Background: Thyroid diseases are the most common endocrinopathies to occur. Thyroid cancer is considered the most evalent endocrine tumour and is growing in most nations. RAI-131 is the most comfortable and cost-effective therapy for Graves' disease or toxic nodular goitre. Since the 1940s, it has been employed because thyroid follicular cells may concentrate sodium-iodide. RAI-131 works physiologically. This research concentrates on RAI-131's impact on renal tubules after treating thyrotoxicosis or thyroid cancer.
Aim of the work: To study the possible hazardous effect of Radioactive Iodine-131 (RAI-131) on renal tubules in patients with and without kidney disease.
Patients and Methods: This is a prospective observational study was conducted on 30 candidates with Grave's disease or thyroid malignancy treated by RAI-131 and they were selected by endocrinology and oncology doctors at El-demerdash hospital during the period from October 2019 to March 2021. All patients were subjected to the following: Medical sheet taken in Ain-shams university hospitals, General examination. Laboratory investigations: Estimation of Thyroid function (measured by radioimmunoassay): To detect associated hypothyroidism or hyperthyroidism. TSH, FT3 and FT4, Serum creatinine, Blood urea, eGFR, Urine analysis and Urinary β2 microgloglobulin as a marker of tubular damage. Renal function assessment were done before RAI-131 administration, and then it will be repeated one week later after the dose. Investigations were repeated after 2 months for patients with deterioration of kidney function tests. Results: A total of 30 patients included in this study, mean age of them was 34.33±7.71 years, 90% of them were females. Diabetes mellitus was reported in 56.7% of patients, while 43.3% of them had hypertension. Majority of the studied patients had grave's disease (93.3%), had picture grave's disease. Also, 50% of the studied patients had chronic kidney disease and 50% hadn't chronic kidney disease. Serum creatinine showed statistically significant increase after one week and two months of RAI-131 dose compared before dose (p < 0.001). While, eGFR MDRD was showed statistically significant decrease after one week and two months of RAI-131 dose compared before treatment (p < 0.001). Additionally, there were highly statistical significant differences between the studied patients regarding presence of WBCs cast in urine after 2 months (p <0.001)). Also, β2 microglobulin in urine was increased after RAI-131 dose than before it (p <0.001). In addition, from the Non-CKD group, 5 patients (33.3%) developed impaired renal functions after 2 months of RAI-131 dose.
Conclusion: RAI-131 affects directly the renal tubular functions as detected by statistically significant increase of urinary β2 microgloglobulin in all study group after 1 week (p 0.002) and 2 months (p <0.001).