Abstract Body: Pre-eclampsia (PE), new-onset hypertension after the 20^th week of pregnancy alongside other organ dysfunction, endothelial dysfunction, and immune activation. We have previously shown that CD19+ B cell adoptive transfer causes a PE phenotype in athymic nude rats. CD19 is present on all B cells including plasma cells. CD20 is absent from plasma cells but is present on mature B2 and memory B cells. The objective of this study was to determine if CD20+ B cells, excluding plasma cells, cause maternal hypertension, fetal growth restriction, and endothelial dysfunction.
Three hundred thousand placental CD20+ B Cells from normal pregnant (NP) or PE patients were isolated by magnetic separation and injected i.p. into nude athymic rats on gestational day (GD) 12. On GD18, carotid catheters were inserted. On GD19, mean arterial pressure (MAP) was measured and blood and tissues were collected. Preproendothelin (PPET) expression was quantified in kidney and placental tissues using RT-PCR. A student’s t-test was used for statistical analysis.
Participants whose placental B cells were used in this study had similar age, pre-pregnancy BMI, and diastolic BP on admission. PE participants had elevated systolic BP at admission (135±4 vs 120±4 mmHg) and delivery (139±6 vs 124±3 mmHg) as well as diastolic BP at delivery (79±4 vs 68±2 mmHg). PE participants also had trending decreases in fetal weight (2621±323 vs 3202±102 g) and gestational age (36±1 vs 39±0 weeks) at delivery.
MAP increased from 107±4 mmHg (n=8) in the NP recipient rats to 123±2 mmHg (n=8, p<0.01) in the PE recipient rats. Pup and placental weights were unchanged following adoptive transfer. Renal PPET expression increased by 2.595±0.61 fold (ΔΔct) in PE recipient rats (n=7, p<0.05) compared to NP recipient rats (n=7). Placental PPET expression was unchanged following adoptive transfer.
CD20+ B cells from women with PE contribute to hypertension and endothelial dysfunction during pregnancy. This data supports the important role of B cells in the development of PE and improves our understanding of the population of B cells responsible for contribution to the disease.