Autoantibodies specific to β2-microglobulin inhibit the Fc receptor-dependent phagocytosis of human monocytes

Abstract Effect of anti- β 2 -microglobulin ( β 2 m ) antibodies was investigated on the in vitro Fc and C 3 receptor-dependent phagocytic capacity of human peripheral monocytes. Both rabbit and human anti- β 2 m antibodies inhibit the Fc receptor-mediated phagocytosis. Anti- β 2 m antibodies do not influence the spontaneous or C3b receptor-mediated ingestion. The inhibitory activity by human autoantibodies but not by rabbit anti-human β 2 m antibodies was diminished when incubation was performed at 37°C instead of 20°C.