title: Increased natural killer cells in fluids. A new, sensitive means of detecting carcinoma.
abstract: OBJECTIVE
  Natural killer (NK) cells are cells of undefined lineage that are capable of lysing certain tumor cell lines in vitro. Determination of NK cell percent (NK%) in effusions by flow cytometry could aid in the detection of malignancies.
  
  
  METHODS
  Over a six-month period at the Houston Veterans Affairs Medical Center, fresh effusions were routinely processed for cytology, and a portion was submitted for lymphocyte immunophenotyping using the FACScan and a panel including CD16/CD56 for NK cells. Seventy fluids (42 pleural, 28 peritoneal) from 62 men were examined.
  
  
  RESULTS
  NK cell percents were markedly increased in 15 cases (29-68%, mean 45.5) and low in 55 (2-20%, mean 8). Fourteen of the 15 cases with increased NK% were positive for carcinoma (93%), while 54/55 cases with low ones were negative for carcinoma (98%). Mesotheliomas, lymphomas and leukemias had low NK%.
  
  
  CONCLUSIONS
  Using the Mann-Whitney U test, an increase in NK% predicts metastatic carcinoma with a P level of < .00001.
authors.affiliation: Department of Pathology, Veterans Affairs Medical Center, Houston, Texas 77030, USA.
authors.forename: L K
authors.initials: LK
authors.lastname: Green
authors.forename: J
authors.initials: J
authors.lastname: Griffin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001202:Ascitic Fluid / Q000276:immunology*; D002277:Carcinoma / Q000175:diagnosis / Q000276:immunology* / Q000556:secondary; D006801:Humans; D007694:Killer Cells, Natural; D008297:Male; D008875:Middle Aged; D016066:Pleural Effusion, Malignant / Q000175:diagnosis / Q000276:immunology*; D012680:Sensitivity and Specificity