Distribution of four subclass‐specific lymphocyte markers in man

A report is given of the relative and absolute distribution of lymphocytes carrying three T or B cell specific markers in cord blood; in children and in the blood of healthy adult human subjects. The determinations were performed from stained cytological cell smears under conditions where no subclass specific lymphocyte selection or depletion takes place. In adult blood 78 896 (S. D.) (1.2 0.4 10⁹/¹) of lymphocytes expressed the acid α‐naphthyl acetate esterase (ANAE) marker. The percentage distribution of the ANAE marker‐carrying lymphocytes was stable in different age groups. The absolute values in cord blood and in young children were approximately three times higher than in adults. A somewhat smaller fraction of adult lymphocytes (5314%; 1.0 0.4 10⁹/¹) formed rosettes with 2‐amino‐ethylisothiouronium bromide‐hydrobromide (AET) sensitized sheep erythrocytes (AET‐SRBC). Although the relative distribution of AET‐SRBC rosette‐forming lymphocytes was slightly lower in children than in adults, the absolute numbers were approximately two to three times higher. The number of surface Ig‐carrying lymphocytes, as detected by rosette formation with Staphylococcus aureus strain Cowan I (StaCw) bacteria in adolescent and adult blood was 19 11 % (0.4 0.2 10⁹/¹). The relative number of surface Ig‐carrying lymphocytes varied very little in the different age groups. The absolute numbers in cord blood and in small children were approximately twice as high as in adults. The distribution of lymphocytes carrying the fourth marker, surface receptor for IgG, was investigated by antibody‐coated human erythrocytes (EA). In adults, the number of lymphocytes forming rosettes with EA was 30 10 % (0.7 0.3 10⁹/¹). Although the relative values were somewhat lower in children, the absolute values were approximately twice as high as in adults.