Differential chemokine expression in tissues involved by Hodgkin's disease: Direct correlation of eotaxin expression and tissue eosinophilia

Hodgkin's disease (HD) is a lymphoid malignancy characterized by infrequent malignant cells surrounded by abundant inflammatory cells. In this study, we examined the potential contribution of chemokines to inflammatory cell r ecruitment in different subtypes of HD. Chemokines are small proteins that are active as chemoattractants and regulators of cell activation. We found that HD tissues generally express higher levels of interferon-gamma-inducib le protein-10 (IP-10), Mig. RANTES, macrophage inflammatory protein-1 alpha (MIP-1 alpha). and eotaxin, but not macrophage-derived chemotactic factor (MDC), than tissues from lymphoid hyperplasia (LH). Within HD subtypes, exp ression of IP-10 and Mig was highest in the mixed cellularity (MC) subtype, whereas expression of eotaxin and MDC was highest in the nodular sclerosis (NS) subtype. A significant direct correlation was detected between eviden ce of Epstein-Barr virus (EBV) infection in the neoplastic cells and levels of expression of IP-10, RANTES, and MIP-1 alpha. Levels of eotaxin express ion correlated directly with the extent of tissue eosinophilia. By immunohi stochemistry, IP-10, Mig, and eotaxin proteins localized in the malignant R eed-Sternberg (RS) cells and their variants, and to some surrounding inflam matory cells. Eotaxin was also detected in fibroblasts and smooth muscle ce lls of vessels. These results provide evidence of high level chemokine expr ession in HD tissues and suggest that chemokines may play an important role in the recruitment of inflammatory cell infiltrates into tissues involved by HD. (C) 1999 by The American Society of Hematology.