A cohort study on the associations between age at natural menopause and rheumatoid arthritis in postmenopausal women from the Canadian Longitudinal Study on Aging

Menopause represents a significant phase in a woman's life, marked by profound physiological changes. An early onset of menopause has been associated with a variety of negative outcomes. Estrogen has been shown to be protective of bone and joint health. Hormonal links to rheumatoid arthritis have been found; previous studies exploring age at natural menopause (ANM) and Rheumatoid arthritis have produced conflicting results. This study investigated the association between ANM and incidence of rheumatoid arthritis among postmenopausal Canadian women. The study included women between the ages of 45-85 years from the Canadian Longitudinal Study on Aging followed over a 10-year period. Analysis was restricted to naturally postmenopausal women that did not have rheumatoid arthritis prior to menopause. ANM was examined using the following categories ≤ 44 (reference), 45-49, and ≥50. Survival analysis was used to determine time to onset of rheumatoid arthritis. Unadjusted and adjusted multivariable Cox regression models were used to examine the relationship between ANM and incidence of rheumatoid arthritis. The adjusted multivariable Cox regression model showed significantly lower risk of rheumatoid arthritis in women with an older ANM of ≥50 years and who have been on hormone replacement therapy for ≥8 years with a hazard ratio of 0.2 (95 % CI: 0.1-0.7) compared to women with an ANM ≤ 44 who have never used hormone replacement therapy. Our findings suggest a potential beneficial effect of longer estrogen exposure on the risk of developing rheumatoid arthritis.

Expression and T cell regulatory action of the PD-1 immune checkpoint in the ovary and fallopian tube

PROBLEM

Immune cell trafficking and surveillance within the ovary and fallopian tube are thought to impact fertility and also tumorigenesis in those organs. However, little is known of how native cells of the ovary and fallopian tube interact with resident immune cells. Interaction of the Programmed Cell Death Protein-1 (PD-1/PDCD-1/CD279) checkpoint with PD-L1 is associated with downregulated immune response. We have begun to address the question of whether PD-1 ligand or its receptors (PD-L1/-L2) can regulate immune cell function in these tissues of the female reproductive tract.

METHOD OF STUDY

PD-1 and ligand protein expression was evaluated in human ovary and fallopian tube specimens, the latter of which included stages of tubal cell transformation and early tumorigenesis. Ovarian expression analysis included the determination of the proteins in human follicular fluid (HFF) specimens collected during in vitro fertilization procedures. Finally, checkpoint bioactivity of HFF was determined by treatment of separately-isolated human T cells and the measurement of interferon gamma (IFNγ).

RESULTS

We show that membrane bound and soluble variants of PD-1 and ligands are expressed by permanent constituent cell types of the human ovary and fallopian tube, including granulosa cells and oocytes. PD-1 and soluble ligands were present in HFF at bioactive levels that control T cell PD-1 activation and IFNγ production; full-length checkpoint proteins were found to be highly enriched in HFF exosome fractions.

CONCLUSION

The detection of PD-1 checkpoint proteins in the human ovary and fallopian tube suggests that the pathway is involved in immunomodulation during folliculogenesis, the window of ovulation, and subsequent egg and embryo immune-privilege. Immunomodulatory action of receptor and ligands in HFF exosomes is suggestive of an acute checkpoint role during ovulation. This is the first study in the role of PD-1 checkpoint proteins in human tubo-ovarian specimens and the first examination of its potential regulatory action in the contexts of normal and assisted reproduction.

Menopausal hormone therapy in women with medical conditions

Hormone therapy is the most effective treatment for menopause-related symptoms. Current evidence supports its use in young healthy postmenopausal women under the age of 60 years, and within 10 years of menopause, with benefits typically outweighing risks. However, decision making is more complex in the more common clinical scenario of a symptomatic woman with one or more chronic medical conditions that potentially alter the risk-benefit balance of hormone therapy use. In this review, we present the evidence relating to the use of hormone therapy in women with chronic medical conditions such as obesity, hypertension, dyslipidemia, diabetes, venous thromboembolism, and autoimmune diseases. We discuss the differences between oral and transdermal routes of administration of estrogen and the situations when one route might be preferred over another. We also review evidence regarding the effect of different progestogens, when available.

Epigenetics of the developing and aging brain: Mechanisms that regulate onset and outcomes of brain reorganization

Brain development is a life-long process that encompasses several critical periods of transition, during which significant cognitive changes occur. Embryonic development, puberty, and reproductive senescence are all periods of transition that are hypersensitive to environmental factors. Rather than isolated episodes, each transition builds upon the last and is influenced by consequential changes that occur in the transition before it. Epigenetic marks, such as DNA methylation and histone modifications, provide mechanisms by which early events can influence development, cognition, and health outcomes. For example, parental environment influences imprinting patterns in gamete cells, which ultimately impacts gene expression in the embryo which may result in hypersensitivity to poor maternal nutrition during pregnancy, raising the risks for cognitive impairment later in life. This review explores how epigenetics induce and regulate critical periods, and also discusses how early environmental interactions prime a system towards a particular health outcome and influence susceptibility to disease or cognitive impairment throughout life.

Do Menopause and Aging Affect the Onset and Progression of Rheumatoid Arthritis and Systemic Lupus Erythematosus?

Rheumatoid arthritis and systemic lupus erythematosus (SLE) are autoimmune diseases that are commonly seen in the female population. Rheumatoid arthritis mainly consists of distal symmetrical deforming polyarthritis. SLE patients have immune complexes that damage the organs and systems of the body, and this can present with one or more symptoms including the characteristic malar rash, serositis, lupus nephritis, photosensitivity, and arthritis of large joints. The onset and progression of the diseases are affected by physiological processes that occur in the body such as menopause and aging. The studies used as evidence were found in the PubMed, ScienceDirect, ProQuest, Taylor & Francis Online, Wiley Online Library, Ovid, and Oxford Academic databases. By analyzing these studies, the effects of aging and menopause on rheumatoid arthritis and SLE were revealed. In relation to menopause and aging, it was found that there was a progression of disease in women who had rheumatoid arthritis. However, aging and menopause caused the progression of SLE to decrease in women. An earlier age of onset of menopause was correlated with an increased chance of developing rheumatoid arthritis and SLE. Furthermore, while some studies showed that a later onset of SLE caused an increase in the progression of the disease, other studies showed that a later onset of SLE led to a decrease in the progression of the disease. Due to the prevalence of rheumatoid arthritis and SLE in females, we believe that the effects of menopause, age, and other factors on these two diseases should be examined in future studies.

Sex differences in stroke across the lifespan: The role of T lymphocytes

Stroke is a sexually dimorphic disease. Ischemic sensitivity changes throughout the lifespan and outcomes depend largely on variables like age, sex, hormonal status, inflammation, and other existing risk factors. Immune responses after stroke play a central role in how these factors interact. Although the post-stroke immune response has been extensively studied, the contribution of lymphocytes to stroke is still not well understood. T cells participate in both innate and adaptive immune responses at both acute and chronic stages of stroke. T cell responses also change at different ages and are modulated by hormones and sex chromosome complement. T cells have also been implicated in the development of hypertension, one of the most important risk factors for vascular disease. In this review, we highlight recent literature on the lymphocytic responses to stroke in the context of age and sex, with a focus on T cell response and the interaction with important stroke risk factors.