Epididymal Inflammation and Male Fertility

Epididymal inflammation, or epididymitis, disrupts the complex environment required for sperm maturation and storage, often leading to compromised sperm motility, reduced sperm counts and impaired fertilisation capacity. The epididymis must balance immune defence against ascending pathogens with tolerance towards immunogenic sperm antigens; failure of this balance can precipitate acute or chronic inflammation. Bacterial infections, notably by gram-negative and gram-positive organisms, and non-infectious triggers such as toxins or autoimmune reactions, initiate inflammatory cascades that alter cytokine networks, damage epithelial integrity and impair the blood–epididymis barrier. Globally, epididymal inflammation represents a significant contributor to male infertility, highlighting the need for improved diagnostic tools and targeted therapies that preserve both antimicrobial defence and reproductive function.

Research from Nature Portfolio

Experimental studies in rats have compared lipopolysaccharide and lipoteichoic acid challenges in the cauda epididymis, revealing distinct cytokine and chemokine expression patterns. A stronger acute response to lipopolysaccharide correlated with a sustained reduction in sperm count and delayed transit time, linking early inflammatory signalling to long-term fertility outcomes. Complementary work in mice has mapped the regional expression of Transforming Growth Factor-β isoforms and receptors throughout the epididymal tubule, uncovering potential mechanisms by which peripheral tolerance to sperm antigens is maintained and suggesting avenues for modulating immune tolerance without compromising host defence.

Epididymal Inflammation and Male Fertility publication trend

The graph below shows the total number of articles in epididymal inflammation and male fertility across all publications each year (not limited to Nature Index journals).

Technical terms

Epididymitis: Inflammation of the epididymis, the duct behind the testes where sperm mature and are stored.

Cytokine: A signalling protein secreted by immune cells that orchestrates inflammatory and repair processes.

Chemokine: A category of cytokines that guides the movement of immune cells to sites of inflammation.

Innate immunity: The body’s immediate, non-specific defence mechanism against pathogens.

MyD88: An adaptor molecule essential for transmitting signals from certain immune receptors to activate inflammatory pathways.

Transforming growth factor beta: A family of cytokines involved in regulating immune tolerance and tissue homeostasis.

References

1. Myd88 Signaling Is Involved in the Inflammatory Response in LPS-Induced Mouse Epididymitis and Bone-Marrow-Derived Dendritic Cells. International Journal of Molecular Sciences (2023).
2. Imaging findings in inflammatory disease of the genital organs. Japanese Journal of Radiology (2024).
3. Lipopolysaccharide and lipotheicoic acid differentially modulate epididymal cytokine and chemokine profiles and sperm parameters in experimental acute epididymitis. Scientific Reports (2018).
4. Exploring the role of mononuclear phagocytes in the epididymis. Asian Journal of Andrology (2015).
5. Differential expression and localisation of TGF-β isoforms and receptors in the murine epididymis. Scientific Reports (2020).
6. The immunobiology of the mammalian epididymis: the black box is now open!. Basic and Clinical Andrology (2013).