SUPPRESSION OF NATURAL-KILLER-CELL ACTIVITY AND INTERLEUKIN-2 CONCENTRATION OF SERUM OBTAINED FROM IN-VITRO FERTILIZATION-EMBRYO TRANSFER PATIENTS

PROBLEM: The effect of serum obtained from in vitro fertilization-embr yo transfer (IV-FET) patients on healthy volunteers' natural killer (N K) cell activity was evaluated. We also measured interleukin (IL)-2 co ncentration with IVF-ET patients' serum and clarified the relationship between IL-2 levels and the suppressive effect on NK cell activity. M ETHOD OF STUDY: A retrospective nonrandomized clinical study was perfo rmed. The suppressive effect on NK cell activity and IL-2 concentratio ns was measured with serum obtained from 30 pregnant and 30 nonpregnan t women during an IVF-ET procedure. The suppressive effect of the seru m on NK cell activity was evaluated by the formula that we defined in our previous study. RESULTS: The suppression of NK cell activity was s ignificantly higher in the nonpregnant women than in the pregnant wome n (P < 0.05); however, IL-2 concentration did not differ. There was a positive correlation between the suppression of NK cell activity and I L-2 levels in the pregnant women, but no significant correlation in th e nonpregnant women. CONCLUSIONS: These results suggest that the suppr ession of NK cell activity may be one of the prognostic factors for IV F-ET. In addition, we speculate that an unidentified humoral factor ot her than IL-2, which could increase NK cell activity, might exist in t he serum of the nonpregnant patient.