The Link Between Reduced Oestrogen Secretion in Middle Age and the Development of Sarcoidosis

Summary

Sarcoidosis is a chronic inflammatory disease of unknown origin that occurs more often in women in middle age. A decrease in oestrogen levels during perimenopause and menopause may play a key role in modulating the immune response, contributing to increased inflammatory activity and the possible development of sarcoidosis. Oestrogen has anti-inflammatory properties and regulates the balance between the Th1 and Th2 immune responses, which is essential for controlling chronic inflammatory diseases. This article explores the possible connection between reduced oestrogen secretion and the development of sarcoidosis, focusing on immune and hormonal mechanisms.

1. Introduction

Sarcoidosis is a multisystem granulomatous disease that most often occurs in people aged 30 to 50, with a higher incidence among women after the age of 40. This is also the period when oestrogen levels in women begin to fall because of perimenopausal and menopausal changes.

Oestrogen plays a key role in:

• regulating the immune response;
• reducing levels of pro-inflammatory cytokines;
• modulating the function of macrophages and T lymphocytes.

Because sarcoidosis is characterised by chronic inflammation and a granulomatous reaction, the question arises whether a fall in oestrogen levels can contribute to the development or progression of the disease.

2. The Role of Oestrogen in the Immune System

2.1. Oestrogen and Immune Balance

Oestrogen is a powerful immunomodulator. It acts through oestrogen receptors (ERα and ERβ) present on immune cells, including macrophages, dendritic cells and lymphocytes.

Its key effects include:

• reducing levels of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β), which are important for granuloma formation in sarcoidosis;
• promoting a Th2 response and reducing excessive activity of Th1 cells, which are dominant in the pathogenesis of sarcoidosis;
• regulating macrophages, thereby preventing excessive activation and accumulation in tissues.

2.2. Hormonal Changes in Middle Age

During perimenopause and menopause, oestrogen levels gradually decline. This may lead to:

• increased systemic inflammation, raising the risk of chronic inflammatory diseases;
• impaired macrophage function, which can result in uncontrolled inflammation and granuloma formation;
• reduced immune tolerance, increasing the risk of autoimmune and inflammatory diseases.

These factors suggest a possible connection between reduced oestrogen secretion and the development of sarcoidosis in middle age.

3. Oestrogen and the Pathogenesis of Sarcoidosis

3.1. Oestrogen and the Th1/Th2 Balance

Sarcoidosis is characterised by a dominant Th1 immune response, with excessive production of IFN-γ and IL-12. This promotes macrophage activation and granuloma formation.

In premenopausal women, oestrogen helps maintain the balance between Th1 and Th2 responses. However, as oestrogen levels fall:

• Th1 activity increases, which may contribute to the development of sarcoidosis;
• levels of IL-10, an important anti-inflammatory cytokine that regulates macrophages, decrease;
• expression of TNF-α increases, and this is associated with active disease and granuloma progression.

This dysregulation may contribute to disease initiation in women in middle age.

3.2. Oestrogen and Macrophage Function

Macrophages are key cells in the pathogenesis of sarcoidosis because they are responsible for granuloma formation. Oestrogen affects macrophage function in several ways:

• it reduces excessive macrophage activation, preventing uncontrolled inflammation;
• it promotes phagocytosis, helping remove potential triggers of a granulomatous reaction;
• it inhibits the production of nitric oxide (NO), which is important for macrophage activation in inflammatory diseases.

As oestrogen levels fall, macrophages can become hyperactive, which may increase susceptibility to granulomatous diseases such as sarcoidosis.

4. Epidemiological Evidence and Clinical Implications

4.1. Epidemiological Association

Several studies suggest a possible association between hormonal changes and sarcoidosis:

• studies have shown that sarcoidosis is diagnosed more often in women between 40 and 60, when oestrogen levels are declining;
• research into autoimmune diseases such as rheumatoid arthritis and lupus indicates that hormonal changes during menopause may increase the risk of inflammatory disease;
• pregnancy and oral contraceptives, which increase oestrogen levels, may have a protective effect against the development of autoimmune diseases, further suggesting that oestrogen has an anti-inflammatory role.

4.2. Hormone Therapy as Potential Protection

The question is whether hormone replacement therapy (HRT) could reduce the risk of developing sarcoidosis in menopausal women. Although there is no direct evidence, it is known that:

• HRT can reduce inflammatory markers such as CRP and IL-6;
• oestrogen therapy can modulate the immune response and reduce excessive macrophage activation.

Further research is needed to clarify the potential role of HRT in preventing or treating sarcoidosis.

5. Conclusion

A reduction in oestrogen levels during middle age may be a significant factor in the pathogenesis of sarcoidosis. Oestrogen plays a key role in regulating the immune response, and its decline may lead to increased inflammatory activity, macrophage dysregulation and an imbalance in the Th1/Th2 response, potentially triggering disease development.

Epidemiological data and immune mechanisms support the hypothesis that hormonal changes during menopause may increase the risk of developing sarcoidosis. Further research is needed to confirm this association.

Potential therapeutic strategies include targeted hormone therapy and immunomodulation, with the aim of reducing inflammatory activity in menopausal women at risk of developing sarcoidosis.