T‐cell acute lymphoblastic leukemia with natural killer cell phenotype

Abstract

To determine the type and proportion of cases within that type of acute lymphoblastic leukemia (ALL) that has a natural killer (NK) cell phenotype, we examined leukemic blasts from 31 children with ALL (14 with T-ALL, 17 with non-T-ALL) for expression of antigens detected by NK-specific monoclonal antibodies Leu 11b, Leu 7, and 1G2 (an antibody we have developed that cross-reacts with Leu 7). None of the patients had leukemic blasts that reacted with Leu 11b. However, leukemic blasts from four T-ALL patients were 1G2+ and/or Leu 7+. Blasts from two of these had spontaneous lytic activity against standard NK target cell line K562; blasts from one killed K562 only when incubated with interferon; blasts from the other had no lytic activity against K562 but did manifest antibody-dependent cell-mediated cytotoxicity against antibody-coated cells from NK-resistant cell line SB. Blasts from all four Leu 7+ patients had L2 morphology. In one, the leukemic blasts had azurophilic cytoplasmic granules similar to those found in NK-enriched normal populations of large granular lymphocytes. These findings suggest that a significant proportion of T-cell acute lymphoblastic leukemias may be malignancies of NK cell origin.

Biology of Natural Killer Cells

“…Another case of aggressive NK cell leukemia was described in an adult. The cells of this patient bore the typical LGL morphology and were CD3-, CD4-, CD8-, CD16+, HNK-l/Leu-7-, with strong cytotoxic activity against K562 target cells (418). An IL-2-dependent cell line derived from this patient was maintained for several months.…”

“…An IL-2-dependent cell line derived from this patient was maintained for several months. All of these cases of acute NK cell leukemia were clonal in origin, as shown by analysis of chromosomal aberrations (416)(417)(418).…”

Childhood blastic NK cell leukemia successfully treated with L‐asparagenase and allogeneic bone marrow transplantation

“…A small number of childhood blastic NK cell leukemia/lymphoma(s) have been reported and they are summarized in Table I 4–9. Age distribution is higher (median 14 years) than that of childhood B precursor ALL and close to that of T cell ALL.…”

Leukemic thyroiditis as the initial relapsing sign in a patient with acute lymphocytic leukemia and blast expression of the neural cell adhesion molecule

“…Kaplan et al [27] retrospectively noted that 4 of 14 (29%) patients with T-cell ALL and 0 of 17 individuals with non-T-cell ALL had CD16 expression but these investigators did not examine NCAM expression. Menckenstock et al [28] described a patient who presented with anemia, lymphadenopathy, hepatosplenomegaly and was found to have T-cell ALL with concomitant sideroblastic anemia prior to his death during induction therapy.…”