Epstein-Barr virus genome level, T-cell clonality and the prognosis of angioimmunoblastic T-cell lymphoma

Department of Pathology, School of Medicine, Fukuoka University, Fukuoka, Japan.

BACKGROUND AND OBJECTIVES: Angioimmunoblastic T-cell lymphoma (AILT) is a peripheral T-cell tumor of unknown etiology with variable biological and clinical presentations. Previous clonality studies have shown heterogeneous clonal restrictions of B- and T-cell populations in this tumor. AILT is characterized by the presence of increased numbers of Epstein-Barr virus (EBV) infected cells. The aim of this study was to clarify the correlation between clonality, EBV and prognosis. DESIGN AND METHODS: Frozen material from 59 cases of AILT was used for DNA isolation and gene analysis by Southern blotting. A real-time polymerase chain reaction was used to quantify the amount of EBV-DNA in the tissue. Survival data were retrieved from clinical records. RESULTS: Clonal T cells were found in 15/50 and clonal B-cells in 2/50 tumors, using Southern blot analysis. Bands of EBV-W were found in 10/50 tumors. Survival rate did not correlate with either T-cell clonality (p=0.84), or presence of EBV-infected cells (p=0.84). The EBV-DNA copy number in EBV-infected tissue did not correlate with disease progression (p=0.87). The survival rate and clinical status according to the international prognostic index (IPI) did not correlate with T-cell clonality status or EBV infection. INTERPRETATION AND CONCLUSIONS: AILT remains a heterogeneous disease with clinical behavior that varies irrespective of the genomic parameters investigated.