Glomerular endotheliosis in normal pregnancy and pre‐eclampsia

Abstract

Objective To investigate the proportion of women with findings characteristic for pre‐eclampsia, as opposed to renal disease, in a controlled study of hypertensive pregnant women undergoing antepartum renal biopsy. Design An observational prospective controlled study. Setting University Hospital of Lund, Sweden. Sample Thirty‐six previously healthy women with hypertensive disease in pregnancy, consecutively admitted to the antenatal ward at onset of disease during a 20 month period and giving informed consent, as well as 12 voluntary healthy pregnant controls. Methods Renal biopsy samples were obtained from all participants and evaluated by light microscopy, electron microscopy and immunofluorescence techniques. Main outcome measures Presence and degree of glomerular endotheliosis. Results Glomerular endotheliosis was present in all women with pre‐eclampsia and gestational hypertension, and in 5 of the 12 controls, although significant differences in the degree of endotheliosis were found between the groups. Clinically undetected renal disease was not diagnosed in any of the women. Conclusion Glomerular endotheliosis was found in women with normal pregnancy as well as in both non‐proteinuric and proteinuric hypertension and is consequently not, as earlier believed, pathognomonic for pre‐eclampsia. The transition between normal term pregnancy, gestational hypertension and pre‐eclampsia appears to be a continuous process, perhaps of increasing adaptation to pregnancy. Pre‐eclampsia may be the extreme of the adaptational process, rather than a separate abnormal condition. Clinically undetected renal disease could be a rare cause of hypertension in pregnancy.

Association of Preeclampsia with Podocyte Turnover

“…VEGF, vascular endothelial growth factor. previous report (16). A dysregulation of, and the resulting imbalance between, proangiogenic and antiangiogenic factors is believed to cause endotheliosis.…”

“…At least 50 glomeruli per section were examined, and the following parameters were scored: presence of endotheliosis, double contours of the glomerular basement membrane (tram tracking), swelling of podocytes (prominent presence of podocytes), mesangial changes, glomerulitis, and FSGS. As previously described by Strevens et al (16), endotheliosis was scored semiquantitatively as follows: 0 (no endotheliosis), 1 (,20% of the lumen was obliterated), 2 (20%-80% of the lumen was obliterated), or 3 (.80% of the lumen was obliterated). Global sclerosis was recorded as a percentage of the total number of glomeruli scored.…”

Obstetric Nephrology

“…These findings were further confirmed in a later study after augmentation of the GFR and RPF with an amino acid infusion (37). There are also very limited uncontrolled data from autopsy cases (38) and, more recently, controversial data from 12 thirdtrimester biopsies (39) to suggest that glomerular diameter may be greater than that measured in nonpregnant participants. Lastly, in the postpartum period, we utilized physiologic techniques to measure GFR, RPF, and oncotic pressure and computed a value for the two-kidney K f in 22 women 2 weeks after delivery and demonstrated that RPF returned to baseline values and oncotic pressure increased above control values.…”

Gestational hypertension as a subclinical preeclampsia in view of serum levels of angiogenesis-related factors

“…Strevens et al 19 obtained renal biopsy samples in women with normal pregnancy, GH and PE; glomerular endotheliosis, which has been believed as a characteristic lesion found in women with PE, was present in all women with GH and PE, and almost half of the controls, although the degree of endotheliosis is more severe in women with PE than in women with GH, and in women with GH than in women with normal pregnancy, supporting our opinion that GH is a type of subclinical PE.…”