Monoclonality and oligoclonality of T cell receptor β gene in angioimmunoblastic T cell lymphoma

Abstract

Angioimmunoblastic T cell lymphoma (AILT) is an aggressive T cell lymphoma with an incidence of approximately 1–2% of all non-Hodgkin lymphoma. The detection of clonal T cell receptor (TCR) gene rearrangements helps in the diagnosis of T cell malignancies such as AILT, where morphological and immunohistological investigations are not always sufficient to reach a definitive diagnosis. TCR β (TCRB) and TCR γ (TCRG) gene rearrangements were analysed from 17 WHO-defined cases of AILT by PCR for the presence of TCR clonality. TCRB gene rearrangements were sequenced to identify molecular signature(s) common among this patient group. Monoclonal and oligoclonal TCRB and TCRG gene rearrangements were detected in all cases. BV17S1 was slightly over-represented compared to the use of other Vβ gene segments; however, no preferential usage of J gene segment(s) was detected. The results of this study emphasise that TCR clonality and oligoclonality is a diagnostic feature of AILT and that BV17S1 is over-represented with no other common molecular findings.