Renal aspects of thalassaemia a changing paradigm

Beta-thalassaemia is characterised by progressive anaemia necessitating regular blood transfusions to sustain life. With the advent of effective chelating agents that can reduce the iron burden and extend patients' survival, renal disease, as in other ageing populations, has become more prevalent. In recent years, chronic kidney disease (CKD) has become overwhelming; indeed, approximately 8% or 6 million people of the UK population has evidence of CKD. Several factors, which occur in patients with thalassaemia, account for the relative explosion of renal disease in the general population including increasing age, diabetes, hypertension and the advent of novel measures of renal function facilitating early detection of kidney disease. In addition, some patients with thalassaemia develop renal tubular dysfunction related to the disease itself, the effects of iron overload and the effects of chelator therapy, while other patients have an increased creatinine clearance leading to hyperfiltration. More recently, there is a noticeable increasing prevalence of impaired renal function and proteinuria because of several putative factors including chelators. We review current data on the potential mechanisms leading to renal abnormalities seen in patients with thalassaemia, the potential effects of iron loading within the kidney and the potential renal effects of chelator therapy. This article gives a speculative account of possible mechanisms and theories to consider providing pause for thought and direct future research in this area.