Variable Natural Killer Cell Activity in Hematological Malignancies at Diagnosis

ABSTRACT

BACKGROUND: Natural killer (NK) cells play a key role in innate immune responses and are an important component of anti-cancer defenses. This study aimed to investigate the clinicopathological characteristics of NK cell activity (NKA) among various hematological malignancies at diagnosis and to evaluate their clinical value as a monitoring marker. METHODS: A total of 111 patients that were newly diagnosed with hematological malignancies were recruited, comprising 18 acute myeloid leukemia (AML), 31 multiple myeloma (MM), and 62 lymphoma. Twenty-three normal control subjects from our health examination center were recruited. NKA was measured using a commercially available enzyme-linked immunosorbent assay kit, which measures interferon-gamma secreted by ex vivo-stimulated NK cells in whole blood. RESULTS: The 111 patients had a median NKA of 202.80 pg/mL (range 40–2,000). NKA was significantly decreased in patients with AML (median 47.05 pg/mL, 40–2,000, P<0.0001), MM (275.00, 40–2,000, P<0.0001), and lymphoma (289.49, 40–2,000, P<0.0001) compared with that in normal controls (1,891, 412–2,000). There was a difference in NKA between AML and lymphoma (P=0.0499). Serial changes in NKA correlated with disease progression. NKA did not correlate with the NK cell count in any group of hematological malignancies. CONCLUSIONS: The measurement of NKA could be useful to evaluate the immunological status in hematological malignancies at diagnosis and during follow-up.