Plasma from patients with HELLP syndrome increases blood-brain barrier permeability

Evidence of Anxiety, Depression and Learning Impairments following Prenatal Hypertension

Background: Hypertensive disorders of pregnancy, such as Preeclampsia (PreE) and HELLP (hemolysis, elevated liver enzyme, low platelet) syndrome, affects approximately 5–10% of pregnancies and increases the risk of women developing disorders, such as anxiety or depression, in the postpartum period. Using preclinical rodent models, we set out to determine whether rats with a history of PreE or HELLP had evidence of anxiety, depression or cognitive impairment and whether immune suppression during pregnancy prevented these changes in mood and/or cognition. Methods: Timed-pregnant rats were infused with sFlt-1 and/or sEng to induce PreE or HELLP beginning on gestational day 12. After delivery, a battery of validated behavioral assays was used to assess post-partum depression, anxiety and learning. Results: There was no negative effect on maternal pup interaction due to PreE or HELLP; however, hypertensive dams spent more time immobile in the forced swim test (p < 0.0001). Hypertensive dams also spent less time in the open area of the open field (p = 0.001). There were no significant changes in recognition memory (p = 0.08); however, spatial learning was impaired in hypertensive dams (p = 0.003). Immobility time in the forced swim test was positively correlated with increased circulating S100B (p = 0.04), while increased time spent in the outer zones of the open field was negatively correlated with BDNF levels (p < 0.0001). Conclusion: The results from this study suggest that hypertensive pregnancy disorders are associated with depression, anxiety and learning impairments in the post-partum period.

Immediate postpartum management of patients with severe hypertensive disorders of pregnancy: pathophysiology guiding practice

Developing clinically-focused evidence and experience-based approaches to improve maternity care is a national priority. Safety and quality collaborative initiatives related to management of hypertensive disorders of pregnancy are vital in the implementation of improved care. We reviewed the obstetric literature to construct a concise summary of the core pathophysiologic issues, practice principles and clinical interventions which are foundational for physicians providing immediate postpartum care for patients with severe pregnancy-related hypertension (including those with eclampsia, HELLP syndrome, and superimposed preeclampsia inclusive of those with gestational hypertension that develop severe range blood pressures). While based largely upon the American College of Obstetrics and Gynecology (ACOG) Hypertension Task Force Guidelines released in 2013 as well as updated 2018 guidelines set forth by ACOG for hypertensive disorders of pregnancy, this summary goes beyond the basic safety bundles for hypertension management and lays a pathophysiologic foundation for the immediate postpartum care of patients with severe hypertensive disorders of pregnancy.

Assessment of blood-brain barrier integrity and neuroinflammation in preeclampsia

BACKGROUND

Although blood-brain barrier integrity is intact under normal pregnancy conditions, animal studies suggest that blood-brain barrier impairment occurs in preeclampsia. Yet, human data are limited, and the integrity of the blood-brain barrier has not been assessed in women with preeclampsia.

OBJECTIVE

We sought to test the hypothesis that the integrity of the blood-brain barrier is impaired and that neuroinflammation is increased in women with preeclampsia.

STUDY DESIGN

We performed an observational case-control study in pregnant women >24 weeks gestation who underwent spinal anesthesia for elective cesarean delivery or combined spinal epidural analgesia for labor. Cases were women with preeclampsia, and control subjects were women with either healthy pregnancy, chronic hypertension, or gestational hypertension. Paired samples of blood, urine, and cerebrospinal fluid were collected from each subject before delivery. We measured albumin, C5a, C5b-9, tumor necrosis factor-α, and interleukin-6 concentrations in plasma and cerebrospinal fluid, and albumin, C5a, and C5b-9 concentrations in urine, using colorimetric or enzyme-linked immunosorbent assays. The ratio of albumin in cerebrospinal fluid to plasma (Qalb) was used as a surrogate for maternal blood-brain barrier integrity. Cerebrospinal fluid concentrations of C5a, C5b-9, tumor necrosis factor-α, and interleukin-6 were used as surrogate markers of neuroinflammation. Differences in Qalb and cerebrospinal fluid protein concentrations between groups were assessed by nonparametric test of medians.

RESULTS

Forty-eight subjects were enrolled, which included 16 cases with preeclampsia, 16 control subjects with healthy pregnancy, and 16 control subjects with either chronic or gestational hypertension. Qalb values were not increased in preeclampsia cases compared with healthy or hypertensive control subjects (Qalb median, 3.5 [interquartile range, 2.9-5.1] vs 3.9 [interquartile range, 3.0-4.8] vs 3.9 [interquartile range, 3.0-4.8]; P=.78]. Moreover, Qalb values were not increased in the subset of women with preeclampsia with severe features (n=8) compared with those without severe features (n=8; Qalb median, 3.5 [interquartile range, 3.3-4.9] vs 3.7 [interquartile range, 2.3-5.5]; P=.62]. Cerebrospinal fluid concentrations of C5a, C5b-9, tumor necrosis factor-α and interleukin-6 were not increased in cases of preeclampsia, compared with control subjects with either healthy pregnancy, chronic hypertension, or gestational hypertension (P>.05, all comparisons). In contrast to the negative findings in cerebrospinal fluid, plasma concentrations of both C5b-9 and interleukin-6 and urine concentrations of C5a and C5b-9 were increased in cases of preeclampsia.

