The objective of the investigation was to assess the effect of one-year treatment with small doses of cyclosporin A (CyA) on the disease activity and organ affection, in particular of the kidneys in systemic lupus erythematosus (SLE). The patients included in this trial suffered from active disease defined by the index of organ activity SLEDAI. Organ affection implied in all patients the presence of active lupus nephritis, classified by renal biopsy according to WHO in some neuropsychic manifestations, polyarthritis, serositis and dermal vasculitis. The trial comprised a total of eleven patients with SLE. After 12 months of treatment with CyA the mean activity score of SLEDAI declined significantly from 24.36 to 5.55 (p < 0.01); there was a similar decline of the antinuclear antibody levels and titre against ds-DNA (both p < 0.01). A particularly marked decline was recorded in proteinuria per 24 hours from 9.10 g to 1.70 g (p < 0.001). The classification of renal biopsies according to WHO changed after one-year treatment in three patients from class IV into class III and in 5 patients from activity grade 2–3 to grade 1. In three patients rebiopsy was not performed. Under- sirable effects of CyA comprised hypertension (in 5 patients), gingival hyperplasia (in one patient) and hirsutism (in two patients) but did not cause discontinuation of treatment in any of these patients. In none of the patients with repeated biopsy histological manifestations of nephrotoxicity of CyA were found. It may thus be concluded that the favourable response observed in patients with active SLE and concurrent serious organ affections, in particular lupus nephritis, provides evidence that small doses of CyA are an effective treatment for reduction of activity of this disease.

        Key words: systemic lupus erythematosus, lupus nephritis, cyclosporin A