Expansion of B lymphocytes with an unusual immunoglobulin rearrangement associated with atypical lymphocytosis and cigarette smoking.

Persistent polyclonal lymphocytosis has been described in a group of female patients who all have the HLA-DR7 antigen in common and who are all heavy cigarette smokers. Immunoglobulin heavy chain gene rearrangement was analyzed by hybridization with specific immunoglobulin heavy chain genes to restriction enzyme-digested genomic DNA samples. The results in two of these patients showed that the lymphocytosis was associated with an expanded subpopulation of B-lineage cells represented by the presence of an unusual immunoglobulin gene rearrangement pattern. Expansion of this subpopulation of B cells appeared to be linked to cigarette smoking since the intensity of the cell population harboring the rearranged gene was much stronger in patients who were smoking heavily compared with the same patients who were temporarily not smoking.