Interstitial cystitis/bladder pain syndrome (IC/BPS) is a bladder disorder difficult to treat. Platelet-rich plasma (PRP) has been found to have anti-inflammatory and regenerative effect on the bladder inflammation and urothelial barrier deficit. Preliminary results have shown a promising treatment outcome. This study tried to investigate which cystoscopic subtypes can benefit from repeated PRP injections.

This study included 66 patients with IC/BPS, including 5 with Hunner’s IC and 61 with non-Hunner’s IC, who were not successfully managed with conventional treatments. The eligible patients underwent videourodynamic studies, completed voiding diaries, and received intravesical PRP injections once a month for a total of four treatments. Cystoscopic hydrodistention was performed, and the maximal bladder capacity and glomerulation grade were recorded. Treatment outcomes were examined using the global response assessment (GRA), and patients with a GRA score of 2 or 3 were considered to have achieved treatment success.

In total, 33 (50%) patients, including 20 (30.3%) who had an excellent outcome (GRA score of 3) and 13 (19.7%) who had moderate improvement (GRA score of 2), reported a successful outcome. The bladder pain visual analog score of 23 (34.8%) patients reduced by ≥ 3, and the functional bladder capacity of 15 (25.9%) patients increased to ≥ 350 mL. The glomerulation grade of 20 (32.8%) patients decreased by ≥ 1. All patients did report adverse events such as urinary tract infection and urination difficulty. The IC symptom scores show improvement in patients with MBC ≥760 mL and MBC <760 mL and grade 2 and 3 glomerulation, but not in those with MBC <760 mL and Gr=0 or 1. Pain reduction was significant in patients with MBC ≥760 mL but not those with MBC <760 mL. Patients with MBC <760 mL at baseline had significant increase of MBC after PRP treatment (Table 1). Further analysis of treatment results is shown in Table 2. Successful treatment outcome was 61.1% and 66.7% in patients with grade 0/1 glomerulation and MBC ≥760 mL and MBC <760 mL, respectively; and 47.8% and 41.1% in patients with grade 2/3 glomerulation and ≥760 mL and MBC <760 mL, respectively. The successful rate was 40% in patients with Hunner’s IC. Glomerulation after hydrodistension decreased by 1 in 20 (32.8%), and 18 (30%) patients had glomerulation reduced to 0 (n=8) or 1 (n=10).

The current study showed that four consecutive monthly intravesical PRP injections were effective in treating 50% of patients with IC/BPS refractory to conventional therapy. Patients with a baseline MBC of ≥ 760 mL and glomerulation grade of 0 or 1 had relatively higher success rates. This finding indicated that patients with IC/BPS who had a lower grade of bladder inflammation may benefit from PRP treatment.

In 50% of patients with IC/BPS, including the non-Hunner’s and Hunner’s IC subtypes, intravesical PRP injections were effective in reducing bladder pain, increasing bladder capacity, and improving glomerulation grade after cystoscopic hydrodistention. Moreover, patients with reduced bladder inflammation who exhibited a low glomerulation grade and a larger maximal bladder capacity at baseline had a relatively higher treatment success rate.