[Polyclonal B lymphocytosis and hyper-IgM: immunodeficiency and/or benign lymphoid proliferation associated with tobacco?].

OBJECTIVE

To study the association of polyclonal B-cell lymphocytosis with binucleated lymphocytes with clinical manifestations suggesting the existence of an immunodeficiency, to evaluate the effect of cigarette smoking on this 'benign lymphoid proliferation', to analyze the clonality of lymphocytes, to determine the levels of immunoglobulins (Ig) G, A, M.

METHODS

Description and analysis of the results obtained in four patients and literature review.

RESULTS

Polyclonal B-cell lymphocytosis is associated with both a decrease in IgA and IgG and an increase in IgM. Recurrent infectious episodes (bronchitis) were observed in two patients. Transient smoking cessation allowed a decrease in lymphocytosis and IgM levels in two patients. No hematological malignancy occurred during the follow-up, while biological abnormalities persisted.

CONCLUSIONS

Persistent polyclonal B-cell lymphocytosis may be associated with minor clinical features of immunodeficiency. Smoking cessation may sometimes lead to a decrease in lymphocytosis and IgM.