is accompanied by increased ribosome biogenesis .The amount of Ag-NOR proteins present during interphase is routinely used to evaluate nucleolar activity and cell proliferation. Thus quantification of Ag-NOR proteins is applied to characterize human cancer cell proliferation ; high levels of Ag-NOR proteins indicate a high rate of proliferation . Methodology : Fifty cervical smears ,representing different cervical lesions ranging from inflammatory lesions (reactive)to LSIL (low grade intraepithelial lesion), HSIL (high grade intraepithelial lesion) and squamous cell carcinoma , were collected and stained using the Standardized Ag-NOR staining technique . After staining, representative areas in each slide were selected and NORs were counted. Results: The results showed that the lowest mean Ag-NOR count was observed in the benign reactive group (control) =2.07, There is a progressive increase in mean Ag-NOR count with increasing severity of cervical lesion, The highest mean Ag-NOR count belonged to squamous cell carcinoma group (9.02). The results also showed a statistically significant difference among the Ag-NOR counts of the different studied categories Conclusion: we can conclude that counts of Ag-NOR could be of great diagnostic value for the cytopathologists and gynecologists in conjunction with routine pap stain to evaluate cellular proliferative activity of the lesion to plan for treatment and for follow up of patients after treatment to detect regression in the severity of the lesion