Measurement of natural killer cell cytotoxicity by area under a cytotoxic curve: A method suitable for rheumatoid arthritis

Abstract Calculation of the area under a curve derived from a 51 Cr cellular release assay gives a reproducible expression of cellular cytoxicity and correlate s well with results at fixed lymphocyte-to-target cell ratios and with lytic units at 20% and 30% cytotoxicity. This method is suitable for quantifying the low cytotoxicity seen in rheumatoid arthritis. The area under the cellular cytotoxic curve may be calculated using a simple mathematical formula or by computer analysis.