OBJECTIVES To evaluate CD200 expression in B-cell proliferative disorders. METHODS We analyzed 180 recent specimens of B-cell neoplasms for CD200 expression by flow cytometric immunophenotypic analysis, which is better able to assess relative intensity of staining than immunohistochemical staining. RESULTS We found that hairy cell leukemia exhibits a high level of staining for CD200 in comp...

Activated T cells synthesize and express a cell membranebound receptor for interleukin-2 (lL-2) and have recently been shown to secrete a soluble form of the same receptor. Hairy cell leukemia is a chronic disorder caused by expansion of a clonal population of an unusual mononuclear cell of B cell origin. These cells have previously been shown to express an 11-2 receptor on the cell membrane. T...

Intensive leukopheresis has been valuable in the short-term palliation of chronic lymphocytic and granulocytic leukemias. A 47-yr-old man with refractory leukemic reticuloendotheliosis (hairy cell leukemia) manifested by anemia, thrombocytopenia, elevated peripheral leukemia cell counts, generalized lymph node enlargement, and leukemic infiltrative skin disease was treated with serial leukopher...

Hairy cell leukemia variant (HCL-v) is a rare form of a chronic B-cell lymphoproliferative disorder. Unlike typical hairy cell leukemia (HCL) where the complete response (CR) rate to 2-chlorodeoxyadenosine and 2'-deoxycoformycin can approach about 90%, in HCL-v CR is rare and partial response (PR) occurs in approximately 50% with these agents. Rituximab treatment in relapsed or refractory HCL r...

A diagnosis of hairy cell leukemia was made by optic microscopy, phase-contrast microscopy, electron microscopy, scanning microscopy, and histochemistry of the abnormal blood cells. In vivo these cells were found to have a half-time in the blood of approximately 150 hr. In vitro they had the capacity to adhere firmly to plastic, making it possible to obtain a pure population of hairy cells. Nei...

In their report in BLOOD 74:320, 1989, Visser et a1 reported on a new monoclonal antibody designated B-ly7 that they suggested to be specific for hairy cells and some scattered normal B cells. Using their antibody (courtesy of Dr Poppema) we can essentially confirm the close association of B-ly7 antigen expression with hairy cell leukemia. However, regarding the specificity of this reagent we w...