Permanent large granular lymphocytosis in the blood of splenectomized individuals without concomitant increase of in vitro natural killer cell cytotoxicity.

Increased numbers of circulating lymphocytes and large granular lymphocytes (LGL) were observed in 115 individuals splenectomized for haematological disease (74 cases) or for trauma (41 cases). LGL lymphocytosis was present in 78.4% of haematologically indicated and in 85.4% of traumatic splenectomies. A 70.5% of these values was above the 97.5 percentile upper tolerance limit of healthy controls (200 cases). In addition, 175 haematological controls were investigated. Forty per cent or more of circulating lymphocytes exhibited LGL morphology in nearly half of repeatedly investigated splenectomized persons. The increase in LGL is not attributable to lymphocytosis. It becomes apparent, and persists after the first postoperative week, irrespective of the cause of surgery. In spite of the two-fold increase in LGL concentration in the blood, in vitro natural killer (NK) and antibody dependent cellular cytotoxic (ADCC) activities did not increase in the investigated 48 (NK) and 31 (ADCC) splenectomized persons, as compared with the appropriate healthy or haematological controls.