Suppression of natural killer activity in patients treated with cisplatin and methylprednisolone.

The achievable concentrations of 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl-3-nitrosourea (ACNU), adriamycin, mitomycin C, vindesine, and epipodophyllotoxin suppressed the natural killer (NK) activity of human peripheral blood lymphocytes in vitro, whereas NK activity was not decreased 24 h after incubation with the maximum achievable concentration of cisplatin (cDDP). NK activity of patients treated with 80 mg per square meter of cDDP alone was not decreased for 3 weeks after cDDP administration. In contrast, NK activity of patients treated with the same dose of cDDP and methylprednisolone was significantly decreased 1 week after cDDP administration. It was concluded that methylprednisolone, used as an antiemetic agent, had an immunosuppressive effect.