Pregnancy-Related Immune Changes and Demyelinating Diseases of the Central Nervous System

Abstract

Demyelinating diseases of the central nervous system comprise a heterogeneous group of autoimmune disorders characterized by myelin loss with relative sparing of axons occurring on a background of inflammation. Some of the most common demyelinating diseases are multiple sclerosis, acute disseminated encephalomyelitis, and neuromyelitis optica spectrum disorders. Besides showing clinical, radiological, and histopathological features that complicate their diagnosis, demyelinating diseases often involve different immunological processes that produce distinct inflammatory patterns. Evidence of demyelination diseases derives mostly from animal studies of experimental autoimmune encephalomyelitis (EAE), a model that relies on direct antibody–antigen interactions induced by encephalitogenic T cells. Pregnancy is characterized by non-self-recognition, immunomodulatory changes and an altered Th1/Th2 balance, generally considered a Th2-type immunological state that protects the mother from infections. During pregnancy, the immune response of patients with autoimmune disease complicated with pregnancy is different. Immune tolerance in pregnancy may affect the course of some diseases, which may reach remission or be exacerbated. In this review, we summarize current knowledge on the immune status during pregnancy and discuss the relationship between pregnancy-related immune changes and demyelinating diseases of the central nervous system.

Maternal Immunological Adaptation During Normal Pregnancy

“…While fetal and maternal obstetric outcomes are often adversely affected by autoimmune diseases, the disease severity or risk of relapse is often reduced during pregnancy. This is especially true for Th1 mediated autoimmune diseases such as rheumatoid arthritis (RA) and multiple sclerosis (MS) whereas Th2 mediated diseases such neuromyelitis optica spectrum disorders worsens during pregnancy [reviewed in ( 265 )]. This dichotomy is attributed to the shift towards Th2 based immunity during pregnancy.…”

Immune cell type and DNA methylation vary with reproductive status in women: possible pathways for costs of reproduction

“…Locally, decidual monocytes establish immune balance between the uterus and placenta, regulating invasion of the extravillous trophoblast and remodeling of the uterine smooth muscle, glands and spiral arteries [ 48 ]. Elevated monocyte counts resulting from pregnancy have been proposed to explain the higher risk of demyelinating diseases, such as multiple sclerosis among childbearing women [ 49 ]. However, most inflammatory and autoimmune diseases that are exacerbated with parity are associated with elevated monocyte counts, and not the depressed levels we observed among breastfeeding and parous women, making the biological connection between lower monocyte counts and CoR unclear.…”

Immune System Alterations and Postpartum Mental Illness: Evidence From Basic and Clinical Research

“…Not surprisingly, immune shifts across the peripartum period also have implications for autoimmune conditions (40). For example, in multiple sclerosis (MS), the increased T reg population is thought to underlie symptom amelioration during pregnancy, while the shift from immunosuppression to inflammation around parturition may trigger aggravation of MS symptoms (58)(59)(60)(61). Rheumatoid arthritis is another pro-inflammatory and T regmediated autoimmune disease characterized both by remission of symptoms during late pregnancy and a significant worsening of symptoms after birth (62,63).…”