Donor variability affects the outcome for the monocyte monolayer assay (MMA)

Abstract

The monocyte monolayer assay (MMA) is used to predict transfusion outcomes when antibodies to red blood cell (RBC) antigens are present and compatible antigen-negative blood isn’t available. Typically, the monocytes used are peripheral blood mononuclear cells (PBMC) isolated from healthy volunteers. This study aimed to determine the between-volunteer variability in monocyte reactivity in the MMA. PBMCs were isolated (Ficoll density gradient) from freshly collected whole blood from 28 individuals and incubated with RBCs sensitised with anti-D (1 hour, 37oC, 5% CO2; positive control).