Human/mouse radiation chimera generated from PBMC of B chronic lymphocytic leukemia patients with autoimmune hemolytic anemia produce anti-human red cell antibodies

Abstract

Previous studies performed in our laboratory have shown that B-CLL cells are involved in the production of anti-red cell auto-antibodies, providing a possible mechanism for the auto-immune hemolytic anemia occurring during the course of B-CLL. In order to confirm this hypothesis, we attempted to transfer human B-CLL with AIHA to immunodeficient mice. Peripheral blood mononuclear cells (PBMC) from 11 B-CLL patients suffering from AIHA were transplanted into the peritoneal cavity of lethally irradiated Balb/c mice reconstituted with SCID bone marrow. Chimeric mice generated from PBMC of these patients (in stage III–IV of the disease) exhibited an engraftment profile with dominance of tumor cells and minuscule levels of T cells. Eighty-five percent of the chimeric mice generated from 10 out of the 11 B-CLL patients with Coombs’-positive AIHA, produced human Ig with anti-human red cell specificity as detected by indirect anti-globulin test. In addition, anti-red cell auto-antibodies were produced in 36% of chimeric mice generated from PBMC of Coombs’-negative B-CLL. In contrast, control experiments in which splenic cells from idiopathic AIHA or PBMC from normal donors were transplanted, failed to produce anti-RBC. This in vivo model further supports the relationship between the B cell expansion and the autoimmune hemolytic process.