Role of serum immunoglobulin E in patients with interstitial cystitis/bladder pain syndrome

ObjectiveThe actual pathophysiology of interstitial cystitis (IC)/bladder pain syndrome (BPS) is still uncertain. Immune or hypersensitivity mechanisms may play an important role in the pathogenesis of IC/BPS. This study was designed to investigate and analyze serum immunoglobulin E (IgE) levels in patients with IC/BPS.Materials and methodsPatients with IC/BPS who were admitted for cystoscopic hydrodistention were enrolled in this study. Blood samples were obtained to investigate their serum IgE levels. A serum IgE level more than 200 IU/mL was considered abnormal. The patients' symptoms, visual analog scale (VAS) scores, O'Leary–Sant symptom (OSS) scores, cystometric bladder capacity (CBC), maximal bladder capacity (MBC), and grading of bladder glomerulation hemorrhage during cystoscopic hydrodistention were recorded. Serum IgE levels were also investigated in women with stress urinary incontinence, who served as the control group.ResultsTwo hundred patients with IC/BPS and 35 controls were investigated. In total, 22 IC/BPS patients (11%) had abnormal serum IgE levels. No abnormal serum IgE levels were detected in the controls. The mean serum IgE level in IC/BPS patients and controls were 102.37 IU/mL ± 250.68 IU/mL and 74.21 IU/mL ± 88.62 IU/mL, respectively (p = 0.204). The VAS, OSS, CBC, MBC, and grading of glomerulations were not significantly correlated with serum IgE levels (p = 0.317, 0.587, 0.774, 0.559, and 0.309, respectively). The serum IgE levels were slightly higher in men than in women, although the difference was not significant (152.98 IU/mL ± 201.73 IU/mL vs. 94.87 IU/mL ± 262.54 IU/mL, p = 0.183).ConclusionIn this study, 11% of patients with IC/BPS had IgE level more than 200 IU/mL, but the mean serum IgE level was not higher than the controls. Aggravating factors such as food or environmental substance should be carefully investigated in IC/BPS patients with elevated serum IgE levels.