Mechanism of non-specific-fistula-in-ano: Hormonal aspects—Review

Abscesses could occur anywhere, but quite few that could proceed forward and develop fistulae. Crypto glandular abscess formation concept has been forming the basis for almost all designed strategies for management of cases of idiopathic fistula-in-ano for ages. Yet, this hypothesis failed to explain the reason(s) for the recorded lower incidences of idiopathic anal fistula in females than in males.Gram negative bacteria are largely the causative agents for these anal glands’ abscesses that processed further and developed fistulae. Lipopolysaccharide component (LPS) of the bacterial cell wall could significantly attenuate the expression of mRNA of the oestrogen receptors and accordingly reduces the down signalling pathway. Yet, this kind of action could be inhibited in the presence of oestrogen.In addition, tumour necrosis factor-alpha (TNFα) is a key proinflammatory cytokine that induces the secretion of other cytokines and enzymes in various cells and tissues. And LPS could activate pro-inflammatory cytokine by activating plasma membrane proteins (e.g. the toll like receptor 4 [TLR4] and CD14 that leads to the production of TNFα and other pro-inflammatory cytokines). This activation could be enhanced by testosterone but inhibited by oestrogen. These are likely the reasons for the higher prevalence of idiopathic fistula-in-ano in males than in females.