Signs of neuroaxonal injury in preeclampsia-A case control study

BACKGROUND

Cerebral injury is a common cause of maternal mortality due to preeclampsia and is challenging to predict and diagnose. In addition, there are associations between previous preeclampsia and stroke, dementia and epilepsy later in life. The cerebral biomarkers S100B, neuron specific enolase, (NSE), tau protein and neurofilament light chain (NfL) have proven useful as predictors and diagnostic tools in other neurological disorders. This case-control study sought to determine whether cerebral biomarkers were increased in cerebrospinal fluid (CSF) as a marker of cerebral origin and potential cerebral injury in preeclampsia and if concentrations in CSF correlated to concentrations in plasma.

METHODS

CSF and blood at delivery from 15 women with preeclampsia and 15 women with normal pregnancies were analysed for the cerebral biomarkers S100B, NSE, tau protein and NfL by Simoa and ELISA based methods. MRI brain was performed after delivery and for women with preeclampsia also at six months postpartum.

RESULTS

Women with preeclampsia demonstrated increased CSF- and plasma concentrations of NfL and these concentrations correlated to each other. CSF concentrations of NSE and tau were decreased in preeclampsia and there were no differences in plasma concentrations of NSE and tau between groups. For S100B, serum concentrations in preeclampsia were increased but there was no difference in CSF concentrations of S100B between women with preeclampsia and normal pregnancy.

CONCLUSION

NfL emerges as a promising circulating cerebral biomarker in preeclampsia and increased CSF concentrations point to a neuroaxonal injury in preeclampsia, even in the absence of clinically evident neurological complications.

[BLOOD AND CEREBROSPINAL FLUID PURINES IN PREGNANT]

The research includes 88 pregnant women, that had their purine basis and malondialdehyde in water thermocoagulate extract of venous blood and cerebrospinal fluid examined (along with common standards clinical-laboratory tests) before the spinal anesthesia for the caesarian section was provided It was detected that preeclampsy and HELLP-syndine feature the increased adenine guanine hypoxantine and uric acid levels in cerebrospinal fluid, as well as increased concentrations of blood malondyaldehyde (higher than upper normal level), accompany with the increased hemotaencephalic barrier permeability for adenine, guanine and hypoxantine. It's demonstrated that level of guanine in blood serum can be used as a prognostic factor of spinal anesthesia quality in obstetrics. It is supposed to examine purine levels in pregnant women not only in blood but also in cere brospinal fluid.

Placental growth factor in the cerebrospinal fluid of women with preeclampsia

OBJECTIVE

Recent data suggest that excess circulating soluble fms-like tyrosine kinase-1 (sFlt-1) may causally relate to preeclampsia. This study investigates the levels of sFlt-1, VEGF, and PlGF in cerebrospinal fluid (CSF) of patients with preeclampsia and normotensive controls.

METHODS

CSF was collected from preeclamptic patients (n=15) and controls (n=7) at the time of spinal anesthesia and assayed for PlGF, sFlt-1, and VEGF (total and free) by specific immunoassays.

RESULTS

All sought angiogenic factors were measurable. Levels of free PlGF but not sFlt-1 or VEGF (total or free) were increased in CSF of preeclamptic women. There was no significant difference in the ratios of angiogenic factors in the CSF of women with preeclampsia. There was no correlation between levels of angiogenic factors and CSF cell counts or severity of symptoms.

CONCLUSION

Elevated levels of PlGF in CSF preeclamptic women may promote vascular permeability and contribute to the hypertensive encephalopathy seen in such patients.

Effects of pre-eclampsia on maternal plasma, cerebrospinal fluid, and umbilical cord urotensin II concentrations: a pilot study † †This work was presented at the Liverpool meeting of the Anaesthetic Research Society, July 8–9, 2004 (E. Cowley, J. Waugh, N. Ali, P. Sharpe, J. P. Thompson and D. G. Lambert. Urotensin II concentrations are not elevated in pre-eclampsia. Br J Anaesth 2004; 612P)

BACKGROUND

Urotensin II (UII) is the most potent endogenous vasoconstrictor identified to date. Pre-eclampsia is associated with arteriolar vasospasm but the precise underlying mechanism is uncertain and we hypothesized that UII concentrations might also be elevated. In this study we measured UII concentrations in maternal plasma and cerebrospinal fluid (CSF), and umbilical vein plasma from pre-eclamptic (PET) and normotensive patients undergoing elective Caesarean section under spinal or combined spinal-epidural anaesthesia.

