PP034. Renal histology in preeclampsia: A special role for the podocyte

Introduction: In preeclampsia (PE), the kidney is one of the major target organs. Growing evidence suggests PE increases the risk of subsequent microalbuminuria and end-stage renal disease (ESRD). Endotheliosis and podocyte changes due to anti-angiogenic factors seem to be salient features of PE. However, it is unknown whether chronic lesions are present in PE patients that could contribute to this increased risk.

Objectives: We hypothesized that women with PE and young women with chronic hypertension might show similarity in renal lesions. Furthermore, we investigated if the number of podocytes within the kidney is decreased under these different circumstances. Methods We performed a search for renal autopsy-tissues using a nationwide computerized database (PALGA) to collect a unique large cohort of preeclamptic patients (n=11). Three control groups were included consisting of young women who died during pregnancy without hypertension (n=25) and non-pregnant controls with (n=14) and without (n=13) chronic hypertension. WT-1 staining was used to quantify the number of podocytes. Results Women with PE had MPGN-like lesions without immune-deposits. Tram tracking and podocyte changes were exclusively observed in these patients. Endotheliosis was significantly more present in PE, but sporadically seen in pregnant- and hypertensive controls. Chronic ischaemic lesions were predominantly found in young women with chronic hypertension, and not in PE and other controls. No differences were found in glomerular podocyte number between the study groups.

Conclusion: All women with PE had MPGN-like lesions in their kidneys which was therefore regarded characteristic for PE. In contrast, no chronic lesions were observed in PE which could explain the increased risk of impaired renal function later in life. Interestingly, we demonstrated no difference in podocyte number between study groups. These results might suggest that neither persistent hypertension or dysbalance in angiogenic factors (i.e. preeclampsia) cause an observable change in podocyte number within the kidney.