Erythrophagocytosis assay in patients with autoimmune hemolytic anemia

The aim of this paper is to evaluate the erythrophagocytosis assay (EA) in patients with autoimmune hemolytic anemia (AIHA). Direct antiglobulin test (DAT), indirect antiglobulin test (IAT) and EA were performed in blood samp les from 46 patients with presumed AIHA. The EA was carried out incubating patients' erythrocytes and peripheral blood monocytes. A total of 200 monoc ytes were analysed to determine the percentage of active phagocytic cells ( % APC). In 9 of these patients the applied treatment was evaluated by DAT, IAT and EA. In 14 transfusion requirements, the compatibility tests and EA were performed. For EA, patients' monocytes were incubated with erythrocyte s from previously selected units sensitized with patients' sera. The % of A PC was 32.1 +/- 1.7 in 35 patients with positive DAT and 17.8 +/- 1.3 in 11 patients with negative DAT. This last value was significantly higher than that with negative controls (3.7 +/- 0.3)(p less than or equal to 0.01). As regards the applied treatment, patients with a successful response (n=6) s howed a significant decrease in the initial % APC (31.8 +/- 1.6 to 15.3 +/- 2.4; p less than or equal to 0.05) while DAT and IAT remained positive. In those patients who required blood transfusion the compatibility tests were positive with all the units to be transfused, whereas the % APC varied for each one. Blood units were selected according to the lower % APC.