[A study of granular lymphocytes (GL) in children and young adults]

In this study, we investigate the percentage and absolute number of granular lymphocytes (GL) in venous blood smears and the percentage of CD16+ and CD57+ lymphocytes in the peripheral venous blood of 91 healthy controls (1 to 29 years old) and 168 patients with various diseases (1 month to 36 years old). GL were morphologically classified into four subsets: large-sized lymphocytes with large granules (LL-LG), large-sized lymphocytes with small granules (LL-SG), medium-sized lymphocytes with large granules (ML-LG) and medium-sized lymphocytes with small granules (ML-SG). The results were as follows: 1) In the controls, the percentage of GL in total lymphocytes was 10.0 +/- 6.2% (mean +/- 1SD). Therefore its normal value was below 22.4% (mean +/- 2SD). The absolute count of GL was 320.7 +/- 221.0/mm3. The percentages of LL-LG, LL-SG, ML-LG and ML-SG in total lymphocytes were 1.7 +/- 2.2%, 2.3 +/- 2.8%, 2.6 +/- 2.3% and 3.4 +/- 2.7%, respectively. 2) In flow cytometric studies, the percentage of CD16+ in the controls was 10.2 +/- 6.7%; CD57+, 8.2 +/- 5.1%; CD57+ CD16+, 4.2 +/- 3.3%; CD57+ CD16-, 4.0 +/- 2.8%; CD57- CD16+, 6.4 +/- 4.8%. The distribution patterns of lymphocytes by two-color analysis with FITC-labelled anti-CD16 and PE-labelled anti-CD57 monoclonal antibodies in the controls were classified into four groups. 3) Only seven of the 168 patients exhibited significantly high percentage of GL in total lymphocytes. They consisted of 4 splenectomized patients and 3 patients with pancytopenia, two of whom had pancytopenia complicated by immunoglobulin deficiency. Five of the 7 patients also had markedly high percentage of CD16+ and/or CD57+ lymphocytes. In these 5 patients, the ratios of four subsets of GL and the distribution patterns of lymphocytes with CD16 and CD57 surface antigens were different from the patient to patient and those for controls.