ISSN 1866-8836
Клеточная терапия и трансплантация

AL-04. Dynamics of different memory T cell recovery in patients with acute leukemia after allogeneic hematopoietic stem cell transplantation

Natalia N. Popova, Mikhail Yu. Drokov, Julia O. Davydova, Nikolay М. Kapranov, Ulyana V. Maslikova, Feruza A. Omarova, Ekaterina D. Mikhaltsova, Olga M. Koroleva, Zoya V. Konova, Anna A. Dmitrova, Mariya V. Dovydenko, Olga S. Starikova, Darya S. Dubnyak, Elmira I. Kolgaeva, Mobil I. Akhmedov, Vera A. Vasilyeva, Irina V. Galtseva, Larisa A. Kuzmina, Elena N. Parovichnikova, Valery G. Savchenko

National Research Center for Hematology, Moscow, Russia

Contact: Dr. Mikhail Drokov, e-mail: mdrokov@gmail.com

doi 10.18620/ctt-1866-8836-2020-9-3-1-152

Summary

Introduction

Reconstitution of T-cell immunity after allogeneic stem cell transplantation determines such posttransplant complications, as infections, GVHD and tumor relapse. Our aim was to study the time course of memory T cell subsets recovery in the patients with acute leukemia after allogeneic stem cell transplantation (allo-HSCT).

Patients and methods

65 patients with acute leukemia were enrolled in the study. All the patients underwent allo-HSCT at the National Research Center for Hematology. The patients were divided into 3 groups, given an impact of immunosuppressive regimens on T cell recovery. The first group included the patients after classical GVHD prophylaxis regimen based on horse ATG (n=32); the 2nd group consisted of the patients after post-transplant cyclophosphamide (PtCy) combined with ATG (n=18), and the last group was presented by the patients after ex vivo TCR αβ depletion (n=15).

Peripheral blood samples were taken on day +30, +60, +90, +180 to analyze reconstitution of T memory cell subsets. Flow cytometry measurements with BD FACS Canto II system (Becton Dickinson, USA) were performed to quantify the following CD4+ and CD8+ subsets: naïve and T memory stem cells (Tnv+Tscm) with CD45R0-CCR7+CD28+ phenotype; T central memory cells (Tcm, CD45R0+CCR7+CD28+); T transitional memory cells (Ttm, the CD45R0+CCR7-CD28+ phenotype); T effector memory (Tem) cells (CD45R0+CCR7-CD28-), and terminal effectors (Tte, CD45R0-CCR7-CD28-). The entire data evaluation was performed using SPSS ver. 23. (IBM, Chicago, Il., USA). The time course of memory T cell recovery (the effect of time factor on repeated measurements) was studied within each subset, with respect to the GVHD prophylaxis regimen. The Friedman criterion was used to evaluate the dynamics. The value of p <0.05 was considered significant.

Results

The recovery of T cell immunity occurs through all studied subsets (Tnv+scm, Tcm and effector T cells) in case of ex vivo ТCR αβ depletion, whereas GVHD prophylaxis with ATG or Cyclophosphamide is accompanied by significant changes in the pool of effector T cells (figure 1).

Popova-fig01.jpg

Figure 1. Time course of T memory cell recovery following allogeneic HSCT

Discussion

Earlier we already presented the data about comparable impact of ТCR αβ depletion and PtCy upon short-term T cell recovery (especially, upon Tnv+scm on day +30). This study suggests further reconstitution of T memory cell subsets (after day +30) to be significantly different in terms of GVHD prophylaxis regimens.

Keywords

Memory T cells, immune reconstitution, allogeneic stem cell transplantation, acute GVHD prophylaxis.



Volume 9, Number 3
09/30/2020

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doi 10.18620/ctt-1866-8836-2020-9-3-1-152

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