Mechanisms accounting for the defective natural killer activity in patients with hairy cell leukemia.

摘要: Natural killer (NK) cell activity is severely impaired in untreated patients with hairy leukemia (HCL). In an attempt to investigate whether this impairment related a defect at the target binding and/or post level, we evaluated peripheral blood mononuclear cells (PBMC) of HCL for their ability to: (1) bind and kill K-562 NK-sensitive targets single level; (2) release NK cytotoxic factor (NKCF) under different vitro stimuli, including phytohemoagglutinin; (3) lectin-dependent cellular cytoxicity (LDCC) assay. This study demonstrates that patients' PBMC show low form conjugates level (5.7% +/- 1.0%) respect studied after treatment (9.3% 1.3%) controls (15.0% 4.0%); P less than .05 .001, respectively. A decreased bound was demonstrated cases (1.2% 1.1%) versus (12.3% 1.6%, 17.0% 3.1% respectively); .001 both conditions. After activation effector interleukin-2 (IL- 2) vitro, increase each group patients. Moreover, IL-2 able cytotoxicity against all tested. Evaluation NKCF production showed levels when were incubated presence stimulators (1.8% 0.7%) interferon-alpha (IFN-alpha) therapy (7.6% 2.1%) (12.9% 2.2%); .02 When recognition mechanisms bypassed by triggering lectins LDCC assay, lytic groups baseline values. However, capacity observed significantly lower subjects IFN-alpha (P .001). These findings suggest defects posttarget levels.