NODULAR LYMPHOCYTE-PREDOMINANT HODGKINS-DISEASE ASSOCIATED WITH LARGE-CELL LYMPHOMA - ANALYSIS OF IG GENE REARRANGEMENTS BY V-J POLYMERASE CHAIN-REACTION

The clonality of nodular lymphocyte-predominant Hodgkin's disease (NLP HD) and the relationship to composite or sequential large-cell lymphom as (LCLs) is poorly understood. Clonal Ig heavy-chain gene rearrangeme nts (IgHGR) have infrequently been observed in NLPHD by Southern hybri dization. The goals of this study were (1) to determine if IgHGR could be identified by polymerase chain reaction (PCR) techniques in the LC L associated with NLPHD; (2) to determine if the IgHGR identified in t he LCL could also be found in the associated NLPHD; and (3) to determi ne if Epstein-Barr virus (EBV) played a role a role in histologic prog ression to LCL. Using consensus primers to conserved regions in the Ig H variable (V) and joining (J) region genes, we analyzed formalin-fixe d paraffin-embedded sections from the biopsies of 25 patients referred to the National Cancer Institute (NCI) registry for NLPHD and LCL usi ng both single-step and seminested V-J PCR. The histologically aggress ive component was further subclassified as frank LCL or as L&H-cell-ri ch, but not fulfilling criteria for LCL. Matched samples representing both NLPHD and aggressive components were available in 13 cases. In 12 cases, only one component was available (aggressive, n = 8; NLPHD, n = 4). In addition, we also amplified, with P-32 labeling, 12 cases of NLPHD without associated LCL, Two clonal IgHGR were identified in 29 c ases (7%) of typical NLPHD, both of which were associated with LCL con taining a similar sized band by PCR. The clonal identity of the bands in the NLPHD and associated LCL was confirmed by sequencing the produc ts in these two cases. Eight of 10 cases (80%) of LCL associated with NLPHD contained a clonal band by this technique. By contrast, none of the cases classified as L&H-cell-rich contained an IgHGR. The single-s tep and seminested PCR methods produced identical results. All clonal LCLs were studied for EBV sequences by in situ hybridization using the EBER1 probe, and were negative. We conclude that the LCLs associated with NLPHD are clonal B-cell malignancies. However, by these methods, the same clone can be identified in only a minority of cases of NLPHD and LCL. EBV does not appear to play a role in histologic progression. Moreover, our results suggest that many cases suspected of being LCL may actually represent NLPHD with increased numbers of L&H cells. In h istologically equivocal cases, the diagnosis of LCL should be reserved for those cases in which a clonal B-cell neoplasm can be demonstrated .