The sera of patients with hairy cell leukaemia (HCL) contain a factor which inhibits the binding of anti-IL-2R antibody to its target (activated T lymphocytes). The presence of this factor, which probably corresponds to the soluble form of IL-2R (sIL-2R), can be easily detected using a simple immunocytochemical inhibition assay. In a series of patients with chronic lymphoproliferative diseases the presence of sIL-2R appeared to be specific for HCL, using the sensitivity of our test, since it could not be detected in sera from normal subjects and patients with B-cell lymphocytic leukaemia or Hodgkin's disease. Thus it might be used as an additional tool for characterizing HCL patients.
KorsmeyerS.J., GreeneW.C., CossmanJ., HsuS.M., JensenJ.P., NeckersL.M., MarshallS.L., BakhshiA., DepperJ.M., LeonardW.J., JaffeE.S., WaldmannT.A.Rearrangement and expression of immunoglobulin genes and expression of Tac antigen in hairy cell leukemia.Proc Natl Acad Sci USA1983; 80: 4522–6.
3.
ChilosiM., PizzoloG., Fiore-DonatiL., BofillM., JanossyG.Routine immunofluorescent and histochemical analysis of bone marrow involvement of lymphoma/leukaemia. The use of cryostat sections.Br J Cancer1983; 48: 763–75.
4.
QuesadaJ.R., ReubenJ., ManningJ.T., HershE.M., Gutter-manJ.U.Alpha interferon for induction of remission in hairy-cell leukaemia.N Engl J Med1984; 310: 15–8.
5.
SemenzatoG., PizzoloG., AgostiniC., AmbrosettiA., ZambelloR., TrentinL., LucaM., MasciarelliM., ChilosiM., VinanteF., PeronaG., CettoG.Alpha-interferon activates the natural killer system in patients with hairy cell leukemia.Blood1986, in press.
6.
FoaR., GiovarelliM., JemmaC., FierroM.T., LussoP., FerrandoM.L., LauriaF., ForniG.Interleukin 2 (IL 2) and interferon-gamma production by T lymphocytes from patients with B-chronic lymphocytic leukemia: Evidence that normally released IL 2 is absorbed by the neoplastic B cell population.Blood1985; 66: 614–9.
7.
PizzoloG., ChilosiM., SemenzatoG., Caligaris-CappioF., Fiore-DonatiL., PeronaG., JanossyG.Immunohistological analysis of Tac expression in tissues involved by Hodgkin's disease.Br J Cancer1984; 50: 415–7.
8.
CordellJ.L., FaliniB., ErberW.N., GhoshA.K., AbdulazizZ., MacDonaldS., PulfordK.A., SteinH., MasonD.Y.Im-munoenzymatic labeling of monoclonal antibodies using immune complexes of alkaline phosphatase and monoclonal anti-alkaline phosphatase (APAAP) complexes.J Histochem Cytochem1984; 32: 219–29.
9.
RubinL.A., KurmanC.C., FritzM.E., BiddsonW.E., BoutinB., YarchoanR., NelsonD.L.Soluble interleukin 2 receptors are released from activated human lymphoid cells in vitro.J Immunol1985; 135: 3172–2.
10.
RucoL.P., ProcopioA., MaccaliniV., CalogeroA., UcciniS., AnninoL., MandelliF., BaroniC.D.Severe deficiency of natural killer activity in the peripheral blood of patients with hairy cell leukemia.Blood1983; 61: 1132–7.
11.
MackowiakP.A., DemianS.E., SutkerW.L., MurphyF.K., SmithJ.W., TompsettR., SheehanW.W., LubyJ.P.Infections in hairy cell leukemia. Clinical evidence of a pronounced defect in cell-mediated immunity.Am J Med1980; 68: 718–24.
