The expression of IgG4 in interstitial cystitis in a tertiary care centre- A hospital based prospective study

• Author Details:   
• Akshara Somaraj Nair ^*
• Ranjit P Kangle
• R B Nerli

Introduction: Interstitial cystitis (IC), also known as bladder pain syndrome (BPS), is a chronic inflammatory condition of the bladder with unclear aetiology. Recent research suggests a possible link between IC and IgG4-related disease (IgG4-RD), characterized by plasma cell infiltration and fibrosis.
Aim and Objective: This study aims to assess IgG4 immunostaining in bladder biopsies of Interstitial Cystitis patients and correlate IgG4 expression with clinicopathological findings.
Materials and Methods:  A total of 30 bladder biopsy samples were examined prospectively over a two-year span in the Department of Pathology at Jawaharlal Nehru Medical College and KLE’s Dr. Prabhakar Kore Hospital and Medical Research Centre, KAHER, Belagavi. Immunohistochemical staining for IgG4 was performed, and its expression was correlated with clinicopathological findings.
Result: Among 30 cases, IC was the most common diagnosis (50%). Most patients were aged 31–50 years (36.7%) with a slight male predominance (53.3%). IgG4 positivity was seen in 56.7%, with 50% having elevated serum IgG4. While no strong correlations emerged, higher serum IgG4 showed a trend toward significance (p = 0.06).
Conclusion: This study highlights a potential IgG4-related subset of IC, warranting further research to refine diagnosis and targeted immunotherapy.

Keywords: Interstitial cystitis, IgG4, bladder pain syndrome, Inflammation, Immunohistochemistry, Chronic cystitis, Uropathology