Inhibition of in vitro adherence of antibody‐coated red cells to monocytes by the dialyzable leukocyte extract

Abstract

The red cell-monocyte assay (RMA), which has been used to evaluate the clinical significance of red cell (RBC) antibodies, was employed to test the effect of the dialyzable leukocyte extract (DLE) on in vitro adherence to monocytes of human RBCs coated with alloantibodies or autoantibodies. The total association index (TAI) of the RMA, expressing the number of RBCs adhering to or phagocytosed by 100 monocytes, indicated a potent inhibitory activity of DLE in the test system. TAI values of 100.4 +/- 20.1 (mean +/- SD) in the control sample, consisting of RBCs coated in vitro with anti-D, dropped to 4.0 +/- 2.1 when DLE was present in the assay medium at a concentration of 0.5 U per mL. Similar results were obtained with RBCs coated with IgG antibodies in vivo. The inhibition was dose dependent and was associated with a thermolabile component of DLE. This study establishes that DLE can modulate monocyte function by inhibiting the recognition of IgG sensitized red cells.

A Very Simple and Nonexpensive Technique to Prevent Febrile Nonhemolytic Transfusion Reactions in HLA-lmmunized Patients

“…Further investigations and clinical trials are necessary to determine the real value of this very simple technique in order to confirm our hypothesis, avoiding the use of many expensive leukocyte filters in all or in some conditions. [16]. Pretreatment of rat recipients (experi mental model) with antibody-coated blood cells results in the suppression of the antibody response against subsequent platelet and leu kocyte transfusions [17].…”