Objective To analyze the clinical characteristics of proximal tubular acidosis induced by deferasirox in children with β-thalassemia major.

Methods This study retrospectively analyzed the clinical manifestations, laboratory test results, radiological features, treatment methods and outcomes of proximal tubular acidosis in 5 children with β-thalassemia major.

Results Five patients aged 5 to 16 years, included 2 males and 3 females. Two patients were diagnosed with Fanconi syndrome. Four patients received deferasirox doses exceeding the conventional dose, including one with a rapid decline in ferritin levels. Gastrointestinal symptoms were the initial manifestations in 3 patients, while only mild anorexia was observed in 2 patients. There were significant correlations between the severity of clinical manifestations, the degree of acidosis and its duration. All patients had abnormally elevated urine β₂-microglobulin levels, and 4 patients had hepatic iron deposition. After reducing or discontinuing deferasirox and providing symptomatic treatment, the renal tubular function of all 5 patients gradually recovered.

Conclusion Proximal tubular acidosis induced by deferasirox in patients with β-thalassemia major can manifest as partial or complete proximal tubular acidosis, which may be associated with high-dose deferasirox administration and rapid decreases in body iron levels. Regular monitoring of relevant indicators is recommended for children receiving long-term deferasirox treatment. Once proximal tubular acidosis is detected, drug dosage adjustment or discontinuation should be promptly implemented, and renal tubular function can recover in most patients.