METHODS

With LREC approval and informed consent we recruited two groups of 10 patients; control [mean (range) age, 29 (22-43) yr; BMI, 25 (20-32); gestation, 273 (267-281) days; mean arterial pressure (MAP) on day of delivery, 81 (75-96) mm Hg] and PET [age, 34 (22-40) yr; BMI, 25 (21-46); gestation, 253 (203-289) days; MAP on day of delivery, 106 (88-128) mm Hg]. Maternal blood and CSF samples and umbilical vein blood samples were taken. UII was extracted and concentrations measured using a radioimmunoassay.

RESULTS

Two plasma and two CSF samples in the control and two CSF samples in the PET group were below the assay detection limits. There were no differences in maternal plasma or CSF or umbilical vein UII concentrations between the groups. However, there was a small ( approximately 40%) but significant increase in cord UII concentrations when compared with paired plasma in the PET group. There was a weak but significant negative correlation (r=-0.4, P=0.049) between cord UII concentrations and gestation in the PET group. In addition, we observed a significant positive correlation between plasma and CSF (r(2)=+0.57, P=0.0009, n=16), plasma and cord (r(2)=+0.43, P=0.0031, n=18) and CSF and cord (r(2)=+0.32, P=0.022, n=16) UII concentrations for the whole data set.

CONCLUSIONS

Collectively the data indicate that UII concentrations do not increase in PET compared with controls but, in PET patients, cord UII concentrations are elevated relative to paired plasma samples. Elevated umbilical vein UII concentrations may simply indicate reduced placental viability and possibly UII metabolism as a result of reduced blood flow or possibly that the placenta is producing UII.

Discriminatory proteomic biomarker analysis identifies free hemoglobin in the cerebrospinal fluid of women with severe preeclampsia

OBJECTIVE

Preeclampsia is an idiopathic multisystem disorder specific to human pregnancy. This study used proteomic analysis of cerebrospinal fluid (CSF) to identify protein biomarkers characteristic of preeclampsia and related to its severity.

STUDY DESIGN

CSF was collected from women diagnosed clinically with severe preeclampsia (sPE: n = 7), mild preeclampsia (mPE: n = 8), and normotensive controls (CRL: n = 8). Samples were subjected to proteomic analysis using surface-enhanced laser desorption/ionization time-of-flight (SELDI-TOF) mass spectroscopy. A discriminative proteomic biomarker profile was extracted by applying Mass Restricted analysis, and a Preeclampsia Proteomic Biomarker (PPB) score developed based on the presence or absence of four discriminatory protein peaks in individual CSF SELDI tracings. In-gel tryptic digests, Western blot analysis, on-chip immunoassays, ELISA, and spectral analysis were used to identify the biomarkers composing the PPB score.

RESULTS

PPB score distinguished patients with a clinical diagnosis of sPE from mPE and CRLs. (PPB median [range]: sPE: 4 [0-4] vs mPE: 1 [0-1] vs CRL: 0 [0-0]; P < 0.001). PPB scores were unaffected by parity, magnesium seizure prophylaxis, CSF leukocyte counts, and total protein content. Proteomic identification techniques matched the discriminatory protein peaks to the alpha- and beta-hemoglobin chains. ELISA confirmed that women diagnosed clinically with sPE had significantly higher CSF hemoglobin concentrations than women with mPE or CRL (median [range]: sPE: 6.6 [0.0-10.3] microg/mL vs mPE: 0 [0-1.3] microg/mL vs CRL: 0 [0-0] microg/mL; P < 0.001).

CONCLUSION

Proteomic analysis of CSF can accurately distinguish sPE from both mPE and CRL. Patients with sPE have nanomolar amounts of free hemoglobin in their CSF. Further studies are needed to confirm these observations and determine their physiologic implications.

Cerebrospinal fluid leptin levels in preeclampsia: relation to maternal serum leptin levels

BACKGROUND

To determine whether cerebrospinal fluid (CSF) and circulating levels of leptin differ between women with preeclampsia and women who had an uncomplicated pregnancy.

