Natural killer frequency determines natural killer cytotoxicity directly in accentuated zones and indirectly in "moderate-to-normal frequency" segment.

Natural killer (NK) frequency and NK cytotoxicity (NKc) are key determining factors of a clinical outcome. In our previous study, we showed the prognostic clinical significance of immune parameters when they are beyond the optimal range (accentuated). In this study, we attempted to explain the disparity of accentuated but physiologically and immunologically normal NK parameters that might serve as negative clinical prognostics indications of failed pregnancies.

Peripheral blood natural killer cells activation status determined by CD69 upregulation predicts implantation outcome in IVF.

Problem: NK lymphocytes play critical yet poorly defined role in implantation and during development in early pregnancy.

Methods Of Study: Recently, we showed that the proportion of NK that expressed CD69⁺ after incubation with K562 (CD69(stim)) cells reflected the NK population excitation potential. In the present study, we investigate the significance of NK activation levels in predicting embryo implantation.