Decreased natural killer cell activity in patients with invasive cervical carcinoma

The cell-mediated immunity in 21,12,14 and 12 patients with preinvasive, stage I and II invasive cervical carcinoma, and in controls respectively, was studied. Lymphocyte subpopulations were enumerated using specific monoclonal antibodies (moAbs) of the Leu series (Leu2, Leu3, Leu4, Leu11b, and Leu15). Double stain using fluorescein-isothiocyanate (FITC) conjugated Leu2 moAb and phycoerythrin (PE) conjugated Leu15 moAb was applied to distinguish cytotoxic T-cells from suppressor T-cells. A 4-hour 51Cr-release assay was used to measure natural killer (NK) cell activity. The results showed that there was no significant difference in lymphocyte subpopulations among these 4 studied groups. However, the NK activity tended to be lower in patients with invasive cervical carcinoma (stage I and II) especially at a high effector/target ratio of 100. It is therefore concluded that functional cytotoxicity assay is more informative in evaluating the status of cell-mediated immunity against tumors than the enumeration of lymphocyte subsets.