# Role of Hyaluronic Acid and Chondroitin Sulphate in Protecting Urinary Epithelium in Patients Operated for Differentiated Thyroid Cancer Undergoing Ablation Therapy with Iodine-131

## TL;DR

This study investigates how hyaluronic acid and chondroitin sulphate protect the urinary tract in thyroid cancer patients undergoing iodine-131 therapy.

## Contribution

The study demonstrates that hyaluronic acid and chondroitin sulphate can reduce urinary infections and epithelial cell damage in patients receiving iodine-131.

## Key findings

- Hyaluronic acid and chondroitin sulphate reduced bacteria and epithelial cell counts in patients with urinary infections.
- Patients treated with hyaluronic acid and chondroitin sulphate showed lower urinary tract infection rates compared to untreated patients.
- The protective effect was observed regardless of the duration of hyaluronic acid and chondroitin sulphate treatment.

## Abstract

The administration of hyaluronic acid and chondroitin sulphate has shown protective properties on the urinary epithelium in several different clinical conditions. We, therefore, explored the possible role of hyaluronic acid and chondroitin sulphate in preventing iodine-131-induced urinary infections in patients treated for thyroid cancer, while assessing whether urinary infections are related to doses of iodine-131 or patients’ preparation. To these purposes, several urine parameters were analyzed at basal time and up to one week. Our results show that urinary infections occur in a relevant percentage of patients undergoing iodine-131, either in patients who were treated with hyaluronic acid and chondroitin sulphate or in patients who were not. Nevertheless, in patients who experienced urinary infections, the use of hyaluronic acid and chondroitin sulphate was able to reduce the epithelial cells and bacteria count in urine. Therefore, similarly to other different clinical conditions, the use of hyaluronic acid and chondroitin sulphate could be a valid option in patients undergoing iodine-131 for thyroid cancer ablation to mitigate urinary infections.

Background: It is not clear if the administration of iodine-131 in patients with differentiated thyroid cancers induces relevant cystitis and lower urinary tract infections (UTIs). The aim of this study was to evaluate the impact of oral administration of hyaluronic acid and chondroitin sulphate (HA&CS) on the frequency of UTIs induced by iodine-131. Methods: In this study, 166 female patients with a surgical diagnosis of differentiated thyroid cancer who were hospitalized in Sant ’Andrea Hospital of Rome to undergo the first cycle of therapy with iodine-131 for thyroid remnant ablation were evaluated. Sixty-one patients were treated with HA&CS for 8 days, and thirty-nine patients were treated with HA&CS for 17 days. Sixty-six patients were not treated with HA&CS and were used as control subjects. Patients underwent urinalysis at different time points: immediately before 131I therapy, two days later, and one week later. Patients were divided in six groups based on whether they received the treatment with HA&CS, its duration, and whether they developed a UTI: group A, n = 51 patients who did not receive HA&CS and did not develop UTI; group B1, n = 37 patients treated with HA&CS for 8 days and did not develop UTI; group B2, n = 29 patients treated with HA&CS for 17 days and did not develop UTI; group C, n = 15 patients who did not receive HA&CS and developed UTI; group D1, n = 24 patients treated with HA&CS for 8 days and developed UTI; group D2, n = 10 patients treated with HA&CS for 17 days and developed UTI. Results: The bacteria count, red blood cells and white blood cells did not change when group A was compared to both group B1 and group B2, while pH and epithelial cells showed a decrease over time when comparing group A and group B2 (p = 0.01 and p < 0.0001, respectively). Comparing group C with group D1 and group D2, patients who did not receive HA&CS (group C) showed a higher bacteria and epithelial cell count compared to those who were pre-treated with HA&CS. Conclusions: HA&CS could be an effective supportive therapy to prevent and mitigate UTIs in patients treated with 131I.