Relationship between urine beta-2-microglobulin and platinum levels during cisplatin treatment.

We evaluated whether urine beta 2-microglobulin (beta 2M) excretion as a function of nephrotoxicity correlated with plasma and urine platinum levels in patients receiving cisplatin. Thirty-one patients had urine platinum measurements in urine samples collected at 0 to 6 and 6 to 24 h after cisplatin administration, 25 of these patients had serial plasma platinum measurements. Sixteen of the 31 patients had an increase in urine beta 2M. A significant correlation was obtained between urine platinum and beta 2M in the 6- to 24-h samples (r = 0.61, p less than 0.02). The mean plasma platinum levels were higher (12.6 +/- 6.1 mumol/L) in the patients with an increase in urine beta 2M compared to those patients with no change in beta 2M (6.8 +/- 4.1 mumol/L) (p less than 0.02). Our study indicates that tubular damage occurs within 24 h after cisplatin administration and that the damage correlates with urine platinum levels.