Longitudinal assessment of inflammatory markers in the peripartum period by depressive symptom trajectory groups

Conventional and new immunotherapies for immune system dysregulation in postpartum mood disorders: comparisons to immune system dysregulations in bipolar disorder, major depression, and postpartum autoimmune thyroid disease

INTRODUCTION

Postpartum mood disorders are heterogenous disorders and comprise postpartum psychosis and postpartum depression. Evidence is accumulating that systemic monocyte/macrophage activation, low-grade inflammation and (premature senescence related) T cell defects increase the risk for mood disorders outside pregnancy by affecting the function of microglia and T cells in the emotional brain (the cortico-limbic system) leading to inadequate mood regulation upon stress.

AREAS COVERED

The evidence in the literature that similar immune dysregulations are present in postpartum mood disorders.

RESULTS

The physiological postpartum period is characterized by a rapid T cell surge and a mild activation of the monocyte/macrophage system. Postpartum mood disorder patients show a diminished T cell surge (including that of T regulatory cells) and an increase in low grade inflammation, that is, an increased inflammatory state of monocytes/macrophages and higher levels of serum pro-inflammatory cytokines.

EXPERT OPINION

Anti-inflammatory agents (e.g. COX-2 inhibitors) and T cell boosting agents (e.g. low-dose IL-2 therapy) should be further investigated as treatment. The hypothesis should be investigated that postpartum mood disorders are active episodes (triggered by changes in the postpartum immuno-endocrine milieu) in ongoing, dynamically fluctuating aberrant neuro-immune-endocrine trajectories leading to mood disorders in women (inheritably) vulnerable to these disorders.

Inflammatory biomarkers and perinatal depression: A systematic review

BACKGROUND

Approximately 10 to 20% of pregnant women worldwide experience perinatal depression (PND), a depressive episode with onset during pregnancy or after childbirth. We performed a systematic review to identify, summarize and discuss studies on inflammatory biomarkers described in relation to PND.

METHOD

Inclusion criteria defined the selection of observational studies written in English, French, Spanish or Portuguese, that evaluate analytical levels of inflammatory molecules (protein levels) in biological fluids in women, with a diagnosis of depression using ICD/DSM diagnostic criteria or depressive symptoms assessed by standardized psychometric instruments, during pregnancy and/or postpartum. Case reports, experimental studies, reviews, qualitative analysis, meta-analysis, gray literature or replicated data were excluded. Three electronic databases were used for search (Pubmed, Web of Science and PsychInfo) and quality assessment of selected studies were performed using the Newcastle-Ottawa Scale. Data extraction included study design; number of subjects; obstetric information; tools and timepoints of depression and inflammatory markers assessment.

RESULTS

56 studies (sample size for cross-sectional and case-control studies ranging from 10 to 469; sample size for longitudinal studies ranging from 26 to 467), where the major aim was to analyze the association between depression and inflammatory biomarkers during pregnancy and postpartum period were included in this systematic review. Overall, the findings of our systematic review lend support to the hypothesis that several inflammatory markers may be associated with peripartum depressive symptoms. The associations were somewhat different looking at pregnancy compared to the delivery time-point and postpartum, and mainly referred to increased levels of IL-6, IL-8, CRP and TNF-α among depressed.

DISCUSSION

In summary, our systematic review findings provide evidence supporting the hypothesis that several inflammatory markers may correlate with peripartum depressive symptoms. However, our work also highlighted notable differences in the timing of biological sampling for inflammatory markers and in the methodologies used to assess depression during the perinatal period. Additionally, variations were observed in how inflammatory biomarkers and depression were approached, including their classification as exposure or outcome variables, and the timing of assessments. It is essential for future research to investigate the influence of biological fluids and the timing of assessments for both inflammatory biomarkers and depression to gain a deeper understanding of their association. This comprehensive exploration is pivotal for elucidating the intricate relationship between inflammation and perinatal depression.

