THE PHENOTYPE OF THE NEOPLASTIC-CELLS OF HAIRY-CELL LEUKEMIA STUDIED WITH MONOCLONAL-ANTIBODIES

  • 1 January 1982
    • journal article
    • research article
    • Vol. 59  (3) , 609-614
Abstract
Eighteen [human] cases of hairy cell leukemia were studied with a battery of polyclonal anti-Ig and 9 monoclonal antibodies to determine the lineage of the hairy cells (HC) and the stage of their maturation arrest. Hairy cells tend to bind nonspecifically many antisera and precautions must be taken to avoid nonspecific fluorescence of the cells. All but 1 case was reactive with 1 L chain type and 1 or more H chain isotype antisera. All cases were positive for monomorphic HLA-DR determinants using monoclonal antibody 7.2. Most cases tested (6 of 7) were positive with the B-lineage related antibody PI 153/3. While most cases (15 of 18) were nonreactive with the B-lineage related antibody BA-1, they became positive (5 of 5) following in vitro culture. Seven of 9 cases were reactive with OKM1. Common acute lymphoblastic leukemia antigen (CALLA) was absent in all (15) cases tested and the ALL associated structure p24/BA-2 was absent from 16 of 18 cases. HC from none of the cases were clearly positive with the T-cell antibodies 9.6 or TA-1, whereas in only 1 of 18 the cells reacted with T101. The B cell lineage of most HC is supported and the presence of multiple phenotypes shown. In combination with the surface Ig present on the cells, a hierarchy of phenotypes is postulated, with Slg-or.mu..delta., BA-1+, PI 153/3+ and HLA-DR+ being the most immature and Slg(.alpha.).gamma., Ba-1-, PI 153/3- and HLA-DR+ the most mature.