Patients with t(8;21) had a significantly higher incidence (89%, 8/9) of CD56 positivity in leukemic cells than those with normal karyotype or other cytogenetic abnormalities (26%, 22/85, p < 0.001).
Moreover, CD56 expression was significantly associated with P-glycoprotein (PGP) hyperexpression (P = 0.007), unfavorable cytogenetic abnormalities (P = 0.008) and with a reduced probability of achieving complete remission (CR) (36% vs 68%) (P = 0.035) as well as with a shorter survival (6 vs 12 months) (P = 0.032).
This study indicates that chromosome aberrations in NK-cell lymphomas are restricted to the CD56+, CD3- and CD5- cell population and that NK-cell lymphomas are indeed derived from mature true NK cells and not from T lymphocytes.