ERYTHROCYTE AUTOIMMUNE DISORDER - RED-CELL ANTIBODIES AND THE HUMAN ALLOGENEIC ROSETTE TEST

  • 1 January 1980
    • journal article
    • research article
    • Vol. 39  (3) , 635-644
Abstract
A new test termed the human allogeneic rosette test (HART) was reported for the detection of small amounts of erythrocyte autoantibodies. It compares the percentage of rosettes formed around lymphocytes from normal subjects when red cells from patients are added or autologous or allogeneic normal red cells. The HART was positive when the percentage of rosettes made with the control''s red blood cells [RBC] was significantly more than the percentage of those made with the patient''s RBC. Of 26 patients with a positive antiglobulin test, 22 had a positive HART. Thirty patients with a negative antiglobulin test but with clinical or biological data suggesting an erythrocyte autoimmune disorder were also studied with the HART. Of 16 patients with chronic lymphatic leukemia, 10 had a positive test; all 3 patients with idiopathic thrombocytopenic purpura showed a positive HART; 2 of 3 patients with cirrhosis and 1 of 4 patients with Hodgkin''s disease also had a positive test. No correlation was found between the positivity of the HART in these patients and their hematological values. Two patients with suspected autoimmune hemolytic anemia and with a negative antiglobulin test but a positive HART were treated with steroids. Both responded very rapidly to the treatment, suggesting an immune origin for the anemia. The HART was reproduced experimentally. Normal human RBC sensitized with different amounts of either an autoantibody or anti-D were rosetted with autologous normal lymphocytes. The results showed that the percentage of rosettes with red cells coated with small amounts of antibody was significantly less than the percentage of rosettes with uncoated red cells. A plot of these results seemed to indicate that the HART was about 20 times more sensitive than the antiglobulin test. The nature of the cells involved in the positive HART-negative direct antiglobulin test red cell binding was also analyzed. They appeared to be related to the T [thymus-derived] cell population. The role of the receptors for Ig[immunoglobulin]G in the HART was demonstrated by showing that aggregated and non-aggregated human IgG could inhibit the HART phenomenon. The HART appears to be a new and sensitive immunological test capable of analyzing erythrocyte autoimmune disorders.