异基因造血干细胞移植后T大颗粒淋巴细胞增多的临床特征及对预后的影响

OBJECTIVE: To explore the clinical characteristics, related factors, and prognostic effect of patients with T cell large granular lymphocytosis following allo-HSCT. METHODS: Consecutive patients with T-LGL following allo-HSCT who visited our center from June 2013 to February 2020 were studied retrospectively. We compared patients undergoing allo-HSCT during this period. The clinical characteristics, related factors, cumulative incidence of patients with T-LGL and rates of overall survival (OS), disease free survival (DFS), relapse, and non-relapse mortality (NRM) were analyzed. RESULTS: Total 359 patients were enrolled, including 17 with T-LGL and 342 without T-LGL following allo-HSCT. The median follow-up duration was 38 (3–92) month. The cumulative incidence at 1-, 2- and 3-years of T-LGL was 3.64% (95%CI 1.09%–6.19%), 4.50% (95%CI 1.36%–7.64%), and 4.84% (95%CI 1.10%–8.76%), respectively. CMV reactivation (P=0.013), EB viremia (P=0.034), and aGVHD (P=0.027) were associated with the development of T-LGL following allo-HSCT. Multivariate analysis showed that benign hematologic diseases [P=0.027, OR=3.36 (95%CI 1.15–9.89)] and haploidentical hematopoietic stem cell transplantation [P=0.030, OR=4.67 (95%CI 1.16–18.75)], unrelated donor transplantation [P=0.041, OR=5.49 (95%CI 1.10–28.16)] were independent predictive factors of T-LGL following allo-HSCT. There was a significant difference in the 3-year OS (100.0% vs. 78.6%, P=0.04), DFS (100.0% vs. 70.0%, P=0.01), and NRM (0 vs. 12.6%, P=0.02) between the 2 cohorts. Subgroup analysis showed that malignant diseases recipients who developed T-LGL had better outcomes after allo-HSCT, and there was a significant difference in the NRM (P=0.042), DFS (P=0.013), and cumulative relapse rate (P=0.028) between the 2 cohorts. In contrast, the appearance of T-LGL after allo-HSCT in patients with benign diseases had no significant effect on the prognosis. CONCLUSION: T-LGL was a durable and clinically benign phenomenon occurring in allo-HSCT recipients with malignant diseases. Factors associated with immune reconstitution and T-cell regulatory mechanisms might be major predictors of T-LGL following allo-HSCT.