HLA Class II Expression by Hodgkin Reed-Sternberg Cells Is an Independent Prognostic Factor in Classical Hodgkin's Lymphoma

Purpose The neoplastic Hodgkin Reed-Sternberg (HRS) cells in classical Hodgkin's lymphoma (cHL) are derived from B cells. The frequency of HLA class II downregulation and its effect on prognosis are unknown. Patients and Methods Immunohistochemistry results for HLA class II were evaluated in 292 primary cHL patients in a population-based approach. Patients were diagnosed between 1989 and 2000 in the northern part of the Netherlands. Median age at diagnosis was 38 years (range, 8 to 88 years); 63% had Ann Arbor stage I or II, 24% stage III, and 13% stage IV disease. Median follow-up was 7.1 years. For 168 patients, HLA genotype data were available. Results Lack of HLA class II cell-surface expression on HRS cells was observed in 41.4% and was more common in patients with extranodal disease, patients with Epstein-Barr virus–negative disease, and patients with HLA class I–negative HRS cells. Alleles of three microsatellite markers in the HLA class II region were associated with presence or absence of protein...