METHODS

Maternal serum and CSF leptin concentrations obtained in the third trimester of the gestation were compared in 16 women with mild preeclampsia and 23 normotensive pregnant women who underwent cesarean section. Before administering local anesthetic for spinal anesthesia, 2 mL CSF and 4 mL venous blood sample were taken and were stored at -30 degrees C until serum and CSF leptin levels were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Mean CSF leptin concentrations were not significantly different between the two groups (preeclampsia 9.7 +/- 4.2 ng/mL, normotensive 13.6 +/- 4.3 ng/mL, p = 0.952). Similarly, mean serum leptin concentrations were similar between the two groups (mild preeclampsia 21.7 +/- 7.1 ng/mL, normotensive 18.3 +/- 6.7 ng/mL, p = 0.698). CSF leptin levels are inversely related to the serum leptin concentrations in preeclamptic patients (r = -0.87, p = 0.000). An inverse relationship was also detected between CSF and serum leptin levels in normotensive pregnant subjects (r = -0.66, p = 0.000).

CONCLUSIONS

CSF and serum leptin levels were similar in patients with preeclampsia and normotensive pregnant women. However, the CSF leptin was negatively correlated with the serum leptin concentrations in preeclamptic and normotensive control subjects, suggesting that leptin enters the brain by a saturable transport system. Further work is needed to confirm our findings.

Cerebrospinal fluid nitric oxide level changes in preeclampsia

OBJECTIVE

The purpose of this study was to determine the level of nitric oxide (NO) metabolites, nitrite and nitrate in human cerebrospinal fluid (CSF) and serum and to assess whether there is any relationship among CSF, serum nitrate-nitrite levels and preeclampsia.

STUDY DESIGN

Twenty-one preeclamptic and 27 healthy pregnant women as control group who underwent cesarean section (C/S) were included in the study. Before administering local anesthetic for spinal anesthesia, 2 ml CSF and 4 ml venous blood sample were taken. CSF and serum total nitrite, direct nitrite and nitrate levels were determined spectrophotometrically.

RESULTS

CSF total nitrite, direct nitrite and nitrate levels were significantly different between the two groups (21.00+/-1.68, 8.28+/-0.89 and 12.71+/-1.08 micromol/l, respectively versus 15.53+/-1.49, 5.57+/-0.39 and 9.96+/-1.45 micromol/l, respectively, P<0.05). Significantly higher serum nitrate level was found (31.84+/-2.31 micromol/l) in the control group compared to the preeclamptic group serum nitrate level (25.06+/-2.02 micromol/l). Statistical comparisons were performed by the Mann-Whitney U-test.

CONCLUSION

CSF-NO is significantly higher but serum NO is lower in preeclamptic group compared with control group may suggest independent regulation of NO in the two compartments. The determination of CSF-NO metabolites could be useful to clarify whether increased NO production is predominantly associated with poor perfusion of the brain in preeclampsia.

Baseline serum and cerebrospinal fluid magnesium levels in normal pregnancy and preeclampsia

OBJECTIVE

To determine whether baseline cerebrospinal fluid magnesium levels in preeclampsia differ from those in normal pregnancy, and to ascertain whether pre-treatment cerebrospinal fluid magnesium levels correlate with serum levels, which would suggest a baseline alteration in the blood-brain barrier in preeclampsia.

METHODS

When spinal analgesia or anesthesia was administered for delivery, serum and cerebrospinal fluid magnesium levels were determined in 20 normal gravidas and 20 preeclamptic women not treated with magnesium sulfate. Data were analyzed by two-sided Student t test and regression analysis.

RESULTS

Mean (+/- standard deviation) cerebrospinal fluid magnesium level for preeclamptic patients was 2.23 +/- 0.09 mEq/L, which was not significantly different from controls. Regression analysis revealed no significant correlation between cerebrospinal fluid and serum magnesium levels for either normal or preeclamptic gravidas.

CONCLUSION

During the third trimester, there is no difference in baseline, pre-treatment cerebrospinal fluid magnesium levels in preeclamptic patients compared to normal subjects, and no correlation between cerebrospinal fluid and serum magnesium over the range of baseline values.

