Axel Brock and Erland J. Erlandsen
Department of Clinical Biochemistry, Viborg Hospital, Denmark.
The ratio between renal clearance of porphyrins and creatinine clearance was determined in 18 PCT patients with normal or slightly impaired renal function (plasma creatinine
The ratio between renal clearance of porphyrins and creatinine clearance was determined in 18 PCT patients with normal or slightly impaired renal function (plasma creatinine 47 – 187 micromol/L). Plasma concentrations of uroporphyrin ranged from 1.6 to 137 nmol/L. Independently of plasma concentrations, renal clearance of 8-COOH, 7-COOH, 5-COOH and 4-COOH porphyrins was found to be round half of creatinine clearance (clearance ratios: 8-COOH 0.49 (SD 0.25), 7-COOH 0.36 (SD 0.13), 5-COOH 0.27 (SD 0.14), 4-COOH 0.84 (SD 0.61)). Renal clearance of 6-COOH porphyrin was significantly lower (p < 0.05) than renal clearance of the other porphyrins and only 8% of that of creatnine (clearance ratio: 0.08 (SD 0.04)).