Urinary GSTP1-1 excretion is markedly increased in normotensive pregnancy as well as in preeclampsia.
BACKGROUND
Glutathione S-transferases (GSTs) are present in large amounts in the human kidney, where they demonstrate a specific distribution. The assessment of urinary excretion of GST alpha (proximal tubules) and pi (distal and collecting tubules) could be helpful in determining if, and to what degree renal tubular damage is present in preeclampsia and whether this damage is in the proximal or distal region.


METHODS
Urine samples were collected from 22 women with severe preeclampsia and/or HELLP syndrome (PE), from 30 non-pregnant women with a history of severe preeclampsia (HPE), from 18 women with uncomplicated pregnancies (PC) and from 30 non-pregnant women with a history of uncomplicated pregnancies (HPC). GSTA1-1 and GSTP1-1 were assayed by ELISA and were expressed as nanograms per 10 mmol creatinine (Cr).


RESULTS
Median urinary GSTP1-1 concentrations were significantly (p<0.001) higher in women with preeclampsia [62.2 (4.3-291.2) ng/10 mmol Cr] compared to non-pregnant women with a history of preeclampsia [22.3 (0-142.6) ng/10 mmol Cr]). In addition, in normotensive pregnant women, urinary GSTP1-1 concentrations were significantly (p<0.01) higher [82.6 (8.3-206.7) ng/10 mmol Cr]) compared to non-pregnant controls [5.1 (0-66.7) ng/10 mmol Cr]. No difference in GSTP1-1 concentrations was found between women with preeclampsia and normotensive pregnant women. GSTA1-1 concentrations were not significantly different between the four groups of women investigated. There were no correlations between the degree of proteinuria and urinary GSTP1-1 or GSTA1-1 concentrations.


CONCLUSIONS
GSTP1-1 metabolism in the distal tubule changes during normotensive as well as preeclamptic pregnancy. Whether this is due to tubular cell damage, disturbed resorption or an increase in cellular levels cannot be determined as yet.
Roes
E M
EM
Department of Obstetrics and Gynecology University Medical Center, Nijmegen - The Netherlands.
Raijmakers
M T M
MT
Roelofs
H M
HM
Peters
W H
WH
Steegers
E A
EA
D000328:Adult; D015415:Biomarkers / Q000652:urine; D001794:Blood Pressure / Q000502:physiology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D051549:Glutathione S-Transferase pi / Q000652:urine*; D005982:Glutathione Transferase / Q000652:urine; D006801:Humans; D007684:Kidney Tubules / Q000378:metabolism; D008875:Middle Aged; D011225:Pre-Eclampsia / Q000503:physiopathology / Q000652:urine*; D011247:Pregnancy; D011507:Proteinuria / Q000209:etiology / Q000652:urine; D012189:Retrospective Studies; D012720:Severity of Illness Index
D015415:Biomarkers; C484555:GSTA1 protein, human; D051549:Glutathione S-Transferase pi; D005982:Glutathione Transferase