Hunner Lesion Phenotype in Interstitial Cystitis/Bladder Pain Syndrome: A Systematic Review and Meta-Analysis.

To compare demographics, clinical presentation, comorbidities, urinary profiles, and treatment responses between interstitial cystitis/bladder pain syndrome (IC/BPS) patients with and without Hunner lesions (HL).

We performed a systematic review of literature in PubMed® in February 2019. Publications were included if they compared data between IC/BPS patients with and without HL, yielding 59 articles. Meta-analysis was performed on a subset of clinical characteristics.

Meta-analysis showed that IC/BPS patients with HL were significantly older (MD=6.7 years, 95%CI 2.0-11.3, p=0.005), reported higher urinary frequency (MD=3.2/day, 95%CI 1.1-5.4, p=0.003), nocturia (MD=1.0/night, 95%CI 0.1-2.0, p=0.034), and IC Symptom Index (MD=2.2, 95%CI 1.4-3.0, p<0.001), but lower cystometric bladder capacity (MD= -113mL, 95%CI -164 to -61 mL, p<0.001) compared to IC/BPS patients without HL. There were no differences in pain scores (p=0.105), symptom duration (p=0.2), or sex (p=0.83) between the two groups. While some studies reported higher rates of comorbid pain syndromes (e.g., fibromyalgia) among patients without HL, overall results were conflicting. Patients with HL had higher urinary levels of pro-inflammatory cytokines/chemokines (CXCL10, NGF, IL-6, IL-8, MIF), luminal nitric oxide (NO), and responded well to endoscopic treatment of the Hunner lesions (e.g. fulguration or triamcinolone injection). In comparative studies, IC/BPS patients with HL responded better to oral cyclosporine A than those without HL.

Systematic review and meta-analysis demonstrated significant differences in demographics, clinical presentation, urinary marker profiles, and treatment responses between patients with and without HL, suggesting that they may represent two distinct clinical phenotypes. Studies are needed to investigate their mechanistic differences.

The Journal of urology. 2020 Mar 30 [Epub ahead of print]

H Henry Lai, Nicholas A Pickersgill, Joel M Vetter

Department of Surgery, Division of Urologic Surgery, Washington University School of Medicine, St. Louis, Missouri.