Immunosuppressive treatment in dialysis patients.

Immunosuppressive treatment is a critical procedure in dialysis patients, in whom an increased risk of infection is already present. Haemodialytic treatment increases the patient's susceptibility to bacterial infection, mainly by impairing polymorphonuclear leukocyte phagocytosis, but it can also restore the patient's immunological defences by improving the T-cell function, which is reduced by pre-dialysis uraemia. Patients on dialysis usually continue the immunosuppressive treatment that had been established for the illness that caused their renal failure [e.g. systemic lupus erythematosus (SLE) or renal vasculitis]. Less frequently, patients on dialysis need immunosuppression for immunological or inflammatory diseases that appear 'de novo' after initiation of dialysis. SLE and antineutrophil cytoplasmic antibody (ANCA)-related vasculitides are immunological illnesses that frequently cause end-stage renal failure (ESRF). A reduction in serological and/or clinical activity is usually observed in SLE patients after they reach ESRF, but a similar or increased frequency of extrarenal relapse episodes in lupus patients after the beginning of the dialysis, compared with the pre-dialysis period, has also been described. Frequency of relapse episodes in patients on dialysis treatment for ANCA-related vasculitides varies from 10 to 30% per patient/year in different reports, and it is higher than the frequency of relapses after renal transplantation; anti-rejection therapy seems to be the most likely protective factor in these conditions. The treatment of relapse episodes in SLE or ANCA vasculitis in dialysis-dependent patients is usually not different from treatment of relapses in patients with dialysis-independent renal function. However, the risk of severe infection caused by immunosuppressive treatment is relevantly higher in dialysis patients. Furthermore, there is a lack of prospective controlled studies indicating the optimal management of immunosuppressive protocols in dialysis patients. A particularly careful assessment of the patient's risks and benefits is necessary in deciding how long immunosuppressive treatment should last after acute or rapidly progressive renal damage, that should require dialysis treatment, in patients with SLE or ANCA vasculitis. In the above conditions, the risks of prolonging immunosuppressive treatment must be balanced against the relatively good prognosis offered to these patients by dialysis and renal transplantation. In a retrospective review of 24 patients receiving long-term steroid therapy (>3 months) in our dialysis unit in the past 5 years, we found relevant clinical differences in the patients receiving steroid treatment compared with 24 controls. Steroid-treated patients showed less favourable nutritional conditions, with lower serum albumin and body mass index vs non-steroid-treated patients; moreover, C-reactive protein values were persistently higher in the steroid-treated group. Steroid treatment in these patients was usually performed at the beginning of regular dialysis, as a continuation of the treatment that started before the initiation of dialysis. Only two patients, who needed a prolonged low-dose steroidal treatment to control a malnutrition-inflammation-atherosclerosis (MIA) syndrome, started steroids many years after beginning dialysis. Steroid treatment was effective in improving the nutritional condition and inflammatory symptoms in these two patients after all conventional measures had failed.