Little is known about the effects of thalassaemia on the kidney. Characterization of underlying renal function abnormalities in thalassaemia is timely because the newer
iron chelator,
deferasirox, can be nephrotoxic. We aimed to determine the prevalence and correlates of renal abnormalities in thalassaemia patients, treated before
deferasirox was widely available, using 24-h collections of urine. We calculated
creatinine clearance and urine
calcium-to-
creatinine ratio and measured urinary β(2) -microglobulin,
albumin, and
protein. We used multivariate modelling to identify clinical, therapeutic, and laboratory predictors of renal dysfunction. One-third of thalassaemia patients who were not regularly transfused had abnormally high
creatinine clearance. Regular transfusions were associated with a decrease in clearance (P = 0·004). Almost one-third of patients with thalassaemia had
hypercalciuria, and regular transfusions were associated with an increase in the frequency and degree of
hypercalciuria (P < 0·0001).
Albuminuria was found in over half of patients, but was not consistently associated with transfusion
therapy. In summary, renal hyperfiltration,
hypercalciuria, and
albuminuria are common in thalassaemia. Higher transfusion intensity is associated with lower
creatinine clearance but more frequent
hypercalciuria. The transfusion effect needs to be better understood. Awareness of underlying renal dysfunction in thalassaemia can inform decisions now about the use and monitoring of
iron chelation.