Natural killer cell activity

Method

Cytotoxic activity of peripheral blood natural killer cells against a standard target cell line, typically K562, by chromium-51 release, flow-cytometric, or lactate dehydrogenase release assay, expressed as percent specific lysis at a stated effector-to-target ratio. The ratio is recorded on the edge and results at different ratios are not comparable.

The method is part of the endpoint identity. Studies measuring the same quantity by a different method are held as separate endpoints.

Notes

A FUNCTIONAL assay - it measures how well cells kill. Its near-miss is the CD3, CD4 and CD8 lymphocyte percentage nodes and the CD4 count, which are ENUMERATION - how many cells are present. Reviews report all of them under one host immune function heading, but they dissociate routinely: cell numbers can be flat while function rises, and the reverse. Because both are reported as percentages, an edge that maps a cytotoxicity value onto a subset percentage also silently changes what the unit means while looking dimensionally consistent.