Tumor cell growth fraction in Hodgkin's disease.

The growth fraction of tumor cells was studied in 45 cases of Hodgkin's disease by means of a recently developed double immunostaining technique using monoclonal antibody Ki-1, which reacts selectively with Hodgkin and Reed-Sternberg cells in tissues affected by Hodgkin's disease, and antibody Ki-67, which recognizes a cell proliferation-associated nuclear antigen. The medians of the growth fractions of the tumor cells in all histologic subtypes of Hodgkin's disease varied between 78% and 83%. In none of the cases investigated did we find a growth fraction below 50%. Furthermore, mononucleated Hodgkin cells as well as multi-nucleated Reed-Sternberg cells showed a similar Ki-67 labeling index, indicating that both tumor cell types belong to the proliferating pool of this malignancy.