Immunologic evaluation of T chronic lymphocyte leukaemia cells in a patient with a concomitant IgA2 myeloma

Peripheral blood lymphocytes from a patient with OKT3, OKT4, OKT17 positive T CLL and a concomitant IgA2/lambda myeloma were found to be suppressive in cocultivation experiments and after in vitro preactivation . Although chromosomal analysis after stimulation with T or B cell mitogens suggested a common origin of the two malignancies, T cells did not carry structures recognized by an anti-idiotypic antiserum raised against the purified M-component. Only Fc mu receptors were found on the T cells with conventional rosetting assays, although a weak binding of Latex particles coated with the purified IgA M-component could occasionally be recorded. When purified T cells were submitted to FACS-analysis after incubation with the FITC-conjugated purified M-component, two subsets could easily be distinguished in normal T cells, whereas only the high affinity-binding subset could be found in the patient.