Twenty-eight women with mild
preeclampsia and 22 with severe
preeclampsia at Nanfang Hospital, Southern Medical University between October 2010 and June 2011 were recruited. Maternal serum
cystatin,
uric acid,
urea nitrogen,
creatinine and
albumin levels were collected and analyzed. Twenty-four hours urinary
protein excretion was measured with immunoturbidimetric assay and ACR with automatic analyzer DCA2000. The correlation between ACR and 24 hours urinary
protein excretion was explored. And the optimal cut-off values of the spot ACR for mild and severe
preeclampsia were determined with receiver operating characteristic curve.
RESULTS: (1) Maternal serum biochemical parameters:
uric acid levels in mild and severe
preeclampsia were (359 ± 114) µmol/L and (450 ± 132) µmol/L, while
cystatin levels were (1.3 ± 0.3) mg/L and (1.6 ± 0.5) mg/L respectively. The differences were statistically significant (P < 0.05). Serum
urea nitrogen,
creatinine and
albumin in mild
preeclampsia were (3.6 ± 1.6) mmol/L, (52 ± 38) µmol/L and (33 ± 3) g/L, while in severe
preeclampsia were (6.2 ± 3.1) mmol/L, (78 ± 59) µmol/L and (29 ± 6) g/L respectively. There were no statistical significant differences (P > 0.05). (2) Twenty-four hours urinary
protein excretion and ACR: 24 hours urinary
protein levels in mild and severe
preeclampsia was (700 ± 160) mg and (4800 ± 2200) mg (P < 0.05). ACR in mild and severe
preeclampsia was (72.7 ± 12.4) mg/mmol and (401 ± 245) mg/mmol respectively (P < 0.05). (3) There was a strong correlation between the spot ACR and 24 hours urine
protein excretion (r = 0.938; P < 0.05). (4) The optimal spot ACR cut-off point for the diagnosis of
preeclampsia: the optimal spot ACR cut-off point was 22.8 mg/mmol for 300 mg/24 hours of
protein excretion in mild
preeclampsia, the area under curve was 0.956, with a sensitivity, specificity of 82.4%, 99.4% respectively. And the optimal spot ACR cut-off point was 155.6 mol for 2000 mg/24 hours of
protein excretion in severe
preeclampsia, the area under curve was 0.956, with a sensitivity, specificity of 88.6%, 91.3% respectively.
CONCLUSIONS: Compared with 24 hours urinary
protein excretion, the spot ACR may be a simple, convenient and accurate
indicator of early diagnosis of
preeclampsia. Spot ACR may be used as a replacement for 24 hours urine
protein excretion in assessment of
preeclampsia. The optimal spot ACR cut off points were 22.8 mg/mmol for mild
preeclampsia and 155.6 mg/mmol for severe
preeclampsia.