Correlation of telomere length of bone marrow mononuclear cells with relapse after allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia / 白血病·淋巴瘤

ABSTRACT

Objective:To investigate the relationship between telomere length of bone marrow mononuclear cells and prognosis of patients with acute myeloid leukemia (AML) who received allogeneic hematopoietic stem cell transplantation (allo-HSCT).Methods:Telomere length of bone marrow mononuclear cells before transplantation, after transplantation and before donor mobilization as well as information related to follow-up of 33 AML patients who received allo-HSCT in the Affiliated Hospital of Guizhou Medical University between June 2020 and June 2021 were retrospectively analyzed. Telomere length was detected by using telomeric terminal restriction fragment (TRF) method. Telomere length was compared among patients with different prognoses. The recurrence within 1 year was treated as the gold standard and receiver operating characteristic (ROC) curve was used to analyze the effect of telomere length before transplantation or before donor mobilization in the judgement of the recurrence within 1 year after transplantation. The patients were stratified according to the optimal threshold value of telomere length for patients or donors, and Kaplan-Meier method was used to compare the progression-free survival (PFS) of patients with different stratification, and log-rank test was performed.Results:The median age of 33 patients was 34 years (14-61 years), and there were 17 males and 16 females; 31 patients were initially diagnosed with AML, 1 patient transferred from myelodysplastic syndrome (MDS) to AML, and 1 patient transferred from chronic granulocytic leukemia (CML) to AML; 14 received identical sibling transplantation and 19 received haploidentical sibling transplantation. The median age of the donors was 30 years (20-65 years), including 24 males and 9 females. Telomere length of bone marrow mononuclear cells before mobilization in 33 donors was longer than that in patients before transplantation (33 cases) and at +30 d after transplantation (31 cases) [(6.67±0.31) kb, (6.40±0.33) kb, (6.48±0.33) kb, respectively; all P < 0.05], and the difference between patients before and at +30 d after transplantation was not statistically significant ( t = 0.89, P = 0.378), and the telomere length of bone marrow mononuclear cells in 11 patients +180 d after transplantation was (6.66±0.18) kb. The incidence of acute graft-versus-host disease (aGVHD) after transplantation was 45.5% (15/33), the incidence of infection with clear imaging and pathogenic basis was 39.4% (13/33), the mortality rate within 1 year after transplantation was 3.0% (1/33), and the recurrence rate within 1 year after transplantation was 15.2% (5/33). There were no statistically significant differences in telomere length of donor pre-mobilization bone marrow mononuclear cells between the groups with and without aGVHD and between the infected and non-infected groups (all P > 0.05).Compared with patients who had not relapsed within 1 year after transplantation, telomere length of donor pre-mobilization bone marrow mononuclear cells was shorter in patients who relapsed within 1 year after transplantation [(6.39±0.19) kb vs. (6.72±0.30) kb, t = -3.23, P = 0.011], telomere length was longer in patients before transplantation [(6.75±0.16) kb vs. (6.35±0.36) kb, t = 4.17, P = 0.001]. ROC curve analysis showed that the optimal threshold values for telomere length of pre-transplantation and donor pre-mobilization bone marrow mononuclear cells were 6.48 and 6.42 kb, respectively for patients who relapsed within 1 year after transplantation. PFS in patients with pre-transplantation bone marrow mononuclear cells telomere length < 6.48 kb was better than that in patients with telomere length ≥ 6.48 kb ( P = 0.003); PFS in patients with pre-mobilization bone marrow mononuclear cells telomere length>6.42 kb was better than that in patients with telomere length ≤ 6.42 kb ( P < 0.001). Conclusions:In allo-HSCT for AML, patients have an increased risk of relapse within 1 year after transplantation when their pre-transplantation bone marrow mononuclear cells telomere length is long and the donor bone marrow mononuclear cells telomere length is short.