[Problems with immunosuppressive agents in nephropathies with chronic renal failure]

Immunosuppressive treatment is widely used in transplant patients, who often have chronic renal failure, while its use in nephropathies of native kidneys with chronic renal insufficiency is still limited. In recent years a number of papers have reported advantages of its use also in this setting. A prerequisite for immunosuppression in this condition is accurate renal histology, in order to define the etiology, activity/chronicity index and prognosis. Although clinicians agree on the use of aggressive treatment for secondary nephropathies, the approach to primary forms in the presence of chronic renal failure remains controversial, as does the definition of a ''point of no return'' beyond which treatment could be ineffective or unsafe. Nonrandomized studies found that immunosuppressive drugs such as cyclophosphamide can be useful in membranous nephropathy with renal insufficiency. The use of immunosuppressive drugs in IgA nephropathy in the presence of established renal insufficiency seems to improve renal survival with a limited occurrence of side effects. Since the pharmacokinetics of the current immunosuppressive agents (steroids, azathioprine, cyclophosphamide, chlorambucil, mycophenolate mofetil) is modified by renal insufficiency, attention should be paid to reducing drug doses and monitoring toxicity. Immunosuppressive treatment is a critical procedure in patients with chronic renal failure, in whom an increased risk of infection is already present. In conclusion, on the basis of the data of the literature, we can hypothesize that the ''point of no return'' exceeds the threshold generally considered safe by clinicians. Nevertheless, a strict definition of a cutoff value for renal function to establish whether or not a certain treatment should be given is not applicable in clinical practice, where the choice of an immunosuppressive approach must be tailored to the individual patient based on a global evaluation including renal histology, clinical conditions and previous immunosuppression.