Measurement of Cytokines in Seminal Plasma

Cytokines are a family of immunoregulatory peptide growth factors. They are produced mainly by immune cells after immune challenge (infection/inflammation). Various cells of nonimmune cell origin such as epithelial, muscle, endothelial, fibroblast, and mesangial, and also sperm cells are capable of producing cytokines. Cytokines are pleiotropic factors with autocrine and paracrine effects and may therefore play an important role in the testicular microenvironment. The main proinflammatory cytokines are tumor necrosis factor-α (TNF-α), interleukin (IL)-1, and IL-6. The first cytokine produced after immunologic challenge is TNF-α, which induces the production of IL-1 followed by IL-6. The amplitude of the immune response is controlled by feedback inhibition of the proinflammatory cytokines and also by downregulator cytokines such as IL-4, IL-10, IL-12, and/or cytokine-soluble receptors and IL-1 receptor antagonist. Ample evidence has accumulated indicating the involvement of cytokines in the physiology and pathophysiology of reproduction (1 ).