Reliability of alpha-naphthyl-acetate esterase staining of blood smears for the enumeration of circulating human T lymphocytes.

Cytocentrifuged preparations of glutaraldehyde-fixed E rosettes were stained for acid alpha-naphthyl-acetate esterase activity (ANAE). On average, 84% of the rosette-forming cells (E+) also stained positively for the enzyme activity (A+). ANAE staining of blood smears of thirty-three healthy controls was compared to E rosetting by a conventional method. A+ and E+ fractional values are highly significantly correlated; the regression of E+ on A+ is E+ = 0.805.A+ + 16.8 (P < 10(-6)). Since the correlation between E+ and A+ cells is both statistically and cytologically significant, we propose blood smear ANAE staining as a simple and convenient method to enumerate circulating T lymphocytes in clinical practice.