The high-risk human papillomavirus continuum along the female reproductive tract and its relationship to infertility and endometriosis

RESEARCH QUESTION

Is there an association between the presence of sexually transmitted pathogens in the lower (LGT) and upper (UGT) female genital tract with endometriosis and infertility?

DESIGN

Case-control study with 60 women submitted to gynaecological laparoscopic surgery. Samples from the UGT and LGT were collected and analysed by single polymerase chain reaction (PCR) for human papillomavirus (HPV) and by multiplex PCR for other sexually transmitted infections (STI). Patients were initially divided into two clinical groups: infertile patients (n = 25) with conjugal infertility and fertile control patients (n = 35). After the surgical findings patients were further divided for additional analysis: an endometriosis group (n = 29) and non-endometriosis control group (n = 31).

RESULTS

Sixty per cent of patients were positive for DNA-HPV in some of the genital tract sites sampled. Infertile patients were associated with high-risk HPV (hrHPV) positivity in the UGT sites (P = 0.027). The endometriosis group was associated with hrHPV positivity in the LGT and UGT sites (P = 0.0002 and P = 0.03, respectively). Only hrHPV types were detected in the UGT in both groups. It may be that there is a hrHPV infection continuum, from LGT to UGT, in infertile and endometriosis patients. No association was observed among the other seven STI studied.

CONCLUSIONS

This study shows both an association between hrHPV infections in the UGT with infertility and endometriosis, and a possible hrHPV infection continuum, from LGT to UGT. Larger studies are needed to fully investigate the role of hrHPV as a cause of endometriosis and infertility.

Circulating pathogen-specific plasmablasts in female patients with upper genital tract infection

Mucosal antibodies constitute the first line of adaptive immune defence against invaders in the female genital tract (FGT), yet the sequence of events leading to their production is surprisingly poorly characterized. We explored the induction of pathogen-specific antibody-secreting cells (ASC) as a response to an acute infection in the upper FGT. We recruited 12 patients undergoing surgery due to an upper FGT infection (7/12 blood culture positive, 5/12 negative) and six healthy controls. Pathogens were sampled during surgery and PBMC collected in the acute phase of the disease (days 7-10). We searched by ELISPOT circulating pathogen-specific ASC and explored their frequency, immunoglobulin isotype distribution, and expressions of homing receptors (α₄β_7, L-selectin, and CLA). All patients had circulating ASC specific to the infective bacteria; the geometric mean was 434 (95%CI 155-1234) ASC (IgA + IgG + IgM)/10⁶ PBMC. IgA ASC predominated in 7/12, IgG ASC in 3/12, and IgM ASC in 2/12 cases. Of all the pathogen-specific ASC, 60% expressed α₄β₇, 67% L-selectin, and 9% CLA. This study is the first to show induction of pathogen-specific ASC in the peripheral blood in bacterial infection in the human FGT. Our findings reveal that such FGT-originating pathogen-specific ASC are predominated by IgA ASC and exhibit a homing receptor profile resembling that of ASC in acute urinary tract infection. The data thus suggest a characteristic profile shared by the urogenital tract.