P16-19. Hormonal contraceptive use affects HIV susceptibility: mechanisms revealed by image analysis

Gabriella Edfeldt [1], Maria Röhl [1], Julie Lajoie [2,3], Annelie Tjernlund [1], Carolina Wählby [4], Genevieve Boily-Larouche [3], Joshua Kimani [2,3,5], Keith R. Fowke [2,3], Kristina Broliden [1]
Affiliates: [1] Unit of Infectious Diseases, Karolinska Institutet. [2] Department of Medical Microbiology, University of Nairobi. [3] Department of Medical Microbiology, University of Manitoba. [4] Centre for Image Analysis, Uppsala University.

Background
For millions of women worldwide the use of injectable hormonal contraceptives is the only affordable and practical contraception method. Injections of depot medroxyprogesterone acetate (DMPA) effectively hinders pregnancy but confers no protection against sexually transmitted infections and may increase the risk of HIV infection. We here aim to identify if DMPA usage affects the immunological milieu within the female genital mucosa. We hypothesize that a thick epithelium, high concentration of epithelial junction proteins, and a low concentration of, and distantly located, HIV target cells are a beneficial combination that hinders sexually transmitted HIV.

Methods
Cervical tissue biopsies from Kenyan women using no contraceptive method (n=23) and using DMPA (n=13) were fluorescently stained and analyzed using the image analysis tool CellProfiler. The epithelial height as well as the anatomic location, percentage and spatial distribution of HIV target cells (e.g. CD4+CCR5+ cells, CD4+CD3+ cells and CD4+langerin+ cells) was defined within the cervical epithelium.

Results & Conclusion
The use of digital image analysis enables high throughput analysis of complex tissue images. Our customized image analysis workflow includes background correction, nuclei- and cytoplasm identification, epithelial height measurement as well as different threshold mechanisms to distinguish single/double stained cells. Preliminary results indicate that DMPA-users display higher number of HIV target cells (CD4+CCR5+ as well as CD4+Langerin+ cells) than the non-DMPA group. No difference in epithelial thickness was seen between the DMPA- and non-DMPA-users. These results indicate that DMPA-users have an altered immunological milieu that may be associated with a higher risk of HIV acquisition.