The etiology of interstitial cystitis (IC) is not yet fully clear, and there are the following hypotheses:
1、Vascular and lymphatic obstruction
It has been speculated that bladder fibrosis may be caused by pelvic surgery or infection, leading to obstruction of lymphatic vessels in the bladder wall and causing thrombotic angiitis or persistent small artery spasm due to vasculitis, but there is insufficient evidence.
2、Infection
It has been proposed that bacterial, viral, or fungal infection may be the cause of IC, but none of the above have been detected in IC patients.3There have been reports of various pathogens.
3、Neurohumoral factors
Mast cells are increased in the bladder固有膜 and detrusor muscle of IC patients, and factors such as cold, neuropeptides, drugs, trauma, toxins can activate mast cells. The release of vasoactive substances can sensitize sensory neurons, which further activate mast cells by releasing neurotransmitters or neuropeptides; mast cells can also directly cause vasodilation or bladder mucosal damage, leading to inflammation.
4、Immunological factors
The disease responds well to corticosteroid therapy, and some patients may detect anti-bladder mucosal antibodies in the blood. Many scholars have also found that autoantibodies or immune complexes produced against vascular antigens may deposit in the vascular wall, activate the complement system, and participate in the pathogenesis of IC.
5、Mucosal permeability
It is speculated that IC is caused by dysfunction of the bladder epithelium, with increased permeability and urine leakage through the transitional epithelium into the bladder wall, causing bladder inflammation. Some people have confirmed that IC patients have an increase in TH protein in the superficial epithelium of the bladder, indicating increased mucosal permeability.