Purine nucleoside phosphorylase (PNP) and adenosine deaminase (ADA)
activities examined cytochemically in unfixed lymphocytes of patients with
lymphoproliferative disorders
K Maeda, K Ito and N Yamaguchi
New techniques have been devised for the cytochemical demonstration of
purine nucleoside phosphorylase (PNP) and adenosine deaminase (ADA)
activities in unfixed human lymphocytes. A suspension of living lymphocytes
is mixed with agarose sol containing the reagents for the detection of PNP
or ADA activity on a glass slide. The mixture solidifies, is incubated, and
then dried for lightmicroscopic observation. Reactive cells are recognized
by the diffusely deposited granules of formazan, the end-product of the
cytochemical reaction, and are divided into three groups of the cell with
the low, middle, and high enzyme activity by the number of the granule. In
healthy adults, the mean percentages of PNP- and ADA-positive cells were
more than 90% in unfractionated lymphocytes, T-cell fractions, and
complement- receptor cell fractions and cells with middle PNP and ADA
activities were predominant. The PNP and ADA staining was observed in
lymphoid cells of patients with lymphoproliferative disorders. A decrease
in the percentage of PNP-positive cells concomitant with a relative
increase of cells with the low enzyme activity was observed in the
lymphocytes of nine patients with chronic lymphocytic leukemia (CLL).
Similar findings were obtained in the ADA staining of the lymphocytes of
five patients with B-cell CLL.
Volume 58,
Issue 5,
pp. 897-903,
11/01/1981
Copyright © 1981 by The American Society of Hematology
