Determination of cisplatin in blood compartments of cancer patients

A new approach has been developed to determine the levels of cisplatin in different blood compartments of treated cancer patients. The cisplatin content of plasma, plasma proteins, red blood cells and white blood cell DNA can be measured by atomic absorption spectroscopy (AAS). The approximate levels of cisplatin were 10, 500 and 100 ng Pt/ml blood in plasma, plasma proteins and haemoglobin, respectively; in white blood cell DNA, the level of cisplatin was about 1 pg/microgram DNA. Preliminary data indicate that cancer patients have measurable amounts of cisplatin in their blood compartments. Furthermore, antibodies have been raised against cisplatin-DNA, with which 50% inhibition occurs at 50-100 fmol cisplatin. The detection limit is about 1-10 fmol cisplatin/microgram DNA. Enzyme immunoassay techniques will be used to detect cisplatin-DNA adducts in white blood cell DNA of cancer patients.