CLASSICAL HODGKINS-DISEASE - CLINICAL IMPACT OF THE IMMUNOPHENOTYPE

Antibodies against CD15, -30, and -20 are often used to support morpho logical diagnosis of Hodgkin's Disease (HD). The classical HD, ie, the non-lymphocyte-predominance types, are CD15(+), CD30(+), and CD20(-) in general, However, the results for CD15 are less clear-cut in many s tudies, showing up to 40% of classical HD that lack positivity for thi s maker. Little is currently known about the relevance of antigen expr ession in relation to clinical outcome in HD, Therefore, the three mar kers were analyzed in 1751 cases from the German Hodgkin Study Group, using microwave epitope retrieval to optimize staining sensitivity. Ei ghty-three percent of the cases showed a classical immunophenotype (CD 15(+), CD30(+), CD20(-)), twelve percent lacked CD15 positivity (CD15( -), CD30(+), CD20(-)), and five percent showed other combinations. For 1286 cases, clinical follow-up was available, which revealed signific ant differences for freedom from treatment failure (P = 0.0022) and ov erall survival (P = 0.0001) between cases with classical immunophenoty pe and CD15 negativity (CD30(+), CD20(-)). Multivariate Cox regression using the three markers, age, sex, histology, stage, B-symptoms (feve r, sweats, weight loss >10% of body weight), hemoglobin, and erythrocy te sedimentation rate as factors showed that lack of CD15 expression i n classical HD is an independent negative prognostic factor for relaps es (P = 0.022) and survival (P = 0.0035). In conclusion, immunohistoch emistry is able to identify classical HD cases with unfavorable clinic al outcome.