Introduction. Cystitis is the most common clinical manifestation of lower urinary tract infection. The main reasons for the high incidence and frequent recurrences of cystitis is a decrease in the body's immunological resistance.

Aim of the study. To evaluate the long-term results of treatment of patients with chronic recurrent cystitis (CRC) with a combination of a nitrofuran preparation and immunomodulatory therapy.

Materials and methods. The PiNCet is a multicenter prospective observational program that was conducted from October 2021 to April 2022 in clinical centers in 19 Russian cities. 447 women aged 34 ± 8 years with a diagnosis of CRC in the acute stage received simultaneously nifuratel (Macmiror^®) 400 mg 3 times a day for 7 days and pidotimod (Imunorix^®) 800 mg 2 times a day for 14 days from followed by a transition to the maintenance regimen of pidotimod 800 mg once a day for another 60 days. Observation for six months included 4 visits – 14; 30±7; 90±7 and 180±7 days after the start of therapy. The primary endpoint was the frequency of exacerbations of CRC during 6 months of follow-up. The rate of resolution of the clinical picture of the disease, using Acute Cystitis Symptom Score (ACSS)), and the safety profile of therapy were also evaluated. Statistical data processing was carried out using the StatTech v. 2.8.8

Results. The percentage of patients with at least one exacerbation of CRC by the 1st, 3rd and 6th month of follow-up was 2%, 9% and 13.9%, respectively. More than 86% of patients (385/447) were free of recurrence within 6 months of follow-up. There was a significant decrease in the frequency of CRC episodes during six months against the background of the prescribed therapy in comparison with the baseline data (0.1 vs. 2.5, respectively, p <0.001). Only one patient had two relapses during 6 months of follow-up. The dynamics of total scores on the ACSS scale on the 14th, 30th, 90th and 180th days of observation showed a significant improvement in all indicators, including quality of life, while maintaining the result throughout the entire observation period. In 95% of cases, the therapy was well tolerated. Adverse events were detected in 6.7% of cases (30 out of 447). In 2 patients, temporary discontinuation of therapy was required due to exacerbation of chronic diseases of the gastrointestinal tract.

Conclusion. The use of pidotimod in combination with antibiotic therapy with nifuratel allows achieving remission of chronic cystitis in 86% of patients during 6 months of follow-up. This treatment regimen is an effective and safe solution to the problem of optimizing therapy in patients with chronic recurrent cystitis.