T-Cell Receptor Rearrangements Determined Using Fragment Analysis in Patients With T-Acute Lymphoblastic Leukemia

• Published in: Annals of laboratory medicine Vol. 39; no. 2; pp. 125 - 132
• Main Authors: Kim, Hyerim, Kim, In-Suk, Chang, Chulhun L., Kong, Sun-Young, Lim, Young Tak, Kong, Seom Gim, Cho, Eun Hae, Lee, Eun-Yup, Shin, Ho-Jin, Park, Hyeon Jin, Eom, Hyeon-Seok, Lee, Hyewon
• Format: Journal Article
• Language: English
• Published: Korea (South) The Korean Society for Laboratory Medicine 01.03.2019; 대한진단검사의학회
• Subjects: Original; 병리학; T-cell receptor; Minimal residual disease; Clonality; T-acute lymphoblastic leukemia; Fragment analysis
• ISSN: 2234-3806; 2234-3814; 2234-3814
• DOI: 10.3343/alm.2019.39.2.125

Chromosomal abnormalities and common genetic rearrangements related to T-acute lymphoblastic leukemia (T-ALL) are not clear. We investigated T-cell receptor ( ) rearrangement in Korean T-ALL patients by fragment analysis, examining frequency, association between clinicopathologic characteristics and clonality, and feasibility for detecting minimal residual disease (MRD). In 51 Korean patients diagnosed as having T-ALL, rearrangement was analyzed using the IdentiClone gene clonality assay (InVivoScribe Technologies, San Diego, CA, USA) from archived bone marrow specimens. Limit of detection (LOD) and clonal stability at relapse were evaluated. The association between clinical prognosis and clonality was examind by age and immunophenotypic classification. Thirty-eight patients (74.5%) had 62 clonal products of , , and/or rearrangements at diagnosis. Children with T-ALL (<12 years) showed a higher frequency of clonality (93.8%) than adolescents/adults (65.7%; ≥12 years). Patients with a mature immunophenotype (84.4%) showed a relatively higher frequency of clonality than those with the immature immunophenotype (57.9%). Survival and event-free survival were not influenced by immunophenotype or clonality. The LOD was 1%. Clonal evolution at the relapse period was noted. The overall detection rate of clonality was 74.5%. Survival did not differ by clonality or immunophenotype and age group. Fragment analysis of rearrangement cannot be used to assess MRD due to low sensitivity. Further research on the relationship between prognosis and frequency of rearrangements is needed, using more sensitive methods to detect clonality and monitor MRD.