IMMUNOPHENOTYPE OF REED-STERNBERG AND HODGKINS CELLS IN SEQUENTIAL BIOPSY SPECIMENS OF HODGKINS-DISEASE - A PARAFFIN-SECTION IMMUNOHISTOCHEMICAL STUDY USING THE HEAT-INDUCED EPITOPE RETRIEVAL METHOD

Other studies have shown that the immunophenotype of Reed-Sternberg an d Hodgkin's (RS-H) cells in Hodgkin's disease commonly changes over ti me, as shown by examination of multiple biopsy specimens obtained from an individual patient. In this study we analyzed 96 sequential biopsy specimens (>1 month apart) obtained from 44 patients (nodular scleros is, 34 specimens; mixed cellularity, 5; lymphocyte depletion, 1; uncla ssified, 4) using fixed, paraffin-embedded sections; heat-induced epit ope retrieval (HIER); a panel of antibodies specific for the CD3, CD15 , CD20, CD30, CD43, CD45/45RB, and CD79a antigens and Epstein-Barr vir us latent-membrane protein; and a streptavidin-biotin method. In selec ted cases in which immunophenotypic changes occurred, studies were rep eated using enzyme predigestion instead of HIER. There was no change i n the immunophenotype of the RS-H cells in 36 (82%) of 44 patients. In 8 patients (18%), the immunophenotype of the RS-H cells varied in exp ression of one or two antigens. The antigens that varied were as follo ws: CD30, 3 patients; CD15, 3 patients; CD20, 1 patient; and CD15 and CD30, 1 patient. We conclude that the immunophenotype of RS-H cells in Hodgkin's disease is relatively stable over time and that CD15 and CD 30 are the most common antigens that change. The frequency of immunoph enotypic changes, 18%, is substantially lower than that reported previ ously. One likely explanation for this discrepancy is that we used HIE R, a relatively recent innovation in diagnostic immunohistochemistry t hat has been shown to reduce artifacts attributable to inconsistent fi xation and processing. The significance of immunophenotypic variation in eight cases (18%) is uncertain. This phenomenon may represent true biologic changes in RS-H cells. Alternatively, these changes may be at tributable to artifacts secondary to inconsistent fixation or processi ng that HIER cannot overcome.