Gene therapy for renal disorders: what are the benefits for the elderly?

Chronic renal failure is one of the major health problems for the elderly. Currently, about 50% of all patients receiving chronic dialysis for end-stage renal disease (ESRD) are aged 65 years or older. Their first-year mortality rate is as high as 30%. The leading causes of ESRD in the elderly are diabetic nephropathy, hypertension and large vessel diseases, and glomerulonephritis. The elderly are also prone to developing acute renal failure induced by ischaemic injury or nephrotoxic drugs. Gene transfer in experimental animals have been tested in all of these conditions, as well as in animal kidney transplantation models, with various degrees of success. However, there are many obstacles to be overcome before gene therapy can be tested clinically for renal disorders. In particular, the major challenges include determining how to prolong and control transgene expression or antisense inhibition and how to minimise the adverse effects of viral or nonviral vectors. Once these problems are solved, gene therapy will have a role in treating age-related renal impairment.