Immunomodulatory Therapies for Interstitial Cystitis/Bladder Pain Syndrome

Abstract

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic, debilitating condition of unknown etiology characterized by persistent pain perceived to be related to the urinary bladder and lower urinary tract symptoms. Evidence shows that immunological inflammatory responses underlie the pathophysiology of IC/BPS with Hunner lesions but not that of IC/BPS without Hunner lesions. Here, we review the current understanding of the immunological inflammatory nature of IC/BPS with Hunner lesions and the clinical outcomes of immunomodulatory therapies. Open trials show that steroids improve validated symptom scores and pain scale score markedly in patients with IC/BPS with Hunner lesions. Open trials and a randomized study show that cyclosporine A improves urinary frequency, pain intensity, and bladder capacity significantly in IC/BPS patients, showing therapeutic superiority in the Hunner lesion subtype. A randomized double-blind study showed that certolizumab pegol significantly improves patient-reported global response assessments of pain, urgency, and overall symptoms, and reduces the Interstitial Cystitis Symptom/Problem Index scores and pain scale score at 18 weeks. These results suggest that immunomodulatory therapy is more effective for IC/BPS patients with Hunner lesions than for IC/BPS without Hunner lesions. IC/BPS with Hunner lesions is associated specifically with immunological overreactions in the bladder; thus, immunomodulatory therapy could be a promising treatment option. Further studies focusing on the therapeutic responsiveness of IC/BPS subtypes are warranted to promote a tailored approach to clinical management of IC/BPS. To achieve this therapeutic strategy, clear and proper subtyping of IC/BPS is mandatory.