Loss of blood isoantigens in exfoliated cells during the progression of CIN demonstrated by monoclonal antibody staining.

The presence of isoantigens A, B and H in exfoliated cervical epithelial cells was readily demonstrable in cervical smears using monoclonal antibodies and an immunoperoxidase staining technique. The progressive decrease in the percentage of immunoperoxidase-positive dysplastic cells and in the proportion of cytologically normal squamous cells associated with these dysplastic cells reflected the loss of isoantigen expression that paralleled increasingly severe stages of cervical intraepithelial neoplasia. The loss of isoantigen expression in morphologically normal epithelial cells and in dysplastic cells may indicate that a particular patient is at greater risk of disease progression and that close follow-up is warranted.