Is inflammation the cause of pre-eclampsia?

Area of Science:

• Obstetrics and Gynecology
• Pathophysiology
• Maternal-Fetal Medicine

Background:

• Pre-eclampsia etiology is debated, with proposed causes including excessive inflammation or angiogenic factor imbalance.
• The Bradford-Hill criteria provide a framework for evaluating disease causation.

Purpose of the Study:

• To critically evaluate the roles of inflammation and angiogenic imbalance in pre-eclampsia causation using the Bradford-Hill criteria.
• To determine the most promising therapeutic targets for pre-eclampsia.

Main Methods:

• Review and analysis of existing literature on inflammation and angiogenic factors in pre-eclampsia.
• Application of the Bradford-Hill criteria (temporality, dose-response, experimental evidence) to assess causation.
• Evaluation of therapeutic interventions targeting inflammation versus angiogenic mechanisms.

Main Results:

• Inflammatory markers lack temporality with pre-eclampsia onset, challenging inflammation as a direct cause.
• Elevated anti-angiogenic factors precede pre-eclampsia, fulfilling the temporality criterion.
• High levels of anti-angiogenic factors correlate with disease incidence and severity (dose-response).
• Removal of soluble Fms-like tyrosine kinase receptor-1 (sFlt-1) improves outcomes, supporting its role as a causal factor.
• Corticosteroid treatment, despite reducing inflammation, does not improve maternal outcomes.

Conclusions:

• Angiogenic imbalance, not excessive inflammation, is the more likely cause of pre-eclampsia.
• Inflammation may exacerbate pre-eclampsia but is not the primary driver.
• Therapies targeting angiogenic and cytoprotective mechanisms hold greater promise for pre-eclampsia treatment.