Exploring the Association between Anxiety, Depression, and Gut Microbiota during Pregnancy: Findings from a Pregnancy Cohort Study in Shijiazhuang, Hebei Province, China

Negative emotions and gut microbiota during pregnancy both bear significant public health implications. However, the relationship between them has not been fully elucidated. This study, utilizing data from a pregnancy cohort, employed metagenomic sequencing to elucidate the relationship between anxiety, depression, and gut microbiota's diversity, composition, species, and functional pathways. Data from 87 subjects, spanning 225 time points across early, mid, and late pregnancy, were analyzed. The results revealed that anxiety and depression significantly corresponded to lower alpha diversity (including the Shannon entropy and the Simpson index). Anxiety and depression scores, along with categorical distinctions of anxiety/non-anxiety and depression/non-depression, were found to account for 0.723%, 0.731%, 0.651%, and 0.810% of the variance in gut-microbiota composition (p = 0.001), respectively. Increased anxiety was significantly positively associated with the abundance of Oscillibacter sp. KLE 1745, Oscillibacter sp. PEA192, Oscillibacter sp. KLE 1728, Oscillospiraceae bacterium VE202 24, and Treponema socranskii. A similar association was significantly noted for Oscillibacter sp. KLE 1745 with elevated depression scores. While EC.3.5.3.1: arginase appeared to be higher in the anxious group than in the non-anxious group, vitamin B12-related enzymes appeared to be lower in the depression group than in the non-depression group. The changes were found to be not statistically significant after post-multiple comparison adjustment.

Is There an Inflammatory Profile of Perinatal Depression?

PURPOSE OF REVIEW

To synthesize and critically examine recent evidence regarding associations between immune system activity and perinatal depression.

RECENT FINDINGS

Despite a significant number of studies assessing potential immunological markers of perinatal depression, it does not appear that levels of any individual pro- or anti-inflammatory marker is a useful predictor of perinatal depression. Some recent studies have observed differences in overall immune system functioning and adaptation across this period, taking into account multiple pro- and anti- inflammatory markers. Furthermore, there is evidence for interactions between depression and maternal psychosocial factors. Immune system functioning may be a mechanism through which social determinants of health contribute to risk for perinatal depression. There is substantial evidence implicating dysregulated immune activity in perinatal depression, yet little clarity regarding a consistent immune profile, especially based on analysis of circulating peripheral cytokines.

The immune phenotype of perinatal anxiety

BACKGROUND

Immune dysregulation has been linked to both psychiatric illness and pregnancy morbidity, including perinatal depression, but little is known about the immune phenotype of perinatal anxiety. Here, we sought to identify the unique immune profile of antenatal anxiety.

MATERIALS AND METHODS

Pregnant women (n = 107) were followed prospectively at 2nd and 3rd trimesters (T2, T3) and 6 weeks postpartum (PP6). Each visit included a blood draw and psychological evaluation, with clinical anxiety assessed using the Spielberg State-Trait Anxiety Scale. We enrolled both healthy controls and participants with anxiety alone; those with comorbid depression were excluded. Multiplex cytokine assays and flow cytometry were used to examine the association of anxiety symptoms with secreted immune markers and PBMC-derived immune cells.

RESULTS

K cluster means revealed three clusters of anxiety symptomatology; due to low numbers in the highest severity anxiety group, these were collapsed into two groups: Non-Anxiety and Anxiety. Principal components analysis revealed two distinct clusters of cytokine secretion including one cluster that consisted of many innate immune cytokines and differed between groups. Compared to women in the Non-Anxiety group, women in the Anxiety group had lower levels of cytokine expression during pregnancy and an increase in levels into the postpartum, whereas Non-Anxiety women experienced a time-dependent decline. Immune cell populations also differed between our two groups, with the Anxiety group showing a decrease in the ratio of B cells to T cells from pregnancy to postpartum, whereas the Non-Anxiety women showed an increase in this ratio over time. Women in the Anxiety group also demonstrated an increased ratio of cytotoxic to helper T cells throughout pregnancy, a modest increase in the Th1:Th2 ratio across pregnancy, and a lower ratio of Th17:T_REG cells in the postpartum as compared with Non-Anxiety women.

CONCLUSION

These data suggest that the immune response throughout the antenatal period differs for women with anxiety symptoms compared to those without, suggestive of a unique immune phenotype of perinatal anxiety.