Evaluating Renal Glomerular Function in Beta-Thalassemia Patients Receiving Deferasirox Using Serum Cystatin-C and Creatinine: A Cross-Sectional Study

The introduction of iron chelation therapies has notably extended the life expectancy of individuals with β-thalassemia, thereby presenting the potential for the emergence of new complications such as renal impairments. Because creatinine levels are influenced by body mass and nutritional status, there is a need for a more sensitive and reliable indicator of renal glomerular function. Here, we studied 27 individuals with β-thalassemia undergoing iron chelation therapy with Deferasirox. The serum levels of cystatin-C, a highly sensitive biomarker for renal dysfunction, were quantified using an immunoturbidimetry assay. We subsequently analyzed the data, examining correlations with other clinical and laboratory parameters. We determined the glomerular filtration rate (GFR) using both creatinine and cystatin-C-based equations. According to the creatinine equation, none of the patients had a reduced GFR, but 59% exhibited a reduced GFR value based on the cystatin-C equation. Patients with elevated cystatin-C levels exhibited higher serum creatinine (<i>p</i> < 0.001) and BUN (<i>p</i> = 0.002) and lower ferritin (<i>p</i> = 0.023) levels. Our study revealed a positive correlation between cystatin-C and creatinine (<i>p</i> = 0.002), BUN (<i>p</i> = 0.018), and BMI (<i>p</i> = 0.046), while a negative correlation was observed with ferritin (<i>p</i> = 0.006). We found no correlation between cystatin-C and age, weight, height, Deferasirox therapy duration, or blood transfusion frequency. Multiple regression analysis indicated that ferritin (<i>p</i> = 0.003) significantly affected cystatin-C levels, while other variables did not. Additionally, no independent variables had a significant impact on creatinine levels. Since there is a high likelihood of subclinical renal impairment in these patients, we recommend regular monitoring of serum cystatin-C as a screening tool.