CONCLUSION

Through measurements of albumin, complement proteins, and cytokines in paired samples of blood and cerebrospinal fluid at the time of delivery, we found no evidence of blood-brain barrier impairment or neuroinflammation in preeclampsia. Larger studies that will investigate a wider range of proteins are suggested to validate our findings.

Hypertension, Anxiety, and Blood-Brain Barrier Permeability Are Increased in Postpartum Severe Preeclampsia/Hemolysis, Elevated Liver Enzymes, and Low Platelet Count Syndrome Rats

Hypertension and inflammation during pregnancy are suggested to contribute to the development of postpartum depression and anxiety. Using a rat model of severe preeclampsia and hemolysis, elevated liver enzymes, and low platelet count syndrome, which displays both hypertension and inflammation during pregnancy, we evaluated whether rats were prone to develop depression or anxiety in the postpartum period. On gestational day 12, miniosmotic pumps infusing sFlt-1 (soluble fms-like tyrosine kinase-1) and sEng (soluble endoglin) were placed into rats, a subset of these rats was infused with 2 mg/kg of Orencia (abatacept) the following day to determine whether immune suppression via T-cell depletion prevented any changes in maternal depression or anxiety-like behavior. All rats, including normal pregnant (NP) controls, delivered between gestational days 21 and 22. Postpartum severe preeclamptic rats buried significantly more marbles compared with NP rats ( P=0.002) and Orencia-treated rats ( P=0.05). Severe preeclamptic rats spent significantly more time in closed arms of the elevated plus maze compared with NP rats ( P=0.009) and Orencia-treated rats ( P=0.05). Severe preeclamptic rats were hypertensive compared with NP ( P=0.03) and Orencia-treated rats ( P=0.01). Finally, severe preeclamptic rats had increased blood-brain barrier permeability compared with NP rats ( P=0.03), which was reversed in Orencia-treated rats ( P=0.008). These results suggest that severe preeclampsia/hemolysis, elevated liver enzymes, and low platelet count syndrome during pregnancy contributes to an increase in anxiety-like behavior, blood-brain barrier permeability, and hypertension in the postpartum. The current results suggest that T-cell suppression during pregnancy can also help prevent chronic hypertension and increased anxiety in the postpartum period.

Peripheral Anti-Angiogenic Imbalance during Pregnancy Impairs Myogenic Tone and Increases Cerebral Edema in a Rodent Model of HELLP Syndrome

Using an animal model of hemolysis elevated liver enzymes low platelets (HELLP) that has systemic inflammation and neuroinflammation we wanted to determine if blood brain barrier (BBB) permeability, cerebral edema, vascular tone, and occludin expression were altered in pregnant rats. Anti-angiogenic proteins sFlt-1 and sEng (4.7 and 7 µg/kg/day, respectively) were chronically infused into normal pregnant (NP) rats beginning on gestational day 12 via a mini-osmotic pump. On gestational day 19, blood pressure was measured via a carotid catheter and brains were collected. BBB permeability was assessed in select brain regions from rats infused with 0.5 mg/mL Texas Red Dextran and phenylephrine. Occludin, sFlt-1, and sEng were analyzed via western blot or ELISA. Infusion of sFlt-1 and sEng into NP rats increased hemolysis and liver enzymes, and decreased platelets and led to hypertension. HELLP rats had significant impairment in the myogenic response and increased BBB permeability in the posterior cortex and brainstem. Brain water content in the posterior cortex was increased and sEng protein expression in the brainstem was significantly increased in HELLP rats. The results from this study suggest that a peripheral anti-angiogenic imbalance during pregnancy is associated with decreased myogenic tone, vasogenic edema, and an increase in BBB permeability, but not anti-angiogenic imbalance in the brain.

Sex differences in stroke: Challenges and opportunities

Biologic sex influences many variables that are important to brain health in general, and to stroke or cerebral ischemia in particular, such as general health status, cerebrovascular anatomy and function, unique risk factors such as pregnancy and preeclampsia, symptomatology, and therapeutic response. A more complete understanding of the scale and depth of sexual dimorphism in the brain and the role of more general sex-based factors is crucial to reducing the burden of stroke in women and men. This focused review highlights recent findings in stroke, including sex differences in epidemiology, risk factor reduction, comparative use of stroke therapeutics in both sexes, the importance of frailty in women, and the biologic basis for sex differences in stroke. Such findings show tremendous promise for the future of personalized medicine in stroke prevention and treatment.

