Detection of Putative T cell Clones Using T cell Receptor β Chain Gene Clonality Assay in Korean Patients with Aplastic Anemia

Abstract

We analyzed T cell receptor beta chain (TCRB) gene to investigate the presence of putative T cell clones and its clinicopathologic implications in Korean patients with aplastic anemia (AA). 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. 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, Dbeta; joining region, Jbeta; variable region, Vbeta) was distributed in Dbeta2+Jbeta2 (6 cases), Dbeta1+Jbeta1 (3 cases), Vbeta+Jbeta1 (2 cases), and Dbeta1+Jbeta2 (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. 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.