Cytochemical study of thymocytes and T lymphocytes.

Summary. Fetal and postnatal thymocytes and circulating T lymphocytes were evaluated for six cytochemical reactions. Acid phosphatase activity was present in a high percentage of cells in all three groups. Beta‐glucuronidase and α‐naphthyl acetate acid esterase were negative in the most immature fetal thymocytes, but become increasingly positive with T‐cell maturation. Only the circulating lymphocytes presented a high percentage of N‐acetyl beta glucosaminidase, α‐naphthyl acetate esterase and α‐naphthyl butyrate esterase positive cells. This study discusses the presence of these enzymes as proportional to different stages in T‐cell maturation, and also of certain cytochemical phenotypes characteristic of these stages. Copyright © 1980, Wiley Blackwell. All rights reserved