GUIDELINES FOR PREVENTING DILUTION FALSE NEGATIVES IN IN-VITRO LABORATORY TESTING OF THE DONOR POPULATION

In this article we develop a calculation or formula for use in determi ning the potential dilution effect of fluids administered during patie nt treatment on serologic testing parameters. The formula uses basic p rinciples of (a) fluid distribution over time from administration; (b) ratios of plasma and extravascular fluid volumes to body weight; and (c) common practices of fluid resuscitation. A dilution threshold of 5 0% was set using data from enzyme-linked immunosorbent assay human imm unodeficiency virus antibody determinations performed on in vitro dilu ted seropositive serum samples. These data respond to issues raised by guidelines from the Centers for Disease Control and the U.S. Food and Drug Administration to achieve recipient safety without unnecessarily restricting the potential donor pool.