Disturbances in T-cell subpopulations in B-cell chronic lymphocytic leukaemia.

The relative proportions of immunoregulatory T-cell subpopulations defined by OKT monoclonal antibodies are disturbed in chronic lymphocytic leukaemia (CLL) patients (even early mild cases) compared with normal subjects in the same age range. The mean ratio OKT4+:OKT8+ (helper:suppressor/cytotoxic) is reversed from the normal 1.6:1 to 1:1.9. The absolute concentration of each OKT population in the circulation is slightly higher than normal, the increase in OKT8+ being the most significant. The E-rosette-forming cells did not always correlate with OKT+ cells and, in four cases, the discrepancy between the size of the OKT3+ population and the sum of OKT4+ and OKT8+ suggested the presence of T cells with an immature (thymic) phenotype in peripheral blood. These abnormalities may account for the depressed immune function of CLL patients.