Cerebrospinal fluid and plasma glucose concentrations of ovine pregnancy toxaemia cases, inappetant ewes and normal ewes during late gestation

Cerebrospinal fluid (CSF) and plasma glucose concentrations of spontaneous ovine pregnancy toxaemia cases, determined within 24 h of the onset of clinical signs, were significantly lower (P < 0.01) compared to inappetant ewes and healthy ewes at a similar stage of gestation. A highly significant correlation (P < 0.001, r = 0.91) was present between the plasma and CSF glucose concentrations when the data from the three groups were combined. The data suggest that plasma glucose concentration accurately reflects CSF glucose concentration across the range of energy states in pregnant ewes and may provide support for the postulate that the neurological signs of ovine pregnancy toxaemia result from cerebral hypoglycaemia, as reflected by CSF glucose concentration. No cerebral glucose estimations were undertaken in this series.

The total peroxyl radical-trapping ability of plasma and cerebrospinal fluid in normal and preeclamptic parturients

Plasma and cerebrospinal fluid total peroxyl radical-trapping antioxidative parameter (TRAP) and the main antioxidant components of TRAP (vitamin E, ascorbic acid, uric acid, protein sulfhydryl groups, and the unidentified antioxidant proportion) were analyzed in 11 preeclamptic parturients, 9 healthy parturients with an uncomplicated pregnancy, and 10 healthy nonpregnant women. In addition, the possible effects of ongoing labor were studied in 10 healthy parturients. The samples of plasma and cerebrospinal fluid (CSF) were collected at cesarean section (pregnant women) or minor surgical procedure (nonpregnant women). Normal pregnancy or ongoing labor induced no significant changes in total TRAP, as compared with nonpregnant women, but significant changes in the percentage contributions of individual antioxidants were noted in plasma and CSF. In preeclampsia, a significant increase in TRAP was noted in both plasma and CSF. This increase was mainly due to an increased proportion of uric acid and unidentified antioxidants in plasma samples, and an increased proportion of unidentified antioxidants in CSF. The concentration of CSF ascorbic acid was decreased in preeclampsia, and a negative correlation between CSF ascorbic acid and blood pressure was observed.

Catecholamine concentrations in venous plasma and cerebrospinal fluid in normal and complicated pregnancy

The concentrations of adrenaline and noradrenaline were determined in venous plasma and cerebrospinal fluid (CSF) of 41 pregnant women at term scheduled for elective or 'hot' caesarean section and in 7 healthy non-pregnant women scheduled for elective surgery. Group 1: 10 pregnant women at term with a normal history of their pregnancy; group 2: like group 1, but in active labour for more than 4 h; group 3: 10 pregnant women with insulin-dependent diabetes mellitus with or without slightly elevated arterial blood pressure; group 4: 11 women with pre-eclampsia gravis; group 5: 7 healthy non-pregnant women of fertile age. The highest values of mean arterial blood pressure and of venous plasma noradrenaline were found in the pre-eclamptic group 4, mean arterial blood pressure and plasma noradrenaline levels correlated to each other. However, concentrations of noradrenaline in CSF in group 4 did not differ significantly from the other groups. It is speculated that a different origin of hypertension may be the reason for the normal noradrenaline concentrations in CSF. This finding is in contrast to earlier findings in which noradrenaline levels in CSF were elevated in patients with essential hypertension.

Cerebrospinal fluid levels of magnesium in patients with preeclampsia after treatment with intravenous magnesium sulfate: a preliminary report

The purpose of this study is twofold: (1) to correlate magnesium levels of serum with those of cerebrospinal fluid in patients with preeclampsia receiving intravenous magnesium sulfate, and (2) to determine whether the magnesium ion crosses the blood-brain barrier in significant amounts after intravenous magnesium sulfate therapy. Of the 21 patients in whom spinal anesthesia was used for delivery, ten patients with preeclampsia with therapeutic serum magnesium levels made up the study group and 11 term nontreated normotensive gravid women served as controls. At the time of spinal anesthesia, a 1 ml aliquot of cerebrospinal fluid was obtained from each patient. The mean cerebrospinal fluid magnesium level for the control group was 2.56 +/- 0.19 mg/dl (range 2.2 to 2.8 mg/dl). For the preeclamptic group who received intravenous magnesium sulfate, the mean cerebrospinal fluid magnesium level was 3.04 +/- 0.12 mg/dl (range 2.9 to 3.2 mg/dl). Although only a small amount of magnesium crosses the blood-brain barrier after intravenous magnesium sulfate treatment, this increment is highly significant (p less than 0.001).