Elevated Serum IgE May be Associated with Development of Ketamine Cystitis

Purpose: Previous studies revealed bladder mast cell and eosinophil cell infiltration in patients with ketamine cystitis. Due to possible hypersensitivity in those with this condition we investigated the association of serum Ig, histology findings and symptoms in patients with ketamine cystitis. Materials and Methods: We evaluated patients with ketamine cystitis for maximal bladder capacity, serum IgE, IgG and IgM, and pain visual analog scale score. Bladder biopsies were assessed for mast cells and eosinophils. Patients with interstitial cystitis/bladder pain syndrome, acute bacterial cystitis and controls were also studied. We used the Mann-Whitney U test for nonparametric data to compare serum IgE among groups with p < 0.017 considered significant. Results: Median serum IgE was significantly higher in the 20 patients with ketamine cystitis (205.5 IU/ml, IQR 36.9, 514.0) than in the 10 controls (33.4 IU/ml, IQR 13.5, 71.7, p = 0.015) and the 15 with acute bacterial cystitis (34.6 IU/ml, IQR 24.2, 101.9, p = 0.015). It was marginally higher than in the 13 patients with interstitial cystitis/bladder pain syndrome (65.8 IU/ml, IQR 11.9, 133.0, p = 0.029). Of patients with ketamine cystitis the median visual analog scale pain score was significantly higher in those with serum IgE greater than compared to less than 200 IU/ml. Maximal bladder capacity was significantly less in patients with ketamine cystitis who had higher IgE. Patients with severe or moderate bladder eosinophil infiltration had a greater visual analog scale score, higher serum IgE and smaller maximal bladder capacity than patients with no or mild eosinophil infiltration. Serum IgE and the visual analog scale score correlated significantly (r(2) = 0.318, p = 0.01). Conclusions: Patients with ketamine cystitis had higher serum IgE than patients with interstitial cystitis/bladder pain syndrome or acute bacterial cystitis, or controls. Serum IgE and the severity of eosinophil infiltration were associated with bladder pain severity and small maximal bladder capacity.