[28].
NKT profile shows slightly increase without the significance of GzB expression, this is reported by Wang et al. who reported that their function is affected by the release of soluble major histocompatibility complex (MHC) class I chain-related molecules by cancer cells impairing the lytic activity via down-regulation of the NKG2D receptor [29].
Circulating cytokines are closely associated with the immune status against many diseases including cancer. In the present study, we also observed the levels of several cytokines in our different groups of patients compared to healthy controls. As shown in our previous study, the levels of IL-1 and CCL-2 in early diagnosis patients showed a 14000, 250 fold increase respectively compared with the control group. This increase adds to the chain of evidence supporting that these cytokines promote tumor growth, chemo-resistance and help sustain an immunosuppressive milieu [30]. Additionally, we found that the levels of IL-6 where increased by 100 fold in lung cancer patients which is also in line with previous studies has shown it to be positively correlated with lymph node metastasis, distant metastasis and worse overall survival [30, 31]. Furthermore, CXCL8 which promotes angiogenesis and tumor progression was increased by 30 folds in diagnosed lung cancer patients weighed against healthy controls. Whereas the proportions of the other 4 cytokines evaluated, including CXCL10, IL-5, CCL11 and CCL4 showed no significant difference between lung cancer patients and the control group [32]. The present study supports the hypothesis that the systemic cytokine cascade exists in lung cancer patients, reflecting the tumor stage and host immune status. Moreover, these changes in the level of cytokines may be of major importance as a diagnostic and prognostic tool in lung cancer and they can be considered as potential targets for immunotherapy.

In summary, these results confirm that the functionality of CTL and NK cells are impaired in cancer patients during and after induction of chemotherapy, while, patients before induction of chemotherapy have the ability to improve their CTL and NK functionality under activation conditions of combination between Con-A and IL-2.