Studies of cellular mediated immunity in malignant melanoma patients by Leukocyte Adherence Inhibition Test

Sixteen malignant melanoma patients with different levels of tumor progression, two patients with melanoma in situ (Clark 10 two bronchogenic carcinoma patients and nine healthy controls were tested by means of the leukocyte adherence inhibition (LAI) test to assess the function of their cellular mediated immunity. Blood leukocytes were incubated with allogeneic melanoma-associated antigen obtained from potassium chloride extract of tumor cells. Fifteen malignant melanoma patients with clinical stage I-III (Clark level 2-5) showed positive LAI-reaction when leukocytes were tested with melanoma associated antigen. Leukocyte adherence inhibition was neither monitored in healthy controls, in patients with melanoma in situ, nor in those two patients with squamous and oat cell type bronchogenic carcinoma. Extracts prepared from normal skin showed no inhibitive effect on leukocyte adherence in malignant melanoma patients and controls. A decreased percentage of LAI was observed in malignant melanoma patients with disseminated disease due to an increased spontaneous leukocyte adherence in these patients. This increase in spontaneous leukocyte adherence was probably caused by non-specific activation of adherent cells (macrophages) as a result of the prolonged therapy and/or the progressive tumor levels in these patients.