Glutathione transferase (GST) activity as well as the expression of di
fferent classes of GST isoenzymes were studied in 14 lymphoma biopsies
. The GST activity measured with 1-chloro-2,4-dinitrobenzene as a subs
trate, varied almost 9-fold. The expression of GSTs classes Pi, Alpha
and Mu was studied by immunoblotting using antibodies against human GS
Ts. All lymphoma samples displayed high levels of class Pi GST. Class
Alpha and Mu GSTs expression varied from not detectable to high. The o
bservations were confirmed by quantitation of the three classes of GST
with an ELISA technique; Nine of the patients were treated with bifun
ctional alkylating agents. A correlation between a clinical complete r
esponse to chemotherapy and low expression of GST Alpha was noted (p <
0.02).