IMMUNOPHENOTYPIC AND MOLECULAR-GENETIC CHARACTERIZATION OF A CASE OF CD8(-CELL CHRONIC LYMPHOCYTIC-LEUKEMIA() B)

We report the case of a patient with chronic B lymphocytic leukemia, w ith stable clinical and hematological conditions in the absence of any treatment. The flow cytometry analysis of the patient's cells reveale d a CD19(+), CD5(+), IgM(+), IgD(+), lambda chain(+) phenotype, along with an unusual expression of CD8 alpha/alpha homodimer. B cells did n ot stain with the anti CD8 beta monoclonal antibody T8/2T8 5H7. Molecu lar biology analyses confirmed the monoclonal rearrangements of immuno globulin heavy and lambda light chain genes in the presence of a germl ine configuration of T cell receptor genes. Moreover, an abnormal conf iguration of the CD8A gene was found in the CD8(+) B lymphocytic clone . We suggest that the aberrant expression of the CD8 gene could be rel ated to its abnormal configuration.