A DEFINITIVE TCRBETA1/ TCRBETA2 ANTIBODY PAIR FOR DETERMINING T-CELL MONOTYPIA AS A SURROGATE FOR CLONALITY IN LYMPHOMA DIAGNOSIS IN FORMALIN FIXED PARAFFIN EMBEDDED MATERIAL

Abstract T-cell lymphomas are often histologically indistinguishable from benign T-cell infiltrates. Clonality testing is frequently required for diagnosis. It lacks the spatial context and is slow and expensive, relying on complex, multiplexed PCR reactions, interpreted by experienced scientists or pathologists. We previously published details of a pair of highly specific monoclonal antibodies against the two alternatively used, but very similar, T-cell receptor β constant regions, TCRβ1 and TCRβ2. We demonstrated the feasibility of immunohistochemical detection of TCRβ1 and TCRβ2 in formalin-fixed, paraffin-embedded (FFPE) tissue as a novel diagnostic strategy for T-cell lymphomas. Here we validate an improved pairing of TCRβ1/2 rabbit monoclonal antibodies, and demonstrate their utility for single and double immunostaining, including with a chimeric mouse anti-TCRβ2 antibody. Finally, we show that this staining is amenable to automated cell counting, permitting accurate calculation of the TCRβ2:TCRβ1 ratio.