Changes in Immunological Parameters after Combination Adjuvant Therapy with Intravenous DTIC, ACNU, and VCR, and Local Injection of IFN‐β (DAV + IFN‐β Therapy) into Malignant Melanoma

Combination adjuvant therapy with intravenous dimethyl triazeno imidazole carboxamide (DTIC), 1‐[4‐amino‐2‐methyl‐5‐pyrimidinyl]‐methyl‐3‐[2‐chloroethyl]‐3‐nitrosourea hydrochloride (ACNU) and vincristine (VCR) and local injection of interferon‐β (IFN‐β) (DAV + IFN‐β therapy) has been widely applied to treat malignant melanoma, and its therapeutic effect is accepted in Japan. Natural killer (NK) activity, CD4+ and CD8+ T cell counts, CD4/CD8 ratio, and white blood cell counts were analyzed before and after DAV + IFN‐β therapy in order to validate its efficacy. After DAV + IFN‐β therapy, the CD4/CD8 ratio was elevated; however, numbers of both CD4+ and CD8+ T cells and NK activity were consecutively depressed. Peripheral lymphocytes were also decreased, possibly by myelosuppression due to the DAV therapy. The posttreatment suppression of NK activity appeared in spite of the administration of IFN‐β. It is suggested that a more effective adjuvant immunomodulator should be introduced to improve the therapeutic effect of the combination adjuvant chemotherapy in malignant melanoma.