ABSTRACT
The achievement of molecular remission is associated with increasing of survival of patients with chronic lymphatic leukemia. The important direction of research is seeking of parameters applicable to forecast of response to therapy. The purpose of the study was evaluating prognostic significance of indicator of minimal residual disease detected by technique of flow cytofluorometry of peripheral blood of patients with chronic lymphatic leukemia during therapy application. The sampling included 112 patients with chronic lymphatic leukemia aged from 43 to 82 years. All patients were given treatment consisted of 6 courses of immune chemotherapy combined with fludarabine with cyclophosphan and rituximab. The samples of peripheral blood were analyzed after 3 courses during therapy and after 6 courses after completion of treatment. The cells were analyzed using 5 and 6 color flow cytometry for the purpose of detection of immune phenotype associated with chronic lymphatic leukemia. The evaluation of minimal residual disease was implemented according international standardized protocol (Rawstron A.C. et al. 2007; 21 (5): 956-64). The minimal residual disease negative status was reached in 87 (78%) patients during evaluation of response after 6th course of treatment. The implementation of indicators of residual disease after 3 courses with fludarabine, cyclophosphan and rituximab permitted to sort out two groups of patients with chronic lymphatic leukemia i.e 67 patients with low (< 0.12%) level of minimal residual disease and 45 patients with high (> 0.12%) level of tumor cells. The rate of molecular remission after completion of treatment. in the given groups consisted 100% and 44% correspondingly. The study demonstrates possibilities of early immune phenotype evaluation of minimal residual disease to forecast differences in response to treatment in patients with chronic lymphatic leukemia that makes it possible to avoid undesirable toxicity of therapy or to choose method of consolidation.
