Serum lipid and lipoprotein profiles were performed in order to investigate lipid abnormalities 2 years post-transplantation in first cadaveric renal allograft recipients immunosuppressed with cyclosporin (CyA), azathioprine (Aza), and methylprednisolone (MP), or with any combination of two drugs. CyA was used in low doses. Total serum cholesterol, triglyceride, LDL cholesterol, HDL cholesterol, HDL2 cholesterol, HDL3 cholesterol, apolipoprotein A1, and apolipoprotein B were determined in 88 prospectively randomized patients with functioning grafts. When considering only the patients who remained on the original randomized treatment, there were no significant differences between the four groups in any of the measured variables. Mean total cholesterol was highest in the group receiving Aza and MP (6.8 mmol/l) and lowest in the group receiving triple therapy (5.8 mmol/l; NS). Mean triglyceride level was highest in the group receiving Aza and MP (2.3 mmol/l) versus 1.8-2.2 mmol/l in the groups receiving triple therapy, Aza + CyA, and CyA + MP. For all patients mean triglyceride level was highest in the group receiving Aza and MP (2.7 mmol/l) and lowest in the group receiving triple therapy (1.7 mmol/l; P less than 0.05). Mean HDL cholesterol ranged from 1.5 to 1.6 mmol/l in all groups. Neither CyA concentration nor CyA or MP dose correlated with cholesterol or triglyceride concentration. However, the average MP dose was twice as high in the group receiving Aza and MP as in the other two groups employing steroids. Serum cholesterol and triglyceride concentrations were related to body mass index (r = 0.28, P = 0.045 and r = 0.30, P = 0.029, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)