Determination of Autophagy in Human Cervicovaginal Smears by Cytological and İmmunocytochemical Methods

Autophagy is a catabolic process whereby organelles and long-lived proteins are recycled through lysosomes to maintain cellular homeostasis. This process is being widely studied using culture techniques and animal models; however, cervicovaginal smears have not been used to detect autophagy.

Our study aims to detect and evaluate autophagy in normal, malignant, infectious, and atypical cells in cervicovaginal smears by using cytological and immunocytochemical methods.

Papanicolaou-stained 200 cervicovaginal smears were examined and 55 of 200 (27.5%) smears containing negative for intraepithelial lesion or malignancy (NILM) with identifiable infections and/or reactive/reparative changes (INF); briefly, NILM-INF (n = 31, 56.4%), atypical (n = 4, 7.3%), and malignant cells (n = 20, 36.3%) were evaluated as a study group. One hundred forty-five of 200 (72.5%) normal smears were accepted as the NILM without any identifiable infections (control group). The autophagy marker protein Microtubule-associated protein 1 light chain 3 A (MAP1LC3A) was used for immunocytochemical examination.

The staining intensity of the MAP1LC3A protein and autophagy positivity were lower in the malignant cells; however, they were higher in the NILM-INF and atypical cells. A statistically significant correlation between the malignant and normal cells was obtained for the autophagy positivity (P = 0.012). In view of the staining intensity of MAP1LC3A protein by the H-score method, a significant correlation was found between the NILM-INF and the normal cells (P = 0.015).

Autophagy was detected in various cervicovaginal smears for the first time in this study. Our findings indicate that an autophagy process is essential in infectious cells as well as in the transformation of atypical cells into malignant cells in carcinogenesis.