PERSISTENT POLYCLONAL LYMPHOCYTOSIS WITH BINUCLEATED B-LYMPHOCYTES - A GENETIC PREDISPOSITION

Persistent lymphocytosis is usually associated with a malignant lympho proliferative disease (MLPD). We report six female patients presenting a chronic, moderate lymphocytosis of 2-16 years duration with atypica l binucleated lymphocytes on peripheral blood smears. Further investig ation showed a polyclonal increase in serum IgM and HLA-DR7 phenotype in ail patients. The B cells were polyclonal because Southern hybridiz ation of DNA and polymerase chain reaction failed to demonstrate a clo nal rearrangement of immunoglobulin heavy chain genes. Peripheral bloo d examination showed binucleated lymphocytes in a family member of two of the cases; taken together with the association with HLA-DR7 these data suggest a genetic predisposition, The identification of this beni gn syndrome is important in order to prevent its misdiagnosis as a MLP D.