Microparticle subpopulations are increased in preeclampsia: possible involvement in vascular dysfunction?

The purpose of this study was to investigate the cellular origin and numbers of circulating microparticles in normal pregnancy and preeclampsia.

Plasma samples from 10 women with preeclampsia, from 10 normal pregnant women, and from 10 nonpregnant women matched for age and gestation, were analyzed by flow cytometry.

The total number of circulating microparticles was unaltered in pregnancy and preeclampsia. The largest portion of microparticles was derived from platelets in all groups. T-suppressor cell microparticle numbers were decreased in normal pregnancy (P =.04). In preeclampsia T-suppressor, T-helper cell, and granulocyte microparticle numbers were increased (P =.008,.008, and.03, respectively). Elastase concentrations were increased in preeclampsia (P =.02) and correlated with granulocyte microparticle numbers (P =.006). Elastase concentrations correlated with systolic and diastolic blood pressure (P =.001 and.003, respectively), and granulocyte microparticle numbers correlated with systolic blood pressure (P =.05).

Numbers of T-cell and granulocyte microparticles are increased in preeclampsia. Whether these altered microparticle numbers cause vascular dysfunction in preeclampsia or are a consequence of the disease remains to be established.