Lysis of Antibody-Treated Human Erythrocytes by Human Leukocytes and Macrophages in Tissue Culture

Abstract

The 51Cr-chromate method was used for quantitation of lysis of antibody-treated human RBC which had been labilized by pretreatment with 1% trypsin. RBC treated with heat-inactivated isoantiserum to A, B or Rh antigens were lysed within 3–6 h by blood leukocytes or peritoneal macrophages. Macrophages or suspensions containing mainly granulocytes and monocytes were cytotoxic at the leukocyte-RBC ratio 1:5 while an excess of purified lymphocytes ( > 99%) had no hemolytic effect. Erythrophagocytosis by monocytes and some granulocytes was frequently seen and is assumed to be the main mechanism of hemolysis. There was no evidence of hemolytic factors released by leukocyte suspensions. This method may be useful for studies of cell mediated hemolysis in human immune hemolytic diseases.