[Characterization of chronic lymphocytic proliferation in a female patient having rheumatoid polyarthritis with neutropenia].

The authors have studied the case of a female patient with rheumatoid polyarthritis, who developed a lymphocytic proliferation in the blood, the marrow, and the liver, associated with a neutropenia. Several similar cases have been recently reported in the literature. The cellular proliferation is made of large granulous lymphocytes and the study of membrane markers enables to find the following homogeneous phenotype: E rosette+, CD8+, HNK-1+, FcR+, CD4-luminal diameter "divided by degrees - -, IgS-, HLA class II-. This lymphocytic sub-population produces little interleukin-2, responds weakly to mitogens (PHA, CON A, PWM), and inhibits the response of normal lymphocytes to the same mitogens. These lymphocytes have a weak natural killer activity but, on the contrary, develop a very strong cytotoxic activity which is antibody-dependent. Clinically, splenomegaly, anemia and infections are frequent and hepatomegaly or thrombopenia more rare. Adenopathies are never present. The evolution is chronic in nature and not very aggressive, although the lymphocytic proliferation is monoclonal in origin, as demonstrated in molecular biology studies. The neutropenia might be secondary to an inhibiting effect of lymphocytes on the granular precursors of the bone marrow. There is a definite association between this lympho-proliferative syndrome and rheumatoid polyarthritis, and this association appears to be different from the Felty's syndrome.