ANGIOIMMUNOBLASTIC LYMPHADENOPATHY WITH DYSPROTEINEMIA AND DERMAL T-CELL LYMPHOMA

Background. T-cell receptor (TCR)-gamma gene rearrangements provide a specific clonal marker for T-cell malignancies of both the alpha beta and gamma delta varieties. A polymerase chain reaction (PCR)-based met hod was used in this study for investigation of clonal TCR-gamma gene rearrangements in a patient with a classical presentation of angioimmu noblastic lymphadenopathy with dysproteinemia (AILD) that subsequently progressed into an indolent form of dermal T-cell lymphoma. Methods. TCR gene rearrangements in patients with cutaneous T-cell lymphoma (CT CL) were examined using conventional Southern blot analysis and a newl y developed PCR-based technique for clonal TCR gene rearrangements. Th e oligoprimers amplified rearranged V gamma and J gamma segments (incl uding the N region) of the TCR-gamma gene, and PCR products were resol ved using high resolution nondenaturing polyacrylamide gel electrophor esis. Results. The authors' results demonstrated good correlation betw een the two techniques in 10 patients with CTCL (9 patients with C bet a and 1 patient with delta 2 rearrangements) and 10 control subjects. The PCR-based technique allowed the authors to detect the presence of an identical T-cell clone in all skin nodules, but not in the original lymph node affected by AILD. Conclusions. This PCR-based method for d etecting clonal TCR rearrangements is a highly sensitive and specific technique for detecting T-cell clones in fresh and paraffin embedded t issues. The presence of a T-cell clone in all skin nodules of this pat ient, but not in the original lymph node affected by AILD, confirms pr evious findings that in some cases of AILD, clonal T-cell expansion ma y not be detectable until a later stage of the disease.