[French Expert advice on the management of valproate in childbearing and pregnant women with bipolar disorder]. / Avis d'experts français sur la prise en charge des femmes en âge de procréer et enceintes souffrant d'un trouble bipolaire traitées par valproate.

INTRODUCTION: The perinatal period is associated with high risk of relapses in women with untreated bipolar disorder (BD) and can have significant consequences on foetal and child development. Valproate is an effective mood stabilizer in BD but it is also the anticonvulsant associated to the highest risks of neurodevelopmental disorders and congenital malformations. The National Agency for the Safety of Medicines and Health Products (ANSM) changed the conditions of use and prescription of valproate in France in 2015. Its prescription is now contraindicated (i.e., not to be prescribed) in women able to have children unless alternative treatments are ineffective or not tolerated. Moreover, valproate could only be prescribed if the protocol of a specific pregnancy prevention program is followed. METHODS: A panel of experts from the French Association for Biological Psychiatry and Neuropsychopharmacology (AFPBN) provided consensus-based recommendations for switching and discontinuation of valproate in women with BD. The development of these recommendations consisted of an adaptation to French clinical practice based on a European expert opinion published in 2019. The experts discussed five real-world clinical situations in light of the scientific evidence and their clinical experience (a. Stable BD patient with valproate monotherapy who is planning pregnancy, b. Stable BD patient with valproate polytherapy who is planning pregnancy, c. Unstable BD patient with frequent relapses and valproate polytherapy who is planning pregnancy, d. Stable BD patient treated with valproate and unexpected pregnancy, e. Unstable BD patient treated with valproate and unexpected pregnancy) and developed, through several rounds of exchange drafts, a French version of clinical recommendations. RESULTS: First of all, some factors need to be considered for establishing personalized practical recommendations for a safe and effective switching or discontinuation of valproate in any clinical situations: planned pregnancy or unplanned pregnancy or current pregnancy, the existence or not of a pregnancy risk minimization program and a complete treatment history. Other factors that should be considered are the predominant polarity, the severity, the stability, the comorbidities associated with BD, the beliefs toward treatments, the family situation and the preference of the patient. The modalities for switching or discontinuation of valproate in women with BD were related to the clinical situation. First-line therapeutic alternatives such as lithium, lamotrigine, quetiapine, olanzapine or aripiprazole were preferred for patients suffering from a clinically stable BD considering pregnancy or pregnant. In patients suffering from clinically unstable BD, to reach stability was considered first. A shared decision-making should be systematically implemented and the patient must be fully informed of the risks related to an in-utero exposure to valproate, and the risks of the discontinuation/switch that is considered. CONCLUSION: Although the adaptation to French practice of the recommendations from the European expert opinion highlighted some differences in the criteria taken into consideration to guide the therapeutic decision, this expert advice will guide the clinician for switching and discontinuation of valproate in BD women able to have children or pregnant.

Toll-like receptor 5 knock-out mice exhibit a specific low level of anxiety.

While toll-like receptors (TLRs), which mediate innate immunity, are known to play an important role in host defense, recent work suggest their involvement in some integrated behaviors, including anxiety, depressive and cognitive functions. Here, we investigated the potential involvement of the flagellin receptor, TLR5, in anxiety, depression and cognitive behaviors using male TLR5 knock-out (KO) mice. We aobserved a specific low level of basal anxiety in TLR5 KO mice with an alteration of the hypothalamo-pituitary axis (HPA) response to acute restraint stress, illustrated by a decrease of both plasma corticosterone level and c-fos expression in the hypothalamic paraventricular nucleus where TLR5 was expressed, compared to WT littermates. However, depression and cognitive-related behaviors were not different between TLR5 KO and WT mice. Nor there were significant changes in the expression of some cytokines (IL-6, IL-10 and TNF-α) and other TLRs (TLR2, TLR3 and TLR4) in the prefrontal cortex, amygdala and hippocampus of TLR5 KO mice compared to WT mice. Moreover, mRNA expression of BDNF and glucocorticoid receptors in the hippocampus and amygdala, respectively, was not different. Finally, acute intracerebroventricular administration of flagellin, a specific TLR5 agonist, or chronic neomycin treatment did not exhibit a significant main effect, only a significant main effect of genotype was observed between TLR5 KO and WT mice. Together, those findings suggest a previously undescribed and specific role of TLR5 in anxiety and open original prospects in our understanding of the brain-gut axis function.

Colonic overexpression of the T-type calcium channel Cav 3.2 in a mouse model of visceral hypersensitivity and in irritable bowel syndrome patients.

BACKGROUND: Among the different mechanisms involved in irritable bowel syndrome (IBS) physiopathology, visceral hypersensitivity seems to play a key role. It involves sensitization of the colonic primary afferent fibers, especially through an overexpression of ion channels. The aims of this translational study were to investigate the colonic expression of Cav 3.2 calcium channels and their involvement in an animal model of colonic hypersensitivity, and to assess their expression in the colonic mucosa of symptomatic IBS patients. METHODS: This bench-to-bed study combined a preclinical experimental study on mice and a case-control clinical study. Preclinical studies were performed on wild-type and Cav 3.2-KO mice. Colonic sensitivity and Cav 3.2 expression were studied after a low-dose treatment of dextran sodium sulfate (DSS 0.5%). Regarding the clinical study, colonic biopsies were performed in 14 IBS patients and 16 controls during a colonoscopy to analyze the mucosal Cav 3.2 expression. KEY RESULTS: Wild-type, but not Cav 3.2-KO, mice developed visceral hypersensitivity without colonic inflammation, after 0.5% DSS treatment. A significant increase of Cav 3.2 mRNA (p = 0.04) was found in the colon of low-dose DSS-treated wild-type (WT) mice compared to their controls. In human colonic biopsies, the Cav 3.2 mRNA level was significantly higher in the IBS group compared to the control group (p = 0.01). The immunofluorescence staining revealed their protein expression in colonic mucosa, particularly in nerve fibers. CONCLUSIONS & INFERENCES: This translational study supports the involvement of the calcium channels Cav 3.2 in abdominal pain, as observed in IBS patients. It opens new therapeutic perspectives based on molecules specifically blocking these channels.