Inhibition of T-cell activation attenuates hypertension, TNFα, IL-17, and blood-brain barrier permeability in pregnant rats with angiogenic imbalance

PROBLEM

Angiogenic imbalance during pregnancy is associated with immune activation, hypertension, increased T cell infiltration, and neurological insults.

METHOD OF STUDY

On gestational day (GD) 12, timed-pregnant rats were infused with anti-angiogenic factors sFlt-1 and sEndoglin (4.7 and 7 μg/kg) to create HELLP syndrome via mini-osmotic pumps for 8 days, with a subset of these rats having Orencia (2 mg/kg) infused on GD13. On GD19, blood-brain barrier (BBB) permeability was evaluated via Evan's Blue infusion, blood was collected for T-cell measurements, inflammatory cytokine secretion. Brain tissues were also collected to examine inflammatory cytokine infiltration.

RESULTS

T-cell attenuation with Orencia decreased circulating CD4(+) and CD8(+) T cells, circulating tumor necrosis factor alpha (TNFα) and IL-17, BBB permeability and significantly decreased biochemical evidence of HELLP compared to untreated HELLP rats.

CONCLUSIONS

These data support the hypothesis that T cells have a critical role in contributing to the pathophysiology that is seen in angiogenic imbalance during pregnancy.

Severe systolic hypertension and the search for safer motherhood

Timely and appropriate response to severe hypertension during gestation is an important component of quality, safe care for pregnant or puerperal mothers regardless of causation. The reduction of severe maternal morbidity and maternal mortality in the hypertensive mother is clearly enhanced by the addition of standard protocols for provider response to severe hypertension, particularly severe systolic hypertension. The program developed in New York State via the Safe Motherhood Initiative promotes the implementation of unit-specific safety bundles, especially one that is focused upon a standardized approach to handling the obstetric emergency of severe hypertension usually associated with preeclampsia/eclampsia. The comprehensive preeclampsia/eclampsia safety bundle as summarized by Drs. Moroz and colleagues is reviewed especially from the perspective of its focus on the timely and specific responses for health care providers to make when severe hypertension is detected in the pregnant patient. Evidence-based guidance to practice considerations and clinical care of patients with preeclampsia/eclampsia is embedded within the program outlined for New York State by Moroz and her District II ACOG colleagues. There is a central focus on timely and appropriate antepartum/postpartum management of severe hypertension, a core concept to lessen maternal risk for cerebral hemorrhage. Ten considerations for further integration into the New York program are suggested. Beyond blood pressure control, there is a need for systematic review of interventions and outcomes over time, attention to possible future variations of the protocol for racial/ethnic patient groups at highest risk for maternal morbidity and mortality, and the identification of biomarker(s) that further specify and quantify risk to the maternal brain and other organ systems when severe hypertension develops. Safer motherhood will happen when evidence for best practice is integrated into systems of care for all patients.

Mechanisms and outcomes of stroke during pregnancy and the postpartum period: A cross-sectional study

BACKGROUND

Pregnancy-associated stroke remains incompletely characterized because of the rarity of these potentially devastating events. We investigated whether mechanism and outcome of ischemic pathophysiology stroke differ between young pregnant and nonpregnant women.

METHODS

We identified 135 consecutive women ages 18-40 years admitted to our center from January 2008 through June 2014 with ischemic stroke, TIA, cerebral venous thrombosis, or nonaneurysmal subarachnoid hemorrhage due to reversible cerebral vasoconstriction syndrome (RCVS). We reviewed charts for pregnancy status, demographics, medical comorbidities, stroke severity, etiology, and discharge outcomes.

RESULTS

There were 33 women with pregnancy-associated stroke (PAS) and 102 with non-pregnancy-associated stroke (NPAS). Among women with PAS, 73% of strokes occurred postpartum. In the PAS group, the most common cause of cerebrovascular events was RCVS (n = 12), 11 postpartum and 4 in women with preeclampsia. There were no significant differences between the groups in demographics. Women with PAS were less likely to have vascular risk factors such as hyperlipidemia and history of thromboembolism but more likely to have cerebral venous thromboses (21% vs 7%, p = 0.02). Women with PAS were more likely to have RCVS as stroke mechanism (36% vs 1%, odds ratio 57.7, 95% confidence interval 7-468, p = 0.0001).

CONCLUSION

Compared with nonpregnant women of the same age group, women with PAS had fewer vascular risk factors. Cerebral venous thrombosis and RCVS were more common in PAS, most of which occurred postpartum. These results provide further evidence for the unique pathophysiology of pregnancy-related stroke, raising important questions for future investigation.