[Functions of large granular lymphocytes--a case of large granular lymphocytosis with characteristic cell surface...

A 58-year-old male visited the hematological clinic of Surugadai Nihon University Hospital, Tokyo, complaining of numbness around both elbows. The peripheral leukocyte count was 12,400/microliters, and large granular lymphocytes (LGL) occupied 79% of the leukocytes. The cell surface antigen studied by flow cytometry were the positive CD 2, 3, 5, 8, 11, and Leu-7, and the negative CD1, 4, 10, 16 (Leu-11), 19, 20, and OKTIa1. IgG-FCR checked by mean of the EA-rosette formation was positive. The LGL showed the negative NK cell activity and the positive ADCC and LAK cell activities. It was interesting that LGL was negative for CD16 (Leu-11) while they had ADCC activity. Since the rearrangement of the receptor gene in T-cells was demonstrated by the southern blot analysis, the proliferation of LGL was considered to be a clonal one. LGL did not inhibit the colony formation of granulocyte and erythrocyte precursors in the plasma clot culture. It was thus considered that this might partially explain the fact that the patient's neutrophil, Hb and platelet levels remained normal.