Efficacy and safety of intravesical dimethyl sulfoxide treatment for patients with refractory Hunner-type interstitial cystitis: Real-world data postofficial approval in Japan

OBJECTIVES

To examine real-world data regarding intravesical dimethyl sulfoxide (DMSO) therapy after official approval as a treatment for Hunner-type interstitial cystitis (HIC) in Japan.

METHODS

This single institution, retrospective observational study was conducted between 2021 and 2022 to evaluate the outcomes of 30 patients with refractory HIC who received intravesical DMSO therapy according to the approved standardized regimen: administration of DMSO every 2 weeks for a total of 12 weeks. Treatment outcomes were evaluated using a 7-graded global response assessment scale, O'Leary and Sant's symptom and problem indices (OSSI/OSPI), the overactive bladder symptom score (OABSS), an 11-point pain intensity numerical rating scale, quality of life (QOL) score, and frequency volume chart variables. Related complications were also documented.

RESULTS

The response rates at 2, 4, 6, 8, 10, and 12 weeks were 36.7%, 43.3%, 53.3%, 60.0%, 70.0%, and 70.0%, respectively. Compared with baseline, OSSI/OSPI, pain intensity, urinary frequency, and the QOL score improved significantly from 4 weeks of treatment. The OABSS score and functional bladder capacity also showed a tendency toward moderate improvement, but the difference was not significant. The mean duration of symptom relapse after termination of treatment was 6.4 ± 3.9 months. No patients discontinued treatment due to adverse events, although acute bladder irritation during infusion was noted in 21 patients (70%), which disappeared within 3 days.

CONCLUSIONS

This study verifies the safety, moderately durable efficacy, and tolerability of the standard intravesical treatment with DMSO for HIC in Japan.

Genome-wide association study identifies risk loci within the major histocompatibility complex region for Hunner-type interstitial cystitis

Hunner-type interstitial cystitis (HIC) is a rare, chronic inflammatory disease of the urinary bladder with unknown etiology and genetic background. Here, we conduct a genome-wide association study of 144 patients with HIC and 41,516 controls of Japanese ancestry. The genetic variant, rs1794275, in the major histocompatibility complex (MHC) region (chromosome 6p21.3) is associated with HIC risk (odds ratio [OR] = 2.32; p = 3.4 × 10^-9). The association is confirmed in a replication set of 26 cases and 1,026 controls (p = 0.014). Fine mapping demonstrates the contribution to the disease risk of a completely linked haplotype of three human leukocyte antigen HLA-DQβ1 amino acid positions, 71, 74, and 75 (OR = 1.94; p = 5 × 10^-8) and of HLA-DPβ1 amino acid position 178, which tags HLA-DPB1∗04:02 (OR = 2.35; p = 7.5 × 10^-8). The three HLA-DQβ1 amino acid positions are located together at the peptide binding groove, suggesting their functional importance in antigen presentation. Our study reveals genetic contributions to HIC risk that may be associated with class II MHC molecule antigen presentation.

Cystectomy for patients with Hunner-type interstitial cystitis at a tertiary referral center in Japan

OBJECTIVES

To evaluate the outcomes of partial and total cystectomy in patients with refractory Hunner-type interstitial cystitis (HIC).

METHODS

Patients with end-stage HIC who underwent supratrigonal partial cystectomy with augmentation ileocystoplasty (PC-CP) or total cystectomy with ileal conduit (TC-IC) were identified retrospectively. Changes in the 11-point numerical rating scale of bladder pain and in 7-grade quality of life (QOL) scores were evaluated. Changes in the O'Leary and Sant's Symptom Index (OSSI) and O'Leary and Sant's Problem Index (OSPI) were analyzed in patients with PC-CP. Peri- and postoperative complications and patient satisfaction with overall outcomes were examined.

RESULTS

Four patients (one female) underwent PC-CP and 13 (nine females) underwent TC-IC. Bladder pain persisted in three PC-CP patients, but resolved completely in all TC-IC patients. Pain scale and QOL scores improved significantly in patients with TC-IC (P < .01), but not in those with PC-CP. OSSI/OSPI scores did not improve significantly in patients with PC-CP. Three PC-CP patients required clean intermittent catheterization due to voiding dysfunction or persistent pain. Two TC-IC patients developed stricture of the ureteroileal anastomosis, resulting in permanent placement of a ureteral stent in one case and nephrostomy in the other. Satisfaction rate was higher in the TC-IC than in the PC-CP group (76.9% vs 25.0%, P < .05).

CONCLUSIONS

TC-IC provided reliable pain relief and improved QOL in patients with end-stage HIC, but the small case number and limited methodology restrict interpretation of the results. Further studies are needed to identify appropriate candidates and optimal surgical procedures.

Clinical characterization of interstitial cystitis/bladder pain syndrome in women based on the presence or absence of Hunner lesions and glomerulations

OBJECTIVES

To compare the clinical characteristics of three groups of female patients with interstitial cystitis/bladder pain syndrome (IC/BPS) classified according to the presence or absence of Hunner lesions (HL) and glomerulations.

METHODS

The clinical records of 100 female patients with IC/BPS who underwent their first bladder hydrodistension at our institution were retrospectively reviewed. They were divided into patients having (HL-IC; n = 57) or lacking (BPS; n = 43) HL. BPS patients were further classified as those with (29) and without (14) glomerulations. Among these three subtypes, demographics, comorbidities, symptom parameters including a visual analog scale for pain scores, O'Leary and Sant Symptom and Problem (OSSI/OSPI) Indices, frequency volume chart variables, and bladder capacity at hydrodistension were compared.

RESULTS

HL-IC patients were older and had higher OSSI/OSPI scores, greater daytime frequency and nocturia, reduced maximum and average voided volumes, and smaller bladder capacity at hydrodistension compared with BPS patients. Pain intensity and illness duration were comparable among the three groups. HL-IC patients had autoimmune disorders as comorbidities more often, but had psychiatric disorders and irritable bowel syndrome less often compared with BPS patients. No discernible differences in clinical characteristics of symptom severity and comorbid disorders were evident between BPS patients with and without glomerulations.

CONCLUSIONS

The presence of HL is associated with distinctive clinical characteristics, while glomerulations are not in female patients with IC/BPS. The presence of HL, but not glomerulations, is a robust phenotypic feature of IC/BPS in women.