AN ORIGINAL METHOD TO STUDY AUTOANTIBODY SPECIFICITY IN HEMOGLOBIN STAINED ELUATES BY THE COLUMN AGGLUTINATION TECHNIQUES

When studying autoantibody specificity by the indirect antiglobulin te st with column agglutination techniques ether and xylene elution techn iques result in haemoglobin stained eluates which give a red colourati on to the gel or glass beads and do not allow the identification of po sitive reactions. Xylene eluates were incubated with commercially avai lable group O-test red cell panels at 37 degrees C for 45 min in the w ells of a microtitre plate in a 3:1 eluate:red cell ratio. After washi ng with normal saline, sensitized red cells, resuspended in low ionic strength solution (LISS), were applied onto the microtubes containing the antiglobulin serum and positive reactions were recorded after cent rifugation. We studied the specificity of 35 autoantibody containing e luates from 12 patients with lymphoproliferative disorders (six having autoimmune haemolysis) and 23 HIV patients without autoimmune haemoly sis. All patients had a gel or column positive (IgG) direct antiglobul in test while the tube direct antiglobulin test failed to show red cel l bound IgG. We found a reactive indirect antiglobulin test in 20/23 e luates from HIV infected patients (with a panreactive specificity), in all patients with autoimmune haemolysis (one with anti-C, two with an ti-E, one with anti-K and two with a panreactive specificity) and in a ll patients with positive direct antiglobulin test but without immune mediate haemolysis (tin all cases with panreactive specificity). The m ethod proposed is a promising tool for the study of the specificity of antibody containing haemoglobin stained eluates; in this study it all owed us to confirm that some HIV patients have specific binding of IgG on their RBC and to identify the specificity of tube test non-reactiv e eluates.