Placental HPV infection – a potential risk factor for HELLP syndrome?

Introduction:

HELLP syndrome is a severe pregnancy related disease and occurs in about 0.5 – 0.9% of all pregnancies. It is characterized by hemolysis, elevated liver enzymes and low platelets and is significantly associated with higher rates of fetomaternal morbidity and mortality.

Incomplete trophoblastic invasion, endothelial dysfunction and an antiangiogenic state accompanied with ischemia contribute to the development and the course of pregnancy related hypertensive disorders like preeclampsia and HELLP syndrome.

Recently, publications describe a possible association between cervical human papilloma virus (HPV) infection and preeclampsia.

We performed a retrospective cohort pilot study to investigate a possible correlation between HELLP syndrome (n = 21) and placental HPV infection in comparison with placentas of pregnancies with an uneventful course (n = 21).

Methods:

Instead of PAP Smear as a surrogate parameter for HPV infection, we performed in situ hybridization (ISH) and polymerase chain reaction (PCR) analysis.

We examined retrospectively 21 paraffin embedded placental tissue blocks of severe HELLP syndromes. As a control group, we analyzed placental biopsies of healthy pregnant women, delivered by cesarean section at term to rule out any genital contamination of HPV virus.

Results:

In our pilot analysis of 21 cases and 21 controls, we could not show a significant difference of placental HPV infection but a trend towards a higher rate of placental HPV infection in early onset HELLP syndromes (< 34 weeks of gestation, p < 0.083) compared to late onset HELLP syndromes (> 34 weeks of gestation) and healthy pregnancies could be observed.

Conclusion:

To our knowledge this pilot study is the first analysis of a possible correlation between HELLP Syndrome and HPV infection. The fact that HPV can colonize or infect the placenta and might even cause adverse pregnancy outcome is new and scarcely examined. Larger prospective studies are needed to thoroughly investigate a possible association between HELLP syndrome or other diseases caused by incomplete trophoblastic invasion and placental HPV infection.