Which immunological parameters are clinically essential to monitor IL-2 cancer immunotherapy?

The evaluation of the immunobiological changes occuring during IL-2 cancer immunotherapy is not only important to correlate them with the clinical response or to understand the immune mechanism involved in tumor growth control, but also to predict the efficacy of treatment itself. As far as the immune status of patients prior to therapy is concerned, the evidence of the activation of the inflammatory response correlates with resistance to IL-2. Therefore, the evidence of abnormally high pretreatment values of inflammatory response markers, including ESR, CRP, neopterin and SIL-2R, may predict a lack of IL-2 efficacy. In contrast, changes in inflammatory parameters during IL-2 administration have no prognostic significance. The evidence of elevated pretreatment levels of the immunosuppressive cytokine IL-10 has also an unfavourable prognostic significance. At the other side, the evidence of a marked increase in hemopoietic cells involved in tumor cell destruction, such as lymphocytes and eosinophils, as well as in blood levels of antitumor cytokines, such as IL-12, correlates with efficacy of IL-2 cancer immunotherapy. A better definition of the prognostic significance of immunoinflammatory markers will allow us to manipulate and improve host biological response during cancer immunotherapy with IL-2.