Hairy cell leukemia (HCL) is one of the few malignancies for which alpha-interferon (IFN alpha) is considered effective first-line therapy. However, the mechanisms of action of this agent in vivo have been the subject of much debate; in particular, the issue of whether clinical improvement in IFN-alpha-treated HCL patients is dependent upon enhancement of host defenses or upon direct actions of...

Hairy cell leukemia (HCL) is one of the few malignancies for which a-interferon (IFNa) is considered effective first-line therapy. However, the mechanisms of action of this agent in vivo have been the subject of much debate; in particular, the issue of whether clinical improvement in IFNa-treated HCL patients is dependent upon enhancement of host defenses or upon direct actions of IFNa upon the...

Monoclonal antibodies defining B-, T-, and myeloid-restricted cell surface antigens were used to characterize the lineage and state of differentiation of tumor cells isolated from 22 patients with hairy cell leukemia (HCL). These tumors were shown to be of B lineage because they strongly expressed the B cell-restricted antigens B1 and B4 and lacked T cell- and monocyte-restricted antigens. More...

A 65-year-old man, with no previous significant complete blood count findings and no preexisting concern for hematopoietic malignancy, presented for baseline bone marrow evaluation as a potential donor for hematopoietic stem cell (HSC) transplant for his brother, a patient with mantle cell lymphoma (cyclin D1). Marrow aspirate smear (panel A) revealed 7% myeloid precursors, 36% erythroid precur...