Detection of putative T cell clones using T cell receptor β Chain Gene clonality assay in Korean patients with aplastic anemia

Abstract

Background: We analyzed T cell receptor β chain (TCRB) gene to investigate the presence of putative T cell clones and its clinicopathologic implications in Korean patients with aplastic anemia (AA). Methods: Twenty-nine bone marrow specimens were collected from 20 AA patients, 19 specimens from initial diagnosis and 10 from follow-up. T cell clonality assay was performed using IdentiClone™ TCRB Gene Clonality Assay kit (InVivoScirbe Technology, USA) and automatic genetic analyzer. Patients' clinical information and laboratory parameters were also analyzed. Results: Five patients had definitive underlying factors related with aplastic anemia, such as hepatitis B virus (4 cases) and benzene exposure (1 case). Putative T cell clones were detected in bone marrow specimens of 11 (58%) out of 19 patients at diagnosis. The location of putative T cell clones of TCRB gene (diversity region, Dβ; joining region, Jβ; variable region, Vβ) was distributed in Dβ2+ Jβ2 (6 cases), Dβ1+Jβ1 (3 cases), Vβ+Jβ1 (2 cases), and Dβ1+Jβ2 (2 cases). Interestingly, among seven patients who underwent stem cell transplantation, five patients with no T cell clones detected at diagnosis developed new T cell clones during the follow-up. Conclusions: Putative pathogenetic T cell clones were detected in most of AA patients in the current study. T cell clonality assay would be useful for investigating the pathophysiology of acquired AA.