We investigated the effects of L-asparaginase
(L-asp) on Epstein–Barr virus (EBV)-positive
T/NK lymphoproliferative diseases (EBV-T/
NK-LPDs). Seven doses of L-asp (6,000 U/
m2) were administered intravenously, with one
dose administered on every alternate day. Five
consecutive patients were enrolled. Three
patients completed the treatment. The clinical
symptoms resolved in 1 patient who started the
administration 8 months after the onset, being
the earliest among the 5 patients. Her EBV-DNA
level in whole blood markedly decreased to 0.08
times of that before treatment, and the level
in plasma became undetectable. In the other 2
patients whose administration was started 3 and
3.5 years after the onset, however, a remarkable
improvement was not detected. Treatment was
discontinued in 2 patients because of disease
progression or idiopathic dystonia. The mRNA
levels of asparagine synthetase in EBV-infected
cells were examined. The level from the patient
who responded to L-asp treatment was low, but
it did not correlate with the effects in the other
patients. Liver dysfunction (grades 2 and 3) was
observed in 2 patients and neutropenia (grade 3)
was noted in 1 patient. In conclusion, the effect of
L-asp as monotherapy in EBV-T/NK-LPDs is limited,
and early treatment initiation might be effective.
View full abstract