Long term follow up of biomarkers of podocyte damage and renal function in patients with and without preeclampsia.

INTRODUCTION: preeclampsia can be associated with future renal disease. OBJECTIVES: To measure changes in renal function overtime in patients with preeclampsia. METHODS: urine and serum samples from eleven patients with preeclampsia and eight patients with a normal pregnancy were obtained during pregnancy, postpartum, and 3 years after delivery. Urine podocalyxin, protein, and serum creatinine were measured. RESULTS: after 3 years, there were no significant differences in urinary podocalyxin in patients with or without preeclampsia: 4.34 ng/mg [2.69, 8.99] vs. 7.66 ng/mg [2.35, 13], p = 0.77. The same applied to urinary protein excretion: 81.5 mg/g [60.6, 105.5] vs. 43.2 mg/g [20.9, 139.3] p = 0.23. Serum creatinine was 0.86 mg/dL [0.7, 0.9] vs. 0.8 mg/dL [0.68, 1] p = 0.74 in those with and without preeclampsia. In normal patients, urinary podocalyxin decreased from 54.4 ng/mg [34.2, 76.9] during pregnancy to 7.66 ng/mg [2.35, 13] three years after pregnancy, p = 0.01. Proteinuria decreased from 123.5 mg/g [65.9, 194.8] to 43.2 mg/g [20.9, 139.3], p = 0.12. In preeclampsia patients, urinary podocalyxin decreased from 97.5 ng/mg [64.9, 318.4] during pregnancy to 37.1 ng/mg within one week post-partum [21.3, 100.4] p = 0.05 and 4.34 ng/mg [2.69, 8.99] three years after, p = 0.003. Proteinuria was 757.2 mg/g [268.4, 5031.7] during pregnancy vs. 757.2 mg/g [288.2, 2917] postpartum, p = 0.09 vs. 81.5 mg/g [60.6, 105.5] three years later, p = 0.01. Two patients still had proteinuria after 3 years. CONCLUSIONS: in preeclampsia patients, postpartum urinary podocalyxin decreased before proteinuria. After three years, serum creatinine, urinary podocalyxin, and protein tended to normalize, although some patients still had proteinuria.

Urinary podocalyxin as a marker of preeclampsia in a Hispanic population.

BACKGROUND: Preeclampsia is associated with significant materno-fetal morbidity and mortality. Podocyturia due to podocyte damage seems to be associated with the disease. The objective of this study was to evaluate the usefulness of urinary podocalyxin as a marker of preeclampsia in a Hispanic population. METHODS: 63 patients were studied. 25 patients had preeclampsia/eclampsia (PE-E). 38 patients had normal pregnancies and served as control group. 24 hour proteinuria, urine protein/creatinine (UPC), urinary podocalyxin and perinatal outcomes were measured. A Podocalyxin ELISA test was used to detect podocyturia. RESULTS: Mean age (years), mean±SD was 30.5±5.4 in normal patients vs 30.6±5.8 in PE-E, p=0.98. Median gestational age (weeks) was, 38 (range 21-42) for normal pregnancies and 36 (range 24-40) for patients with PE-E, <0.001. Urine podocalyxin/creatinine on admission (ng/mg), median [IQR] in normal patients was 55.9 [29.4, 74.9] vs 109.7 [63.8, 234.1] in PE-E, p=0.001. After adjusting for admission proteinuria, urinary podocalyxin remained independently associated with preeclampsia: OR=1.0040 (95% CI 1.0003-1.0078), p=0.03. There was low to moderate correlation between UPC and urinary podocalyxin, Spearman's =0.31, p=0.01. In PE-E, post-partum urine podocalyxin was lower, median [IQR]: 69.7 [32.7, 184.8] p=0.19 vs admission. There was a trend towards more podocyturia and proteinuria in patients with eclampsia, comparing to those with preeclampsia. There was no association observed between podocyturia and neonatal mortality, IUGR or Apgar scores. CONCLUSIONS: Significantly higher levels of urinary podocalyxin are seen in preeclampsia/eclampsia. They tend to normalize after delivery.