Oxytocin: an unexpected risk for cardiologic and broncho-obstructive effects, and allergic reactions in susceptible delivering women

Addressing sex and gender to improve asthma management

Sex (whether one is 'male' or 'female', based on biological characteristics) and gender (defined by socially constructed roles and behaviors) influence asthma diagnosis and management. For example, women generally report more severe asthma symptoms than men; men and women are exposed to different asthma-causing triggers; men tend to be more physically active than women. Furthermore, implicit, often unintended gender bias by healthcare professionals (HCPs) is widespread, and may result in delayed asthma diagnosis, which can be greater in women than men. The sex and gender of the HCP can also impact asthma management. Pregnancy, menstruation, and menopause can all affect asthma in several ways and may be associated with poor asthma control. This review provides guidance for considering sex- and gender-associated impacts on asthma diagnosis and management and offers possible approaches to support HCPs in providing personalized asthma care for all patients, regardless of their sex or gender.

State-of-the-Art on Biomarkers for Anaphylaxis in Obstetrics

Anaphylaxis is an unpredictable systemic hypersensitivity reaction and constitutes a high risk of maternal and fetal morbidity and mortality when occurring during pregnancy. Currently, the acute management of anaphylaxis is based on clinical parameters. A total serum tryptase is only used to support an accurate diagnosis. There is a need to detect other biomarkers to further assess high-risk patients in obstetrics. Our objective is to present biomarkers in this complex interdisciplinary approach beyond obstetrician and anaesthetic management. Candidate biomarkers derive either from mediators involved in immunopathogenesis or upcoming molecules from systems biology and proteomics. Serum tryptase is determined by singleplex immunoassay method and is important in the evaluation of anaphylactic mast cell degranulation but also in the assessment of other risk factors for anaphylaxis such as systemic mastocytosis. Another category of biomarkers investigates the IgE-mediated sensitization to triggers potentially involved in the etiology of anaphylaxis in pregnant women, using singleplex or multiplex immunoassays. These in vitro tests with natural extracts from foods, venoms, latex or drugs, as well as with molecular allergen components, are useful because in vivo allergy tests cannot be performed on pregnant women in such a major medical emergency due to their additional potential risk of anaphylaxis.

Therapeutic Potential of Oxytocin in Atherosclerotic Cardiovascular Disease: Mechanisms and Signaling Pathways

Coronary artery disease (CAD) is a major cardiovascular disease responsible for high morbidity and mortality worldwide. The major pathophysiological basis of CAD is atherosclerosis in association with varieties of immunometabolic disorders that can suppress oxytocin (OT) receptor (OTR) signaling in the cardiovascular system (CVS). By contrast, OT not only maintains cardiovascular integrity but also has the potential to suppress and even reverse atherosclerotic alterations and CAD. These protective effects of OT are associated with its protection of the heart and blood vessels from immunometabolic injuries and the resultant inflammation and apoptosis through both peripheral and central approaches. As a result, OT can decelerate the progression of atherosclerosis and facilitate the recovery of CVS from these injuries. At the cellular level, the protective effect of OT on CVS involves a broad array of OTR signaling events. These signals mainly belong to the reperfusion injury salvage kinase pathway that is composed of phosphatidylinositol 3-kinase-Akt-endothelial nitric oxide synthase cascades and extracellular signal-regulated protein kinase 1/2. Additionally, AMP-activated protein kinase, Ca²⁺/calmodulin-dependent protein kinase signaling and many others are also implicated in OTR signaling in the CVS protection. These signaling events interact coordinately at many levels to suppress the production of inflammatory cytokines and the activation of apoptotic pathways. A particular target of these signaling events is endoplasmic reticulum (ER) stress and mitochondrial oxidative stress that interact through mitochondria-associated ER membrane. In contrast to these protective effects and machineries, rare but serious cardiovascular disturbances were also reported in labor induction and animal studies including hypotension, reflexive tachycardia, coronary spasm or thrombosis and allergy. Here, we review our current understanding of the protective effect of OT against varieties of atherosclerotic etiologies as well as the approaches and underlying mechanisms of these effects. Moreover, potential cardiovascular disturbances following OT application are also discussed to avoid unwanted effects in clinical trials of OT usages.

Approaches Mediating Oxytocin Regulation of the Immune System

The hypothalamic neuroendocrine system is mainly composed of the neural structures regulating hormone secretion from the pituitary gland and has been considered as the higher regulatory center of the immune system. Recently, the hypothalamo-neurohypophysial system (HNS) emerged as an important component of neuroendocrine–immune network, wherein the oxytocin (OT)-secreting system (OSS) plays an essential role. The OSS, consisting of OT neurons in the supraoptic nucleus, paraventricular nucleus, their several accessory nuclei and associated structures, can integrate neural, endocrine, metabolic, and immune information and plays a pivotal role in the development and functions of the immune system. The OSS can promote the development of thymus and bone marrow, perform immune surveillance, strengthen immune defense, and maintain immune homeostasis. Correspondingly, OT can inhibit inflammation, exert antibiotic-like effect, promote wound healing and regeneration, and suppress stress-associated immune disorders. In this process, the OSS can release OT to act on immune system directly by activating OT receptors or through modulating activities of other hypothalamic–pituitary–immune axes and autonomic nervous system indirectly. However, our understandings of the role of the OSS in neuroendocrine regulation of immune system are largely incomplete, particularly its relationship with other hypothalamic–pituitary–immune axes and the vasopressin-secreting system that coexists with the OSS in the HNS. In addition, it remains unclear about the relationship between the OSS and peripherally produced OT in immune regulation, particularly intrathymic OT that is known to elicit central immunological self-tolerance of T-cells to hypophysial hormones. In this work, we provide a brief review of current knowledge of the features of OSS regulation of the immune system and of potential approaches that mediate OSS coordination of the activities of entire neuroendocrine–immune network.

Oxytocin use during Caesarean sections in Denmark - are we getting the dose right?

BACKGROUND

In Denmark, an iv bolus of 10 IU oxytocin was traditionally given after delivery to prevent atony during caesarean sections. Randomized controlled trials have shown that lower iv bolus doses have same efficacy with fewer side effects and many countries now recommend a 5 IU maximum dose. The aims of this study were to investigate whether patients referred for allergy testing after oxytocin exposure had dose-related side effects to oxytocin rather than true allergic reactions and to investigate whether updated international recommendations on lower bolus doses had been implemented in practice.

METHODS

Medical notes of patients tested with oxytocin as part of investigations in the Danish Anaesthesia Allergy Centre from May 2004 to January 2014 were reviewed retrospectively. A telephone survey of on-duty obstetricians at all Danish obstetric departments was performed and most recent online recommendations from the Danish societies of obstetrics and anaesthesia about the use of oxytocin were identified.

RESULTS

In total 30 women were tested with oxytocin as part of investigations. None were allergic to oxytocin but 19 had symptoms consistent with dose-related side effects on iv provocation. The telephone survey revealed that iv doses of 10 IU oxytocin were still used and recommendations on the websites were not updated.

CONCLUSION

Too high oxytocin doses are still used in Denmark leading to dose-related side effects mimicking allergic reactions. Coordination between obstetricians and anaesthesiologists on producing common updated guidelines on the administration of oxytocin and dissemination of this information to obstetric and anaesthetic departments in Denmark is needed.