Bio-P-01 - Prognostic value of the clonal rearrangement of T-cell receptor genes detection in the bone marrow in patients with mycosis fungoides

Abstract

<h3>Introduction:</h3> Mycosis fungoides constitutes more than 60% of primary cutaneous T-cell lymphomas. The course of disease is progradient: the gradual changes of macular, plaque and tumor stages are noted. The evaluation of the spreading process is critically important for the prognosis determination and therapy choosing. T-cell clonality detection by rearranging genes of the gamma chain of the T-cell receptor in the blood and bone marrow aspirates can be detected at the early stages. It is known to be a prognostically unfavorable factor for diagnostics in peripheral blood, while the value of the rearranging presence of T-cell receptor gene in the bone marrow aspirates has not been fully studied. <h3>Aim:</h3> To evaluate the frequency and prognostic value of the T-cell clonality detection by the gamma chain of the T-cell receptor in the bone marrow in patients with mycosis fungoides/Sézary syndrome (MF/SS). <h3>Materials and methods:</h3> The patients with mycosis fungoides/Sézary syndrome were observed at the National Research Centre of Hematology during the period from 2000 to 2015. <h3>Results:</h3> 45 patients diagnosed with mycosis fungoides/Sézary syndrome (MF/SS) corresponded to inclusion criteria. Men/women 1:1. The age of the participants is varied from 20 to 81 years. The diagnosis of mycosis fungoides was made in 36 cases (80%) and the diagnosis of Sézary syndrome was made in 9 cases (20%) respectively. The early stages were diagnosed in 13 patients (29%), the later stages were diagnosed in 32 patients. T-cell clonality by the gamma chain rearrangement of the T-cell receptor was detected in the bone marrow in 15 out of 45 patients (33%). 13 cases were the patients with the late disease stages and clonality at the early Ib stage was detected only in 2 cases. The morphological bone marrow involvement was identified in 5 patients, but in two cases T-cell clonality was not detected. The median survival of patients with morphologically confirmed bone marrow damage was 3 months. The median survival of patients with defined T-cell clonality in the bone marrow was 21 months. The median survival with no molecular damages of bone marrow was 41 months. <h3>Conclusions:</h3> T-cell clonality by gamma chain rearranging of the T-cell receptor in the bone marrow in patients with mycosis fungoides/Sézary syndrome is determined in a third of patients mainly at the late MF stages. This is an unfavorable prognostic factor.