HPV L1 capsid protein expression in squamous intraepithelial lesions of cervix uteri and its relevance to disease outcome.

PURPOSE

The purpose of this study was to investigate the usefulness of immunocytochemical detection of HPV L1 capsid protein expression in predicting the course of cervical intraepithelial neoplasia.

BACKGROUND

It is known that most of the low grade dysplastic lesions of cervix uteri regress spontaneously and only some will progress to high grade dysplastic lesions. HPV L1 capsid protein represents about 90% of the total protein on the surface of the virus and can be detected in mild to moderate dysplasia and rarely in severe dysplasia.

METHODS

Pap smears from 65 women, in whom diagnoses of LSIL (n = 43) and HSIL (n = 22) were made on cytology and histology specimens, were immunocytochemically stained using antibody against HPV L1capsid protein. The results of immunocytochemical analysis were correlated with the outcome during the 24-month follow-up. p value <0.05 was considered significant.

RESULTS

The immunostaining reaction for L1 capsid protein was positive in 28 cases (65.1%) of LSIL while 15 (34.9%) cases of LSIL and all of the 22 cases of HSIL were negative (p < 0.001). After 24 months of follow-up, among the 28 L1-positive LSIL cases, we found a 60.7% (17/28) spontaneous regression rate, whereas in the 15 L1-negative LSIL patients, the regression rate was 33.3% (5/15). Out of the 22 HSIL cases, 13.6% (3/22) had regression.

CONCLUSION

Our data support that immunocytochemical detection of HPV-L1 protein could present prognostic information about the evolution of early dysplastic cervical lesions and can be useful in predicting their biologic potential.