Among malignant diseases, chronic myeloid leukaemia (CML) is one of the best suited candidates for immunotherapy. For this purpose it is necessary to broaden the present knowledge on the immunology of this disease. As a part of such a project, the levels of kynurenine (KYN) and neopterin (NPT) were studied in 28 CML patients and in the same number of healthy subjects. At diagnosis, both KYN and NPT levels were found to be elevated in a significant portion of the patients and dependent on their leukocyte count. As in the case of KYN, increased NPT levels dropped after achieving remission. When correlating KYN and NPT levels with a selection of other markers tested, significant association was revealed only in the case of CRP and IL-6. However, there were several patients with increased KYN levels in whom NPT was not detected, and vice versa. The relapse of the disease observed in two patients was accompanied by an increased level of NPT in both cases, but by an increased level of KYN in only one of them. No significant correlation was found between KYN and NPT levels in sera taken at diagnosis. However, when the whole set of sera was taken into consideration, the association became statistically significant. Although the data obtained revealed a number of similarities between KYN and NPT production in CML patients, it also suggested a difference in the kinetics of these two biomarkers' production.

Department of Analytical Chemistry Faculty of Pharmacy in Hradec Králové Charles University and 3rd Internal Gerontometabolic Clinic University Hospital Hradec Králové Czech Republic

Department of Experimental Virology Institute of Haematology and Blood Transfusion Prague Czech Republic

Institute of Immunology and Microbiology 1st Faculty of Medicine Charles University and General University Hospital Prague Czech Republic